INOVIO PHARMACEUTICALS, INC., 10-K filed on 3/18/2025
Annual Report
v3.25.1
Cover Page - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Mar. 12, 2025
Jun. 30, 2024
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2024    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-14888    
Entity Registrant Name INOVIO PHARMACEUTICALS, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 33-0969592    
Entity Address, Address Line One 660 W. Germantown Pike    
Entity Address, Address Line Two Suite 110    
Entity Address, City or Town Plymouth Meeting    
Entity Address, State or Province PA    
Entity Address, Postal Zip Code 19462    
City Area Code 267    
Local Phone Number 440-4200    
Title of 12(b) Security COMMON STOCK, $0.001 PAR VALUE    
Trading Symbol INO    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction false    
Entity Shell Company false    
Entity Public Float     $ 208.0
Entity Common Stock, Shares Outstanding   36,667,221  
Documents Incorporated by Reference
DOCUMENTS INCORPORATED BY REFERENCE
Portions of the registrant’s definitive proxy statement to be filed with the Commission pursuant to Regulation 14A in connection with the registrant’s 2025 Annual Meeting of Stockholders (the “Proxy Statement’) are incorporated by reference into Part III of this Report. Such Proxy Statement will be filed with the Commission not later than 120 days after the conclusion of the registrant’s fiscal year ended December 31, 2024.
    
Amendment Flag false    
Document Fiscal Year Focus 2024    
Document Fiscal Period Focus FY    
Entity Central Index Key 0001055726    
v3.25.1
Audit Information
 12 Months Ended
Dec. 31, 2024
Audit Information [Abstract]  
Auditor Location San Diego, California
Auditor Name Ernst & Young LLP
Auditor Firm ID 42
v3.25.1
Consolidated Balance Sheets - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Current assets:    
Cash and cash equivalents $ 65,813,297 $ 14,310,862
Short-term investments 28,300,232 130,982,913
Accounts receivable 1,199,056 2,405,228
Prepaid expenses and other current assets, including with affiliated entity 2,517,465 5,414,097
Total current assets 97,830,050 153,113,100
Fixed assets, net 3,659,818 4,960,986
Investments in affiliated entity 1,613,844 2,780,287
Operating lease right-of-use assets 8,113,840 9,491,735
Other assets 1,979,654 605,315
Total assets 113,197,206 170,951,423
Current liabilities:    
Accrued clinical trial expenses 2,021,860 2,365,382
Common stock warrant liability 13,255,188 0
Operating lease liability 2,497,360 2,406,522
Grant funding liability, including from affiliated entity 0 109,407
Convertible senior notes 0 16,770,654
Total current liabilities 35,325,584 42,570,228
Operating lease liability, net of current portion 9,367,827 11,032,066
Total liabilities 44,693,411 53,602,294
Commitments and contingencies
Inovio Pharmaceuticals, Inc. stockholders’ equity:    
Preferred stock—par value $0.001; Authorized shares: 10,000,000, issued and outstanding shares: 9 at December 31, 2024 and 2023 0 0
Common stock—par value $0.001; Authorized shares: 600,000,000 at December 31, 2024 and 2023, issued and outstanding: 36,099,991 at December 31, 2024 and 22,793,075 at December 31, 2023 36,099 22,792
Additional paid-in capital 1,799,362,625 1,740,954,074
Accumulated deficit (1,730,219,262) (1,622,965,136)
Accumulated other comprehensive loss (675,667) (662,601)
Total Inovio Pharmaceuticals, Inc. stockholders’ equity 68,503,795 117,349,129
Total liabilities and stockholders’ equity 113,197,206 170,951,423
Nonrelated Party    
Current liabilities:    
Accounts payable and accrued expenses 16,200,013 19,847,744
Related Party    
Current liabilities:    
Accounts payable and accrued expenses $ 1,351,163 $ 1,070,519
v3.25.1
Consolidated Balance Sheets (Parenthetical) - $ / shares
Dec. 31, 2024
Dec. 31, 2023
Statement of Financial Position [Abstract]    
Preferred stock, par value (in dollars per share) $ 0.001 $ 0.001
Preferred stock, shares authorized (in shares) 10,000,000 10,000,000
Preferred stock, shares issued (in shares) 9 9
Preferred stock, shares outstanding (in shares) 9 9
Common stock, par value (in USD per share) $ 0.001 $ 0.001
Common stock, shares authorized (in shares) 600,000,000 600,000,000
Common stock, shares issued (in shares) 36,099,991 22,793,075
Common stock, shares outstanding (in shares) 36,099,991 22,793,075
v3.25.1
Consolidated Statements of Operations - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Revenues [Abstract]    
Revenue from collaborative arrangements and other contracts, including affiliated entity $ 217,756 $ 832,010
Operating expenses:    
Research and development 75,620,340 86,676,563
General and administrative 36,996,338 47,582,104
Impairment of goodwill 0 10,513,371
Total operating expenses 112,616,678 144,772,038
Loss from operations (112,398,922) (143,940,028)
Other income (expense):    
Interest income 4,766,993 8,133,290
Interest expense (177,833) (1,222,789)
Change in fair value of common stock warrant liability 2,808,608 0
(Loss) gain on investment in affiliated entity (1,166,443) 773,145
Net unrealized gain on available-for-sale equity securities 2,077,182 5,850,626
Other expense, net (3,163,711) (4,711,596)
Net loss $ (107,254,126) $ (135,117,352)
Net loss per share    
Basic (in dollars per share) $ (3.95) $ (6.09)
Diluted (in dollars per share) $ (3.95) $ (6.09)
Weighted average number of common shares outstanding    
Basic (in shares) 27,160,863 22,173,662
Diluted (in shares) 27,160,863 22,173,662
v3.25.1
Consolidated Statements of Comprehensive Loss - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Statement of Comprehensive Income [Abstract]    
Net loss $ (107,254,126) $ (135,117,352)
Other comprehensive loss:    
Foreign currency translation 32,403 (3,920)
Unrealized (loss) gain on short-term investments, net of tax (45,469) 40,060
Comprehensive loss attributable to Inovio Pharmaceuticals, Inc. $ (107,267,192) $ (135,081,212)
v3.25.1
Consolidated Statements of Stockholders' Equity - USD ($)
Total
Preferred stock
Common stock
Additional paid-in capital
Accumulated deficit
Accumulated other comprehensive loss
Beginning balance (in shares) at Dec. 31, 2022   9        
Beginning balance (in shares) at Dec. 31, 2022     21,090,938      
Beginning balance at Dec. 31, 2022 $ 222,362,756 $ 0 $ 21,090 $ 1,710,888,191 $ (1,487,847,784) $ (698,741)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock for legal settlement (in shares)     760,083      
Issuance of common stock for legal settlement 14,000,000   $ 760 13,999,240    
Issuance of common stock for cash, net of financing costs (in shares)     875,305      
Issuance of common stock for cash, net of financing costs 5,461,745   $ 875 5,460,870    
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments (in shares)     66,749      
Exercise of stock options for cash and vesting of RSUs, net of tax payments (466,646)   $ 67 (466,713)    
Stock-based compensation 11,072,486     11,072,486    
Net loss (135,117,352)       (135,117,352)  
Unrealized gain (loss) on short-term investments, net of tax 40,060         40,060
Foreign currency translation $ (3,920)         (3,920)
Ending balance (in shares) at Dec. 31, 2023 9 9        
Ending balance (in shares) at Dec. 31, 2023 22,793,075   22,793,075      
Ending balance at Dec. 31, 2023 $ 117,349,129 $ 0 $ 22,792 1,740,954,074 (1,622,965,136) (662,601)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Issuance of common stock for cash, net of financing costs (in shares)     13,213,778      
Issuance of common stock for cash, net of financing costs 36,033,473   $ 13,214 36,020,259    
Issuance of warrants for cash, net of financing costs 16,146,397     16,146,397    
Exercise of stock options and warrants for cash and vesting of RSUs, net of tax payments (in shares)     93,138      
Exercise of stock options for cash and vesting of RSUs, net of tax payments (353,120)   $ 93 (353,213)    
Stock-based compensation 6,595,108     6,595,108    
Net loss (107,254,126)       (107,254,126)  
Unrealized gain (loss) on short-term investments, net of tax (45,469)         (45,469)
Foreign currency translation $ 32,403         32,403
Ending balance (in shares) at Dec. 31, 2024 9 9        
Ending balance (in shares) at Dec. 31, 2024 36,099,991   36,099,991      
Ending balance at Dec. 31, 2024 $ 68,503,795 $ 0 $ 36,099 $ 1,799,362,625 $ (1,730,219,262) $ (675,667)
v3.25.1
Consolidated Statements of Cash Flows - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Cash flows from operating activities:    
Net loss $ (107,254,126) $ (135,117,352)
Adjustments to reconcile net loss to net cash used in operating activities:    
Depreciation 1,752,147 2,621,649
Amortization of intangible assets 0 145,417
Amortization of operating lease right-of-use assets 1,377,895 736,472
Change in fair value of common stock warrant liability (2,808,608) 0
Impairment of goodwill 0 10,513,371
Impairment of intangible assets 0 1,984,444
Deferred taxes 0 (32,046)
Non-cash stock-based compensation 6,595,108 11,072,486
Non-cash interest on senior convertible notes (355,654) 155,814
Amortization of discounts on investments (1,690,527) (4,686,144)
Realized loss on sales of short-term investments 1,905,369 4,805,804
Net (gain) loss on disposal of fixed assets (22,466) 317,997
Loss (gain) on equity investment in affiliated entity 1,166,443 (773,145)
Net unrealized gain on available-for-sale equity securities (2,077,182) (5,850,626)
Changes in operating assets and liabilities:    
Accounts receivable, including from affiliated entities 1,206,172 9,332,988
Prepaid expenses and other current assets, including from affiliated entities 1,483,393 39,020,611
Other assets 38,900 78,729
Accounts payable and accrued expenses, including due to affiliated entities (3,367,087) (45,989,061)
Accrued clinical trial expenses (343,522) (8,228,691)
Operating lease right-of-use assets and liabilities, net (1,573,401) (2,020,971)
Grant funding liability, including from affiliated entity (109,407) (2,453,297)
Net cash used in operating activities (104,076,553) (124,365,551)
Cash flows from investing activities:    
Purchases of investments (54,138,026) (203,475,052)
Proceeds from sale or maturity of investments 158,637,578 284,932,562
Purchases of capital assets (487,832) (320,898)
Proceeds from sale of capital assets 59,319 6,219,263
Net cash provided by investing activities 104,071,039 87,355,875
Cash flows from financing activities:    
Repayment of convertible senior notes (16,415,000) 0
Proceeds from issuance of pre-funded warrants, net of issuance costs 16,146,397 0
Proceeds from issuance of common stock, net of issuance costs 36,033,473 5,461,745
Proceeds from issuance of warrants 16,063,796 0
Proceeds from stock option exercises 67,675 0
Taxes paid related to net share settlement of equity awards (420,795) (466,646)
Net cash provided by financing activities 51,475,546 4,995,099
Effect of exchange rate changes on cash and cash equivalents 32,403 (3,920)
Increase (decrease) in cash and cash equivalents 51,502,435 (32,018,497)
Cash and cash equivalents, beginning of period 14,310,862 46,329,359
Cash and cash equivalents, end of period 65,813,297 14,310,862
Supplemental disclosure:    
Interest paid 533,487 1,066,975
Issuance of common stock as part of litigation settlement $ 0 $ 14,000,000
v3.25.1
The Company
 12 Months Ended
Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
The Company The Company
Inovio Pharmaceuticals, Inc. (the “Company” or “INOVIO”) is a clinical-stage biotechnology company focused on developing and commercializing DNA medicines to help treat and protect people from HPV-associated diseases, cancer and infectious diseases. INOVIO's platform harnesses the power of in vivo protein production, featuring optimized design and delivery of DNA medicines that teach the body to manufacture its own disease-fighting tools.
INOVIO uses proprietary technology to design DNA plasmids, which are small circular DNA molecules that work like software the body’s cells can download to produce specific proteins to target and fight disease. The Company's proprietary investigational CELLECTRA devices are designed to deliver the plasmids into the body's cells for optimal effect, without the use of chemical adjuvants, lipid nanoparticles or viral vectors.
INOVIO's lead candidate is INO-3107 for the treatment of recurrent respiratory papillomatosis (RRP), a chronic, rare and debilitating disease of the respiratory tract caused by HPV infection. In its completed Phase 1/2 clinical trial of INO-3107 for the treatment of HPV-6 and HPV-11-associated RRP, 81.3% of patients experienced a reduction in the number of surgical interventions in the year following administration of INO-3107, when compared with the year prior to treatment.
In addition to its development efforts with INO-3107, INOVIO is actively developing or planning to develop DNA medicines for other indications, including HPV-related oropharyngeal squamous cell carcinoma (OPSCC) and anal dysplasia; glioblastoma multiforme (GBM), a deadly form of brain cancer; and a potential vaccine booster to protect against the Ebola virus. The Company was previously conducting clinical trials of a DNA medicine candidate for the treatment of HPV-related cervical high-grade squamous intraepithelial lesions (HSIL) but announced in 2023 that it was ceasing development for this indication in the United States. However, its collaborator ApolloBio Corporation continues to conduct a Phase 3 clinical trial of this candidate in China and plans to seek regulatory approval for and potentially commercialize the candidate in that jurisdiction.
The Company's partners and collaborators include Advaccine Biopharmaceuticals Suzhou Co, ApolloBio Corporation, AstraZeneca, Coherus Biosciences, Defense Advanced Research Projects Agency (DARPA), HIV Vaccines Trial Network, International Vaccine Institute (IVI), Kaneka Eurogentec, National Cancer Institute (NCI), National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID), Plumbline Life Sciences, Regeneron Pharmaceuticals, Richter BioLogics, the University of Pennsylvania, the Walter Reed Army Institute of Research, and The Wistar Institute.
INOVIO was incorporated in Delaware in June 2001 and has its principal executive offices in Plymouth Meeting, Pennsylvania.
v3.25.1
Summary of Significant Accounting Policies
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies Summary of Significant Accounting Policies
Basis of Presentation and Liquidity
The Company incurred a net loss of $107.3 million for the year ended December 31, 2024. The Company had working capital of $62.5 million and an accumulated deficit of $1.7 billion as of December 31, 2024. The Company has incurred losses in each year since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future in connection with the research and preclinical and clinical development of its product candidates. The Company’s cash, cash equivalents and short-term investments of $94.1 million as of December 31, 2024 are not sufficient to support the Company's operations for a period of at least 12 months from the date it is issuing these financial statements.
On December 16, 2024, the Company closed an underwritten public offering (the "December 2024 Offering"), relating to the issuance and sale of 10,000,000 shares of its common stock, par value $0.001 per share, and warrants to purchase 10,000,000 shares of common stock (the “Warrants”), at an offering price of $3.00 per share and accompanying Warrant. The exercise price of the Warrants is $3.76 per share. The net proceeds from the December 2024 Offering were $27.6 million, after deducting the underwriting discounts and commissions and offering expenses paid by the Company.
On April 18, 2024, the Company closed an underwritten registered direct offering (the “April 2024 Offering”), relating to the issuance and sale of 2,536,258 shares (the “Shares”) of its common stock, par value $0.001 per share, at a price of $7.693 per share and pre-funded warrants to purchase up to 2,135,477 shares of common stock (the “Pre-Funded Warrants”) at a price of $7.692 per Pre-Funded Warrant, which represents the per share price for the Shares less the $0.001 per share exercise price for each Pre-Funded Warrant. The net proceeds from the April 2024 Offering were $33.2 million, after deducting the underwriting discounts and commissions and offering expenses paid by the Company.
Going Concern
The Company’s cash, cash equivalents and short-term investments of $94.1 million as of December 31, 2024 are expected to be sufficient to support the Company's planned operations through the fourth quarter of 2025. The Company's current
financial resources may not be sufficient to support its planned operations beyond this date without securing additional financing.
In order to continue to fund future research and development activities, the Company will need to seek additional capital. This may occur through strategic alliance and licensing arrangements, grant agreements and/or future public or private debt or equity financings, including under At-the-Market Equity Offering Sales Agreements (“Sales Agreements”). The Company has a history of conducting debt and equity financings, including the receipt of net proceeds of $60.8 million from equity offerings during the year ending December 31, 2024, and $6.1 million and $5.5 million from equity offerings under Sales Agreements during the years ending December 31, 2024 and 2023, respectively. However, sufficient funding may not be available in the future, or if available, may be on terms that significantly dilute or otherwise adversely affect the rights of existing stockholders. If adequate funds are not available, the Company may need to delay, reduce the scope of or put on hold one or more of its clinical and/or preclinical programs.
The Company’s ability to continue its operations is dependent upon its ability to obtain additional capital in the future and achieve profitable operations. The Company expects to continue to rely on outside sources of financing to meet its capital needs and may never achieve positive cash flow. In light of these factors, management believes that there is substantial doubt about the Company's ability to continue as a going concern beyond the fourth quarter of 2025. The Company's consolidated financial statements as of and for the year ended December 31, 2024 do not include any adjustments that might result from the outcome of this uncertainty. The Company has evaluated subsequent events after the balance sheet date through the date it issued these consolidated financial statements.
The Company is, and from time to time in the future may be, subject to various legal proceedings and claims arising in the ordinary course of business. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its consolidated financial statements. An estimated loss contingency is accrued in the consolidated financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Legal proceedings, including litigation, government investigations and enforcement actions, could result in material costs, occupy significant management resources and entail civil and criminal penalties, even if the Company ultimately prevails. Any of the foregoing consequences could result in serious harm to the Company’s business, results of operations and financial condition.
Reverse Stock Split
On January 24, 2024, the Company filed with the Secretary of State of the State of Delaware a certificate of amendment to its certificate of incorporation, as previously amended, to effect a 1-for-12 reverse stock split of its common stock (the “Reverse Stock Split”). As a result of the Reverse Stock Split, every 12 issued and outstanding shares of the Company's common stock were automatically combined into one issued and outstanding share of common stock. The reverse stock split was reflected on the Nasdaq Capital Market beginning with the opening of trading on January 25, 2024. Accordingly, an amount equal to the par value of the decreased shares resulting from the reverse stock split was reclassified from "Additional paid-in capital" to "Common stock" on the balance sheet and statement of changes in stockholders’ equity. Any fractional post-split shares as a result of the reverse stock split were eliminated by the payment of cash for the value of such fractional share. As a result of the Reverse Stock Split, proportionate adjustments were made to the number of shares underlying, and the exercise or conversion prices of, the Company's outstanding stock options and outstanding shares of Series C Cumulative Convertible Preferred Stock and to the number of shares of common stock issuable under the Company's equity incentive plans. The reverse stock split did not change the par value of the Company's common stock or the authorized number of shares of the Company's common stock.
Consolidation
The consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its wholly-owned subsidiary Inovio Asia LLC.
Segment Reporting
Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker ("CODM"), the President and Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one segment operating primarily within the United States, as further described in Note 16.
Use of Estimates
The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Concentration of Credit Risk
Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and short-term investments. The Company limits its exposure to credit loss by placing its cash and investments with high credit quality financial institutions. Additionally, the Company has established guidelines regarding diversification of its investments and their maturities which are designed to maintain principal and maximize liquidity.
The Company has contracts with certain of its customers that have represented more than 10% of the Company's total revenues, as discussed in Note 3.
Fair Value Measurements
The guidance regarding fair value measurements establishes a three-tier fair value hierarchy which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets that are accessible at the measurement date; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
The Company’s financial instruments include cash equivalents, short-term investments, investments in affiliated entity, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses and common stock warrant liability. The carrying amounts of cash equivalents, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses approximate the related fair values due to the short-term maturities of these instruments. Short-term investments are recorded at fair value on a recurring basis, based on current market valuations. The estimated fair value of the common stock warrant liability is determined by using the Black-Scholes pricing model, as discussed in Note 5.
Cash and Cash Equivalents
Cash equivalents are considered by the Company to be highly liquid investments purchased with original maturities of three months or less from the date of purchase. Cash and cash equivalents included certain mutual funds and U.S. treasury securities at December 31, 2024 and 2023.
Short-term Investments
The Company defines investments as income-yielding securities that can be readily converted into cash or equity investments classified as available-for-sale. Investments included mutual funds, U.S. treasury securities, certificates of deposit, U.S. agency mortgage-backed securities and an equity investment in the Company’s affiliated entity, PLS, at December 31, 2024 and 2023.
Short-term investments are recorded at fair value, based on current market valuations. Unrealized gains and losses on the Company's short-term debt securities are excluded from earnings and reported as a separate component of other comprehensive loss until realized. Realized gains and losses and unrealized gains and losses on available-for-sale equity securities are included in non-operating other income (expense) on the consolidated statements of operations and are derived using the specific identification method for determining the cost of the securities sold.
Accounts Receivable from Affiliated Entities
Accounts receivable from affiliated entities are recorded at invoiced amounts and do not bear interest. The Company performs ongoing credit evaluations of its customers’ financial condition. Credit is extended to customers as deemed necessary and generally does not require collateral. Management believes that the risk of loss is significantly reduced due to the quality and financial position of the Company's customers. There was no allowance for doubtful accounts for potential credit losses as of December 31, 2024 or 2023.
Fixed Assets
Fixed assets include property and equipment and leasehold improvements. Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful life of the assets, generally three to five years. Leasehold improvements are amortized over the shorter of the remaining term of the related leases or the estimated economic useful lives of the improvements. Repairs and maintenance are expensed as incurred.
The Company evaluates the carrying value of long-lived assets, which includes fixed assets and right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying amounts of the asset may not be fully recoverable. No impairment losses have been recognized related to long-lived assets for the years ended December 31, 2024 or 2023.
Warrants
The Company accounts for warrants as either equity-classified or liability-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in Accounting Standards Codification (“ASC”) 480, Distinguishing Liabilities from Equity (“ASC 480”) and ASC 815, Derivatives and Hedging (“ASC 815”). This assessment, which requires the use of professional judgment, is conducted at the time of warrant issuance and as of each subsequent
reporting period while the warrants are outstanding. The Pre-Funded Warrants issued in April 2024 met all the criteria for equity classification and were recorded as a component of additional paid-in capital on issuance. However, the Warrants issued in December 2024 did not meet all the criteria for equity classification and were recorded as a liability at fair value upon issuance. The Warrants met the definition of a derivative and did not meet any scope exceptions under ASC 815. As a result, the fair value of the liability associated with the Warrants will be remeasured at the end of each reporting period while the Warrants are outstanding, and any change in fair value between reporting periods will be recognized as gain or loss on the consolidated statement of operations for that reporting period.
Transaction costs associated with the issuance of the Warrants classified as a liability were expensed at the time of issuance and have been included as part of other expense, net, on the consolidated statement of operations for the year ended December 31, 2024.
Income Taxes
The Company recognizes deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities along with net operating loss and tax credit carryforwards. The Company records a valuation allowance against its deferred tax assets to reduce the net carrying value to an amount that it believes is more likely than not to be realized. When the Company establishes or reduces the valuation allowance against its deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made.
Valuation allowances against the Company’s deferred tax assets were $349.2 million and $327.5 million at December 31, 2024 and 2023, respectively. Changes in the valuation allowances, when they are recognized in the provision for income taxes, are included as a component of the estimated annual effective tax rate.
Collaboration Agreements and Revenue Recognition
The Company assesses whether its collaboration agreements are subject to Accounting Standards Codification ("ASC") Topic 808: Collaborative Arrangements (“Topic 808”) based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. To the extent that the arrangement falls within the scope of Topic 808 and the Company concludes that its collaboration partner is not a customer, the Company presents such payments as a reduction of research and development expense. If payments from the collaboration partner to the Company represent consideration from a customer, then the Company accounts for those payments within the scope of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (“Topic 606”).
Grants
The Company accounts for various grant agreements under the contributions guidance under Subtopic 958-605, Not-for-Profit Entities-Revenue Recognition, which is outside the scope of Topic 606, as the government agencies granting the Company funds are not receiving reciprocal value for their contributions. All contributions received from current grant agreements are recorded as a contra-research and development expense as opposed to revenue on the consolidated statement of operations.
Equity Investments
Under ASC Topic 321, Investments - Equity Securities, the Company must measure equity investments (except those accounted for under the equity method, those that result in consolidation of the investee and certain other investments) at fair value and recognize any changes in fair value in the consolidated statement of operations. The Company can elect a measurement alternative for equity investments that do not have readily determinable fair values and do not qualify for the practical expedient in ASC Topic 820, Fair Value Measurement, to estimate fair value using the net asset value per share (or its equivalent). The Company's equity investments that do not have readily determinable fair values and do not qualify for the net asset value practical expedient for estimating fair value are measured at cost, less any impairments, plus or minus changes resulting from observable price changes in orderly transactions for identifiable or similar investments of the same issuer. 
Research and Development Expenses - Clinical Trial Accruals
The Company's activities have largely consisted of research and development efforts related to developing its proprietary device technology and DNA medicine candidates. For clinical trial expenses, judgements used in estimating accruals rely on estimates of total costs incurred based on participant enrollment, completion of studies and other events. Accrued clinical trial costs are subject to revisions as trials progress. Revisions are charged to expense in the period in which the facts that give rise to the revision become known. Historically, revisions have not resulted in material changes to research and development expense; however, a modification in the protocol of a clinical trial or cancellation of a trial could result in a charge to the Company's results of operations.
Net Loss Per Share
Basic net loss per share is computed by dividing the net loss for the year by the weighted average number of shares of common stock outstanding during the year. The outstanding Pre-Funded Warrants (see Note 10) are included in the weighted-average common shares outstanding in the basic net loss per share calculation for the year ended December 31, 2024 given their nominal exercise price.
Diluted net loss per share is calculated in accordance with the treasury stock method for the outstanding Warrants, stock options and restricted stock units ("RSUs") and reflects the potential dilution that would occur if securities or other contracts to issue common stock were exercised or converted to common stock. The dilutive impact of the Notes previously issued by the Company (discussed in Note 9) was considered using the "if-converted" method. The calculation of diluted net loss per share requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the options or other securities and the presumed exercise of such securities are dilutive to net loss per share for the period, an adjustment to net loss used in the calculation is required to remove the change in fair value of such securities from the numerator for the period. Likewise, an adjustment to the denominator is required to reflect the related dilutive shares, if any. For the years ended December 31, 2024 and 2023, basic and diluted net loss per share are the same, as the assumed exercise or settlement of common stock warrants, stock options, service-based RSUs, performance-and market-based RSUs and the potentially dilutive shares issuable upon conversion of the Notes prior to their repayment on March 1, 2024 would have been anti-dilutive.
Basic and diluted net loss per share for the year ended December 31, 2024 and 2023 are calculated as follows:
Year Ended December 31,
20242023
Numerator:
    Net loss$(107,254,126)$(135,117,352)
Denominator:
     Shares used to compute net loss per share, basic and diluted
          Weighted-average common shares outstanding25,655,527 22,173,662 
          Weighted-average shares underlying pre-funded warrants1,505,336 — 
     Weighted-average common shares outstanding used to compute basic and diluted net loss per share27,160,863 22,173,662 
Net loss per share
     Basic and diluted$(3.95)$(6.09)
The following table summarizes potential shares of common stock that were excluded from diluted net loss per share calculation because of their anti-dilutive effect:
Year Ended December 31,
20242023
Warrants to purchase common stock10,000,000 — 
Options to purchase common stock1,337,228 1,128,864 
Service-based restricted stock units337,911 274,794 
Performance-and market-based restricted stock units
128,800 — 
Convertible preferred stock275 275 
Convertible notes— 254,165 
Total11,804,214 1,658,098 

Leases
For its long-term operating leases, the Company recognized an operating lease right-of-use asset and an operating lease liability on its consolidated balance sheets. The lease liability is determined as the present value of future lease payments using an estimated rate of interest that the Company would pay to borrow equivalent funds on a collateralized basis at the lease commencement date. The right-of-use asset is based on the liability adjusted for any prepaid or deferred rent. The Company determines the lease term at the commencement date by considering whether renewal options and termination options are reasonably assured of exercise.
Fixed rent expense for the Company's operating leases is recognized on a straight-line basis over the term of the lease and is included in operating expenses on the consolidated statements of operations. Variable lease payments including lease operating expenses are recorded as incurred.
Stock-Based Compensation
The Company incurs stock-based compensation expense related to service-based RSUs, performance-and market-based RSUs and stock options. The fair value of restricted stock is determined by the closing price of the Company's common stock reported on the Nasdaq Capital Market on the date of grant. The Company estimates the fair value of stock options granted using the Black-Scholes option pricing model. The Black-Scholes option pricing model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of subjective assumptions, including the expected stock price volatility and expected option life. The Company amortizes the fair value of the awards on a straight-line basis over the requisite vesting period of the awards. Expected volatility is based on historical volatility. The expected life of options granted is based on historical expected life. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant. The dividend yield is based on the fact that no dividends have been paid historically and none are currently expected to be paid in the foreseeable future. The Company recognizes forfeitures as they occur.
The weighted average assumptions used in the Black-Scholes model for option grants to employees and directors are presented below:
 Year Ended December 31,
 20242023
Risk-free interest rate4.22%4.05%
Expected volatility105%100%
Expected life in years5.55.5
Dividend yield——

The weighted average assumptions used in the Black-Scholes model for option grants to non-employees are presented below:
 Year Ended December 31,
 20242023
Risk-free interest rate4.21%3.90%
Expected volatility100%89%
Expected life in years6.510.0
Dividend yield——

Recent Accounting Pronouncements
The recent accounting pronouncements below may have a significant effect on the Company's financial statements. Recent accounting pronouncements that are not anticipated to have an impact on or are unrelated to the Company's financial condition, results of operations, or related disclosures are not discussed.
ASU No. 2023-07. In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. The ASU expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly reviewed by the Chief Operating Decision Maker (CODM) and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items, and interim disclosures of a reportable segment’s profit or loss and assets. The ASU also allows, in addition to the measure that is most consistent with U.S. GAAP, the disclosure of additional measures of segment profit or loss that are used by the CODM in assessing segment performance and deciding how to allocate resources. All disclosure requirements under ASU 2023-07 are also required for public entities with a single reportable segment. The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, on a retrospective basis, with early adoption permitted. The Company has adopted ASU 2023-07 and included the segment disclosures in Note 16 below.
ASU No. 2023-09. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU 2023-09 is effective for public entities with annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of this guidance its consolidated financial statements.
ASU No. 2024-03. In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. ASU
2024-03 requires public business entities to disaggregate operating expenses into specific categories such as employee compensation, depreciation, and intangible asset amortization, by relevant expense caption on the statement of operations. ASU 2024-03 is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, and may be applied either prospectively or retrospectively. Early adoption is permitted. The Company is currently evaluating the impact of adopting this guidance on the consolidated financial statements.
v3.25.1
Revenue Recognition and Concentration of Credit Risk
 12 Months Ended
Dec. 31, 2024
Revenue from Contract with Customer [Abstract]  
Revenue Recognition and Concentration of Credit Risk Revenue Recognition and Concentration of Credit Risk
During the years ended December 31, 2024 and 2023, the Company recognized revenue from various license and other agreements. The following table indicates the percentage of total revenues in excess of 10% with any single customer:

Customer2024 Revenue% of Total
Revenue		2023 Revenue% of Total
Revenue
ApolloBio Corporation$217,756 100 %$245,056 29 %
All other, including affiliated entity— — 586,954 71 
Total revenue$217,756 100 %$832,010 100 %

No revenue recognized during the years ended December 31, 2024 and 2023 was in deferred revenue as of December 31, 2023 and 2022, respectively.
As of December 31, 2024 and 2023, the Company had no accounts receivable balance.
v3.25.1
Collaborative Agreements
 12 Months Ended
Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Collaborative Agreements Collaborative Agreements
Advaccine Biopharmaceuticals Suzhou Co., Ltd.
In 2020, the Company entered into a Collaboration and License Agreement with Advaccine Biopharmaceuticals Suzhou Co., Ltd. (“Advaccine”), which was amended and restated in 2021 (as amended and restated, the “Advaccine Agreement”). Under the terms of the Advaccine Agreement, the Company granted to Advaccine the exclusive right to develop, manufacture and commercialize the Company’s vaccine candidate INO-4800 within the territories of China, Taiwan, Hong Kong and Macau (referred to collectively as “Greater China”) and 33 additional countries in Asia. The 2021 amendment related to a collaboration between the Company and Advaccine to jointly conduct a global Phase 3 segment of the Company’s clinical trial of INO-4800 that was planned. The parties were jointly participating in the trial and were to equally share the global development costs for the trial, including the Company’s manufacturing costs to supply INO-4800. Advaccine agreed to be fully responsible for conducting the trial in Greater China, including its costs and expenses incurred. The Company has discontinued its internally funded efforts to develop INO-4800 as a COVID-19 heterologous booster vaccine. Advaccine continues to develop INO-4800 with its own resources under the terms of the Advaccine Agreement.
In connection with the 2021 amendment, the Company determined that the global Phase 3 trial component of the agreement was a collaboration and not a contract with a customer and therefore accounts for the 2021 amendment under ASC Topic 808. Reimbursements from Advaccine are recognized as contra-research development expense on the consolidated statement of operations once earned and collectibility is assured. During the years ended December 31, 2024 and 2023, the Company received funding of $0 and $3.6 million respectively, from Advaccine that was recorded as contra-research and development expense.
ApolloBio Corporation
In 2017, the Company entered into an Amended and Restated License and Collaboration Agreement (the "ApolloBio Agreement"), with ApolloBio Corporation ("ApolloBio"), which was amended in June 2023. Under the terms of the ApolloBio Agreement, the Company granted to ApolloBio the exclusive right to develop and commercialize VGX-3100, its DNA immunotherapy product candidate designed to treat pre-cancers caused by HPV, within the agreed upon territories.
The Company is entitled to receive up to an aggregate of $20.0 million, less required income, withholding or other taxes, upon the achievement of specified milestones related to the regulatory approval of VGX-3100 in accordance with the ApolloBio Agreement. In the event that VGX-3100 is approved for marketing, the Company will be entitled to receive royalty payments based on a tiered percentage of annual net sales, with such percentage being in the low- to mid-teens, subject to reduction in the event of generic competition in a particular territory. ApolloBio’s obligation to pay royalties will continue for 10 years after the first commercial sale in a particular territory or, if later, until the expiration of the last-to-expire patent covering the licensed products in the specified territory.
During the years ended December 31, 2024 and 2023, the Company received $218,000 and $245,000, respectively, from the ApolloBio Agreement that was recorded as revenue.
Coalition for Epidemic Preparedness Innovations (CEPI)
The Company previously entered into agreements with CEPI pursuant to which the Company intended to develop vaccine candidates against Lassa fever and MERS. As part of the arrangement between the parties, CEPI agreed to fund up to an aggregate of $56 million of costs over a five-year period for preclinical studies, as well as planned Phase 1 and Phase 2 clinical trials, to be conducted by the Company and collaborators, with funding from CEPI based on the achievement of identified milestones. In 2022, the Company announced that it and CEPI would discontinue the development of these product candidates targeting Lassa fever and MERS, following the initial analysis of data from the studies conducted by the Company and funded by CEPI.
During the year ended December 31, 2024, the Company received funding of $1.6 million in connection with the final close-out of these grants, which was recorded as contra-research and development expense. During the year ended December 31, 2023, the Company received funding of $1.8 million in connection with these grants.
Bill & Melinda Gates Foundation
In 2018, Gates awarded and funded the Company a grant of $2.2 million to advance the development of dMAbs to address issues in infectious disease prevention and therapy. This technology has high relevance for the control of influenza and HIV. This next-generation approach to the delivery of monoclonal antibodies would make the technology accessible to low and middle-income countries. In 2019, Gates funded an additional $1.1 million for the project. During the years ended December 31, 2024 and 2023, the Company recorded $39,000 and $70,000, respectively, as contra-research and development expense related to the Gates dMAb grant.
v3.25.1
Short-term Investments and Fair Value Measurements
 12 Months Ended
Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]  
Short-term Investments and Fair Value Measurements Short-term Investments and Fair Value Measurements
The following is a summary of available-for-sale securities as of December 31, 2024 and 2023:
 
 As of December 31, 2024
 Contractual
Maturity (in years)		CostGross Unrealized
Gains		Gross Unrealized
Losses		Fair Market Value
Mutual funds---$25,926,415 $— $(1,445,706)$24,480,709 
Certificates of deposit
Less than 1
2,980,273 9,750 (281)2,989,742 
U.S. agency mortgage-backed securities*1,260,745 — (430,964)829,781 
$30,167,433 $9,750 $(1,876,951)$28,300,232 
 As of December 31, 2023
 Contractual
Maturity (in years)		CostGross Unrealized
Gains		Gross Unrealized
Losses		Fair Market Value
Mutual funds---$55,389,289 $— $(3,522,888)$51,866,401 
U.S. treasury securities
Less than 1
75,164,782 24,938 — 75,189,720 
Certificates of deposit
Less than 1
2,978,917 11,709 (300)2,990,326 
U.S. agency mortgage-backed securities*1,340,439 — (403,973)936,466 
$134,873,427 $36,647 $(3,927,161)$130,982,913 

*No single maturity date.

During the years ended December 31, 2024 and 2023, the Company recorded gross realized gain on investments of $900 and $1,000, respectively, and gross realized loss on investments of $1.9 million and $4.8 million, respectively. During the years ended December 31, 2024 and 2023, the Company recorded net unrealized gain on available-for-sale equity securities of $2.1 million and $5.9 million, respectively. No material balances were reclassified out of accumulated other comprehensive loss for the years ended December 31, 2024 and 2023. Interest and dividends on investments classified as available-for-sale are included in interest income in the consolidated statements of operations. As of December 31, 2024, the Company had 19 available-for-sale securities with an aggregate total unrealized loss of $1.9 million. All of the securities had been in a loss position for longer than 12 months as of December 31, 2024.
The Company periodically reviews its portfolio of available-for-sale debt securities to determine if any investment is impaired due to credit loss or other potential valuation concerns. For the debt securities where the fair value of the investment is less than the amortized cost basis, the Company has assessed at the individual security level for various quantitative factors
including, but not limited to, the nature of the investments, changes in credit ratings, interest rate fluctuations, industry analyst reports, and the severity of impairment. Unrealized losses on available-for-sale debt securities as of December 31, 2024 were primarily due to changes in interest rates, and not due to increased credit risks associated with specific securities. Based on the credit quality of the available-for-sale debt securities that are in an unrealized loss position, and the Company’s estimates of future cash flows to be collected from those securities, the Company believes the unrealized losses are not credit losses. Accordingly, at December 31, 2024, the Company did not record an allowance for credit losses related to its available-for-sale debt securities.
The following table presents the Company’s assets and liabilities that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2024:
 
Fair Value Measurements at
 December 31, 2024
 TotalQuoted Prices
in Active Markets
(Level 1)		Significant
Other Unobservable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Assets:
Short-term investments
    Mutual funds$24,480,709 $24,480,709 $— $— 
    Certificates of deposit2,989,742 — 2,989,742 — 
    U.S. agency mortgage-backed securities829,781 — 829,781 — 
Total short-term investments28,300,232 24,480,709 3,819,523 — 
Investment in affiliated entity1,613,844 1,613,844 — — 
Total assets measured at fair value$29,914,076 $26,094,553 $3,819,523 $— 
Liabilities:
Common stock warrant liability$13,255,188 $— $— $13,255,188 
Total liabilities$13,255,188 $— $— $13,255,188 

The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2023:
 
Fair Value Measurements at
 December 31, 2023
 TotalQuoted Prices
in Active Markets
(Level 1)		Significant
Other Unobservable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Short-term investments
     Mutual funds$51,866,401 $51,866,401 $— $— 
     U.S. treasury securities75,189,720 75,189,720 — — 
     Certificates of deposit2,990,326 — 2,990,326 — 
     U.S. agency mortgage-backed securities936,466 — 936,466 — 
Total short-term investments130,982,913 127,056,121 3,926,792 — 
Investments in affiliated entity2,780,287 2,780,287 — — 
Total assets measured at fair value$133,763,200 $129,836,408 $3,926,792 $— 

Level 1 assets at December 31, 2024 consisted of mutual funds and the Company’s investment in its affiliated entity, PLS. Level 1 assets at December 31, 2023 consisted of mutual funds and U.S. treasury securities held by the Company that are
valued at quoted market prices, as well as the Company’s investment in its affiliated entity, PLS. The Company accounts for its investment in 597,808 common shares of PLS based on the closing price of the shares on the Korea New Exchange Market on the applicable balance sheet date. Unrealized gains and losses on the Company's equity securities are reported in the consolidated statement of operations as unrealized gain or loss on available-for-sale equity securities or as a gain or loss on investment in affiliated entity.
Level 2 assets at December 31, 2024 and 2023 consisted of certificates of deposit and U.S. agency mortgage-backed securities held by the Company that are initially valued at the transaction price and subsequently valued, at the end of each reporting period, typically utilizing market observable data. The Company obtains the fair value of its Level 2 assets from a professional pricing service, which may use quoted market prices for identical or comparable instruments, or inputs other than quoted prices that are observable either directly or indirectly. The professional pricing service gathers quoted market prices and observable inputs from a variety of industry data providers. The valuation techniques used to measure the fair value of the Company's Level 2 financial instruments were derived from non-binding market consensus prices that are corroborated by observable market data, quoted market prices for similar instruments, or pricing models such as discounted cash flow techniques. The Company validates the quoted market prices provided by the primary pricing service by comparing the service's assessment of the fair values of the Company's investment portfolio balance against the fair values of the Company's investment portfolio balance obtained from an independent source.
There were no Level 3 assets held as of December 31, 2024 or 2023.
Level 3 liabilities held as of December 31, 2024 consisted of liabilities associated with the Warrants to purchase common stock issued in the Company's underwritten public offering that closed in December 2024. See Note 10 for additional information about the liability-classified warrants.
The Company reassesses the fair value of the common stock warrant liability at each reporting date utilizing a Black-Scholes pricing model. The following assumptions were used to estimate the fair value of the warrant liability:

On Issuance DateDecember 31, 2024
Risk-free interest rate4.3%4.4%
Expected volatility111%111%
Expected life in years55
Dividend yield——

Changes in these assumptions as well as fluctuations in the Company's stock price between the valuation dates can have a
significant impact on the fair value of the common stock warrant liability. Expected volatility was based on historical volatility. Historical volatility was computed using daily pricing observations for recent periods. The Company believes this method produced an estimate that was representative of the Company’s expectations of future volatility over the expected term. Expected term is calculated based on the remaining contractual term of the Warrants. The risk-free rate was based on the U.S. Treasury rate that corresponds to the expected term of the Warrants. As a result of these calculations, the Company recorded a decrease in fair value of the liability of $2.8 million on the consolidated statement of operations for the year ended December 31, 2024.
The following table presents the changes in fair value of the Company’s total Level 3 financial liabilities for the year ended December 31, 2024:
Common Stock Warrant Liability
Balance at December 31, 2023— 
Issuance of common stock warrants in December 202416,063,796 
Decrease in fair value of liability(2,808,608)
Balance at December 31, 2024$13,255,188 
Short-term Investments and Fair Value Measurements Short-term Investments and Fair Value Measurements
The following is a summary of available-for-sale securities as of December 31, 2024 and 2023:
 
 As of December 31, 2024
 Contractual
Maturity (in years)		CostGross Unrealized
Gains		Gross Unrealized
Losses		Fair Market Value
Mutual funds---$25,926,415 $— $(1,445,706)$24,480,709 
Certificates of deposit
Less than 1
2,980,273 9,750 (281)2,989,742 
U.S. agency mortgage-backed securities*1,260,745 — (430,964)829,781 
$30,167,433 $9,750 $(1,876,951)$28,300,232 
 As of December 31, 2023
 Contractual
Maturity (in years)		CostGross Unrealized
Gains		Gross Unrealized
Losses		Fair Market Value
Mutual funds---$55,389,289 $— $(3,522,888)$51,866,401 
U.S. treasury securities
Less than 1
75,164,782 24,938 — 75,189,720 
Certificates of deposit
Less than 1
2,978,917 11,709 (300)2,990,326 
U.S. agency mortgage-backed securities*1,340,439 — (403,973)936,466 
$134,873,427 $36,647 $(3,927,161)$130,982,913 

*No single maturity date.

During the years ended December 31, 2024 and 2023, the Company recorded gross realized gain on investments of $900 and $1,000, respectively, and gross realized loss on investments of $1.9 million and $4.8 million, respectively. During the years ended December 31, 2024 and 2023, the Company recorded net unrealized gain on available-for-sale equity securities of $2.1 million and $5.9 million, respectively. No material balances were reclassified out of accumulated other comprehensive loss for the years ended December 31, 2024 and 2023. Interest and dividends on investments classified as available-for-sale are included in interest income in the consolidated statements of operations. As of December 31, 2024, the Company had 19 available-for-sale securities with an aggregate total unrealized loss of $1.9 million. All of the securities had been in a loss position for longer than 12 months as of December 31, 2024.
The Company periodically reviews its portfolio of available-for-sale debt securities to determine if any investment is impaired due to credit loss or other potential valuation concerns. For the debt securities where the fair value of the investment is less than the amortized cost basis, the Company has assessed at the individual security level for various quantitative factors
including, but not limited to, the nature of the investments, changes in credit ratings, interest rate fluctuations, industry analyst reports, and the severity of impairment. Unrealized losses on available-for-sale debt securities as of December 31, 2024 were primarily due to changes in interest rates, and not due to increased credit risks associated with specific securities. Based on the credit quality of the available-for-sale debt securities that are in an unrealized loss position, and the Company’s estimates of future cash flows to be collected from those securities, the Company believes the unrealized losses are not credit losses. Accordingly, at December 31, 2024, the Company did not record an allowance for credit losses related to its available-for-sale debt securities.
The following table presents the Company’s assets and liabilities that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2024:
 
Fair Value Measurements at
 December 31, 2024
 TotalQuoted Prices
in Active Markets
(Level 1)		Significant
Other Unobservable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Assets:
Short-term investments
    Mutual funds$24,480,709 $24,480,709 $— $— 
    Certificates of deposit2,989,742 — 2,989,742 — 
    U.S. agency mortgage-backed securities829,781 — 829,781 — 
Total short-term investments28,300,232 24,480,709 3,819,523 — 
Investment in affiliated entity1,613,844 1,613,844 — — 
Total assets measured at fair value$29,914,076 $26,094,553 $3,819,523 $— 
Liabilities:
Common stock warrant liability$13,255,188 $— $— $13,255,188 
Total liabilities$13,255,188 $— $— $13,255,188 

The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2023:
 
Fair Value Measurements at
 December 31, 2023
 TotalQuoted Prices
in Active Markets
(Level 1)		Significant
Other Unobservable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Short-term investments
     Mutual funds$51,866,401 $51,866,401 $— $— 
     U.S. treasury securities75,189,720 75,189,720 — — 
     Certificates of deposit2,990,326 — 2,990,326 — 
     U.S. agency mortgage-backed securities936,466 — 936,466 — 
Total short-term investments130,982,913 127,056,121 3,926,792 — 
Investments in affiliated entity2,780,287 2,780,287 — — 
Total assets measured at fair value$133,763,200 $129,836,408 $3,926,792 $— 

Level 1 assets at December 31, 2024 consisted of mutual funds and the Company’s investment in its affiliated entity, PLS. Level 1 assets at December 31, 2023 consisted of mutual funds and U.S. treasury securities held by the Company that are
valued at quoted market prices, as well as the Company’s investment in its affiliated entity, PLS. The Company accounts for its investment in 597,808 common shares of PLS based on the closing price of the shares on the Korea New Exchange Market on the applicable balance sheet date. Unrealized gains and losses on the Company's equity securities are reported in the consolidated statement of operations as unrealized gain or loss on available-for-sale equity securities or as a gain or loss on investment in affiliated entity.
Level 2 assets at December 31, 2024 and 2023 consisted of certificates of deposit and U.S. agency mortgage-backed securities held by the Company that are initially valued at the transaction price and subsequently valued, at the end of each reporting period, typically utilizing market observable data. The Company obtains the fair value of its Level 2 assets from a professional pricing service, which may use quoted market prices for identical or comparable instruments, or inputs other than quoted prices that are observable either directly or indirectly. The professional pricing service gathers quoted market prices and observable inputs from a variety of industry data providers. The valuation techniques used to measure the fair value of the Company's Level 2 financial instruments were derived from non-binding market consensus prices that are corroborated by observable market data, quoted market prices for similar instruments, or pricing models such as discounted cash flow techniques. The Company validates the quoted market prices provided by the primary pricing service by comparing the service's assessment of the fair values of the Company's investment portfolio balance against the fair values of the Company's investment portfolio balance obtained from an independent source.
There were no Level 3 assets held as of December 31, 2024 or 2023.
Level 3 liabilities held as of December 31, 2024 consisted of liabilities associated with the Warrants to purchase common stock issued in the Company's underwritten public offering that closed in December 2024. See Note 10 for additional information about the liability-classified warrants.
The Company reassesses the fair value of the common stock warrant liability at each reporting date utilizing a Black-Scholes pricing model. The following assumptions were used to estimate the fair value of the warrant liability:

On Issuance DateDecember 31, 2024
Risk-free interest rate4.3%4.4%
Expected volatility111%111%
Expected life in years55
Dividend yield——

Changes in these assumptions as well as fluctuations in the Company's stock price between the valuation dates can have a
significant impact on the fair value of the common stock warrant liability. Expected volatility was based on historical volatility. Historical volatility was computed using daily pricing observations for recent periods. The Company believes this method produced an estimate that was representative of the Company’s expectations of future volatility over the expected term. Expected term is calculated based on the remaining contractual term of the Warrants. The risk-free rate was based on the U.S. Treasury rate that corresponds to the expected term of the Warrants. As a result of these calculations, the Company recorded a decrease in fair value of the liability of $2.8 million on the consolidated statement of operations for the year ended December 31, 2024.
The following table presents the changes in fair value of the Company’s total Level 3 financial liabilities for the year ended December 31, 2024:
Common Stock Warrant Liability
Balance at December 31, 2023— 
Issuance of common stock warrants in December 202416,063,796 
Decrease in fair value of liability(2,808,608)
Balance at December 31, 2024$13,255,188 
v3.25.1
Certain Balance Sheet Items
 12 Months Ended
Dec. 31, 2024
Certain Balance Sheet Items [Abstract]  
Certain Balance Sheet Items Certain Balance Sheet Items
Prepaid and other current assets at December 31, 2024 and 2023 consisted of the following:
 
20242023
Prepaid clinical expenses (a)627,962 3,410,442 
Other prepaid expenses1,889,503 2,003,655 
$2,517,465 $5,414,097 
Accounts payable and accrued expenses at December 31, 2024 and 2023 consisted of the following:
20242023
Trade accounts payable$5,091,503 $3,577,826 
Accrued compensation10,007,180 9,837,104 
Other accrued expenses (b) 1,101,330 6,432,814 
$16,200,013 $19,847,744 

(a)As of December 31, 2024 and 2023, balance included $0 and $1.5 million, respectively, of prepaid manufacturing expenses.
(b)As of December 31, 2024 and 2023, balance included $0 and $4.3 million, respectively, of liability for unused grant funding.
v3.25.1
Fixed Assets
 12 Months Ended
Dec. 31, 2024
Property, Plant and Equipment [Abstract]  
Fixed Assets Fixed Assets
Fixed assets at December 31, 2024 and 2023 consisted of the following:
 
CostAccumulated
Depreciation
and
Amortization		Net Book
Value
As of December 31, 2024
Leasehold improvements$11,761,522 $(8,390,612)$3,370,910 
Research and development equipment2,835,298 (2,571,747)263,551 
Office furniture and fixtures2,431,633 (2,416,232)15,401 
Computer equipment and other 3,093,812 (3,083,856)9,956 
$20,122,265 $(16,462,447)$3,659,818 
As of December 31, 2023
Leasehold improvements$15,917,596 $(11,753,081)$4,164,515 
Research and development equipment3,538,698 (3,078,165)460,533 
Office furniture and fixtures2,827,476 (2,816,577)10,899 
Computer equipment and other 3,529,129 (3,204,090)325,039 
$25,812,899 $(20,851,913)$4,960,986 
Depreciation expense for the years ended December 31, 2024 and 2023 was $1.8 million and $2.6 million, respectively. The Company determined that the carrying value of its fixed assets was not impaired during the periods presented. During the year ended December 31, 2024, the Company sold fixed assets with no net book value for a gain of $59,000 and disposed of fixed assets with a net book value of $37,000. During the year ended December 31, 2023, the Company sold fixed assets with no net book value for a gain of $148,000 and disposed of fixed assets with a net book value of $466,000.
v3.25.1
Goodwill and Intangible Assets
 12 Months Ended
Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets Goodwill and Intangible Assets
During 2023, as a result of the sustained decline in the Company’s stock price and related market capitalization, and a general decline in equity values in the biotechnology industry, the Company performed a quantitative impairment assessment of
its goodwill and long-lived assets. The goodwill was determined to be fully impaired as of September 30, 2023, and the Company recorded an impairment charge of $10.5 million.
During 2023, the Company also recorded an impairment charge of $2.0 million to research and development expense for the remaining book value of intangible assets acquired in 2016 from Bioject Medical Technologies, as the Company had no plans to further develop or utilize this technology.
v3.25.1
Convertible Debt
 12 Months Ended
Dec. 31, 2024
Debt Disclosure [Abstract]  
Convertible Debt Convertible Debt
Convertible Senior Notes
In 2019, the Company completed a private placement of $78.5 million aggregate principal amount of its 6.50% convertible senior notes due 2024 (the “Notes”). The Notes were sold in a private offering to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended. Net proceeds from the offering were $75.7 million.
The Notes were senior unsecured obligations of the Company and accrued interest payable in cash semi-annually in arrears on March 1 and September 1 of each year at a rate of 6.50% per annum. The Notes matured on March 1, 2024 and the Company paid the then remaining $16.9 million obligation in full, including accrued interest.
For the years ended December 31, 2024 and 2023,  the Company recognized $178,000 and $1.2 million, respectively, of interest expense related to the Notes, of which $178,000 and $1.1 million, respectively, related to the contractual interest coupon.
v3.25.1
Stockholders' Equity
 12 Months Ended
Dec. 31, 2024
Stockholders' Equity Note [Abstract]  
Stockholders' Equity Stockholders’ Equity
Preferred Stock
   Shares Outstanding as of
December 31,
 Shares AuthorizedShares Issued20242023
Series C Preferred Stock, par $0.001
1,091 1,091 9 9 

The holder of a share or shares of Series C preferred stock has the right at any time, at such holder’s option, to convert all or any lesser portion of such holder’s shares of the preferred stock into fully paid and non-assessable shares of common stock. As of December 31, 2024, the conversion value was $326.40 per share, such that the outstanding shares of Series C preferred stock were convertible into an aggregate of 275 shares of common stock.
Offerings of Common Stock and Warrants
On December 16, 2024, the Company closed the December 2024 Offering (see “Basis of Presentation and Liquidity” in Note 2 above).
Each Warrant issued in the December 2024 Offering has an initial exercise price per share of $3.76, subject to certain adjustments. The Warrants may be exercised at any time, in whole or in part, until expiration on December 16, 2029. In the event there is no effective registration statement covering the shares of common stock underlying a Warrant exercise, the Warrants may be exercised via cashless exercise. A holder (together with its affiliates and other attribution parties) may not exercise any portion of a Warrant to the extent that immediately prior to or after giving effect to such exercise the holder would own more than 4.99% (or, for certain holders who so elected prior to the issuance of the Warrants, 9.99%) of the Company’s outstanding Common Stock immediately after exercise, which percentage may be changed at the holder’s election to a lower or higher percentage not in excess of 19.99% upon 61 days’ notice to the Company subject to the terms of the Warrants.
As the Warrants are not indexed to the Company’s common stock, the Company recorded a liability for the Warrants at fair value upon issuance on the Company's consolidated balance sheet. The common stock warrant liability is remeasured to fair value at the end of each reporting period.
As of December 31, 2024, no Warrants issued in the December 2024 Offering had been exercised.
On April 18, 2024, the Company closed the April 2024 Offering (see “Basis of Presentation and Liquidity” in Note 2 above).
Each Pre-Funded Warrant issued in the April 2024 Offering has an initial exercise price per share of $0.001, subject to certain adjustments. The Pre-Funded Warrants may be exercised at any time until exercised in full. A holder (together with its affiliates and other attribution parties) may not exercise any portion of a Pre-Funded Warrant to the extent that immediately prior to or after giving effect to such exercise the holder would own more than 9.99% of the Company’s outstanding Common
Stock immediately after exercise, which percentage may be changed at the holder’s election to a lower or higher percentage not in excess of 19.99% upon 61 days’ notice to the Company subject to the terms of the Pre-Funded Warrants.
As the Pre-Funded Warrants issued in the April 2024 Offering are indexed to the Company's own shares of common stock (and otherwise meet the requirements to be classified in equity), the Company recorded the consideration received from the issuance of the Pre-Funded Warrants as additional paid-in capital on the Company's condensed consolidated balance sheet as of December 31, 2024.
As of December 31, 2024, no Pre-Funded Warrants had been exercised.
At-The-Market Sales Agreements
On August 13, 2024, the Company entered into an Equity Distribution Agreement (the "2024 Sales Agreement") with an outside sales agent (the "Sales Agent") for the offer and sale of its common stock for an aggregate offering price of up to $60.0 million. The 2024 Sales Agreement provides that the Sales Agent is entitled to compensation in an amount equal to up to 3.0% of the gross sales proceeds of any common stock sold through the Sales Agent under the 2024 Sales Agreement, and the Company has provided the Sales Agent with certain indemnification rights.
During the year ended December 31, 2024, the Company sold 133,900 shares of its common stock under the 2024 Sales Agreement. The sales were made at a weighted average price of $7.02 per share, resulting in aggregate net proceeds of $925,000. As of December 31, 2024, there was $59.1 million of remaining capacity under the 2024 Sales Agreement.
On November 9, 2021, the Company entered into an ATM Equity Offering Sales Agreement (the “2021 Sales Agreement”) with outside sales agents for the offer and sale of its common stock for an aggregate offering price of up to $300.0 million. The 2021 Sales Agreement provides that the sales agents were entitled to compensation in an amount equal to up to 3.0% of the gross sales proceeds of any common stock sold under the 2021 Sales Agreement. During the three months ended March 31, 2024, the Company sold 543,620 shares of its common stock under the 2021 Sales Agreement at a weighted average price of $9.76 per share, resulting in aggregate net proceeds of $5.2 million. During the year ended December 31, 2023, the Company sold 875,305 shares of its common stock under the 2021 Sales Agreement at a weighted average price of $6.33 per share, resulting in aggregate net proceeds of $5.5 million. The 2021 Sales Agreement was terminated in August 2024 in connection with the entry into the 2024 Sales Agreement described above.
Other Issuances of Common Stock
During the three months ended March 31, 2023, the Company issued 760,083 shares of common stock pursuant to a securities class action litigation settlement, as described in Note 11.
Stock Options and Restricted Stock Units
The Board of Directors adopted the 2023 Omnibus Incentive Plan (the “2023 Plan”) on March 24, 2023, pursuant to which the Company may grant stock options, restricted stock awards, RSUs and other stock-based awards or short-term cash incentive awards to employees, directors and consultants.
The 2023 Plan was approved by stockholders on May 16, 2023. The aggregate number of shares of the Company’s common stock that may be issued under the 2023 Plan will not exceed the sum of 1,166,666 shares plus any shares that may return from time to time from the 2016 Omnibus Incentive Plan (as amended, the “2016 Plan”) as a result of expirations, terminations or forfeitures of awards outstanding under the 2016 Plan as of May 16, 2023. At December 31, 2024, the Company had 800,526 shares of common stock available for future grant under the 2023 Plan, 188,082 shares underlying outstanding but unvested RSUs and 282,579 shares underlying options outstanding to purchase common stock under the 2023 Plan. The awards granted and available for future grant under the 2023 Plan generally vest over three years and have a maximum contractual term of ten years. The 2023 Plan terminates by its terms on March 24, 2033.
Following adoption of the 2023 Plan, no further awards may be made under the 2016 Plan, but outstanding awards continue to be governed by their existing terms. At December 31, 2024, the Company had 129,000 shares underlying outstanding but unvested RSU and options outstanding to purchase 904,669 shares of common stock under the 2016 Plan. The outstanding awards granted under the 2016 Plan generally vest over three years and have a maximum contractual term of ten years.
On June 24, 2022, the Company's board of directors adopted a stock-based incentive plan (the "2022 Inducement Plan"), which provides for the discretionary grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, RSU awards, performance awards, and other awards to individuals as a material inducement to entering into employment with the Company. The aggregate number of shares of the Company’s common stock that may be issued under the 2022 Inducement Plan will not exceed 166,666 shares. At December 31, 2024 the Company had 84,328 shares of common stock available for future grant under the 2022 Inducement Plan, 20,829 shares underlying outstanding but unvested RSUs and options outstanding to purchase 53,684 shares of common stock under the 2022 Inducement Plan. The 2022 Inducement Plan can be terminated by the Company's board of directors at any time.
The Amended and Restated 2007 Omnibus Incentive Plan (the "2007 Incentive Plan") was adopted on March 31, 2007 and terminated by its terms on March 31, 2017. At December 31, 2024, the Company had options outstanding to purchase 96,296 shares of common stock under the 2007 Incentive Plan. The awards granted under the 2007 Incentive Plan generally vested over three years and have a maximum contractual term of ten years.
Total employee and director stock-based compensation expense recognized in the consolidated statements of operations for the years ended December 31, 2024 and 2023 was $6.4 million and $10.4 million, respectively, of which $2.8 million and $4.5 million was included in research and development expenses and $3.6 million and $5.9 million was included in general and administrative expenses, respectively.
At December 31, 2024 and 2023, there was $2.1 million and $4.3 million, respectively, of total unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of 1.5 years and 1.3 years, respectively.
At December 31, 2024 and 2023, there was $2.0 million and $3.5 million, respectively, of total unrecognized compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of 1.6 years and 1.5 years, respectively.
The fair value of stock options granted to non-employees was estimated using the Black-Scholes pricing model. Total stock-based compensation expense for stock options and RSUs granted to non-employees for the years ended December 31, 2024 and 2023 was $226,000 and $669,000, respectively. As of December 31, 2024, options to purchase 66,056 shares of common stock granted to non-employees remained outstanding.
The following table summarizes total stock options outstanding at December 31, 2024:
 
 Options OutstandingOptions Exercisable
Exercise PriceShares Underlying Options
Outstanding		Weighted-Average
Remaining
Contractual Life
(in Years)		Weighted
Average
Exercise Price		Shares Underlying Options
Exercisable		Weighted Average
Exercise Price
$1.78-$18.00
568,085 8.8$10.95 205,698 $12.08 
$18.01-$39.00
249,917 6.2$35.52 191,644 $35.28 
$39.01-$52.00
152,066 3.5$44.95 151,949 $44.95 
$52.01-$90.00
126,336 3.2$76.92 123,316 $77.39 
$90.01-$130.00
112,293 3.4$98.68 112,293 $98.68 
$130.01-$233.28
128,531 5.3$137.48 128,531 $137.48 
1,337,228 6.4$45.17 913,431 $59.52 

At December 31, 2024, the aggregate intrinsic value of options outstanding was $1,000, the aggregate intrinsic value of options exercisable was $0, and the weighted average remaining contractual term of options exercisable was 5.5 years.
At December 31, 2024, the aggregate intrinsic value of unvested RSUs was $618,000 and the aggregate intrinsic value of RSUs which vested during the year ended December 31, 2024 was $1.3 million.
At December 31, 2024, options to purchase 1,337,228 shares of common stock and 337,911 RSUs were expected to vest.
Stock option activity under the Company’s equity incentive plans during the year ended December 31, 2024 was as follows:
Number of
Shares		Weighted-Average
Exercise Price
Balance, December 31, 20231,128,864 $58.76 
Granted328,376 8.27 
Exercised(8,159)8.29 
Cancelled(111,853)76.67 
Balance, December 31, 20241,337,228 $45.17 

Restricted stock unit activity under the Company’s equity incentive plans during the year ended December 31, 2024 was as follows:
Number of
Shares
Balance, December 31, 2023274,794 
Granted214,207 
Vested(126,133)
Cancelled(24,957)
Balance, December 31, 2024337,911 

The weighted average exercise price per share was $139.02 for the 38,503 options which expired during the year ended December 31, 2024 and $38.86 for the 9,357 options which expired during the year ended December 31, 2023.
The weighted average grant date fair value per share was $6.69 and $11.19 for options granted during the years ended December 31, 2024 and 2023, respectively.
The weighted average grant date fair value was $8.30 and $10.34 per share for RSUs granted during the years ended December 31, 2024 and 2023, respectively.
The Company received $68,000 in proceeds from the exercise of stock options during the years ended December 31, 2024. No stock options were exercised during the year ended December 31, 2023. The aggregate intrinsic value of options exercised was $39,000 during the year ended December 31, 2024.
Performance- and Market-Based RSUs
In May 2024, the Company granted performance- and-market-based RSUs (such performance-based grants, the "PSU Awards") to key employees under the 2023 Plan. Each PSU was expressed as a target number of RSUs. With respect to the PSU Awards, the Company's Board of Directors established specified performance goals and corresponding performance periods over which the goals must be attained, the satisfaction of which are conditions to earning the PSU Awards and vesting of the underlying RSUs. As of December 31, 2024, 83,800 performance- and market-based RSUs were outstanding.
Of the target number of RSUs underlying each PSU Award, up to 70% (the "Milestone-based RSUs") will vest based on the achievement of specified milestones relating to the development, regulatory status and commercialization of the Company’s lead product candidate INO-3107 (each, a "Milestone," and collectively, the "Milestones"). Each Milestone has a specified deadline for achievement ranging between the end of 2025 and the end of 2027.
The remaining 30% of the target number of RSUs underlying each PSU Award (the "Market-based RSUs") will be eligible to vest based on the Company’s achievement of total stockholder return relative to a peer group consisting of companies in the Russell 2000 Biotechnology Subsector index (the “Relative TSR”) over the period beginning on June 1, 2024 and ending on December 31, 2027 (the “Performance Period”), expressed as a percentile ranking.
The number of Market-based RSUs, if any, actually earned based on the achievement of the Relative TSR goal may range from 50% of the target number of RSUs for performance at a specified threshold percentile, to 100% of the target number of RSUs for performance at the target percentile, and up to 150% of the target number of RSUs for performance at or above a specified maximum percentile. In the event that actual Relative TSR performance is between the threshold and target levels or between the target and maximum levels, the number of RSUs earned based on Relative TSR will be determined based on linear interpolation between the specified percentiles. If the Company’s actual Relative TSR performance is below the threshold percentile, then no RSUs would be earned based on Relative TSR. The number of RSUs earned based on Relative TSR may not exceed the target number of RSUs eligible to vest based on Relative TSR if the Company’s total stockholder return is negative for the Performance Period.
The Company valued the Milestone-based RSUs based on the grant date closing price per share. The Company recognizes stock-based compensation expense over the performance period, if it is probable that the performance condition will be achieved. Adjustments to stock-based compensation expense are made, as needed, each reporting period based on changes in the Company's estimate of the number of units that are probable of vesting.
The Company valued the Market-based RSUs on the grant date using the Monte Carlo simulation method, a generally accepted statistical technique used to simulate a range of possible future stock prices for the Company and the peer group. The determination of fair value was affected by the Company's stock price and a number of assumptions including the expected volatility and the risk-free interest rate. The Company will recognize stock-based compensation expense ratably over the performance period of the award. The market-based RSUs will cliff-vest at the end of the three-year period ranging from zero to 150% of the target number of awards granted.
The significant assumptions used in the Monte Carlo simulation method were as follows:
Risk-free interest rate4.60%
Expected volatility90%
Expected life in years3.61
Dividend yield—
The grant date fair value of the Milestone-based RSUs was $643,000 based on the grant date closing price per share of $10.96. As of December 31, 2024, the underlying performance milestones of the Milestone-based RSUs were determined to be not probable of achievement, and no stock-based compensation expense was recognized for the year then ended.
The grant date fair value of the Market-based RSUs was $269,000 based on the fair value of $10.69 per share as determined using the Monte Carlo simulation method. For the year ended December 31, 2024, the Company recognized $44,000 in stock-based compensation for the Market-based RSUs.
December 2024 Performance-Based Awards
In December 2024, the Company granted performance-based stock options and RSUs (such performance-based grants, the "December 2024 Awards") to key employees under the 2023 Plan. Each award was expressed as a target number of stock options and RSUs. With respect to the December 2024 Awards, the Company's Board of Directors established specified performance goals and a corresponding performance period over which the goals must be attained, the satisfaction of which are conditions to earning the December 2024 Awards and vesting of the underlying stock options and RSUs. As of December 31, 2024, December 2024 Awards were outstanding covering 25,686 shares of common stock underlying stock options and 19,314 shares of common stock underlying RSUs.
The grant date fair value of the performance-based RSUs was $34,000 based on the grant date closing price per share of $1.78. The grant date fair value of the performance-based stock options was $38,000 based on the Black-Scholes per share value of $1.46. As of December 31, 2024, the underlying performance milestones of the December 2024 Awards were determined to be not probable of achievement, and no stock-based compensation expense was recognized for the year then ended.
v3.25.1
Commitments and Contingencies
 12 Months Ended
Dec. 31, 2024
Leases [Abstract]  
Commitments and Contingencies Commitments and Contingencies
Leases
The Company leases approximately 56,600 square feet of office, laboratory, and manufacturing space in San Diego, California and approximately 57,400 square feet of office space in Plymouth Meeting, Pennsylvania under various non-cancellable operating lease agreements with remaining lease terms as of December 31, 2024 of 2.4 to 5.0 years, which represent the non-cancellable periods of the leases. The Company has excluded the extension options from its lease terms in the calculation of future lease payments as they are not reasonably certain to be exercised. The Company's lease payments consist primarily of fixed rental payments for the right to use the underlying leased assets over the lease terms as well as payments for common area maintenance and administrative services. The Company has received customary incentives from its landlords, such as reimbursements for tenant improvements and rent abatement periods, which effectively reduce the total lease payments owed for these leases.
The base rent adjusts periodically throughout the term of the leases. Rent payments under the leases include base rent with annual increases of approximately two to three percent, and additional monthly fees to cover the Company's share of certain facility expenses, including utilities, property taxes, insurance and maintenance.
The Company performed an evaluation of its contracts with customers and suppliers in accordance with ASC Topic 842 and determined that, except for the real estate leases described above and various copier leases, none of its other contracts contain a right-of-use asset.
Operating lease right-of-use assets and liabilities on the consolidated balance sheet represents the present value of the remaining lease payments over the remaining lease terms. Payments for additional monthly fees to cover the Company's share of certain facility expenses are not included in operating lease right-of-use assets and liabilities. The Company uses its incremental borrowing rate to calculate the present value of its lease payments, as the implicit rates in the leases are not readily determinable.
As of December 31, 2024, the maturities of the Company's operating lease liabilities were as follows:
Year ending December 31,
2025$3,483,000 
20263,555,000 
20272,955,000 
20282,310,000 
20292,132,000 
   Total remaining lease payments14,435,000 
Less: present value adjustment(2,570,000)
   Total operating lease liabilities11,865,000 
Less: current portion(2,497,000)
Long-term operating lease liabilities$9,368,000 
Weighted-average remaining lease term4.3 years
Weighted-average discount rate9.0 %

Lease costs included in operating expenses in the consolidated statements of operations for the years ended December 31, 2024 and 2023 were $2.6 million and $3.5 million, respectively. Operating lease costs consisting of the fixed lease payments included in operating lease liabilities are recorded on a straight-line basis over the lease terms. Variable lease costs are recorded as incurred.
In 2023, the Company entered into agreements to sublease a total of approximately 11,400 square feet in its Plymouth Meeting headquarters with sublease terms through December 31, 2026.
During 2024, the Company amended the sublease agreements for its Plymouth Meeting headquarters to extend one sublease term through December 31, 2027 and the other through December 31, 2029.
In the normal course of business, the Company is a party to a variety of agreements pursuant to which it may be obligated to indemnify the other party. It is not possible to predict the maximum potential amount of future payments under these types of agreements due to the conditional nature of the Company's obligations and the unique facts and circumstances involved in each particular agreement. Historically, payments made by the Company under these types of agreements have not had a material effect on its business, consolidated results of operations or financial condition.
Legal Proceedings
Securities Litigation
In 2020, a purported shareholder class action complaint was filed naming the Company and its former President and Chief Executive Officer as defendants and alleging that the Company made materially false and misleading statements in violation of certain federal securities laws. In 2022 the parties negotiated an agreement in principle to settle the shareholder class action complaint, which was approved by the court in January 2023. Under the settlement, the Company agreed to pay $30.0 million in cash and issued 760,083 shares of its common stock, with a value of $14.0 million at the time, to settle all outstanding claims. The Company's insurance carriers paid the $30.0 million cash component of the settlement.
Shareholder Derivative Litigation
In 2020, a purported shareholder derivative complaint was filed naming eight current and former directors of the Company as defendants. The lawsuit asserted state and federal claims and was based on the same alleged misstatements as the shareholder class action complaint described above. The lawsuit accused the Company’s board of directors of failing to exercise reasonable and prudent supervision over the Company’s management, policies, practices, and internal controls. The plaintiff sought unspecified monetary damages on behalf of the Company as well as governance reforms.
Between 2020 and 2022, additional shareholder derivative complaints were filed.
In June 2023, the court entered an order preliminarily approving a proposed settlement of the derivative claims, in accordance with a Stipulation of Settlement. The Stipulation of Settlement contemplated that, following the settlement hearing and the final approval of the settlement by the court, the Company would implement certain corporate governance reforms described in the Stipulation of Settlement. The preliminary order also approved the form and manner of the notice of the Settlement. As part of the Settlement, in July 2023 the Company paid $1.2 million to plaintiffs’ counsel for their fees and expenses. In October 2023, the court entered an order and final judgment approving the Settlement, which became effective in November 2023. The Company has implemented the corporate governance reforms in response to the provisions of the Stipulation of Settlement.
VGXI Litigation
In June 2020, the Company filed a complaint in the Court of Common Pleas of Montgomery County, Pennsylvania against VGXI, Inc. and GeneOne Life Science, Inc., or GeneOne, and together with VGXI, Inc. collectively referred to as VGXI, alleging that VGXI had materially breached the Company’s supply agreement with them. The complaint seeks declaratory judgments, specific performance of the agreement, injunctive relief, an accounting, damages, attorneys’ fees, interest, costs and other relief from VGXI. In June 2020, the Company filed a petition for preliminary injunction, which was denied.
Following an appeal by the Company, in July 2020, VGXI filed counterclaims against the Company, alleging that the Company had breached the supply agreement, as well as misappropriation of trade secrets and unjust enrichment. The counterclaims seek injunctive relief, damages, attorneys’ fees, interest, costs and other relief from the Company. VGXI also filed a third-party complaint against Ology Bioservices, Inc., a contract manufacturing organization that the Company had engaged to provide services similar to those that were being provided by VGXI, but VGXI later discontinued its third-party claims. The Company filed an answer to VGXI’s counterclaims, disputing the allegations and the claims raised in VGXI’s filing. In October 2020, the Company filed a notice of discontinuance of appeal with the Pennsylvania Superior Court. A trial date for the litigation has not been set.
The Company intends to aggressively prosecute the claims set forth in its complaint against VGXI and to vigorously defend itself against VGXI’s counterclaims.
GeneOne Litigation
In December 2020, GeneOne filed a complaint in the Court of Common Pleas of Montgomery County, Pennsylvania against the Company, alleging that the Company had breached the CELLECTRA Device License Agreement, or the Agreement, between the Company and GeneOne. The Company terminated the Agreement in October 2020. The complaint asserts claims for breach of contract, declaratory judgment, unfair competition, and unjust enrichment. The complaint seeks injunctive relief, an accounting, damages, disgorgement of profits, attorneys’ fees, interest, and other relief from the Company. The Company filed preliminary objections to the complaint, which were overruled by the court. In September 2021, the Company filed an answer to the complaint, new matter, and counterclaims. The Company’s counterclaims allege that GeneOne breached the Agreement and assert claims for breach of contract and declaratory judgment. The counterclaims seek damages, interest, expenses, attorney’s fees, and costs. In October 2021, GeneOne filed its answer to the Company’s counterclaims and new matter. On February 29, 2024, the Company filed a motion for summary judgment. On April 1, 2024, GeneOne filed an opposition to the Company’s motion for summary judgment. On June 28, 2024, the court denied the motion for summary judgment. A trial date for this litigation has not been set.
The Company intends to aggressively prosecute the claims set forth in its counterclaims against GeneOne and to vigorously defend itself against the claims in GeneOne’s complaint.
Other Matters
From time to time, the Company may be involved in disputes, including litigation, relating to claims arising out of operations in the normal course of its business. Any of these claims could subject the Company to costly legal expenses and, while the Company generally believes that it has adequate insurance to cover many different types of liabilities, its insurance carriers may deny coverage or its policy limits may be inadequate to fully satisfy any damage awards or settlements. If this were to happen, the payment of any such awards could have a material adverse effect on the Company's consolidated results of operations and financial position. Additionally, any such claims, whether or not successful, could damage the Company's reputation and business. Except as described above, the Company is not a party to any legal proceedings, the adverse outcome of which, in management’s opinion, individually or in the aggregate, would be reasonably expected to have a material adverse effect on the Company’s consolidated results of operations or financial position.
v3.25.1
Income Taxes
 12 Months Ended
Dec. 31, 2024
Income Tax Disclosure [Abstract]  
Income Taxes Income Taxes
In accordance with the guidance pursuant to accounting for income taxes, a deferred tax asset or liability is determined based on the difference between the financial statement and tax basis of assets and liabilities as measured by the enacted tax rates which will be in effect when these differences reverse. The Company provides a valuation allowance against net deferred tax assets unless, based upon the available evidence, it is more likely than not that the deferred tax asset will be realized.
The components of pretax loss from operations are as follows:
Year Ended December 31,
20242023
     U.S. Domestic$(107,254,126)$(134,979,579)
     Foreign— (137,772)
Pretax loss from operations$(107,254,126)$(135,117,351)

There was no provision for or benefit from income taxes for the years ended December 31, 2024 and 2023.
The reconciliation of income taxes attributable to continuing operations computed at the statutory tax rates to income tax benefit, using a 21% statutory tax rate for December 31, 2024 and 2023, is as follows: 
Year Ended December 31,
20242023
Benefit from income taxes at statutory rates$(22,523,000)$(28,375,000)
State income tax, net of federal benefit(1,543,000)(3,922,000)
Change in valuation allowance21,749,000 28,394,000 
Research and development tax credits(5,846,000)(2,139,000)
Stock-based compensation1,579,000 2,099,000 
Uncertain tax positions2,344,000 861,000 
Goodwill impairment— 1,962,000 
Expired NOLs and credits4,687,000 1,352,000 
Limited NOLs and credits(2,056,000)(997,000)
Change in tax rates403,000 365,000 
Foreign tax rate differential— (4,000)
Other1,206,000 404,000 
$— $— 

Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2024 and 2023 are shown below:
As of December 31,
20242023
Deferred tax assets:
Capitalized research expense$54,204,000 $50,143,000 
NOL carryforwards250,336,000 235,624,000 
Research and development and other tax credits31,250,000 27,734,000 
Deferred revenue— 22,000 
Stock-based compensation3,060,000 3,683,000 
Acquired intangibles774,000 907,000 
Investment in affiliated entity1,651,000 1,406,000 
Lease liability2,492,000 2,822,000 
Fixed assets441,000 337,000 
Other6,720,000 6,808,000 
350,928,000 329,486,000 
Valuation allowance(349,224,000)(327,493,000)
Total deferred tax assets1,704,000 1,993,000 
Deferred tax liabilities:
Right of use asset(1,704,000)(1,993,000)
Total deferred tax liabilities(1,704,000)(1,993,000)
Net deferred tax liabilities$— $— 

As of December 31, 2024, the Company had federal, California and other state tax net operating loss (NOL) carryforwards of $1.1 billion, $259.9 million and $88.6 million, respectively, net of the net operating losses that will expire due to IRC Section 382 limitations. The aggregate federal net operating losses generated in 2018 and after for the amount of $801.9 million will carryforward indefinitely and be available to offset up to 80% of future taxable income each year. The federal NOL carryforward began to expire in 2025, and the California and other state NOL carryforwards will begin and have begun to expire in 2028 and 2025, respectively, unless previously utilized.
The Company also had Korean NOL carryforward of $1.0 million as of December 31, 2024. The Korean NOLs are available to offset up to 60% of future taxable income and will begin to expire in 2035, unless previously utilized.
In addition, as of December 31, 2024, the Company had federal and state research and development (R&D) tax credit carryforwards of $46.1 million and $7.9 million, respectively. The federal tax credit carryforwards will begin to expire in 2029. The California research tax credits do not expire.
Based upon statute, federal and state losses and credits are expected to expire as follows (in millions):
Expiration Date:Federal NOLsState NOLsForeign NOLsFederal R&DState R&D
2025$16.0 $5.2 $— $— $— 
202617.1 7.1 — — — 
20276.1 1.9 — — — 
2028 and thereafter245.9 333.6 1.0 46.1 — 
Indefinite801.9 0.7 — — 7.9 
$1,087.0 $348.5 $1.0 $46.1 $7.9 

Pursuant to Internal Revenue Code (IRC) Sections 382 and 383, annual use of the Company’s NOL and R&D credit carryforwards may be limited in the event that a cumulative change in ownership of more than 50% occurs within a three-year period. The Company has completed an IRC Section 382/383 analysis regarding the limitation of NOL and R&D credit carryforwards as of December 31, 2024. As a result of the analysis, the Company estimates that approximately $5.3 million of tax benefits related to NOL and R&D carryforwards will expire unused. Accordingly, the related NOL and R&D credit carryforwards have been removed from deferred tax assets, accompanied by a corresponding reduction of the valuation allowance. Due to the existence of the valuation allowance, limitations created by current and future ownership changes, if any,
related to the Company's operations in the United States will not impact its effective tax rate. Any additional ownership changes, could further limit the ability to use the NOL and R&D carryforwards.
The Tax Cuts and Jobs Act of 2017 subjects a U.S. stockholder to tax on Global Intangible Low-Taxed Income (GILTI) earned by certain foreign subsidiaries. The FASB Staff Q&A, Topic 740, No. 5, Accounting for Global Intangible Low-Taxed Income, states that an entity can make an accounting policy election to recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. The Company has elected to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. For 2024 and 2023, the Company did not generate any GILTI due to losses earned by its foreign subsidiary.
The following table summarizes the activity related to the Company's unrecognized tax benefits:
 Year ended December 31,
 20242023
Balance at beginning of the year$22,114,000 $21,139,000 
Increases related to current year tax positions2,297,000 1,816,000 
Increases (decreases) related to prior year tax positions197,000 (841,000)
Balance at end of the year$24,608,000 $22,114,000 

The amount of unrecognized tax benefits that, if recognized and realized, would affect the effective tax rate was $22.9 million and $20.5 million as of December 31, 2024 and 2023, respectively, subject to valuation allowances. The Company has not recorded any interest and penalties on the unrecognized tax positions as the Company has continued to generate net operating losses after accounting for the unrecognized tax benefits. The Company does not anticipate that the total amount of unrecognized tax benefits will significantly increase or decrease within twelve months of the reporting date.
The Company and its subsidiaries are subject to U.S. federal income tax as well as income tax in multiple state and foreign jurisdictions. With few exceptions, the Company is no longer subject to United States federal income tax examinations for years before 2021 and state and local income tax examinations before 2020. However, to the extent allowed by law, the tax authorities may have the right to examine prior periods where net operating losses were generated and carried forward, and make adjustments up to the amount of the NOL carryforward amount. The Company is not to its knowledge currently under Internal Revenue Service (“IRS”), state, local or foreign tax examination.
v3.25.1
401(k) Plan
 12 Months Ended
Dec. 31, 2024
Retirement Benefits [Abstract]  
401(k) Plan 401(k) Plan
The Company has adopted a 401(k) Profit Sharing Plan covering substantially all of its employees. The defined contribution plan allows the employees to contribute a percentage of their compensation each year. The Company currently matches 50% of its employees’ contributions, up to 6% of their annual compensation. The Company’s contributions are recorded as expense in the accompanying consolidated statements of operations and totaled $961,000 and $1.4 million for the years ended December 31, 2024 and 2023, respectively.
v3.25.1
Related Party Transactions
 12 Months Ended
Dec. 31, 2024
Related Party Transactions [Abstract]  
Related Party Transactions Related Party Transactions
Plumbline Life Sciences, Inc.
The Company owned 597,808 shares of common stock in PLS as of December 31, 2024 and 2023, representing a 17.3% and 17.8% ownership interest, respectively. The Company's investment in PLS is recorded as investment in affiliated entity on the consolidated balance sheet as of December 31, 2024 and 2023, and was valued at $1.6 million and $2.8 million, respectively, based on the closing price of the shares on the Korea New Exchange Market at the applicable balance sheet date. One of the Company's directors, Dr. David B. Weiner, acts as a consultant to PLS.

The Wistar Institute
Dr. Weiner is a director of the Vaccine Center of The Wistar Institute ("Wistar") and an Executive Vice President of Wistar.
In 2016, the Company entered into collaborative research agreements with Wistar for preventive and therapeutic DNA-based immunotherapy applications and products developed by Dr. Weiner and Wistar for the treatment of cancers and infectious diseases. Under the terms of the agreement, the Company reimbursed Wistar for all direct and indirect costs incurred in the conduct of the collaborative research, not to exceed $3.1 million during the five-year term of the agreement. In 2021,
upon expiration of the 2016 agreements, the Company entered into new collaborative research agreements with Wistar with the same terms. The Company has the exclusive right to in-license new intellectual property developed under this agreement.
In 2020, the Company received a $10.7 million sub-grant through Wistar, which was amended in 2021 to $13.6 million, for the preclinical development and translational studies of dMAbs as countermeasures for COVID-19. In August 2024, the sub-grant was amended to a total of $12.5 million in funding through September 2025.
In 2022, the Company received a $1.2 million sub-grant through Wistar, which was amended in 2024 to $2.4 million with funding through November 2024, with an option for an additional $4.2 million in funding that extends the sub-grant through November 2027. The Company will support the Wistar lead consortium in the research and development of synthetic DNA-launched nanoparticles (dLNPs) for vaccination against HIV infection.
Deferred grant funding recognized from Wistar and recorded as contra-research and development expense is related to work performed by the Company on the research sub-contract agreements. For the years ended December 31, 2024 and 2023, the Company recorded $482,000 and $1.0 million, respectively, as contra-research and development expense from Wistar.
Research and development expenses recorded from Wistar relate primarily to the collaborative research agreements. Research and development expenses recorded from Wistar for the years ended December 31, 2024 and 2023 were $1.5 million and $1.8 million, respectively. At December 31, 2024 and 2023, the Company had an accounts receivable balance of $1.2 million and $2.4 million, respectively, and an accounts payable and accrued liability balance of $1.4 million and $1.1 million, respectively, related to Wistar. As of December 31, 2024 and 2023, the Company had a prepaid expense balance of $0 and $20,000, respectively, and recorded $0 and $22,000, respectively, as deferred grant funding on its consolidated balance sheet related to Wistar.
v3.25.1
Geneos Therapeutics, Inc.
 12 Months Ended
Dec. 31, 2024
Noncontrolling Interest [Abstract]  
Geneos Therapeutics, Inc. Geneos Therapeutics, Inc.
In 2016, the Company formed Geneos Therapeutics ("Geneos") to develop and commercialize neoantigen-based personalized cancer therapies. The Company's Chief Scientific Officer Dr. Laurent Humeau is on the Board of Directors of Geneos. The Company's director Dr. David B. Weiner is the Chairman of the Scientific Advisory Board of Geneos.
As of December 31, 2024, the Company held 23% of the outstanding equity of Geneos, on an as-converted to common stock basis. The Company accounts for its common stock investment in Geneos as an equity method investment under ASC 323. Due to continuing net losses of Geneos, the Company’s investment had been reduced to $0 as of each of December 31, 2024 and 2023. The Company has not made any further investment in Geneos. The Company will not reduce its investment below $0 and will not record its share of further net losses of Geneos, as the Company has no obligation to fund Geneos.
The Company continues to exclusively license its immunotherapy platform and CELLECTRA technology to Geneos to be used in the field of personalized, neoantigen-based therapy for cancer. The license agreement provides for potential royalty payments to the Company in the event that Geneos commercializes any products using the licensed technology. The Company is not obligated to use any of its assets to fund the future operations of Geneos.
v3.25.1
Segment Information
 12 Months Ended
Dec. 31, 2024
Segment Reporting [Abstract]  
Segment Information Segment Information
The Company operates as one reportable segment in the United States, which includes all activities related to the development and commercialization of its DNA medicines to help treat and protect people from HPV-associated diseases, cancer and infectious diseases.
The Company's Chief Executive Officer (CEO) is its Chief Operating Decision Maker (CODM), responsible for allocating resources and assessing Company performance using aggregated financial information. Utilizing aggregated financial information enables the CODM to determine the most appropriate resource allocation across the organization, research and development projects or other initiatives consistent with the Company's corporate objectives. The CODM primarily uses total net loss as reported on the statements of operations and comprehensive loss to measure segment loss, supplemented by certain additional significant expense details reflected in the table below. The measure of segment assets is reported on the consolidated balance sheet as total assets.
Detailed information regarding the Company's single operating segment's revenues, expenses and operating loss are as follows:
Year Ended December 31,
20242023
Revenue from collaborative arrangements and other contracts, including affiliated entity
$217,756 $832,010 
Less:
Research and development:
     INO-310729,930,344 17,840,728 
     INO-5401 and other Immuno-oncology6,293,401 11,758,935 
     Other programs (a)(77,955)18,701,675 
     Engineering and device-related19,393,929 8,863,170 
     Stock-based compensation2,821,226 4,606,341 
     Other unallocated expenses (b)17,259,395 24,905,714 
General and administrative36,996,338 47,582,104 
Impairment of goodwill— 10,513,371 
Total operating expenses112,616,678 144,772,038 
Interest income4,766,993 8,133,290 
Interest expense(177,833)(1,222,789)
Change in fair value of common stock warrant liability2,808,608 — 
(Loss) gain on investment in affiliated entity(1,166,443)773,145 
Net unrealized gain on available-for-sale equity securities2,077,182 5,850,626 
Other expense, net(3,163,711)(4,711,596)
Net loss$(107,254,126)$(135,117,352)

(a) Net of contributions received from grant agreements and recorded as contra-research and development expense.
(b) Includes impairment of intangible assets of $2.0 million recorded in 2023.
v3.25.1
Subsequent Events
 12 Months Ended
Dec. 31, 2024
Subsequent Events [Abstract]  
Subsequent Events Subsequent Events
From January 1, 2025 through the date of these financial statements, the Company sold 512,518 shares of common stock under the 2024 Sales Agreement at a weighted average price of $2.16 per share, for net proceeds of $1.1 million.
v3.25.1
Pay vs Performance Disclosure - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Pay vs Performance Disclosure    
Net loss $ (107,254,126) $ (135,117,352)
v3.25.1
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2024
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.1
Insider Trading Policies and Procedures
 12 Months Ended
Dec. 31, 2024
Insider Trading Policies and Procedures [Line Items]  
Insider Trading Policies and Procedures Adopted true
v3.25.1
Cybersecurity Risk Management and Strategy Disclosure
 12 Months Ended
Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]
We have implemented and maintain various information security processes designed to identify, assess and manage material risks from cybersecurity threats to our critical computer networks, third party hosted services, communications systems, hardware and software, and our critical data (including intellectual property, confidential information that is proprietary, strategic or competitive in nature, and clinical trial data) (collectively, “Information Systems and Data”).
Our Information Technology department (“IT Department”) (including its Senior Director), with support from service providers, helps identify, assess and manage our cybersecurity threats and risks. The IT Department identifies and assesses risks from cybersecurity threats by monitoring and evaluating our threat environment and our risk profile using various methods. For example, the methods include manual and automated tools; subscriptions to reports and services that identify cybersecurity threats; analysis of threat and threat actor reports; threat environment scans; law enforcement coordination; audits; threat assessments; and vulnerability assessments.
Depending on the environment, we implement and maintain various technical, physical, and organizational measures, processes, standards and policies designed to manage and mitigate material risks from cybersecurity threats to our Information Systems and Data, including, for example: security incident response strategies; tools designed to detect and respond to security incidents; data encryption strategies; access controls; physical security controls; asset management strategies; systems monitoring; personnel training; penetration testing; and cybersecurity insurance.
Our assessment and management of material risks from cybersecurity threats are integrated into our overall risk management processes. For example, the IT Department works with management to prioritize our risk management processes and mitigate cybersecurity threats that are more likely to lead to a material impact to our business and our management evaluates material risks from cybersecurity threats against our overall business objectives and reports to the audit committee of the board of directors, which evaluates our overall enterprise risk.
We use service providers to assist us from time to time to identify, assess, and manage material risks from cybersecurity threats, including for example: professional services firms (including legal counsel); cybersecurity consultants; cybersecurity software providers; managed cybersecurity service providers; and penetration testing firms.
We use service providers to perform a variety of functions throughout our business, such as application providers; hosting providers; and contract research organizations. Depending on the nature of the services provided, in order to analyze the cybersecurity processes of certain vendors we review their internal security assessment reports and certifications, if available.
For a description of the risks from cybersecurity threats that may materially affect us and how they may do so, see our risk factors under Part 1. Item 1A. Risk Factors in this Annual Report on Form 10-K, including in particular under the caption “if our information technology systems or those of third parties upon which we rely or our data, are or were compromised, we could experience adverse consequences resulting from such compromise, including but not limited to, regulatory investigations and actions; litigation; fines and penalties; disruptions of our business operations; reputational harm; loss of revenue and profits; and other adverse consequences.”
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block]
We have implemented and maintain various information security processes designed to identify, assess and manage material risks from cybersecurity threats to our critical computer networks, third party hosted services, communications systems, hardware and software, and our critical data (including intellectual property, confidential information that is proprietary, strategic or competitive in nature, and clinical trial data) (collectively, “Information Systems and Data”).
Our Information Technology department (“IT Department”) (including its Senior Director), with support from service providers, helps identify, assess and manage our cybersecurity threats and risks. The IT Department identifies and assesses risks from cybersecurity threats by monitoring and evaluating our threat environment and our risk profile using various methods. For example, the methods include manual and automated tools; subscriptions to reports and services that identify cybersecurity threats; analysis of threat and threat actor reports; threat environment scans; law enforcement coordination; audits; threat assessments; and vulnerability assessments.
Cybersecurity Risk Management Third Party Engaged [Flag] true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag] true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag] false
Cybersecurity Risk Board of Directors Oversight [Text Block] Our board of directors addresses our cybersecurity risk management as part of its general oversight function. The board of directors’ audit committee is responsible for overseeing our cybersecurity risk management processes, including oversight and mitigation of risks from cybersecurity threats.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block] Our board of directors addresses our cybersecurity risk management as part of its general oversight function. The board of directors’ audit committee is responsible for overseeing our cybersecurity risk management processes, including oversight and mitigation of risks from cybersecurity threats.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] As indicated above, the audit committee receives reports from the Senior Director of IT or other designee concerning significant cybersecurity threats and risk and the processes we have implemented to address them.
Cybersecurity Risk Role of Management [Text Block]
Our board of directors addresses our cybersecurity risk management as part of its general oversight function. The board of directors’ audit committee is responsible for overseeing our cybersecurity risk management processes, including oversight and mitigation of risks from cybersecurity threats.
Our cybersecurity risk assessment and management processes are implemented and maintained by certain members of our management, including the Senior Director of the IT Department. This individual has previously held roles as a head of cybersecurity, cybersecurity consultant and information security specialist for other organizations. This individual holds several certifications related to cybersecurity including Certified Information Systems Security Professional (CISSP).
The IT Department reports to our Chief Financial Officer (CFO) who is responsible for helping the IT Department hire appropriate personnel, integrate cybersecurity risk considerations into our overall risk management strategy, and communicating key priorities to relevant personnel. The Senior Director of the IT Department is responsible for approving budgets, helping prepare for cybersecurity incidents, approving cybersecurity processes, and reviewing security assessments and other security-related reports.
Our cybersecurity incident response and vulnerability management processes are designed to escalate certain cybersecurity incidents to members of management depending on the circumstances, including the CFO. The Senior Director of IT and the CFO work with our incident response team to help mitigate and remediate cybersecurity incidents of which they
are notified. In addition, our incident response and vulnerability management processes include reporting to the audit committee of the board of directors for certain cybersecurity incidents.
As indicated above, the audit committee receives reports from the Senior Director of IT or other designee concerning significant cybersecurity threats and risk and the processes we have implemented to address them. The audit committee also receives various written reports, summaries or presentations related to cybersecurity threats, risk and mitigation. In turn, the audit committee routinely provides reports to the board on cybersecurity matters.
Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block] The IT Department reports to our Chief Financial Officer (CFO) who is responsible for helping the IT Department hire appropriate personnel, integrate cybersecurity risk considerations into our overall risk management strategy, and communicating key priorities to relevant personnel. The Senior Director of the IT Department is responsible for approving budgets, helping prepare for cybersecurity incidents, approving cybersecurity processes, and reviewing security assessments and other security-related reports.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block] This individual has previously held roles as a head of cybersecurity, cybersecurity consultant and information security specialist for other organizations. This individual holds several certifications related to cybersecurity including Certified Information Systems Security Professional (CISSP).
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]
Our cybersecurity risk assessment and management processes are implemented and maintained by certain members of our management, including the Senior Director of the IT Department. This individual has previously held roles as a head of cybersecurity, cybersecurity consultant and information security specialist for other organizations. This individual holds several certifications related to cybersecurity including Certified Information Systems Security Professional (CISSP).
The IT Department reports to our Chief Financial Officer (CFO) who is responsible for helping the IT Department hire appropriate personnel, integrate cybersecurity risk considerations into our overall risk management strategy, and communicating key priorities to relevant personnel. The Senior Director of the IT Department is responsible for approving budgets, helping prepare for cybersecurity incidents, approving cybersecurity processes, and reviewing security assessments and other security-related reports.
Our cybersecurity incident response and vulnerability management processes are designed to escalate certain cybersecurity incidents to members of management depending on the circumstances, including the CFO. The Senior Director of IT and the CFO work with our incident response team to help mitigate and remediate cybersecurity incidents of which they
are notified. In addition, our incident response and vulnerability management processes include reporting to the audit committee of the board of directors for certain cybersecurity incidents.
As indicated above, the audit committee receives reports from the Senior Director of IT or other designee concerning significant cybersecurity threats and risk and the processes we have implemented to address them. The audit committee also receives various written reports, summaries or presentations related to cybersecurity threats, risk and mitigation. In turn, the audit committee routinely provides reports to the board on cybersecurity matters.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
v3.25.1
Summary of Significant Accounting Policies (Policies)
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Basis of Presentation and Liquidity
Basis of Presentation and Liquidity
The Company incurred a net loss of $107.3 million for the year ended December 31, 2024. The Company had working capital of $62.5 million and an accumulated deficit of $1.7 billion as of December 31, 2024. The Company has incurred losses in each year since its inception and expects to continue to incur significant expenses and operating losses for the foreseeable future in connection with the research and preclinical and clinical development of its product candidates. The Company’s cash, cash equivalents and short-term investments of $94.1 million as of December 31, 2024 are not sufficient to support the Company's operations for a period of at least 12 months from the date it is issuing these financial statements.
On December 16, 2024, the Company closed an underwritten public offering (the "December 2024 Offering"), relating to the issuance and sale of 10,000,000 shares of its common stock, par value $0.001 per share, and warrants to purchase 10,000,000 shares of common stock (the “Warrants”), at an offering price of $3.00 per share and accompanying Warrant. The exercise price of the Warrants is $3.76 per share. The net proceeds from the December 2024 Offering were $27.6 million, after deducting the underwriting discounts and commissions and offering expenses paid by the Company.
On April 18, 2024, the Company closed an underwritten registered direct offering (the “April 2024 Offering”), relating to the issuance and sale of 2,536,258 shares (the “Shares”) of its common stock, par value $0.001 per share, at a price of $7.693 per share and pre-funded warrants to purchase up to 2,135,477 shares of common stock (the “Pre-Funded Warrants”) at a price of $7.692 per Pre-Funded Warrant, which represents the per share price for the Shares less the $0.001 per share exercise price for each Pre-Funded Warrant. The net proceeds from the April 2024 Offering were $33.2 million, after deducting the underwriting discounts and commissions and offering expenses paid by the Company.
Going Concern
The Company’s cash, cash equivalents and short-term investments of $94.1 million as of December 31, 2024 are expected to be sufficient to support the Company's planned operations through the fourth quarter of 2025. The Company's current
financial resources may not be sufficient to support its planned operations beyond this date without securing additional financing.
In order to continue to fund future research and development activities, the Company will need to seek additional capital. This may occur through strategic alliance and licensing arrangements, grant agreements and/or future public or private debt or equity financings, including under At-the-Market Equity Offering Sales Agreements (“Sales Agreements”). The Company has a history of conducting debt and equity financings, including the receipt of net proceeds of $60.8 million from equity offerings during the year ending December 31, 2024, and $6.1 million and $5.5 million from equity offerings under Sales Agreements during the years ending December 31, 2024 and 2023, respectively. However, sufficient funding may not be available in the future, or if available, may be on terms that significantly dilute or otherwise adversely affect the rights of existing stockholders. If adequate funds are not available, the Company may need to delay, reduce the scope of or put on hold one or more of its clinical and/or preclinical programs.
The Company’s ability to continue its operations is dependent upon its ability to obtain additional capital in the future and achieve profitable operations. The Company expects to continue to rely on outside sources of financing to meet its capital needs and may never achieve positive cash flow. In light of these factors, management believes that there is substantial doubt about the Company's ability to continue as a going concern beyond the fourth quarter of 2025. The Company's consolidated financial statements as of and for the year ended December 31, 2024 do not include any adjustments that might result from the outcome of this uncertainty. The Company has evaluated subsequent events after the balance sheet date through the date it issued these consolidated financial statements.
The Company is, and from time to time in the future may be, subject to various legal proceedings and claims arising in the ordinary course of business. The Company assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its consolidated financial statements. An estimated loss contingency is accrued in the consolidated financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Legal proceedings, including litigation, government investigations and enforcement actions, could result in material costs, occupy significant management resources and entail civil and criminal penalties, even if the Company ultimately prevails. Any of the foregoing consequences could result in serious harm to the Company’s business, results of operations and financial condition.
Consolidation
Consolidation
The consolidated financial statements include the accounts of Inovio Pharmaceuticals, Inc. and its wholly-owned subsidiary Inovio Asia LLC.
Segment Reporting
Segment Reporting
Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker ("CODM"), the President and Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one segment operating primarily within the United States, as further described in Note 16.
Use of Estimates
Use of Estimates
The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Concentration of Credit Risk
Concentration of Credit Risk
Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and short-term investments. The Company limits its exposure to credit loss by placing its cash and investments with high credit quality financial institutions. Additionally, the Company has established guidelines regarding diversification of its investments and their maturities which are designed to maintain principal and maximize liquidity.
Fair value of Financial Instruments
Fair Value Measurements
The guidance regarding fair value measurements establishes a three-tier fair value hierarchy which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets that are accessible at the measurement date; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.
The Company’s financial instruments include cash equivalents, short-term investments, investments in affiliated entity, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses and common stock warrant liability. The carrying amounts of cash equivalents, accounts receivable, prepaid expenses and other assets, accounts payable and accrued expenses approximate the related fair values due to the short-term maturities of these instruments. Short-term investments are recorded at fair value on a recurring basis, based on current market valuations. The estimated fair value of the common stock warrant liability is determined by using the Black-Scholes pricing model, as discussed in Note 5.
Cash and Cash Equivalents
Cash and Cash Equivalents
Cash equivalents are considered by the Company to be highly liquid investments purchased with original maturities of three months or less from the date of purchase. Cash and cash equivalents included certain mutual funds and U.S. treasury securities at December 31, 2024 and 2023.
Short Term Investments
Short-term Investments
The Company defines investments as income-yielding securities that can be readily converted into cash or equity investments classified as available-for-sale. Investments included mutual funds, U.S. treasury securities, certificates of deposit, U.S. agency mortgage-backed securities and an equity investment in the Company’s affiliated entity, PLS, at December 31, 2024 and 2023.
Short-term investments are recorded at fair value, based on current market valuations. Unrealized gains and losses on the Company's short-term debt securities are excluded from earnings and reported as a separate component of other comprehensive loss until realized. Realized gains and losses and unrealized gains and losses on available-for-sale equity securities are included in non-operating other income (expense) on the consolidated statements of operations and are derived using the specific identification method for determining the cost of the securities sold.
Accounts Receivable from Affiliated Entities
Accounts Receivable from Affiliated Entities
Accounts receivable from affiliated entities are recorded at invoiced amounts and do not bear interest. The Company performs ongoing credit evaluations of its customers’ financial condition. Credit is extended to customers as deemed necessary and generally does not require collateral. Management believes that the risk of loss is significantly reduced due to the quality and financial position of the Company's customers.
Fixed Assets
Fixed Assets
Fixed assets include property and equipment and leasehold improvements. Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful life of the assets, generally three to five years. Leasehold improvements are amortized over the shorter of the remaining term of the related leases or the estimated economic useful lives of the improvements. Repairs and maintenance are expensed as incurred.
The Company evaluates the carrying value of long-lived assets, which includes fixed assets and right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying amounts of the asset may not be fully recoverable.
Warrants
Warrants
The Company accounts for warrants as either equity-classified or liability-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in Accounting Standards Codification (“ASC”) 480, Distinguishing Liabilities from Equity (“ASC 480”) and ASC 815, Derivatives and Hedging (“ASC 815”). This assessment, which requires the use of professional judgment, is conducted at the time of warrant issuance and as of each subsequent
reporting period while the warrants are outstanding. The Pre-Funded Warrants issued in April 2024 met all the criteria for equity classification and were recorded as a component of additional paid-in capital on issuance. However, the Warrants issued in December 2024 did not meet all the criteria for equity classification and were recorded as a liability at fair value upon issuance. The Warrants met the definition of a derivative and did not meet any scope exceptions under ASC 815. As a result, the fair value of the liability associated with the Warrants will be remeasured at the end of each reporting period while the Warrants are outstanding, and any change in fair value between reporting periods will be recognized as gain or loss on the consolidated statement of operations for that reporting period.
Income Taxes
Income Taxes
The Company recognizes deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities along with net operating loss and tax credit carryforwards. The Company records a valuation allowance against its deferred tax assets to reduce the net carrying value to an amount that it believes is more likely than not to be realized. When the Company establishes or reduces the valuation allowance against its deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made.
Valuation allowances against the Company’s deferred tax assets were $349.2 million and $327.5 million at December 31, 2024 and 2023, respectively. Changes in the valuation allowances, when they are recognized in the provision for income taxes, are included as a component of the estimated annual effective tax rate.
Collaboration Agreements
Collaboration Agreements and Revenue Recognition
The Company assesses whether its collaboration agreements are subject to Accounting Standards Codification ("ASC") Topic 808: Collaborative Arrangements (“Topic 808”) based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. To the extent that the arrangement falls within the scope of Topic 808 and the Company concludes that its collaboration partner is not a customer, the Company presents such payments as a reduction of research and development expense. If payments from the collaboration partner to the Company represent consideration from a customer, then the Company accounts for those payments within the scope of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (“Topic 606”).
Revenue Recognition
Collaboration Agreements and Revenue Recognition
The Company assesses whether its collaboration agreements are subject to Accounting Standards Codification ("ASC") Topic 808: Collaborative Arrangements (“Topic 808”) based on whether they involve joint operating activities and whether both parties have active participation in the arrangement and are exposed to significant risks and rewards. To the extent that the arrangement falls within the scope of Topic 808 and the Company concludes that its collaboration partner is not a customer, the Company presents such payments as a reduction of research and development expense. If payments from the collaboration partner to the Company represent consideration from a customer, then the Company accounts for those payments within the scope of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (“Topic 606”).
Grants
Grants
The Company accounts for various grant agreements under the contributions guidance under Subtopic 958-605, Not-for-Profit Entities-Revenue Recognition, which is outside the scope of Topic 606, as the government agencies granting the Company funds are not receiving reciprocal value for their contributions. All contributions received from current grant agreements are recorded as a contra-research and development expense as opposed to revenue on the consolidated statement of operations.
Equity Method Investments
Equity Investments
Under ASC Topic 321, Investments - Equity Securities, the Company must measure equity investments (except those accounted for under the equity method, those that result in consolidation of the investee and certain other investments) at fair value and recognize any changes in fair value in the consolidated statement of operations. The Company can elect a measurement alternative for equity investments that do not have readily determinable fair values and do not qualify for the practical expedient in ASC Topic 820, Fair Value Measurement, to estimate fair value using the net asset value per share (or its equivalent). The Company's equity investments that do not have readily determinable fair values and do not qualify for the net asset value practical expedient for estimating fair value are measured at cost, less any impairments, plus or minus changes resulting from observable price changes in orderly transactions for identifiable or similar investments of the same issuer.
Research and Development Expenses - Clinical Trial Accruals
Research and Development Expenses - Clinical Trial Accruals
The Company's activities have largely consisted of research and development efforts related to developing its proprietary device technology and DNA medicine candidates. For clinical trial expenses, judgements used in estimating accruals rely on estimates of total costs incurred based on participant enrollment, completion of studies and other events. Accrued clinical trial costs are subject to revisions as trials progress. Revisions are charged to expense in the period in which the facts that give rise to the revision become known. Historically, revisions have not resulted in material changes to research and development expense; however, a modification in the protocol of a clinical trial or cancellation of a trial could result in a charge to the Company's results of operations.
Net Loss Per Share
Net Loss Per Share
Basic net loss per share is computed by dividing the net loss for the year by the weighted average number of shares of common stock outstanding during the year. The outstanding Pre-Funded Warrants (see Note 10) are included in the weighted-average common shares outstanding in the basic net loss per share calculation for the year ended December 31, 2024 given their nominal exercise price.
Diluted net loss per share is calculated in accordance with the treasury stock method for the outstanding Warrants, stock options and restricted stock units ("RSUs") and reflects the potential dilution that would occur if securities or other contracts to issue common stock were exercised or converted to common stock. The dilutive impact of the Notes previously issued by the Company (discussed in Note 9) was considered using the "if-converted" method. The calculation of diluted net loss per share requires that, to the extent the average market price of the underlying shares for the reporting period exceeds the exercise price of the options or other securities and the presumed exercise of such securities are dilutive to net loss per share for the period, an adjustment to net loss used in the calculation is required to remove the change in fair value of such securities from the numerator for the period. Likewise, an adjustment to the denominator is required to reflect the related dilutive shares, if any. For the years ended December 31, 2024 and 2023, basic and diluted net loss per share are the same, as the assumed exercise or settlement of common stock warrants, stock options, service-based RSUs, performance-and market-based RSUs and the potentially dilutive shares issuable upon conversion of the Notes prior to their repayment on March 1, 2024 would have been anti-dilutive.
Leases
Leases
For its long-term operating leases, the Company recognized an operating lease right-of-use asset and an operating lease liability on its consolidated balance sheets. The lease liability is determined as the present value of future lease payments using an estimated rate of interest that the Company would pay to borrow equivalent funds on a collateralized basis at the lease commencement date. The right-of-use asset is based on the liability adjusted for any prepaid or deferred rent. The Company determines the lease term at the commencement date by considering whether renewal options and termination options are reasonably assured of exercise.
Fixed rent expense for the Company's operating leases is recognized on a straight-line basis over the term of the lease and is included in operating expenses on the consolidated statements of operations. Variable lease payments including lease operating expenses are recorded as incurred.
Stock-Based Compensation
Stock-Based Compensation
The Company incurs stock-based compensation expense related to service-based RSUs, performance-and market-based RSUs and stock options. The fair value of restricted stock is determined by the closing price of the Company's common stock reported on the Nasdaq Capital Market on the date of grant. The Company estimates the fair value of stock options granted using the Black-Scholes option pricing model. The Black-Scholes option pricing model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of subjective assumptions, including the expected stock price volatility and expected option life. The Company amortizes the fair value of the awards on a straight-line basis over the requisite vesting period of the awards. Expected volatility is based on historical volatility. The expected life of options granted is based on historical expected life. The risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant. The dividend yield is based on the fact that no dividends have been paid historically and none are currently expected to be paid in the foreseeable future. The Company recognizes forfeitures as they occur.
Recent Accounting Pronouncements
Recent Accounting Pronouncements
The recent accounting pronouncements below may have a significant effect on the Company's financial statements. Recent accounting pronouncements that are not anticipated to have an impact on or are unrelated to the Company's financial condition, results of operations, or related disclosures are not discussed.
ASU No. 2023-07. In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. The ASU expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly reviewed by the Chief Operating Decision Maker (CODM) and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items, and interim disclosures of a reportable segment’s profit or loss and assets. The ASU also allows, in addition to the measure that is most consistent with U.S. GAAP, the disclosure of additional measures of segment profit or loss that are used by the CODM in assessing segment performance and deciding how to allocate resources. All disclosure requirements under ASU 2023-07 are also required for public entities with a single reportable segment. The ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, on a retrospective basis, with early adoption permitted. The Company has adopted ASU 2023-07 and included the segment disclosures in Note 16 below.
ASU No. 2023-09. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU 2023-09 is effective for public entities with annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of this guidance its consolidated financial statements.
ASU No. 2024-03. In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. ASU
2024-03 requires public business entities to disaggregate operating expenses into specific categories such as employee compensation, depreciation, and intangible asset amortization, by relevant expense caption on the statement of operations. ASU 2024-03 is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, and may be applied either prospectively or retrospectively. Early adoption is permitted. The Company is currently evaluating the impact of adopting this guidance on the consolidated financial statements.
v3.25.1
Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method
Basic and diluted net loss per share for the year ended December 31, 2024 and 2023 are calculated as follows:
Year Ended December 31,
20242023
Numerator:
    Net loss$(107,254,126)$(135,117,352)
Denominator:
     Shares used to compute net loss per share, basic and diluted
          Weighted-average common shares outstanding25,655,527 22,173,662 
          Weighted-average shares underlying pre-funded warrants1,505,336 — 
     Weighted-average common shares outstanding used to compute basic and diluted net loss per share27,160,863 22,173,662 
Net loss per share
     Basic and diluted$(3.95)$(6.09)
Schedule of Common Shares That Were Excluded From The Diluted Net Loss Per Share Calculation Because of Their Anti-Dilutive Effect
The following table summarizes potential shares of common stock that were excluded from diluted net loss per share calculation because of their anti-dilutive effect:
Year Ended December 31,
20242023
Warrants to purchase common stock10,000,000 — 
Options to purchase common stock1,337,228 1,128,864 
Service-based restricted stock units337,911 274,794 
Performance-and market-based restricted stock units
128,800 — 
Convertible preferred stock275 275 
Convertible notes— 254,165 
Total11,804,214 1,658,098 
Schedule of Assumptions Used To Estimate The Fair Value Of Stock Options
The weighted average assumptions used in the Black-Scholes model for option grants to employees and directors are presented below:
 Year Ended December 31,
 20242023
Risk-free interest rate4.22%4.05%
Expected volatility105%100%
Expected life in years5.55.5
Dividend yield——

The weighted average assumptions used in the Black-Scholes model for option grants to non-employees are presented below:
 Year Ended December 31,
 20242023
Risk-free interest rate4.21%3.90%
Expected volatility100%89%
Expected life in years6.510.0
Dividend yield——
v3.25.1
Revenue Recognition and Concentration of Credit Risk (Tables)
 12 Months Ended
Dec. 31, 2024
Revenue from Contract with Customer [Abstract]  
Schedule of Revenue From External Customers The following table indicates the percentage of total revenues in excess of 10% with any single customer:
Customer2024 Revenue% of Total
Revenue		2023 Revenue% of Total
Revenue
ApolloBio Corporation$217,756 100 %$245,056 29 %
All other, including affiliated entity— — 586,954 71 
Total revenue$217,756 100 %$832,010 100 %
v3.25.1
Short-term Investments and Fair Value Measurements (Tables)
 12 Months Ended
Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]  
Schedule of Available-for-sale Securities
The following is a summary of available-for-sale securities as of December 31, 2024 and 2023:
 
 As of December 31, 2024
 Contractual
Maturity (in years)		CostGross Unrealized
Gains		Gross Unrealized
Losses		Fair Market Value
Mutual funds---$25,926,415 $— $(1,445,706)$24,480,709 
Certificates of deposit
Less than 1
2,980,273 9,750 (281)2,989,742 
U.S. agency mortgage-backed securities*1,260,745 — (430,964)829,781 
$30,167,433 $9,750 $(1,876,951)$28,300,232 
 As of December 31, 2023
 Contractual
Maturity (in years)		CostGross Unrealized
Gains		Gross Unrealized
Losses		Fair Market Value
Mutual funds---$55,389,289 $— $(3,522,888)$51,866,401 
U.S. treasury securities
Less than 1
75,164,782 24,938 — 75,189,720 
Certificates of deposit
Less than 1
2,978,917 11,709 (300)2,990,326 
U.S. agency mortgage-backed securities*1,340,439 — (403,973)936,466 
$134,873,427 $36,647 $(3,927,161)$130,982,913 

*No single maturity date.
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis
The following table presents the Company’s assets and liabilities that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2024:
 
Fair Value Measurements at
 December 31, 2024
 TotalQuoted Prices
in Active Markets
(Level 1)		Significant
Other Unobservable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Assets:
Short-term investments
    Mutual funds$24,480,709 $24,480,709 $— $— 
    Certificates of deposit2,989,742 — 2,989,742 — 
    U.S. agency mortgage-backed securities829,781 — 829,781 — 
Total short-term investments28,300,232 24,480,709 3,819,523 — 
Investment in affiliated entity1,613,844 1,613,844 — — 
Total assets measured at fair value$29,914,076 $26,094,553 $3,819,523 $— 
Liabilities:
Common stock warrant liability$13,255,188 $— $— $13,255,188 
Total liabilities$13,255,188 $— $— $13,255,188 

The following table presents the Company’s assets that were measured at fair value on a recurring basis, determined using the following inputs as of December 31, 2023:
 
Fair Value Measurements at
 December 31, 2023
 TotalQuoted Prices
in Active Markets
(Level 1)		Significant
Other Unobservable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Short-term investments
     Mutual funds$51,866,401 $51,866,401 $— $— 
     U.S. treasury securities75,189,720 75,189,720 — — 
     Certificates of deposit2,990,326 — 2,990,326 — 
     U.S. agency mortgage-backed securities936,466 — 936,466 — 
Total short-term investments130,982,913 127,056,121 3,926,792 — 
Investments in affiliated entity2,780,287 2,780,287 — — 
Total assets measured at fair value$133,763,200 $129,836,408 $3,926,792 $— 
Fair Value Measurement Inputs and Valuation Techniques The following assumptions were used to estimate the fair value of the warrant liability:
On Issuance DateDecember 31, 2024
Risk-free interest rate4.3%4.4%
Expected volatility111%111%
Expected life in years55
Dividend yield——
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
The following table presents the changes in fair value of the Company’s total Level 3 financial liabilities for the year ended December 31, 2024:
Common Stock Warrant Liability
Balance at December 31, 2023— 
Issuance of common stock warrants in December 202416,063,796 
Decrease in fair value of liability(2,808,608)
Balance at December 31, 2024$13,255,188 
v3.25.1
Certain Balance Sheet Items (Tables)
 12 Months Ended
Dec. 31, 2024
Certain Balance Sheet Items [Abstract]  
Schedule of Prepaid Expenses And Other Current Assets
Prepaid and other current assets at December 31, 2024 and 2023 consisted of the following:
 
20242023
Prepaid clinical expenses (a)627,962 3,410,442 
Other prepaid expenses1,889,503 2,003,655 
$2,517,465 $5,414,097 
Schedule of Accounts Payable And Accrued Expenses
Accounts payable and accrued expenses at December 31, 2024 and 2023 consisted of the following:
20242023
Trade accounts payable$5,091,503 $3,577,826 
Accrued compensation10,007,180 9,837,104 
Other accrued expenses (b) 1,101,330 6,432,814 
$16,200,013 $19,847,744 

(a)As of December 31, 2024 and 2023, balance included $0 and $1.5 million, respectively, of prepaid manufacturing expenses.
(b)As of December 31, 2024 and 2023, balance included $0 and $4.3 million, respectively, of liability for unused grant funding.
v3.25.1
Fixed Assets (Tables)
 12 Months Ended
Dec. 31, 2024
Property, Plant and Equipment [Abstract]  
Schedule Of Fixed Assets
Fixed assets at December 31, 2024 and 2023 consisted of the following:
 
CostAccumulated
Depreciation
and
Amortization		Net Book
Value
As of December 31, 2024
Leasehold improvements$11,761,522 $(8,390,612)$3,370,910 
Research and development equipment2,835,298 (2,571,747)263,551 
Office furniture and fixtures2,431,633 (2,416,232)15,401 
Computer equipment and other 3,093,812 (3,083,856)9,956 
$20,122,265 $(16,462,447)$3,659,818 
As of December 31, 2023
Leasehold improvements$15,917,596 $(11,753,081)$4,164,515 
Research and development equipment3,538,698 (3,078,165)460,533 
Office furniture and fixtures2,827,476 (2,816,577)10,899 
Computer equipment and other 3,529,129 (3,204,090)325,039 
$25,812,899 $(20,851,913)$4,960,986 
v3.25.1
Stockholders' Equity (Tables)
 12 Months Ended
Dec. 31, 2024
Stockholders' Equity Note [Abstract]  
Schedule of Preferred Stock Authorized, Issued And Outstanding
   Shares Outstanding as of
December 31,
 Shares AuthorizedShares Issued20242023
Series C Preferred Stock, par $0.001
1,091 1,091 9 9 
Schedule Of Shares Authorized Under Stock Option Plans, By Exercise Price Range
The following table summarizes total stock options outstanding at December 31, 2024:
 
 Options OutstandingOptions Exercisable
Exercise PriceShares Underlying Options
Outstanding		Weighted-Average
Remaining
Contractual Life
(in Years)		Weighted
Average
Exercise Price		Shares Underlying Options
Exercisable		Weighted Average
Exercise Price
$1.78-$18.00
568,085 8.8$10.95 205,698 $12.08 
$18.01-$39.00
249,917 6.2$35.52 191,644 $35.28 
$39.01-$52.00
152,066 3.5$44.95 151,949 $44.95 
$52.01-$90.00
126,336 3.2$76.92 123,316 $77.39 
$90.01-$130.00
112,293 3.4$98.68 112,293 $98.68 
$130.01-$233.28
128,531 5.3$137.48 128,531 $137.48 
1,337,228 6.4$45.17 913,431 $59.52 
Schedule Of Stock Options, Activity
Stock option activity under the Company’s equity incentive plans during the year ended December 31, 2024 was as follows:
Number of
Shares		Weighted-Average
Exercise Price
Balance, December 31, 20231,128,864 $58.76 
Granted328,376 8.27 
Exercised(8,159)8.29 
Cancelled(111,853)76.67 
Balance, December 31, 20241,337,228 $45.17 
Schedule Of Restricted Stock Unit Activity
Restricted stock unit activity under the Company’s equity incentive plans during the year ended December 31, 2024 was as follows:
Number of
Shares
Balance, December 31, 2023274,794 
Granted214,207 
Vested(126,133)
Cancelled(24,957)
Balance, December 31, 2024337,911 
Schedule of Assumptions Used To Estimate The Fair Value Of Warrants
The significant assumptions used in the Monte Carlo simulation method were as follows:
Risk-free interest rate4.60%
Expected volatility90%
Expected life in years3.61
Dividend yield—
v3.25.1
Commitments and Contingencies (Tables)
 12 Months Ended
Dec. 31, 2024
Leases [Abstract]  
Schedule Of Maturities Of Operating Lease Liabilities
As of December 31, 2024, the maturities of the Company's operating lease liabilities were as follows:
Year ending December 31,
2025$3,483,000 
20263,555,000 
20272,955,000 
20282,310,000 
20292,132,000 
   Total remaining lease payments14,435,000 
Less: present value adjustment(2,570,000)
   Total operating lease liabilities11,865,000 
Less: current portion(2,497,000)
Long-term operating lease liabilities$9,368,000 
Weighted-average remaining lease term4.3 years
Weighted-average discount rate9.0 %
v3.25.1
Income Taxes (Tables)
 12 Months Ended
Dec. 31, 2024
Income Tax Disclosure [Abstract]  
Schedule Of Components Of Pretax Loss From Operations
The components of pretax loss from operations are as follows:
Year Ended December 31,
20242023
     U.S. Domestic$(107,254,126)$(134,979,579)
     Foreign— (137,772)
Pretax loss from operations$(107,254,126)$(135,117,351)
Schedule Of Effective Income Tax Rate Reconciliation
The reconciliation of income taxes attributable to continuing operations computed at the statutory tax rates to income tax benefit, using a 21% statutory tax rate for December 31, 2024 and 2023, is as follows: 
Year Ended December 31,
20242023
Benefit from income taxes at statutory rates$(22,523,000)$(28,375,000)
State income tax, net of federal benefit(1,543,000)(3,922,000)
Change in valuation allowance21,749,000 28,394,000 
Research and development tax credits(5,846,000)(2,139,000)
Stock-based compensation1,579,000 2,099,000 
Uncertain tax positions2,344,000 861,000 
Goodwill impairment— 1,962,000 
Expired NOLs and credits4,687,000 1,352,000 
Limited NOLs and credits(2,056,000)(997,000)
Change in tax rates403,000 365,000 
Foreign tax rate differential— (4,000)
Other1,206,000 404,000 
$— $— 
Schedule Of Deferred Tax Assets And Liabilities
Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2024 and 2023 are shown below:
As of December 31,
20242023
Deferred tax assets:
Capitalized research expense$54,204,000 $50,143,000 
NOL carryforwards250,336,000 235,624,000 
Research and development and other tax credits31,250,000 27,734,000 
Deferred revenue— 22,000 
Stock-based compensation3,060,000 3,683,000 
Acquired intangibles774,000 907,000 
Investment in affiliated entity1,651,000 1,406,000 
Lease liability2,492,000 2,822,000 
Fixed assets441,000 337,000 
Other6,720,000 6,808,000 
350,928,000 329,486,000 
Valuation allowance(349,224,000)(327,493,000)
Total deferred tax assets1,704,000 1,993,000 
Deferred tax liabilities:
Right of use asset(1,704,000)(1,993,000)
Total deferred tax liabilities(1,704,000)(1,993,000)
Net deferred tax liabilities$— $— 
Schedule Of Operating Loss And Tax Credit Carryforward Expirations
Based upon statute, federal and state losses and credits are expected to expire as follows (in millions):
Expiration Date:Federal NOLsState NOLsForeign NOLsFederal R&DState R&D
2025$16.0 $5.2 $— $— $— 
202617.1 7.1 — — — 
20276.1 1.9 — — — 
2028 and thereafter245.9 333.6 1.0 46.1 — 
Indefinite801.9 0.7 — — 7.9 
$1,087.0 $348.5 $1.0 $46.1 $7.9 
Schedule Of Unrecognized Tax Benefits Rollforward
The following table summarizes the activity related to the Company's unrecognized tax benefits:
 Year ended December 31,
 20242023
Balance at beginning of the year$22,114,000 $21,139,000 
Increases related to current year tax positions2,297,000 1,816,000 
Increases (decreases) related to prior year tax positions197,000 (841,000)
Balance at end of the year$24,608,000 $22,114,000 
v3.25.1
Segment Information (Tables)
 12 Months Ended
Dec. 31, 2024
Segment Reporting [Abstract]  
Schedule of Segment Reporting Information, by Segment
Detailed information regarding the Company's single operating segment's revenues, expenses and operating loss are as follows:
Year Ended December 31,
20242023
Revenue from collaborative arrangements and other contracts, including affiliated entity
$217,756 $832,010 
Less:
Research and development:
     INO-310729,930,344 17,840,728 
     INO-5401 and other Immuno-oncology6,293,401 11,758,935 
     Other programs (a)(77,955)18,701,675 
     Engineering and device-related19,393,929 8,863,170 
     Stock-based compensation2,821,226 4,606,341 
     Other unallocated expenses (b)17,259,395 24,905,714 
General and administrative36,996,338 47,582,104 
Impairment of goodwill— 10,513,371 
Total operating expenses112,616,678 144,772,038 
Interest income4,766,993 8,133,290 
Interest expense(177,833)(1,222,789)
Change in fair value of common stock warrant liability2,808,608 — 
(Loss) gain on investment in affiliated entity(1,166,443)773,145 
Net unrealized gain on available-for-sale equity securities2,077,182 5,850,626 
Other expense, net(3,163,711)(4,711,596)
Net loss$(107,254,126)$(135,117,352)

(a) Net of contributions received from grant agreements and recorded as contra-research and development expense.
(b) Includes impairment of intangible assets of $2.0 million recorded in 2023.
v3.25.1
Summary of Significant Accounting Policies - Narrative (Details)
 12 Months Ended
Dec. 16, 2024
USD ($)
$ / shares
shares
Apr. 18, 2024
USD ($)
$ / shares
shares
Jan. 24, 2024
Dec. 31, 2024
USD ($)
segment
$ / shares
Dec. 31, 2023
USD ($)
$ / shares
Property, Plant and Equipment [Line Items]          
Net loss from operations       $ 107,254,126 $ 135,117,352
Working capital       62,500,000  
Accumulated deficit       1,730,219,262 $ 1,622,965,136
Cash, cash equivalents, and short-term investments       $ 94,100,000  
Common stock, par value (in USD per share) | $ / shares       $ 0.001 $ 0.001
Proceeds from issuance of common stock       $ 36,033,473 $ 5,461,745
Stock split, conversion ratio     0.0833    
Number of reportable segments | segment       1  
Allowance for doubtful accounts       $ 0 0
Valuation allowance       $ 349,224,000 327,493,000
Minimum          
Property, Plant and Equipment [Line Items]          
Property, plant, and equipment, useful life       3 years  
Maximum          
Property, Plant and Equipment [Line Items]          
Property, plant, and equipment, useful life       5 years  
December 2024 Offering Warrants          
Property, Plant and Equipment [Line Items]          
Class of warrant or right, exercise price of warrants or rights (in USD per share) | $ / shares $ 3.76        
December 2024 Offering          
Property, Plant and Equipment [Line Items]          
Consideration received $ 27,600,000        
December 2024 Offering | December 2024 Offering Warrants          
Property, Plant and Equipment [Line Items]          
Sale of stock, price per share (in dollars per share) | $ / shares $ 3.00        
Class of warrant or right, exercise price of warrants or rights (in USD per share) | $ / shares 3.76        
April 2024 Offering          
Property, Plant and Equipment [Line Items]          
Consideration received   $ 33,200,000      
April 2024 Offering | April 2024 Offering Warrants          
Property, Plant and Equipment [Line Items]          
Sale of stock, price per share (in dollars per share) | $ / shares   $ 7.692      
Class of warrant or right, exercise price of warrants or rights (in USD per share) | $ / shares   0.001      
Common stock          
Property, Plant and Equipment [Line Items]          
Common stock, par value (in USD per share) | $ / shares $ 0.001 $ 0.001      
Proceeds from issuance of common stock       $ 60,800,000  
Common stock | December 2024 Offering          
Property, Plant and Equipment [Line Items]          
Number of shares issued in transaction (in shares) | shares 10,000,000        
Common stock | December 2024 Offering | December 2024 Offering Warrants          
Property, Plant and Equipment [Line Items]          
Number of securities called by warrants or rights (in shares) | shares 10,000,000        
Common stock | April 2024 Offering          
Property, Plant and Equipment [Line Items]          
Number of shares issued in transaction (in shares) | shares   2,536,258      
Sale of stock, price per share (in dollars per share) | $ / shares   $ 7.693      
Common stock | April 2024 Offering | April 2024 Offering Warrants          
Property, Plant and Equipment [Line Items]          
Number of securities called by warrants or rights (in shares) | shares   2,135,477      
Common stock | Sales Agreement          
Property, Plant and Equipment [Line Items]          
Proceeds from issuance of common stock       $ 6,100,000 $ 5,500,000
v3.25.1
Summary of Significant Accounting Policies - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Numerator:    
Net loss $ (107,254,126) $ (135,117,352)
Denominator:    
Weighted-average common shares outstanding (in shares) 25,655,527 22,173,662
Weighted-average pre-funded warrants (in shares) 1,505,336 0
Weighted-average common shares outstanding used to compute basic and diluted net loss per share, basic (in shares) 27,160,863 22,173,662
Weighted-average common shares outstanding used to compute basic and diluted net loss per share, diluted (in shares) 27,160,863 22,173,662
Net loss per share    
Basic (in dollars per share) $ (3.95) $ (6.09)
Diluted (in dollars per share) $ (3.95) $ (6.09)
v3.25.1
Summary of Significant Accounting Policies - Antidilutive Securities Table (Details) - shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total antidilutive securities (in shares) 11,804,214 1,658,098
Warrants to purchase common stock    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total antidilutive securities (in shares) 10,000,000 0
Options to purchase common stock    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total antidilutive securities (in shares) 1,337,228 1,128,864
Service-based restricted stock units    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total antidilutive securities (in shares) 337,911 274,794
Performance-and market-based restricted stock units    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total antidilutive securities (in shares) 128,800 0
Convertible preferred stock    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total antidilutive securities (in shares) 275 275
Convertible notes | 6.50% Convertible Senior Notes Due 2024    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Total antidilutive securities (in shares) 0 254,165
v3.25.1
Summary of Significant Accounting Policies - Summary of Stock-Based Compensation Assumptions (Details) - Stock Options
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Employees and Directors    
Summary of assumptions used to estimate the fair value of stock options    
Risk-free interest rate 4.22% 4.05%
Expected volatility 105.00% 100.00%
Expected life in years 5 years 6 months 5 years 6 months
Dividend yield 0.00% 0.00%
Non Employee    
Summary of assumptions used to estimate the fair value of stock options    
Risk-free interest rate 4.21% 3.90%
Expected volatility 100.00% 89.00%
Expected life in years 6 years 6 months 10 years
Dividend yield 0.00% 0.00%
v3.25.1
Revenue Recognition and Concentration of Credit Risk- Revenue from External Customers (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Disaggregation of Revenue [Line Items]    
Revenue from collaborative arrangements and other contracts, including affiliated entity $ 217,756 $ 832,010
Revenue from Contract with Customer Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
% of Total Revenue 100.00% 100.00%
ApolloBio Corporation    
Disaggregation of Revenue [Line Items]    
Revenue from collaborative arrangements and other contracts, including affiliated entity $ 217,756 $ 245,056
ApolloBio Corporation | Revenue from Contract with Customer Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
% of Total Revenue 100.00% 29.00%
All other, including affiliated entity    
Disaggregation of Revenue [Line Items]    
Revenue from collaborative arrangements and other contracts, including affiliated entity $ 0 $ 586,954
All other, including affiliated entity | Revenue from Contract with Customer Benchmark | Customer Concentration Risk    
Disaggregation of Revenue [Line Items]    
% of Total Revenue 0.00% 71.00%
v3.25.1
Revenue Recognition and Concentration of Credit Risk - Additional Information (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
Revenue from Contract with Customer [Abstract]  
Revenue recognized from deferred revenue $ 0
v3.25.1
Collaborative Agreements (Details) - Collaborative Arrangement - USD ($)
$ in Thousands
 1 Months Ended 12 Months Ended
Apr. 30, 2018
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2019
Dec. 31, 2018
ApolloBio Corporation          
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Upfront payment received   $ 0 $ 3,600    
ApolloBio          
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Additional revenue to be achieved   $ 20,000      
Obligation period to pay royalties   10 years      
Funding received   $ 218 245    
Coalition for Epidemic Preparedness Innovations          
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Upfront payment received   1,600 1,800    
Coalition for Epidemic Preparedness Innovations | Lassa Fever And MERS Vaccine          
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Collaborative agreement, funding to be received   56,000      
Collaborative agreement, period to receive funding for research and development 5 years        
Bill And Melinda Gates Foundation | D N A Encoded Monoclonal Antibody Technology          
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]          
Collaborative agreement, funding to be received   $ 39 $ 70 $ 1,100 $ 2,200
v3.25.1
Short-term Investments and Fair Value Measurements - Schedule of Available-for-sale Securities (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Debt Securities, Available-for-sale, Sale [Abstract]    
Cost $ 30,167,433 $ 134,873,427
Gross Unrealized Gains 9,750 36,647
Gross Unrealized Losses (1,876,951) (3,927,161)
Fair Market Value 28,300,232 130,982,913
Mutual funds    
Debt Securities, Available-for-sale, Sale [Abstract]    
Cost 25,926,415 55,389,289
Gross Unrealized Gains 0 0
Gross Unrealized Losses (1,445,706) (3,522,888)
Fair Market Value 24,480,709 51,866,401
U.S. treasury securities    
Debt Securities, Available-for-sale, Sale [Abstract]    
Cost   75,164,782
Gross Unrealized Gains   24,938
Gross Unrealized Losses   0
Fair Market Value   75,189,720
Certificates of deposit    
Debt Securities, Available-for-sale, Sale [Abstract]    
Cost 2,980,273 2,978,917
Gross Unrealized Gains 9,750 11,709
Gross Unrealized Losses (281) (300)
Fair Market Value $ 2,989,742 $ 2,990,326
Certificates of deposit | Maximum    
Debt Securities, Available-for-sale [Line Items]    
Contractual maturity 1 year 1 year
U.S. agency mortgage-backed securities    
Debt Securities, Available-for-sale, Sale [Abstract]    
Cost $ 1,260,745 $ 1,340,439
Gross Unrealized Gains 0 0
Gross Unrealized Losses (430,964) (403,973)
Fair Market Value $ 829,781 $ 936,466
v3.25.1
Short-term Investments and Fair Value Measurements - Narrative (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
position
shares
Dec. 31, 2023
USD ($)
shares
Debt Securities, Available-for-sale [Line Items]    
Debt securities, available-for-sale, realized gain $ 900 $ 1,000
Debt securities, available-for-sale, realized gain 1,900,000 4,800,000
Net unrealized gain on available-for-sale equity securities $ 2,077,182 $ 5,850,626
Number of securities in a gross unrealized loss position | position 19  
Unrealized loss on investments $ 1,900,000  
Decrease in fair value of liability $ 2,808,608  
Fair Value, Inputs, Level 1    
Debt Securities, Available-for-sale [Line Items]    
Number of shares owned (in shares) | shares 597,808 597,808
v3.25.1
Short-term Investments and Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Assets:    
Short-term investments $ 28,300,232 $ 130,982,913
Mutual funds    
Assets:    
Short-term investments 24,480,709 51,866,401
Certificates of deposit    
Assets:    
Short-term investments 2,989,742 2,990,326
U.S. agency mortgage-backed securities    
Assets:    
Short-term investments 829,781 936,466
Fair Value, Measurements, Recurring    
Assets:    
Short-term investments 28,300,232 130,982,913
Investments in affiliated entity 1,613,844 2,780,287
Total assets measured at fair value 29,914,076 133,763,200
Liabilities:    
Common stock warrant liability 13,255,188  
Total liabilities 13,255,188  
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)    
Assets:    
Short-term investments 24,480,709 127,056,121
Investments in affiliated entity 1,613,844 2,780,287
Total assets measured at fair value 26,094,553 129,836,408
Liabilities:    
Common stock warrant liability 0  
Total liabilities 0  
Fair Value, Measurements, Recurring | Significant Other Unobservable Inputs (Level 2)    
Assets:    
Short-term investments 3,819,523 3,926,792
Investments in affiliated entity 0 0
Total assets measured at fair value 3,819,523 3,926,792
Liabilities:    
Common stock warrant liability 0  
Total liabilities 0  
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)    
Assets:    
Short-term investments 0 0
Investments in affiliated entity 0 0
Total assets measured at fair value 0 0
Liabilities:    
Common stock warrant liability 13,255,188  
Total liabilities 13,255,188  
Fair Value, Measurements, Recurring | Mutual funds    
Assets:    
Short-term investments 24,480,709 51,866,401
Fair Value, Measurements, Recurring | Mutual funds | Quoted Prices in Active Markets (Level 1)    
Assets:    
Short-term investments 24,480,709 51,866,401
Fair Value, Measurements, Recurring | Mutual funds | Significant Other Unobservable Inputs (Level 2)    
Assets:    
Short-term investments 0 0
Fair Value, Measurements, Recurring | Mutual funds | Significant Unobservable Inputs (Level 3)    
Assets:    
Short-term investments 0 0
Fair Value, Measurements, Recurring | U.S. treasury securities    
Assets:    
Short-term investments   75,189,720
Fair Value, Measurements, Recurring | U.S. treasury securities | Quoted Prices in Active Markets (Level 1)    
Assets:    
Short-term investments   75,189,720
Fair Value, Measurements, Recurring | U.S. treasury securities | Significant Other Unobservable Inputs (Level 2)    
Assets:    
Short-term investments   0
Fair Value, Measurements, Recurring | U.S. treasury securities | Significant Unobservable Inputs (Level 3)    
Assets:    
Short-term investments   0
Fair Value, Measurements, Recurring | Certificates of deposit    
Assets:    
Short-term investments 2,989,742 2,990,326
Fair Value, Measurements, Recurring | Certificates of deposit | Quoted Prices in Active Markets (Level 1)    
Assets:    
Short-term investments 0 0
Fair Value, Measurements, Recurring | Certificates of deposit | Significant Other Unobservable Inputs (Level 2)    
Assets:    
Short-term investments 2,989,742 2,990,326
Fair Value, Measurements, Recurring | Certificates of deposit | Significant Unobservable Inputs (Level 3)    
Assets:    
Short-term investments 0 0
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities    
Assets:    
Short-term investments 829,781 936,466
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities | Quoted Prices in Active Markets (Level 1)    
Assets:    
Short-term investments 0 0
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities | Significant Other Unobservable Inputs (Level 2)    
Assets:    
Short-term investments 829,781 936,466
Fair Value, Measurements, Recurring | U.S. agency mortgage-backed securities | Significant Unobservable Inputs (Level 3)    
Assets:    
Short-term investments $ 0 $ 0
v3.25.1
Short-term Investments and Fair Value Measurements - Schedule of Assumptions Used To Estimate The Fair Value Of Warrants (Details)
Dec. 31, 2024
yr
Dec. 16, 2024
yr
Risk-free interest rate    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Warrant liability, measurement input 0.044 0.043
Expected volatility    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Warrant liability, measurement input 1.11 1.11
Expected life in years    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Warrant liability, measurement input 5 5
Dividend yield    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Warrant liability, measurement input 0 0
v3.25.1
Short-term Investments and Fair Value Measurements - Changes In Fair Value Of The Company’s Total Level 3 Financial Liabilities (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
Investments, Debt and Equity Securities [Abstract]  
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Change in fair value of common stock warrant liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]  
Beginning balance $ 0
Issuance of common stock warrants in December 2024 16,063,796
Decrease in fair value of liability (2,808,608)
Ending balance $ 13,255,188
v3.25.1
Certain Balance Sheet Items - Schedule of Prepaid and Other Current Assets (Details) - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Certain Balance Sheet Items [Abstract]    
Prepaid clinical expenses $ 627,962 $ 3,410,442
Other prepaid expenses 1,889,503 2,003,655
Prepaid expenses and other current assets $ 2,517,465 $ 5,414,097
v3.25.1
Certain Balance Sheet Items - Schedule of Accounts Payable and Accrued Expenses (Details) - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Accounts Payable and Accrued Expenses [Line Items]    
Prepaid manufacturing expense, current $ 0 $ 1,500,000
Unused grant funding 0 4,300,000
Nonrelated Party    
Accounts Payable and Accrued Expenses [Line Items]    
Trade accounts payable 5,091,503 3,577,826
Accrued compensation 10,007,180 9,837,104
Other accrued expenses 1,101,330 6,432,814
Accounts payable and accrued liabilities $ 16,200,013 $ 19,847,744
v3.25.1
Fixed Assets (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Property, Plant and Equipment [Line Items]    
Cost $ 20,122,265 $ 25,812,899
Accumulated Depreciation and Amortization (16,462,447) (20,851,913)
Net Book Value 3,659,818 4,960,986
Depreciation 1,752,147 2,621,649
Gain (loss) on sale of fixed assets, no net book value 59,000 148,000
Property, plant and equipment disposed of 37,000 466,000
Leasehold improvements    
Property, Plant and Equipment [Line Items]    
Cost 11,761,522 15,917,596
Accumulated Depreciation and Amortization (8,390,612) (11,753,081)
Net Book Value 3,370,910 4,164,515
Research and development equipment    
Property, Plant and Equipment [Line Items]    
Cost 2,835,298 3,538,698
Accumulated Depreciation and Amortization (2,571,747) (3,078,165)
Net Book Value 263,551 460,533
Office furniture and fixtures    
Property, Plant and Equipment [Line Items]    
Cost 2,431,633 2,827,476
Accumulated Depreciation and Amortization (2,416,232) (2,816,577)
Net Book Value 15,401 10,899
Computer equipment and other    
Property, Plant and Equipment [Line Items]    
Cost 3,093,812 3,529,129
Accumulated Depreciation and Amortization (3,083,856) (3,204,090)
Net Book Value $ 9,956 $ 325,039
v3.25.1
Goodwill and Intangible Assets - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Acquired Finite-Lived Intangible Assets [Line Items]    
Impairment of goodwill $ 0 $ 10,513,371
Impairment of intangible assets $ 0 1,984,444
Bioject    
Acquired Finite-Lived Intangible Assets [Line Items]    
Impairment of intangible assets   $ 2,000,000
v3.25.1
Convertible Debt - Narrative (Details) - USD ($)
 12 Months Ended
Mar. 01, 2024
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2019
Debt Instrument [Line Items]        
Repayments of convertible debt   $ 16,415,000 $ 0  
Interest expense   177,833 1,222,789  
6.50% Convertible Senior Notes Due 2024 | Convertible Debt        
Debt Instrument [Line Items]        
Debt instrument, face amount       $ 78,500,000
Debt interest based on the fixed rate       6.50%
Proceeds from issuance of debt       $ 75,700,000
Repayments of convertible debt $ 16,900,000      
Interest expense   178,000 1,200,000  
Interest expense, debt   $ 178,000 $ 1,100,000  
v3.25.1
Stockholders' Equity - Schedule of Preferred Stock (Details) - $ / shares
Dec. 31, 2024
Dec. 31, 2023
Summary of common and preferred stock authorized, issued and outstanding    
Preferred stock, par value (in dollars per share) $ 0.001 $ 0.001
Preferred stock, shares authorized (in shares) 10,000,000 10,000,000
Preferred stock, shares issued (in shares) 9 9
Preferred stock, shares outstanding (in shares) 9 9
Series C Preferred Stock    
Summary of common and preferred stock authorized, issued and outstanding    
Preferred stock, par value (in dollars per share) $ 0.001 $ 0.001
Preferred stock, shares authorized (in shares) 1,091  
Preferred stock, shares issued (in shares) 1,091  
Preferred stock, shares outstanding (in shares) 9 9
v3.25.1
Stockholders' Equity - Preferred Stock (Details)
 12 Months Ended
Dec. 31, 2022
$ / shares
shares
Class of Stock [Line Items]  
Convertible preferred stock, shares issued upon conversion, conversion price (in dollars per share) | $ / shares $ 326.40
Series C Preferred Stock  
Class of Stock [Line Items]  
Convertible preferred stock, shares issued upon conversion (in shares) | shares 275
v3.25.1
Stockholders' Equity - Offering of Common Stock, Warrants, and Pre-funded Warrants (Details) - $ / shares
Dec. 16, 2024
Apr. 18, 2024
Underwritten Registered Direct Offering    
Class of Warrant or Right [Line Items]    
Class of warrant or right, common stock ownership (percent)   19.99%
Warrants to purchase common stock | Underwritten Registered Direct Offering    
Class of Warrant or Right [Line Items]    
Class of warrant or right, exercise price of warrants or rights (in USD per share)   $ 0.001
Common stock | Underwritten Registered Direct Offering    
Class of Warrant or Right [Line Items]    
Class of warrant or right, common stock ownership (percent)   9.99%
December 2024 Offering Warrants    
Class of Warrant or Right [Line Items]    
Class of warrant or right, exercise price of warrants or rights (in USD per share) $ 3.76  
Class of warrant or right, common stock ownership (percent) 4.99%  
Class of warrant or right, common stock, prior to issuance (percent) 9.99%  
Class of warrant or right, common stock, maximum (percent) 19.99%  
v3.25.1
Stockholders' Equity - At-The-Market Sales Agreements (Details) - Common stock - USD ($)
 3 Months Ended 12 Months Ended
Aug. 13, 2024
Nov. 09, 2021
Mar. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
2024 Sales Agreement          
Class of Stock [Line Items]          
Common stock aggregate offering price $ 60,000,000        
Sales Agents will be entitled to compensation 3.00%        
Stock sale agreement, aggregate number of shares issued (in shares)       133,900  
Sales made at a weighted average price (in dollars per share)       $ 7.02  
Stock sale agreement, aggregate proceeds from issuance of stock       $ 925,000  
Stock sale agreement, remaining capacity, amount       $ 59,100,000  
2021 Sales Agreement          
Class of Stock [Line Items]          
Common stock aggregate offering price   $ 300,000,000      
Sales Agents will be entitled to compensation   3.00%      
Stock sale agreement, aggregate number of shares issued (in shares)     543,620   875,305
Sales made at a weighted average price (in dollars per share)     $ 9.76   $ 6.33
Stock sale agreement, aggregate proceeds from issuance of stock     $ 5,200,000   $ 5,500,000
v3.25.1
Stockholders' Equity - Other Issuances of Common Stock (Details) - shares
Mar. 31, 2023
Jan. 31, 2023
McDermid v. Inovio Pharmaceuticals, Inc. and J. Joseph Kim    
Class of Stock [Line Items]    
Shares issued in settlement (in shares) 760,083 760,083
v3.25.1
Stockholders' Equity - Stock Options and Restricted Stock Units (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
May 16, 2023
Jun. 24, 2022
Class of Stock [Line Items]        
Allocated share-based compensation expense $ 6,400,000 $ 10,400,000    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized $ 2,100,000 $ 4,300,000    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition 1 year 6 months 1 year 3 months 18 days    
Number of options outstanding to purchase common stock (in shares) 1,337,228 1,128,864    
Aggregate intrinsic value of options outstanding $ 1,000      
Aggregate intrinsic value for options exercisable $ 0      
Options exercisable, remaining contractual term 5 years 6 months      
Number of options expected to vest (in shares) 1,337,228      
Options, expirations in period, weighted average exercise price (in dollars per share) $ 139.02 $ 38.86    
Options, expirations in period (in shares) 38,503 9,357    
Options, grants in period, weighted average grant date fair value (in dollars per share) $ 6.69 $ 11.19    
Proceeds from stock option exercises $ 67,675 $ 0    
Options, exercises in period, aggregate intrinsic value 39,000      
Nonemployee        
Class of Stock [Line Items]        
Allocated share-based compensation expense $ 226,000 $ 669,000    
Number of options outstanding to purchase common stock (in shares) 66,056      
Performance-and market-based restricted stock units        
Class of Stock [Line Items]        
Number of shares of unvested restricted stock units and options outstanding (in shares) 337,911 274,794    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized $ 2,000,000.0 $ 3,500,000    
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition 1 year 7 months 6 days 1 year 6 months    
Aggregate intrinsic value of unvested $ 618,000      
Aggregate intrinsic value of vested $ 1,300,000      
RSU's expected to vest (in shares) 337,911      
Weighted-average grant date fair value (in USD per share) $ 8.30 $ 10.34    
Performance-and market-based restricted stock units | Former President and Chief Executive Officer        
Class of Stock [Line Items]        
Awards settled in cash, percentage 50.00%      
Research and Development Expense        
Class of Stock [Line Items]        
Allocated share-based compensation expense $ 2,800,000 $ 4,500,000    
General and Administrative Expense        
Class of Stock [Line Items]        
Allocated share-based compensation expense $ 3,600,000 $ 5,900,000    
2023 Incentive Plan        
Class of Stock [Line Items]        
Reserved number of shares under the Incentive Plan (in shares)     1,166,666  
Number of shares available for grants under the Incentive Plan (in shares) 800,526      
Number of shares of unvested restricted stock units and options outstanding (in shares) 188,082      
Number of common stock shares outstanding under the Incentive Plan (in shares) 282,579      
Award vesting period (in years) 3 years      
Contractual year term of incentive plan (in years) 10 years      
2016 Incentive Plan        
Class of Stock [Line Items]        
Number of common stock shares outstanding under the Incentive Plan (in shares) 904,669      
Award vesting period (in years) 3 years      
Contractual year term of incentive plan (in years) 10 years      
Number of shares of vested restricted stock outstanding under the plan (in shares) 129,000      
2022 Inducement Plan        
Class of Stock [Line Items]        
Reserved number of shares under the Incentive Plan (in shares)       166,666
Number of shares available for grants under the Incentive Plan (in shares) 84,328      
Number of shares of unvested restricted stock units and options outstanding (in shares) 20,829      
Number of common stock shares outstanding under the Incentive Plan (in shares) 53,684      
2007 Incentive Plan        
Class of Stock [Line Items]        
Number of common stock shares outstanding under the Incentive Plan (in shares) 96,296      
Award vesting period (in years) 3 years      
Contractual year term of incentive plan (in years) 10 years      
v3.25.1
Stockholders' Equity - Schedule of Stock Options Outstanding (Details)
 12 Months Ended
Dec. 31, 2024
$ / shares
shares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]  
Options outstanding (in shares) | shares 1,337,228
Weighted-average remaining contractual life (in Years) 6 years 4 months 24 days
Weighted average exercise price (in dollars per share) $ 45.17
Options exercisable (in shares) | shares 913,431
Weighted average exercise price (in dollars per share) $ 59.52
$1.78-$18.00  
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]  
Exercise price, lower range limit (in dollars per share) 1.78
Exercise price, upper range limit (in dollars per share) $ 18.00
Options outstanding (in shares) | shares 568,085
Weighted-average remaining contractual life (in Years) 8 years 9 months 18 days
Weighted average exercise price (in dollars per share) $ 10.95
Options exercisable (in shares) | shares 205,698
Weighted average exercise price (in dollars per share) $ 12.08
$18.01-$39.00  
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]  
Exercise price, lower range limit (in dollars per share) 18.01
Exercise price, upper range limit (in dollars per share) $ 39.00
Options outstanding (in shares) | shares 249,917
Weighted-average remaining contractual life (in Years) 6 years 2 months 12 days
Weighted average exercise price (in dollars per share) $ 35.52
Options exercisable (in shares) | shares 191,644
Weighted average exercise price (in dollars per share) $ 35.28
$39.01-$52.00  
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]  
Exercise price, lower range limit (in dollars per share) 39.01
Exercise price, upper range limit (in dollars per share) $ 52.00
Options outstanding (in shares) | shares 152,066
Weighted-average remaining contractual life (in Years) 3 years 6 months
Weighted average exercise price (in dollars per share) $ 44.95
Options exercisable (in shares) | shares 151,949
Weighted average exercise price (in dollars per share) $ 44.95
$52.01-$90.00  
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]  
Exercise price, lower range limit (in dollars per share) 52.01
Exercise price, upper range limit (in dollars per share) $ 90.00
Options outstanding (in shares) | shares 126,336
Weighted-average remaining contractual life (in Years) 3 years 2 months 12 days
Weighted average exercise price (in dollars per share) $ 76.92
Options exercisable (in shares) | shares 123,316
Weighted average exercise price (in dollars per share) $ 77.39
$90.01-$130.00  
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]  
Exercise price, lower range limit (in dollars per share) 90.01
Exercise price, upper range limit (in dollars per share) $ 130.00
Options outstanding (in shares) | shares 112,293
Weighted-average remaining contractual life (in Years) 3 years 4 months 24 days
Weighted average exercise price (in dollars per share) $ 98.68
Options exercisable (in shares) | shares 112,293
Weighted average exercise price (in dollars per share) $ 98.68
$130.01-$233.28  
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]  
Exercise price, lower range limit (in dollars per share) 130.01
Exercise price, upper range limit (in dollars per share) $ 233.28
Options outstanding (in shares) | shares 128,531
Weighted-average remaining contractual life (in Years) 5 years 3 months 18 days
Weighted average exercise price (in dollars per share) $ 137.48
Options exercisable (in shares) | shares 128,531
Weighted average exercise price (in dollars per share) $ 137.48
v3.25.1
Stockholders' Equity - Schedule of Stock Option Activity Under Equity Incentive Plan (Details)
 12 Months Ended
Dec. 31, 2024
$ / shares
shares
Number of Shares  
Beginning balance (in shares) | shares 1,128,864
Granted (in shares) | shares 328,376
Exercised (in shares) | shares (8,159)
Cancelled (in shares) | shares (111,853)
Ending balance (in shares) | shares 1,337,228
Weighted-Average Exercise Price  
Beginning balance (in dollars per share) | $ / shares $ 58.76
Granted (in dollars per share) | $ / shares 8.27
Exercised (in dollars per share) | $ / shares 8.29
Cancelled (in dollars per share) | $ / shares 76.67
Ending balance (in dollars per share) | $ / shares $ 45.17
v3.25.1
Stockholders' Equity - Schedule of RSU Activity Under Equity Incentive Plan (Details) - Performance-and market-based restricted stock units
 12 Months Ended
Dec. 31, 2024
shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]  
Beginning balance (in shares) 274,794
Granted (in shares) 214,207
Vested (in shares) (126,133)
Cancelled (in shares) (24,957)
Ending balance (in shares) 337,911
v3.25.1
Stockholders' Equity - Significant Assumption Used in Monte Carlo Simulation Method (Details) - Market-Based RSUs
 12 Months Ended
Dec. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Risk-free interest rate 4.60%
Expected volatility 90.00%
Expected life in years 3 years 7 months 9 days
Dividend yield 0.00%
v3.25.1
Stockholders' Equity - Performance-and Market-Based RSUs (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
$ / shares
shares
Dec. 31, 2023
USD ($)
$ / shares
shares
Class of Stock [Line Items]    
Allocated share-based compensation expense $ 6,400,000 $ 10,400,000
Performance Shares    
Class of Stock [Line Items]    
Number of shares of unvested restricted stock units and options outstanding (in shares) | shares 83,800  
Milestone-based RSUs (in percent) 0.70  
Market-based RSUs (in percent) 0.30  
Restricted Stock Units (RSUs)    
Class of Stock [Line Items]    
Number of shares of unvested restricted stock units and options outstanding (in shares) | shares 337,911 274,794
Weighted-average grant date fair value (in USD per share) | $ / shares $ 8.30 $ 10.34
Restricted Stock Units (RSUs) | Performance RSUs, Specified Threshold Percentile    
Class of Stock [Line Items]    
Threshold percentage 50.00%  
Restricted Stock Units (RSUs) | Performance RSUs, Target Percentile    
Class of Stock [Line Items]    
Threshold percentage 100.00%  
Restricted Stock Units (RSUs) | Performance RSUs, Specified Maximum Percentile    
Class of Stock [Line Items]    
Threshold percentage 150.00%  
Market-Based RSUs    
Class of Stock [Line Items]    
Award vesting period (in years) 3 years  
Grant date fair value $ 269,000  
Weighted-average grant date fair value (in USD per share) | $ / shares $ 10.69  
Allocated share-based compensation expense $ 44,000  
Market-Based RSUs | Minimum    
Class of Stock [Line Items]    
Vesting percentage 0  
Market-Based RSUs | Maximum    
Class of Stock [Line Items]    
Vesting percentage 1.50  
Restricted Stock Units (RSUs), Milestone-Based    
Class of Stock [Line Items]    
Grant date fair value $ 643,000  
Weighted-average grant date fair value (in USD per share) | $ / shares $ 10.96  
Allocated share-based compensation expense $ 0  
v3.25.1
Stockholders' Equity - December 2024 Performance-Based Awards (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Class of Warrant or Right [Line Items]    
Options, grants in period, weighted average grant date fair value (in dollars per share) $ 6.69 $ 11.19
Allocated share-based compensation expense $ 6,400 $ 10,400
Stock Options | December 2024    
Class of Warrant or Right [Line Items]    
Underlying common stock (in shares) 25,686  
Restricted Stock Units (RSUs) | December 2024    
Class of Warrant or Right [Line Items]    
Underlying common stock (in shares) 19,314  
Restricted Stock Units, Performance-Based    
Class of Warrant or Right [Line Items]    
Grant date fair value $ 34  
Share price $ 1.78  
Stock Options, Performance-Based    
Class of Warrant or Right [Line Items]    
Grant date fair value $ 38  
Options, grants in period, weighted average grant date fair value (in dollars per share) $ 1.46  
v3.25.1
Commitments and Contingencies - Narrative (Details)
$ in Millions
 1 Months Ended 12 Months Ended
Nov. 30, 2023
Jul. 31, 2023
USD ($)
Apr. 30, 2020
defendent
Dec. 31, 2024
USD ($)
ft²
Dec. 31, 2023
USD ($)
ft²
Mar. 31, 2023
shares
Jan. 31, 2023
USD ($)
shares
Other Commitments [Line Items]              
Lease, cost       $ 2.6 $ 3.5    
McDermid v. Inovio Pharmaceuticals, Inc. and J. Joseph Kim              
Other Commitments [Line Items]              
Estimate of cash settlement             $ 30.0
Shares issued in settlement (in shares) | shares           760,083 760,083
Estimate of shares settlement             $ 14.0
Behesti v. Kim, et al.              
Other Commitments [Line Items]              
Number of defendants | defendent     8        
Damages paid   $ 1.2          
Minimum              
Other Commitments [Line Items]              
Operating lease, remaining lease term       2 years 4 months 24 days      
Maximum              
Other Commitments [Line Items]              
Operating lease, remaining lease term       5 years      
San Diego, California              
Other Commitments [Line Items]              
Lessee, operating lease, area of land under lease | ft²       56,600      
San Diego, California | Minimum              
Other Commitments [Line Items]              
Annual increase of base rent percentage 2.00%            
San Diego, California | Maximum              
Other Commitments [Line Items]              
Annual increase of base rent percentage 3.00%            
Plymouth Meeting, Pennsylvania              
Other Commitments [Line Items]              
Lessee, operating lease, area of land under lease | ft²       57,400 11,400    
v3.25.1
Commitments and Contingencies - Summary of Maturities of Operating Lease Payments (Details) - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Leases [Abstract]    
2025 $ 3,483,000  
2026 3,555,000  
2027 2,955,000  
2028 2,310,000  
2029 2,132,000  
Total remaining lease payments 14,435,000  
Less: present value adjustment (2,570,000)  
Total operating lease liabilities 11,865,000  
Less: current portion (2,497,360) $ (2,406,522)
Long-term operating lease liabilities $ 9,367,827 $ 11,032,066
Weighted-average remaining lease term 4 years 3 months 18 days  
Weighted-average discount rate 9.00%  
v3.25.1
Income Taxes - Components of Pretax Loss from Operations (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Income Tax Disclosure [Abstract]    
U.S. Domestic $ (107,254,126) $ (134,979,579)
Foreign 0 (137,772)
Net loss $ (107,254,126) $ (135,117,351)
v3.25.1
Income Taxes - Reconciliation of Income Taxes (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]      
Benefit from income taxes at statutory rates $ (22,523,000) $ (28,375,000)  
State income tax, net of federal benefit (1,543,000) (3,922,000)  
Change in valuation allowance 21,749,000 28,394,000  
Research and development tax credits (5,846,000) (2,139,000)  
Stock-based compensation 1,579,000 2,099,000  
Uncertain tax positions 2,344,000 861,000  
Goodwill impairment 0 1,962,000  
Expired NOLs and credits 4,687,000 1,352,000  
Limited NOLs and credits (2,056,000) (997,000)  
Change in tax rates 403,000 365,000  
Foreign tax rate differential 0 (4,000)  
Other 1,206,000 404,000  
Income tax expense (benefit) $ 0 $ 0 $ 0
v3.25.1
Income Taxes - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2018
Operating Loss Carryforwards [Line Items]        
Income tax expense (benefit) $ 0 $ 0 $ 0  
Tax benefits expired 5,300,000      
Unrecognized tax benefits that would impact effective tax rate 22,900,000 $ 20,500,000    
Federal        
Operating Loss Carryforwards [Line Items]        
Net operating loss carryforwards that will expire due to IRC Section 382 limitations 1,100,000,000      
Federal | Research Tax Credit Carryforward        
Operating Loss Carryforwards [Line Items]        
Tax credit carryforward amount 46,100,000      
California        
Operating Loss Carryforwards [Line Items]        
Net operating loss carryforwards that will expire due to IRC Section 382 limitations 259,900,000      
Pennsylvania        
Operating Loss Carryforwards [Line Items]        
Net operating loss carryforwards that will expire due to IRC Section 382 limitations 88,600,000      
Federal        
Operating Loss Carryforwards [Line Items]        
Net operating loss carryforwards 1,087,000,000     $ 801,900,000
Federal | Research Tax Credit Carryforward        
Operating Loss Carryforwards [Line Items]        
Tax credit carryforward amount 46,100,000      
Foreign Tax Jurisdiction        
Operating Loss Carryforwards [Line Items]        
Net operating loss carryforwards 1,000,000      
State        
Operating Loss Carryforwards [Line Items]        
Net operating loss carryforwards 348,500,000      
State | Research Tax Credit Carryforward        
Operating Loss Carryforwards [Line Items]        
Tax credit carryforward amount $ 7,900,000      
v3.25.1
Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2024
Dec. 31, 2023
Deferred tax assets:    
Capitalized research expense $ 54,204 $ 50,143
NOL carryforwards 250,336 235,624
Research and development and other tax credits 31,250 27,734
Deferred revenue 0 22
Stock-based compensation 3,060 3,683
Acquired intangibles 774 907
Investment in affiliated entity 1,651 1,406
Lease liability 2,492 2,822
Fixed assets 441 337
Other 6,720 6,808
Deferred tax assets, gross 350,928 329,486
Valuation allowance (349,224) (327,493)
Total deferred tax assets 1,704 1,993
Deferred tax liabilities:    
Right of use asset (1,704) (1,993)
Total deferred tax liabilities (1,704) (1,993)
Net deferred tax liabilities $ 0 $ 0
v3.25.1
Income Taxes - Expected Expirations of Federal and State Losses and Credits (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2018
Federal    
Expirations of Operating Loss Carryforwards, Components [Abstract]    
2025 $ 16.0  
2026 17.1  
2027 6.1  
2028 and thereafter 245.9  
Indefinite 801.9  
Total 1,087.0 $ 801.9
State    
Expirations of Operating Loss Carryforwards, Components [Abstract]    
2025 5.2  
2026 7.1  
2027 1.9  
2028 and thereafter 333.6  
Indefinite 0.7  
Total 348.5  
Foreign Tax Jurisdiction    
Expirations of Operating Loss Carryforwards, Components [Abstract]    
2025 0.0  
2026 0.0  
2027 0.0  
2028 and thereafter 1.0  
Indefinite 0.0  
Total 1.0  
Research Tax Credit Carryforward | Federal    
Expirations of Tax Credit Carryforwards [Abstract]    
2025 0.0  
2026 0.0  
2027 0.0  
2028 and thereafter 46.1  
Indefinite 0.0  
Total 46.1  
Research Tax Credit Carryforward | State    
Expirations of Tax Credit Carryforwards [Abstract]    
2025 0.0  
2026 0.0  
2027 0.0  
2028 and thereafter 0.0  
Indefinite 7.9  
Total $ 7.9  
v3.25.1
Income Taxes - Unrecognized Tax Benefits Activity (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Unrecognized Tax Benefits [Roll Forward]    
Balance at beginning of the year $ 22,114 $ 21,139
Increases related to current year tax positions 2,297 1,816
Increases (decreases) related to prior year tax positions 197  
Increases (decreases) related to prior year tax positions   (841)
Balance at end of the year $ 24,608 $ 22,114
v3.25.1
401(k) Plan (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Retirement Benefits [Abstract]    
Employer matching contribution, percent 50.00%  
Maximum annual contribution per employee, percent 6.00%  
Company's contribution to 401(k) plan $ 961 $ 1,400
v3.25.1
Related Party Transactions (Details) - USD ($)
 1 Months Ended 12 Months Ended
Aug. 31, 2024
Dec. 31, 2022
Mar. 31, 2016
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2021
Dec. 31, 2020
Related Party Transaction [Line Items]              
Accounts receivable       $ 1,199,056 $ 2,405,228    
Research and development       75,620,340 86,676,563    
Affiliated Entity              
Related Party Transaction [Line Items]              
Expenses to reimburse     $ 3,100,000        
Term     5 years        
Grant proceeds received       482,000 1,000,000.0    
Plumbline Life Sciences              
Related Party Transaction [Line Items]              
Accounts receivable       1,600,000 2,800,000    
The Wistar Institute              
Related Party Transaction [Line Items]              
Agreement amended amount           $ 13,600,000  
The Wistar Institute | Affiliated Entity              
Related Party Transaction [Line Items]              
Awarded amount   $ 1,200,000         $ 10,700,000
Agreement amended amount $ 12,500,000     2,400,000      
Awarded option amount   $ 4,200,000          
Research and development       1,500,000 1,800,000    
Accounts receivable       1,200,000 2,400,000    
Accounts payable and accrued expenses       1,400,000 1,100,000    
Prepaid expense       0 20,000    
Deferred grant funding from affiliate       $ 0 $ 22,000    
Plumbline Life Sciences              
Related Party Transaction [Line Items]              
Number of shares owned (in shares)       597,808 597,808    
Ownership percentage       17.30% 17.80%    
v3.25.1
Geneos Therapeutics, Inc. - Narrative (Details) - Geneos Therapeutics, Inc. - USD ($)
$ in Thousands
Dec. 31, 2024
Dec. 31, 2023
Noncontrolling Interest [Line Items]    
Noncontrolling interest, ownership percentage by parent 23.00%  
Investment in Geneos $ 0 $ 0
Equity method investments, minimum $ 0  
v3.25.1
Segment Information (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
segment
Dec. 31, 2023
USD ($)
Segment Reporting [Abstract]    
Number of reportable segments | segment 1  
Segment Reporting Information [Line Items]    
Revenue from collaborative arrangements and other contracts, including affiliated entity $ 217,756 $ 832,010
Less:    
Research and development $ 75,620,340 86,676,563
Impairment, Intangible Asset, Statement of Income or Comprehensive Income [Extensible Enumeration] Research and development  
General and administrative $ 36,996,338 47,582,104
Impairment of goodwill 0 10,513,371
Total operating expenses 112,616,678 144,772,038
Interest income 4,766,993 8,133,290
Interest expense (177,833) (1,222,789)
Gain (loss) on investment in affiliated entities (1,166,443) 773,145
Net unrealized gain on available-for-sale equity securities 2,077,182 5,850,626
Other income (expense), net (3,163,711) (4,711,596)
Net loss (107,254,126) (135,117,352)
Reportable Segments    
Segment Reporting Information [Line Items]    
Revenue from collaborative arrangements and other contracts, including affiliated entity 217,756 832,010
Less:    
General and administrative 36,996,338 47,582,104
Impairment of goodwill 0 10,513,371
Total operating expenses 112,616,678 144,772,038
Interest income 4,766,993 8,133,290
Interest expense (177,833) (1,222,789)
Change in fair value of common stock warrant liability 2,808,608 0
Gain (loss) on investment in affiliated entities (1,166,443) 773,145
Net unrealized gain on available-for-sale equity securities 2,077,182 5,850,626
Other income (expense), net (3,163,711) (4,711,596)
Net loss (107,254,126) (135,117,352)
Reportable Segments | INO-3107    
Less:    
Research and development 29,930,344 17,840,728
Reportable Segments | INO-5401 And Other Immuno-oncology    
Less:    
Research and development 6,293,401 11,758,935
Reportable Segments | Other Programs    
Less:    
Research and development (77,955) 18,701,675
Reportable Segments | Engineering And Device-Related    
Less:    
Research and development 19,393,929 8,863,170
Reportable Segments | Stock-Based Compensation    
Less:    
Research and development 2,821,226 4,606,341
Reportable Segments | Other Unallocated Expenses    
Less:    
Research and development $ 17,259,395 24,905,714
Impairment   $ 2,000,000
v3.25.1
Subsequent Events (Details)
 2 Months Ended 12 Months Ended
Mar. 01, 2024
USD ($)
Jan. 24, 2024
Mar. 12, 2025
USD ($)
$ / shares
shares
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Subsequent Event [Line Items]          
Repayments of convertible debt       $ 16,415,000 $ 0
Stock split, conversion ratio   0.0833      
Subsequent Event | 2024 Sales Agreement          
Subsequent Event [Line Items]          
Number of shares issued in transaction (in shares) | shares     512,518    
Consideration received     $ 1,100,000    
Sale of stock, price per share (in dollars per share) | $ / shares     $ 2.16    
6.50% Convertible Senior Notes Due 2024 | Convertible Debt          
Subsequent Event [Line Items]          
Repayments of convertible debt $ 16,900,000