SUMMIT THERAPEUTICS INC., 10-K filed on 2/23/2026
Annual Report
v3.25.4
Cover - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Feb. 17, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-36866    
Entity Registrant Name Summit Therapeutics Inc.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 37-1979717    
Entity Address, Address Line One 601 Brickell Key Drive, Suite 1000    
Entity Address, City or Town Miami    
Entity Address, State or Province FL    
Entity Address, Postal Zip Code 33131    
City Area Code 305    
Local Phone Number 203-2034    
Title of 12(b) Security Common Stock, par value $0.01 per share    
Trading Symbol SMMT    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 2,483.8
Entity Common Stock, Shares Outstanding   775,372,700  
Documents Incorporated by Reference
Portions of the registrant’s definitive proxy statement relating to the registrant’s 2026 annual meeting of stockholders to be filed hereafter are incorporated by reference into Part III of this Annual Report on Form 10-K. The registrant’s definitive proxy statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
    
Amendment Flag false    
Entity Central Index Key 0001599298    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
v3.25.4
Audit Information
 12 Months Ended
Dec. 31, 2025
Audit Information [Abstract]  
Auditor Firm ID 238
Auditor Name PricewaterhouseCoopers LLP
Auditor Location San Jose, California
v3.25.4
Consolidated Balance Sheets - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Current assets:    
Cash and cash equivalents $ 225,266 $ 104,862
Restricted cash 316 325
Short-term investments 488,182 307,487
Prepaid expenses and other current assets 6,537 11,076
Total current assets 720,301 423,750
Non-current assets:    
Property and equipment, net 1,059 254
Operating lease right-of-use assets 20,616 7,144
Goodwill 2,001 1,864
Other assets 7,205 2,548
Total assets 751,182 435,560
Current liabilities:    
Accounts payable 20,292 4,636
Accrued liabilities 32,100 19,554
Accrued compensation 14,925 11,977
Operating lease liabilities, current portion 3,388 3,765
Other current liabilities 2,283 1,797
Total current liabilities 72,988 41,729
Non-current liabilities:    
Operating lease liabilities, net of current portion 17,502 3,453
Other non-current liabilities 1,832 1,630
Total liabilities 92,322 46,812
Commitments and contingencies (Note 16)
Stockholders’ equity:    
Preferred stock, $0.01 par value, 20,000,000 shares authorized; none issued and outstanding at December 31, 2025 and 2024, respectively 0 0
Common stock, $0.01 par value: 1,000,000,000 shares authorized; 775,371,200 and 737,626,004 shares issued and outstanding at December 31, 2025 and 2024, respectively 7,754 7,376
Additional paid-in capital 2,947,805 1,598,230
Accumulated other comprehensive loss (2,540) (2,285)
Accumulated deficit (2,294,159) (1,214,573)
Total stockholders' equity 658,860 388,748
Total liabilities and stockholders' equity $ 751,182 $ 435,560
v3.25.4
Consolidated Balance Sheets (Parenthetical) - $ / shares
Dec. 31, 2025
Dec. 31, 2024
May 13, 2024
Apr. 27, 2023
Jan. 31, 2023
Jan. 19, 2023
Jan. 18, 2023
Statement of Financial Position [Abstract]              
Preferred stock par value (in dollars per share) $ 0.01 $ 0.01          
Preferred stock, shares authorized (in shares) 20,000,000 20,000,000          
Preferred stock, shares issued (in shares) 0 0          
Preferred stock, shares outstanding (in shares) 0 0          
Common stock par value (in dollars per share) $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01    
Common stock, shares authorized (in shares) 1,000,000,000 1,000,000,000       1,000,000,000 350,000,000
Common stock, shares issued (in shares) 775,371,200 737,626,004          
Common stock, shares outstanding (in shares) 775,371,200 737,626,004          
v3.25.4
Consolidated Statements of Operations and Comprehensive Loss - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Operating expenses:      
Research and development [1] $ 537,674 $ 150,777 $ 59,471
Acquired in-process research and development 0 15,007 520,915
General and administrative 556,750 60,214 29,264
Total operating expenses 1,094,424 225,998 609,650
Other income, net 14,838 13,369 11,183
Interest expense 0 (8,686) (16,461)
Net loss $ (1,079,586) $ (221,315) $ (614,928)
Net loss per share:      
Basic (in dollars per share) $ (1.44) $ (0.31) $ (0.99)
Diluted (in dollars per share) $ (1.44) $ (0.31) $ (0.99)
Weighted average common shares outstanding:      
Basic (in shares) 747,702,265 718,541,896 619,646,180
Diluted (in shares) 747,702,265 718,541,896 619,646,180
Other comprehensive income (loss):      
Foreign currency translation adjustments $ (327) $ 60 $ (172)
Reclassification of unrealized loss on short-term investments to other income, net 0 3 0
Reclassification of cumulative currency translation gain to other income, net 0 0 (419)
Unrealized gain on short-term investments 72 100 36
Comprehensive loss $ (1,079,841) $ (221,152) $ (615,483)
[1] Refer to Note 15 – Related Party Transactions for expenses incurred.
v3.25.4
Consolidated Statements of Stockholders' Equity - USD ($)
$ in Thousands
Total
Rights Offering
 [1]
Private Placement
At Market Offering
Common Stock
Common Stock
Rights Offering
 [1]
Common Stock
Private Placement
Common Stock
At Market Offering
Additional Paid-In Capital
Additional Paid-In Capital
Rights Offering
 [1]
Additional Paid-In Capital
Private Placement
Additional Paid-In Capital
At Market Offering
Accumulated Other Comprehensive Loss
Total Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2022         211,091,425                  
Beginning balance at Dec. 31, 2022 $ 126,654       $ 2,110       $ 504,767       $ (1,893) $ (378,330)
Increase (Decrease) in Stockholders' Equity [Roll Forward]                            
Rights Offering of common stock, net of offering costs / Private placement of common stock, net of offering costs / Proceeds from at-the-market offering, net of commissions and offering costs (in shares)           476,190,471 2,976,190              
Rights Offering of common stock, net of offering costs / Private placement of common stock, net of offering costs / Proceeds from at-the-market offering, net of commissions and offering costs   $ 499,381 $ 5,000     $ 4,762 $ 30     $ 494,619 $ 4,970      
Issuance of common stock under employee stock purchase plans and exercise of stock options and warrants (in shares)         596,472                  
Issuance of common stock under stock purchase plans and exercise of stock options and warrants 929       $ 7       922          
Issuance of common stock in lieu of cash for Akeso upfront payment (in shares)         10,000,000                  
Issuance of common stock in lieu of cash for Akeso upfront payment 45,900       $ 100       45,800          
Exercise of warrants (in shares) [1]         805,495                  
Exercise of warrants [1] 1,203       $ 8       1,195          
Stock-based compensation 14,108               14,108          
Net other comprehensive (loss) gain (555)                       (555)  
Net loss (614,928)                         (614,928)
Ending balance (in shares) at Dec. 31, 2023         701,660,053                  
Ending balance at Dec. 31, 2023 77,692       $ 7,017       1,066,381       (2,448) (993,258)
Increase (Decrease) in Stockholders' Equity [Roll Forward]                            
Rights Offering of common stock, net of offering costs / Private placement of common stock, net of offering costs / Proceeds from at-the-market offering, net of commissions and offering costs (in shares)             32,574,640 [1] 1,807,093            
Rights Offering of common stock, net of offering costs / Private placement of common stock, net of offering costs / Proceeds from at-the-market offering, net of commissions and offering costs     434,860 [1] $ 43,033     $ 326 [1] $ 18     434,534 [1] $ 43,015    
Issuance of common stock under employee stock purchase plans and exercise of stock options and warrants (in shares)         1,584,218                  
Issuance of common stock under stock purchase plans and exercise of stock options and warrants 3,334       $ 15       3,319          
Stock-based compensation 50,981               50,981          
Net other comprehensive (loss) gain 163                       163  
Net loss $ (221,315)                         (221,315)
Ending balance (in shares) at Dec. 31, 2024 737,626,004       737,626,004                  
Ending balance at Dec. 31, 2024 $ 388,748       $ 7,376       1,598,230       (2,285) (1,214,573)
Increase (Decrease) in Stockholders' Equity [Roll Forward]                            
Rights Offering of common stock, net of offering costs / Private placement of common stock, net of offering costs / Proceeds from at-the-market offering, net of commissions and offering costs (in shares)             26,682,846 [1] 5,339,339            
Rights Offering of common stock, net of offering costs / Private placement of common stock, net of offering costs / Proceeds from at-the-market offering, net of commissions and offering costs     $ 500,037 [1] $ 104,528     $ 267 [1] $ 53     $ 499,770 [1] $ 104,475    
Issuance of common stock under employee stock purchase plans and exercise of stock options and warrants (in shares)         5,723,011                  
Issuance of common stock under stock purchase plans and exercise of stock options and warrants 12,968       $ 58       12,910          
Stock-based compensation 732,420               732,420          
Net other comprehensive (loss) gain (255)                       (255)  
Net loss $ (1,079,586)                         (1,079,586)
Ending balance (in shares) at Dec. 31, 2025 775,371,200       775,371,200                  
Ending balance at Dec. 31, 2025 $ 658,860       $ 7,754       $ 2,947,805       $ (2,540) $ (2,294,159)
[1] Refer to Note 13 – Stockholders’ Equity for related party transactions.
v3.25.4
Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Rights Offering      
Adjustments to additional paid in capital, stock issued, issuance costs [1]     $ 619
Private placement      
Adjustments to additional paid in capital, stock issued, issuance costs [1]   $ 140  
At Market Offering      
Adjustments to additional paid in capital, stock issued, issuance costs $ 1,969 $ 1,190  
[1] Refer to Note 13 – Stockholders’ Equity for related party transactions.
v3.25.4
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Cash flows used in operating activities:      
Net loss $ (1,079,586) $ (221,315) $ (614,928)
Adjustments to reconcile net loss to net cash used in operating activities:      
Non-cash interest expense 0 0 6,253
Amortization of discount on short-term investments (7,006) (2,576) (1,924)
Unrealized foreign exchange loss (gain) (320) 229 (812)
Reclassification of currency translation gain 0 0 (419)
Impairment of fixed assets 0 0 474
Depreciation 146 89 198
Stock-based compensation 732,420 50,981 14,108
Loss on disposal of assets 0 0 (109)
Acquired in-process research and development expense 0 15,007 520,915
Changes in operating assets and liabilities:      
Prepaid expenses and other current assets 4,866 (7,370) 3,613
Other assets (4,875) 2,470 (3,421)
Accounts payable 15,303 2,015 2,263
Accrued liabilities and other current liabilities 12,930 11,879 (2,377)
Accrued compensation 2,909 6,557 (235)
Other long-term liabilities 80 95 0
Operating lease right-of-use assets and lease liabilities, net 203 (167) (359)
Net cash used in operating activities (322,930) (142,106) (76,760)
Cash flows used in investing activities:      
Maturities and sales of short-term investments 311,340 489,837 208,165
Purchase of short-term investments (484,993) (680,032) (321,022)
Purchase of property and equipment (657) (139) (128)
Proceeds from sale of property, plant and equipment 0 0 226
Payments to Akeso for upfront milestone payments and associated direct transaction costs 0 (15,007) (475,015)
Net cash used in investing activities (174,310) (205,341) (587,774)
Cash flows provided by financing activities:      
Proceeds from the issuance of common stock via private placements, net of offering costs [1] 500,037 434,860 5,000
Proceeds from exercise of warrants [1] 7,315 598 1,203
Proceeds received related to employee stock purchase plan and exercise of stock options 5,653 2,736 929
Transaction costs from the issuance of common stock for rights offering 0 0 (619)
Re-payment of related party promissory notes 0 (100,000) (24,686)
Net cash provided by financing activities 617,533 381,227 86,513
Effect of exchange rates on cash and cash equivalents 102 (18) 839
Increase (decrease) in cash, cash equivalents and restricted cash 120,395 33,762 (577,182)
Cash, cash equivalents and restricted cash at beginning of period 105,187 71,425 648,607
Cash, cash equivalents and restricted cash at end of period 225,582 105,187 71,425
Supplemental Disclosure of Cash Flow Information:      
Cash paid for interest on related party promissory note 0 8,806 10,650
Cash paid for income taxes 0 0 52
Supplemental Disclosure of Non-Cash Investing and Financing Activities:      
Leased assets obtained in exchange for operating lease liabilities 17,056 4,216 4,245
Unpaid amounts related to purchase of property, plant and equipment 291 0 0
At Market Offering      
Cash flows provided by financing activities:      
Proceeds from issuance of common stock 104,528 43,033 0
Rights Offering      
Cash flows provided by financing activities:      
Proceeds from issuance of common stock [1] 0 0 104,686
Supplemental Disclosure of Non-Cash Investing and Financing Activities:      
Issuance of common stock 0 0 395,314
Akeso License Agreement      
Supplemental Disclosure of Non-Cash Investing and Financing Activities:      
Issuance of common stock $ 0 $ 0 $ 45,900
[1] Refer to Note 13 – Stockholders’ Equity for related party transactions.
v3.25.4
Organization
 12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Organization Organization
Summit Therapeutics Inc. (“we”, “Summit” or the “Company”) is a biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. The Company’s pipeline of product candidates is designed with the goal to become the patient-friendly, new-era standard-of-care medicines, in the therapeutic area of oncology.

The Company’s current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into the License Agreement with Akeso, Inc. and its affiliates (collectively, “Akeso”) pursuant to which the Company has in-licensed intellectual property rights related to ivonescimab (as amended, the “License Agreement”), as further described in Note 4. Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan. The License Agreement and transaction closed in January 2023 following customary waiting periods. On June 3, 2024, the Company entered into an amendment to the License Agreement (the “Second Amendment”) with Akeso to expand its territories covered under the License Agreement to also include Latin America, including Mexico and all countries in Central America and South America, the Middle East and Africa (collectively, and as expanded, the “Licensed Territory“) . The Company’s operations are focused on the development of ivonescimab and other future activities, as the Company determines.

Basis of Presentation

The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). Certain reclassifications have been made to the prior years’ financial statements to conform to current year presentation.

Use of Estimates

The preparation of these financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of income and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments, including those related to accrued research and development expenses, stock-based compensation, and income taxes. Management bases its estimates and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.

Liquidity and Capital Resources

During the year ended December 31, 2025, the Company incurred a net loss of $1,079,586 and cash used in operating activities was $322,930. As of December 31, 2025, the Company had an accumulated deficit of $2,294,159, and cash and cash equivalents of $225,266 and short-term investments of $488,182. The Company expects to continue to generate operating losses for the foreseeable future.

During the year ended December 31, 2025, the Company raised gross proceeds of $500,037 from a private placement and $106,498 from the Company’s at-the-market sales agreement, both described further in Note 13. With these recent financings, the Company has evaluated and concluded that its cash, cash equivalents and short-term investments provide sufficient cash to fund its operating cash needs for at least the next 12 months from the date of issuance of these consolidated financial statements.

Until the Company can generate substantial revenue and achieve profitability, the Company will need to raise additional capital to fund its ongoing operations and capital needs. The Company continues to evaluate options to further finance its operating
cash needs for its product candidates through a combination of some, or all, of the following: equity and debt offerings, collaborations, strategic alliances, grants and clinical trial support from government entities, philanthropic, non-government and not-for-profit organizations, and marketing, distribution or licensing arrangements. There is no assurance, however, that additional financing will be available when needed or that management of the Company will be able to obtain financing on terms acceptable to the Company. If the Company is unable to obtain funding when required in the future, the Company could be required to delay, reduce, or eliminate research and development programs, product portfolio expansion, or future commercialization efforts, which could adversely affect its business prospects.
v3.25.4
Summary of Significant Accounting Policies and Recent Accounting Pronouncements
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies and Recent Accounting Pronouncements Summary of Significant Accounting Policies and Recent Accounting Pronouncements
The significant accounting policies adopted by the Company in the preparation of these consolidated financial statements are set out below. These policies have been consistently applied to all the years presented, unless otherwise stated.

Principles of Consolidation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. GAAP and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. The consolidated financial statements reflect the accounts of Summit Therapeutics Inc. and its wholly owned subsidiaries. Intercompany balances and transactions are eliminated in consolidation.

Foreign Currency Translation

The financial statements of the Company’s subsidiaries with functional currencies other than the U.S. dollar are translated into U.S. dollars using period-end exchange rates for assets and liabilities, historical exchange rates for stockholders’ equity and weighted average exchange rates for operating results. Translation gains and losses are included in accumulated other comprehensive (loss) income in stockholders’ equity. Foreign currency transaction gains and losses are included in other income, net in the consolidated statements of operations and comprehensive loss. The Company recorded realized and unrealized foreign currency transaction (loss) gain of ($610), $(97) and $613 for the years ended December 31, 2025, 2024 and 2023, respectively, which is included in other income, net in the consolidated statements of operations and comprehensive loss.

Net Loss Per Share

Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period. Diluted net loss per share is computed by dividing the diluted net loss by the weighted-average number of common shares outstanding for the period, including potentially dilutive common shares. The dilutive effect of share options and warrants are determined under the treasury stock method using the average market price for the period. In addition, the assumed proceeds under the treasury stock method include the average unrecognized compensation expense of stock options and warrants that are in-the-money.

Goodwill

Goodwill represents the excess of the consideration transferred over the fair value of net assets acquired. Goodwill is assigned to reporting units at the time of acquisition or when there is a change in the reporting structure and bases that allocation on which reporting units will benefit from the acquired assets and liabilities. Reporting units are defined as operating segments or one level below an operating segment, referred to as a component. Typically acquisitions related to a single reporting unit do not require the allocation of goodwill to multiple reporting units. If the net assets obtained in an acquisition are assigned to multiple reporting units, the goodwill is distributed to the respective reporting units as part of the purchase price allocation process.

The Company assesses goodwill for impairment on an annual basis as of December 31 or more frequently when events and circumstances occur indicating that the recorded goodwill may be impaired. The Company regularly monitors current business conditions and other factors including, but not limited to, adverse industry or economic trends and lower projections of
profitability that may impact future operating results. The process of evaluating the potential impairment of goodwill requires significant judgment. In performing the Company’s annual goodwill impairment test, the Company is permitted to first assess qualitative factors to determine whether it is more likely than not that the fair value of the Company’s reporting unit is less than its carrying amount, including goodwill. In performing the qualitative assessment, the Company considers certain events and circumstances specific to the reporting unit and to the entity as a whole, such as macroeconomic conditions, industry and market considerations, overall financial performance and cost factors when evaluating whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount. The Company is also permitted to bypass the qualitative assessment and proceed directly to the quantitative test. If the Company chooses to undertake the qualitative assessment and concludes that it is more likely than not that the fair value of the reporting unit is less than its carrying amount, the Company would then proceed to the quantitative impairment test. In the quantitative assessment, the Company compares the fair value of the reporting unit to its carrying amount, which includes goodwill. If the fair value exceeds the carrying value, no impairment loss exists. If the fair value is less than the carrying amount, a goodwill impairment loss is measured and recorded.

Leases

The Company has operating leases for real estate. The Company does not have any finance leases. A contract is or contains a lease when the lessee has the right to control the use of an identified asset. The Company determines if an arrangement is a lease at inception of the contract, which is the date on which the terms of the contract are agreed to and the agreement creates enforceable rights and obligations. The lease term used to calculate the lease liability include options to extend or terminate the lease when it is reasonably certain that the option will be exercised.

At the lease commencement date, the Company measures and recognizes a lease liability and a right-of-use asset in the financial statements. Lease liabilities are recognized based on the present value of the future lease payments over the lease term at commencement date. The right-of use asset is measured by taking the present value of future lease payments, plus any incremental direct costs incurred, less any lease incentives received. As most of the Company’s leases do not provide an implicit rate, the Company uses an estimated incremental borrowing rate based on the lease term and the economic environment of the lease at the lease commencement date, which is then utilized to determine the present value of future lease payments. Lease expense for minimum lease payments are recognized on a straight-line basis over the lease term, with variable lease payments recognized in the periods in which they are incurred.

The Company has existing lease agreements with lease and non-lease components, has elected to account for the lease and non-lease components as a single lease component, and has allocated all of the contract consideration to the lease component only.

Leases with an initial lease term of 12 months or less are not recorded on the balance sheet. The Company recognizes lease expense for its short-term leases on a straight-line basis over the lease term.

Acquired In-Process Research and Development

The Company may enter into agreements with collaboration partners for the development and commercialization of its products. These arrangements may include payments contingent on the occurrence of certain events such as development, regulatory or sales-based milestones. The Company considers the unique nature, terms and facts and circumstances of each transaction. The Company considers whether or not the assets acquired have an alternative future use.

The fair value associated with acquired in-process research and development which does not have an alternative future use is expensed and is recorded as research and development expense. Any development or commercial milestone payments are recognized when the achievement of the associated milestone becomes probable and will either be expensed or capitalized depending upon whether or not regulatory approval has been obtained.

Research and Development Costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred to discover, research and develop product candidates, including personnel expenses, stock-based compensation expense, allocated facility-related and depreciation expenses, third-party license fees and external costs of outside vendors engaged to conduct preclinical and clinical development activities and clinical trials as well as to manufacture clinical trial materials. Non-
refundable prepayments for goods or services that will be used or rendered for future research and development activities are recorded as prepaid expenses. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered. Milestone and other payments made to third-parties with respect to in-process research and development, in accordance with the Company’s license, acquisition and other similar agreements are expensed when determined to be probable and estimable.

The Company has entered into various research and development contracts with other companies. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs or prepaid expenses where the payments made exceed the estimated costs. These amounts are determined based on the estimated costs to complete each study or activity, the estimation of the current stage of completion and the invoices received, as well as predetermined milestones which are not reflective of the current stage of development for prepaid expenses. Actual results could differ from the Company’s estimates. In all cases, the full cost of each study or activity is expensed by the time the final report or where applicable, product, has been received. The Company’s historical estimates have not been materially different from the actual costs.

Stock-Based Compensation

The Company measures and recognizes compensation expense for all stock option awards based on the estimated fair value of the award on the grant date. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock option awards. Additionally, the Company uses a Monte Carlo simulation model to calculate the estimated fair value on the date of grant related to awards with market-based service conditions. The fair value is recognized as expense, over the requisite service period, which is generally the vesting period of the respective award, on a straight-line basis for each separately vesting portion of the award when the only condition to vesting is continued service. If vesting is subject to a market or performance condition, recognition is based on the derived service period of the award. Expense for awards with performance conditions is estimated and adjusted on a quarterly basis based upon the assessment of the probability that the performance condition will be met. Use of the Black-Scholes option-pricing model requires management to apply judgment under subjective assumptions. These assumptions include:
•Expected term—The expected term of stock options represents the weighted-average period the stock options are expected to be outstanding. The Company uses the simplified method for estimating the expected term as provided by the SEC. The simplified method calculates the expected term as the average of the time-to-vesting and the contractual life of the options.
•Expected volatility—The expected volatility is calculated based on historical volatility of the Company’s share price.
•Risk-free interest rate—The risk-free rate assumption is based on the U.S. Treasury instruments, the terms of which were consistent with the expected term of the Company’s stock options.
•Expected dividend—The expected dividend assumption is based on the Company’s history and expectation of dividend payouts. The Company has not paid and does not intend to pay dividends.

The Company uses a Monte Carlo simulation model to estimate the fair value of Performance and Market-based Stock Options at the date of grant which utilizes multiple input variables to estimate the probability that the market condition will be achieved. Key assumptions used in the model include the risk-free interest rate, which reflects the US Treasury Constant Maturity Yield with a term commensurate with the contractual term of the award, and stock price volatility, which is derived based on the historical volatility of the Company’s stock.

The Company estimates expected forfeitures at the time of grant instead of accounting for forfeitures as they occur. Stock option awards have been granted at fair value to non-employees in connection with research and consulting services provided to the Company. Equity awards generally vest over terms of 3 or 4 years.

The Company classifies stock-based compensation expense in the consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified.

Income Taxes

The provision for income taxes is determined using the asset and liability approach. Tax laws may require items to be included in tax filings at different times than the items are reflected in the financial statements. A current asset or liability is recognized
for the estimated taxes receivable or payable for the current year. Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. Deferred taxes are initially recognized at enacted tax rates in force at the time of initial recognition and are subsequently adjusted for any enacted changes in tax rates and tax laws. Subsequent changes to deferred taxes originally recognized in equity are recognized in income. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized. The Company has recorded a full valuation allowance against the deferred tax assets in excess of its deferred tax liabilities, as the deferred tax liabilities represent future reversals of existing taxable temporary differences. The Company records interest and penalties related to income tax matters as part of income tax expense.

Concentration of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash and short-term investments. The Company’s cash is comprised of short-term cash deposits at a variety of financial institutions which the Company believes are of high credit ratings in amounts that may exceed federally insured limits. The Company has not experienced any losses on such accounts. Cash balances maintained during the year have been principally held with U.S.-based and U.K.-based banks. The Company does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships.

The Company relies, and expects to continue to rely, on a number of vendors to conduct its clinical trials and preclinical studies, manufacture drug product and supply clinical trial and preclinical study materials for its development programs. These programs could be adversely affected by a significant interruption in these services or the availability of materials.

Fair Value Measurements

In accordance with the provisions of fair value accounting, a fair value measurement assumes that the transaction to sell an asset or transfer a liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability and defines fair value based on the exit price model.

The fair value measurement guidance establishes a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance describes three levels of inputs that may be used to measure fair value:

Level 1
Quoted prices in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2
Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 assets and liabilities include debt securities with quoted prices that are traded less frequently than exchange-traded instruments or securities or derivative contracts that are valued using a pricing model with inputs that are observable in the market or can be derived principally from or corroborated by observable market data.

Level 3
Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation.

In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the Company categorizes such assets and liabilities based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset.
Cash and Cash Equivalents

The Company considers only those investments that are highly liquid, readily convertible to cash and that mature within 90 days or less from date of purchase to be cash equivalents. As of December 31, 2025, cash equivalents were comprised of money market funds and U.S. treasury securities. As of December 31, 2024, cash equivalents were comprised of money market funds.

Restricted Cash

Restricted cash represents amounts which are legally restricted to withdrawal or usage and is presented in the consolidated balance sheet as restricted cash. As of December 31, 2025 the Company has $316 of restricted cash associated with an irrevocable letter of credit required by the landlord to enter into the lease for Company’s corporate office.

The Company’s total cash, cash equivalents and restricted cash balances were as follows:
Year Ended December 31,
202520242023
Cash and cash equivalents$225,266 $104,862 $71,425 
Restricted cash316 325 — 
Total cash, cash equivalents and restricted cash$225,582 $105,187 $71,425 

Short-term Investments

Short-term investments consist of marketable securities with original maturities greater than ninety days from the date of acquisition. The Company classifies marketable securities with original maturities of greater than 90 days and less than one year as short-term, based on the liquid nature of the marketable securities and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of marketable securities as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices or other observable inputs. Unrealized gains and losses are recorded as a component of other comprehensive income (loss). Realized gains and losses are determined on a specific identification basis and are included in other income, net. Amortization and accretion of discounts and premiums are also recorded in other income, net.

When the fair value is below the amortized cost of the asset, an estimate of expected credit losses is made. This estimate is limited to the amount by which fair value is less than amortized cost. The credit-related impairment amount is recognized in the consolidated statements of operations and comprehensive loss and the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in the consolidated statements of operations and comprehensive loss.
Recently Issued Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update “ASU” 2023-09, “Improvements to Income Tax Disclosures”, which requires disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 and allows for adoption on a prospective basis, with a retrospective option. Early adoption is permitted. The Company adopted ASU 2023-09 for the year ended December 31, 2025 using a retrospective approach. The adoption of ASU-2023-09 did not have a material impact on the Company’s consolidated financial statements and related disclosures.
In November 2024, the FASB issued ASU 2024-03, “Disaggregation of Income Statement Expenses”, which requires disclosures about specific types of expenses included in the expense captions presented on the face of the income statement as well as disclosures. The guidance is to be applied prospectively, with the option for retrospective application and is effective for public business entities for fiscal years beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s consolidated financial statements and related disclosures.

In December 2025, the FASB issued ASU 2025-11, “Narrow-Scope Improvements”, which is intended to improve the navigability of the guidance in ASC 270 and clarify when the guidance is applicable. ASU 2025-11 is effective for interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s consolidated financial statements and related disclosures.

Other recent authoritative guidance issued by the FASB (including technical corrections to the FASB ASC), the American Institute of Certified Public Accountants, and the SEC did not or are not expected to have a material impact on the Company’s consolidated financial statements and related disclosures.
v3.25.4
Segment Reporting
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Segment Reporting Segment Reporting
The Company’s chief operating decision makers (the “CODM function”), which are the Company’s Co-Chief Executive Officers, Mr. Duggan and Dr. Zanganeh, and Chief Operating Officer and Chief Financial Officer, Mr. Soni, utilize consolidated net loss that is reported on the consolidated statement of operations and comprehensive loss to make decisions about allocating resources and assessing performance for the entire Company. The CODM function approves of key operating and strategic decisions, including key decisions in clinical development and clinical operating activities, entering into significant contracts, such as revenue contracts and collaboration agreements and approves the Company’s consolidated operating budget. The CODM function views the Company's operations and manages its business on a consolidated basis and as a single reportable operating segment. The CODM function is regularly provided with the following significant segment expenses:

Year Ended December 31,
 202520242023
Oncology clinical trial related costs$266,439 $100,937 $35,224 
Acquired in-process research and development— 15,007 520,915 
Compensation related costs, excluding stock-based compensation75,575 48,295 31,371 
Stock-based compensation732,420 50,981 14,108 
Other expenses (1)
19,990 10,778 8,032 
Total segment expenses
1,094,424 225,998 609,650 
Other income, net14,838 13,369 11,183 
Interest expense— (8,686)(16,461)
Net loss$(1,079,586)$(221,315)$(614,928)

(1) Other expenses include general and administrative expenses excluding compensation and stock-based compensation.

As of December 31, 2025 and 2024, substantially all of our long-lived assets are located in the United States.
v3.25.4
Akeso License and Collaboration Agreement
 12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Akeso License and Collaboration Agreement Akeso License and Collaboration Agreement
On December 5, 2022, the Company entered into the License Agreement with Akeso pursuant to which the Company is in-licensing its breakthrough bispecific antibody, ivonescimab. The License Agreement and transaction closed in January 2023 following customary waiting periods.
Ivonescimab, known as AK112 in China and Australia, and also as SMT112 in the United States, Canada, Europe, and Japan, is a novel, potential first-in-class bispecific antibody intending to combine the effect of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF into a single molecule. Ivonescimab was engineered to bring two well established oncology targeted mechanisms together. Ivonescimab is currently in clinical development and, pursuant to the terms of the License Agreement, Summit will design and conduct the clinical trial activities to support regulatory filings in the Licensed Territory that Summit will submit.

Pursuant to the terms of the License Agreement, Summit will have final decision making authority with respect to clinical development strategy and execution in the Licensed Territory. For co-joined studies in which both Summit and Akeso participate, mutual agreement is required for material decisions; Summit retains the exclusive decision making with respect to participating in, and continuing its participation in, co-joined studies. Pursuant to the terms of the License Agreement, Summit will have final decision-making authority with respect to commercial strategy, pricing and reimbursement and other commercialization matters in the Licensed Territory. In connection with the License Agreement, the Company agreed to purchase a certain portion of drug substance and/or drug product for clinical and commercial supply and to enter into a supply agreement with Akeso. Summit is not assuming any liabilities (including contingent liabilities), acquiring any physical assets or trade names, or hiring or acquiring any employees from Akeso in connection with the License Agreement. Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan.

In exchange for the rights obtained, the Company made an upfront payment of $500,000 to Akeso, of which $274,900 was paid in cash and, pursuant to the License Agreement and Issuance Agreement, Akeso elected to receive 10,000,000 shares of the Company’s common stock, par value $0.01 per share (“common stock”) in lieu of $25,100 in cash. The remaining $200,000 amount of the upfront payment was paid on March 6, 2023.

Effective June 3, 2024, the Company and Akeso entered into the Second Amendment to the License Agreement to expand the Company’s territories covered under the License Agreement to include the Latin America, Middle East and Africa regions. Pursuant to the Second Amendment, the Company paid an upfront payment to Akeso of $15,000 in the third quarter of 2024. Akeso will also be eligible to receive up to an additional $55,000 upon the achievement of certain commercial milestones. Except as specifically modified by the Second Amendment, the terms and conditions of the License Agreement remain in full force and effect.

The Company has accounted for the License Agreement and Second Amendment to acquire the rights to develop and commercialize ivonescimab as the acquisition of an asset. All of the consideration relates to ivonescimab and technological feasibility of the asset has not yet been established since ivonescimab is in clinical development. As such, the Company has expensed the consideration as acquired in-process research and development upon closing of the transaction in the consolidated statement of operations and comprehensive loss. Acquired in-process research and development expense for the year ended December 31, 2025 was nil. Acquired in-process research and development expense for the year ended December 31, 2024, was $15,007 which is comprised of the upfront payment and immaterial transaction costs. For the year ended December 31, 2023, acquired in-process research and development expense totaled $520,915 pursuant to the License Agreement, which was comprised of the $474,900 paid in cash, the fair value of the 10,000,000 shares of common stock on the date of closing the transaction of $45,900, and $115 of direct transactions costs incurred.

In addition to the payments already made to Akeso, under the License Agreement and Second Amendment, there are additional potential milestone payments of up to $4,555,000, as Akeso will be eligible to receive regulatory milestones of up to $1,050,000 and commercial milestones of up to $3,505,000. In addition, Akeso will be eligible to receive low double-digit royalties on net sales.
v3.25.4
Other Income, Net
 12 Months Ended
Dec. 31, 2025
Other Income and Expenses [Abstract]  
Other Income, Net Other Income, Net
The following table sets forth the components of other income, net:
Year Ended December 31,
202520242023
Foreign currency (loss) gain$(610)$(97)$613 
Investment income (1)
15,501 13,466 10,403 
Reclassification of cumulative currency translation gain (2)
— — 419 
Other expense, net
(53)— (252)
$14,838 $13,369 $11,183 

(1) Investment income relates to the Company’s money market funds and short-term investments in U.S. treasury securities. Refer to Note 9 for details.

(2) The reclassification of cumulative currency translation gain related to the reclassification of cumulative foreign currency translation gains from accumulated other comprehensive loss due to the dissolution of certain dormant entities.
v3.25.4
Income Tax
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Income Tax Income Tax 
The Company is primarily subject to corporation taxes in the U.S. and the U.K. The calculation of the Company’s tax provision involves the application of both U.S. and U.K. tax law and requires judgment and estimates. The Company has also assessed the applicability of the OECD/G20 Inclusive Framework on Base Erosion and Profit Shifting (BEPS) Pillar 2 rules, which establish a global minimum tax rate. Based on the Company’s current financial position and revenue it does not meet the thresholds for Pillar 2 to apply. Therefore, the provisions and requirements under Pillar 2 do not impact our financial statements for the reporting period.

The provision for income taxes is determined using the asset and liability approach. Tax laws may require items to be included in tax filings at different times than the items are reflected in the financial statements. A current asset or liability is recognized for the estimated taxes receivable or payable for the current year.

Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. Deferred taxes are initially recognized at enacted tax rates in force at the time of initial recognition and are subsequently adjusted for any enacted changes in tax rates and tax laws. Subsequent changes to deferred taxes originally recognized in equity are recognized in income.

Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized. The Company has recorded a full valuation allowance against the deferred tax assets in excess of its deferred tax liabilities, as the deferred tax liabilities represent future reversals of existing taxable temporary differences. The Company records interest and penalties related to income tax matters as part of income tax expense.

Uncertain Tax Positions

The Company accounts for uncertain tax positions taken in its tax filings by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities having full knowledge of the facts and applicable tax rules. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed as the amount of benefit to recognize in the consolidated financial statements. The amount of benefits that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate, as well as the related net interest and penalties.

Due to the Company’s full valuation allowance, the unrecognized tax benefits are not expected to materially impact the Company’s effective tax rate when recognized or significantly increase or decrease in the next 12 months. In addition, the
Company’s policy is to recognize interest and penalties related to uncertain tax positions as part of its income tax provision. However, for the years ended December 31, 2025 and 2024, the Company had no interest or penalties related to unrecognized tax benefits because any potential disallowance would not result in current tax but only result in a reduction to the Company’s net operating loss carryforwards.

Loss Before Income Taxes

The components of the Company’s loss before income taxes are as follows:
Year Ended December 31,
202520242023
Foreign$(326,729)$(199,040)$(499,810)
United States(752,857)(22,275)(115,118)
Loss before income taxes$(1,079,586)$(221,315)$(614,928)

Deferred Income Taxes

The Company has not recognized a current or deferred provision for federal, state or non-United States income taxes in either of the years ending December 31, 2025 or December 31, 2024.

Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes.

The major components of deferred tax assets and liabilities are as follows:
Year Ended December 31,
20252024
Deferred tax assets:
Net operating loss carryforward$73,583 $59,413 
Research and development credit carryforward16,092 7,869 
Stock-based compensation32,158 14,001 
Section 174 Research and Development Capitalization11,034 14,167 
Other711 475 
Total deferred tax assets133,578 95,925 
Deferred tax liabilities:
Other(417)(337)
Total deferred tax liabilities(417)(337)
Net deferred tax assets before valuation allowance 133,16195,588
Valuation allowance(133,161)(95,588)
Deferred tax, net$— $— 

For the year ended December 31, 2025 and 2024, the Company recorded a deferred tax asset of $133,578 and $95,925, respectively.

The Company has evaluated the positive and negative evidence bearing upon its ability to realize its deferred tax assets, which are comprised primarily of net operating loss carryforwards, research and development credits, stock-based compensation expense, and research and development costs capitalized for tax purposes. Management has considered the Company’s history of cumulative net losses in each taxing jurisdiction, estimated future taxable income, as well as prudent and feasible tax planning strategies, and has concluded that it is more likely than not that the Company will not realize the tax benefits in each
jurisdiction. Accordingly, a full valuation allowance has been established against these net deferred tax assets as of December 31, 2025 and 2024, respectively. The Company reevaluates the positive and negative evidence at each reporting period.

The changes in the valuation allowance during the years ended December 31, 2025, 2024 and 2023 primarily related to net operating loss carryforwards and capitalized research and development expenses.

The change in the valuation allowance was as follows:
Year Ended December 31,
202520242023
Valuation allowance as of beginning of year$(95,588)$(84,751)$(64,016)
Net increases recorded to income tax provision(37,573)(10,837)(20,735)
Valuation allowance as of end of year$(133,161)$(95,588)$(84,751)

Net Operating Loss and Tax Credit Carryforwards

As of December 31, 2025 and 2024, the Company had U.S. Federal gross operating loss carryforwards of approximately $93,210 and $44,270, respectively, which may be available to offset future income tax liabilities. The 2017 Tax Cuts and Jobs Act (“TCJA”) will generally allow losses incurred after 2017 to be carried over indefinitely but generally limits the net operating loss deduction to the lesser of the net operating loss carryover or 80% of a corporation’s taxable income (subject to Section 382 of the Internal Revenue Code of 1986, as amended). In addition, the Company has approximately $21,335 in U.S. State gross loss carryforwards which expire through various dates through 2044.

As of December 31, 2025, the Company had an estimated U.S. federal and state research and development tax credit carryforwards of $15,565 and $5,002, respectively, which may be available to offset future tax liabilities, and each begin to expire in 2041 and 2037, respectively.

As of December 31, 2025 and 2024, the Company had U.K. gross operating loss carryforwards of approximately $211,096 and $198,653 respectively, which may be available to offset future income tax liabilities. To the extent that U.K. taxable profits exceed £5,000 in each year, the loss available to utilize against profits in excess of £5,000 will be restricted to 50%. The U.K. loss carryforwards do not lapse and therefore, the full amount will be relieved over time provided there are sufficient profits against which the losses can be utilized.

Utilization of the U.S. net operating loss carryforwards and research and development tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50% over a three-year period. The Company has not completed a study to assess whether a change of ownership has occurred, or whether there have been multiple ownership changes since its formation. Any limitation may result in the loss of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization.

U.K. tax losses are subject to additional restrictions where there is a change in ownership in the business and certain other conditions are met. An ownership change of a U.K. tax resident company would occur where (directly or indirectly) a single person acquires more than half of the ordinary share capital of a company, or two or more persons each acquire a holding of at least 5% of the ordinary share capital of a company and these holdings together amount to more than half the ordinary share capital of a company. Where a change in ownership has occurred, and within three years prior to that change in ownership and five years afterwards, there is a major change in the nature and conduct of trade of that company or the trade of that business becomes small or negligible, any losses carried forward will be extinguished from the point of the change in ownership. In addition, losses accrued subsequent to April 1, 2017 will be extinguished on a change of ownership when there is a major change in the nature or conduct of a company’s business, or where there is a major change in the scale of that business, or a company ceases to carry on a particular trade or business. The Company has not completed a study to assess whether a change of ownership has occurred since its formation, or whether there has been a major change in the Company’s business that would
restrict the U.K. tax losses. Any limitation may result in the loss of a portion of the net operating loss carryforwards before utilization.

Deemed U.S. Income Inclusions

The TCJA created a requirement that US corporations include in income earnings of certain controlled foreign corporations under the global intangible low taxed income (“GILTI”) regime. Pursuant to the FASB Staff Q&A, Topic 740 No.5. Accounting for Global Intangible Low-taxed Income, the Company is allowed to make an accounting policy election to either 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 period expense only. The Company has elected to account for GILTI in the year the tax is incurred and include the current tax impact of GILTI in the effective tax rate. Given the Company’s loss position in the U.S. and the valuation allowance recorded against its U.S. net deferred tax assets, these provisions have not had a material impact on the Company’s consolidated financial statements.

Annual Effective Tax Rate Reconciliation

A reconciliation of the Company’s effective tax rate to the U.S. federal statutory rate is as follows:
Year Ended December 31,
202520242023
Tax at federal statutory rate(226,702)21.0 %(46,476)21.0 %(129,048)21.0 %
State income tax, net of federal tax benefit—— %(17)— %—— %
Research and development credits(6,828)0.6 %(4,782)2.2 %(2,275)0.4 %
Nontaxable or nondeductible Items
Stock-based compensation134,033(12.4)%(130)0.1 %2,978(0.5)%
Other299— %77— %521(0.1)%
Foreign Tax Effects
Cayman Islands Statutory income tax rate differential
67,969(6.3)%41,570(18.8)%104,282(17.0)%
Other foreign jurisdictions644(0.1)%229(0.1)%678(0.1)%
Changes in unrecognized tax benefits1,357(0.1)%956(0.4)%800(0.1)%
Change in valuation allowance29,228(2.7)%8,573(4.0)%22,064(3.6)%
Total
$— — %$— — %$— — %

Unrecognized Tax Benefit Reconciliation

The Company records unrecognized tax benefits in accordance with ASC 740-10, Income Taxes. ASC 740-10 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of uncertain tax positions taken or expected to be taken in the Company’s income tax return and also provides guidance on de-recognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition. As of December 31, 2025, 2024, and 2023, the Company had total unrecognized tax benefits of $3,903, $2,122, and $1,064, respectively.

A reconciliation of unrecognized tax benefits from continuing operations is as follows:
Year Ended December 31,
202520242023
Unrecognized tax benefits, beginning of year$2,122 $1,064 $— 
Increases related to prior year tax positions592 122 610 
Increases related to current year tax positions1,189 936 454 
Unrecognized tax benefits, end of year$3,903 $2,122 $1,064 
Audit Examinations

In the U.S., the Company files a Federal consolidated income tax return and income tax returns in various states. In the U.S., the filings for tax years from 2020 remain subject to examination by the U.S. Internal Revenue Service and state tax authorities. The Company is not currently under examination by the Internal Revenue Service or any other jurisdiction for years 2020 through present. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may be adjusted upon examination by the Internal Revenue Service or state tax authorities to the extent utilized in a future period. In the U.K., tax returns for the year ended December 31, 2023 remains subject to examination by HMRC.

Legislative Impacts

On July 4, 2025, H.R. 1, a U.S. budget reconciliation bill, was signed into law. The Company has assessed the provisions of the new legislation and has integrated the resulting impacts into its effective income tax rate. Management has concluded that the bill does not have an impact on the Company's consolidated financial statements for the current period.
v3.25.4
Net Loss per Share
 12 Months Ended
Dec. 31, 2025
Earnings Per Share [Abstract]  
Net Loss per Share Net Loss per Share
The following table sets forth the computation of basic and diluted net loss per share:
Year Ended December 31,
202520242023
Net loss$(1,079,586)$(221,315)$(614,928)
Basic and diluted weighted average number of shares of common stock outstanding747,702,265 718,541,896 619,646,180 
Basic net loss per share$(1.44)$(0.31)$(0.99)
Diluted net loss per share$(1.44)$(0.31)$(0.99)

Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period. Diluted net loss per share is computed by dividing the diluted net loss by the weighted-average number of common shares outstanding for the period, including potentially dilutive common shares. Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods, as the inclusion of all potential common share equivalents outstanding would have been antidilutive.

Because the 2023 Rights Offering (see Note 13) exercise price of $1.05 per share was less than the closing price of $1.82 per share on March 1, 2023, the expiration, the Company has retroactively adjusted earnings per share and the weighted average number of shares outstanding for the bonus element for the year ended December 31, 2023.

The following potentially dilutive securities were excluded from the computation of the diluted net loss per share of common stock for the periods presented because their effect would have been anti-dilutive:
Year Ended December 31,
202520242023
Options to purchase common stock115,614,72868,920,33454,209,289
Warrants—4,629,9885,015,642
Shares expected to be purchased under employee stock purchase plan65,90586,550155,163
Total
115,680,63373,636,87259,380,094

Stock options that are outstanding and contain improbable vesting criteria are excluded from the presentation of common stock equivalents outstanding in the table above.
v3.25.4
Goodwill
 12 Months Ended
Dec. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill Goodwill
In December 2017, the Company expanded its activities in the field of infectious diseases with the acquisition of Discuva Limited, a privately held United Kingdom-based company. Through this acquisition, the Company obtained a bacterial genetics platform and a suite of software-based technologies, which facilitates the discovery and development of new mechanism antibiotics. This resulted in the recognition of goodwill of £1.5 million, which is translated into U.S. dollars at each reporting period.

As of December 31, 2025 and 2024, goodwill was $2,001 and $1,864, respectively. Changes year over year are the result of changes in foreign currency.

The Company assesses goodwill for impairment on an annual basis as of December 31 or more frequently when events and circumstances occur indicating that recorded goodwill may be impaired. As of December 31, 2025, the Company performed its annual impairment assessment of goodwill and determined that it is more likely than not that the fair value of the reporting unit exceeds its carrying amount. The Company has recorded no goodwill impairment charges to date.
v3.25.4
Fair Value Measurements and Short-Term Investments
 12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Fair Value Measurements and Short-Term Investments Fair Value Measurements and Short-Term Investments
The following tables sets forth the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2025 and 2024:
December 31, 2025
Fair Value Hierarchy LevelAmortized CostUnrealized GainUnrealized (Loss)Credit (Loss)Fair Value
Financial assets included within cash and cash equivalents:
Money market fundsLevel 1$163,588 $— $— $— $163,588 
U.S. Government treasury billsLevel 245,300 12 — — 45,312 
Financial assets included within short-term investments:
Certificate of deposit
Level 225,000 — — — 25,000 
U.S. Government treasury billsLevel 2463,022 160 — — 463,182 
Total$696,910 $172 $— $— $697,082 

December 31, 2024
Fair Value Hierarchy LevelAmortized CostUnrealized GainUnrealized (Loss)Credit (Loss)Fair Value
Financial assets included within cash and cash equivalents:
Money market fundsLevel 1$88,599 $— $— $— $88,599 
Financial assets included within short-term investments:
U.S. Government treasury billsLevel 2307,387 100 — — 307,487 
Total$395,986 $100 $— $— $396,086 

The tables above do not include cash at December 31, 2025 and 2024 of $16,366 and $16,263, respectively.

The Company believes that the carrying amounts of prepaid expenses, other current assets, accounts payable, and accrued expenses approximates their fair values due to the short-term nature of those instruments.
Realized gain (loss) on short-term investments for the years ended December 31, 2025 and 2024 were immaterial, respectively.
v3.25.4
Research and Development Prepaid Expenses and Accrued Liabilities
 12 Months Ended
Dec. 31, 2025
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]  
Research and Development Prepaid Expenses and Accrued Liabilities Research and Development Prepaid Expenses and Accrued Liabilities
Included within prepaid expenses and other current assets at December 31, 2025 and 2024 is $3,996 and $8,338, respectively, of prepayments relating to research and development expenditures. Included within accrued liabilities at December 31, 2025 and 2024 is $31,498 and $17,441, respectively, relating to research and development expenditures.

These amounts are determined based on the estimated costs to complete each study or activity related to the ongoing clinical trials for ivonescimab, the estimation of the current stage of completion and the invoices received, as well as predetermined milestones which are not reflective of the current stage of development for prepaid expenses. However, accrued liabilities increase as the activities progress. The key sensitivity is the estimated current stage of completion of each study or activity, which is based on information received from the supplier and the Company’s operational knowledge of the work completed under those contracts.
v3.25.4
Leases
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Leases Leases
The Company has operating leases for real estate. The Company does not have any finance leases.

The Company leases its offices and facilities in Miami, FL, Palo Alto, CA, Princeton, NJ, Oxford, U.K., and Menlo Park, CA under non-cancellable operating lease agreements. The lease agreements for the Company’s offices and facilities in Miami, FL, Palo Alto, CA, Princeton, NJ and Oxford, U.K., expire in April 2029, October 2033, August 2028, and February 2027, respectively. The remaining lease agreement for the Company’s office and facility in Menlo Park, CA expires in May 2026. Under the terms of the lease agreements, the Company is responsible for certain repair and maintenance, utilities, licensing and permit fees.

During the year ended December 31, 2025, the Company recorded $17,056 of operating right-of-use assets and operating lease liabilities related to new leases for office space for its Palo Alto, CA and Princeton, NJ locations. Total future lease payments as of December 31, 2025 are approximately $23,117 on an undiscounted basis. The Palo Alto lease commenced on December 1, 2025 and has a term of approximately 8 years. The Princeton, NJ lease commenced on August 18, 2025 and has a term of 3 years. The Company recorded $4,216 of right-of-use assets during the year ended December 31, 2024 related to its Miami, Florida headquarters.

The carrying value of the right-of-use assets as of December 31, 2025 and 2024 is $20,616 and $7,144, respectively.

The elements of lease expense were as follows:
Year Ended December 31,
202520242023
    Fixed lease costs$3,853 $3,461 $2,214 
    Variable lease costs225 48 83 
Total lease cost$4,078 $3,509 $2,297 

The weighted average discount rate and the weighted average remaining lease term were 7.6% and 6.7 years, respectively, as of December 31, 2025. The weighted average discount rate and the weighted average remaining lease term were 6.9% and 2.8 years, respectively, as of December 31, 2024. The Company made cash payments related to lease liabilities of $3,741 and $2,568 for the years ended December 31, 2025 and 2024, respectively.
Future lease payments under non-cancelable leases as of December 31, 2025 are detailed as follows:
Year Ending December 31,
2026$3,492 
20274,052 
20284,158 
20293,349 
20303,073 
Thereafter9,205 
Total lease payments27,328 
Less: imputed interest6,438 
Total operating lease liabilities$20,890 
Less: Operating lease liabilities, current portion3,388 
Operating lease liabilities, net of current portion$17,502 
v3.25.4
Promissory Note Payable to Related Parties
 12 Months Ended
Dec. 31, 2025
Related Party Transactions [Abstract]  
Promissory Note Payable to Related Parties Promissory Note Payable to Related Parties
December 2022 Promissory Notes

On December 6, 2022, the Company entered into a Note Purchase Agreement (the “Note Purchase Agreement”), with Mr. Duggan and Dr. Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. Pursuant to the Note Purchase Agreement, the Company issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400,000 (the “Duggan February Note”) and $20,000 (the “Zanganeh Note”), respectively, which matured and became due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100,000 (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which was originally due on September 15, 2023. The maturity dates of the December 2022 Notes could have been extended one or more times at the Company’s election, but in no event to a date later than September 6, 2024. In addition, if the Company consummated a public offering, then upon the later to occur of (i) five business days after the Company receives the net cash proceeds therefrom or (ii) May 15, 2023, the Duggan February Note and the Zanganeh Note were to be prepaid by an amount equal to the lesser of (a) 100% of the amount of the net proceeds of such offering and (b) the outstanding principal amount on such Notes.

On January 19, 2023, the Company provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024. Furthermore, on January 19, 2023, the Company and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that the Company may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by Summit in the approximate amount of $500,000, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the rights offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) Duggan September Note following the completion of a capital raising transaction subsequent to the rights offering in an amount equal to the lesser of (A) the net proceeds of such capital raise or (B) the full amount outstanding of the Duggan September Note. Following the issuance of the two new Promissory Notes (the “Revised Duggan February Note” and the “Revised Duggan September Note”, respectively), the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Revised Duggan February Note and the Revised Duggan September Note (together with the Zanganeh Note, the “Notes”).

On February 15, 2023, the $20,000 Zanganeh Note matured and the Company repaid the outstanding principal balance. In connection with the closing of the rights offering in 2023 (the “2023 Rights Offering”), the $400,000 Revised Duggan February Note matured and became due, and the Company repaid all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price of shares subscribed by Mr. Duggan in the 2023 Rights Offering.
The Notes accrued interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the period through February 15, 2023. Such prepaid interest was paid in a number of shares of the Company’s common stock equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time the Company entered into the Note Purchase Agreement, plus $0.01), which was 9,720,291 shares. For all applicable periods following February 15, 2023, interest accrued on the outstanding principal balance of the Notes at the U.S. prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the U.S. prime rate plus 300 basis points, as adjusted monthly. Accrued interest was paid in cash, quarterly in arrears, on each of March 31, June 30, September 30 and December 31. Debt issuance costs associated with the Notes were $44 and were capitalized as part of the carrying value of the promissory notes payable to related parties.

On February 17, 2024, the Revised Duggan February Note was amended to extend the maturity date from September 6, 2024 to April 1, 2025. For all applicable periods commencing February 17, 2024, interest accrued on the outstanding principal balance at the greater of 12% or the U.S. prime interest rate, as reported in the Wall Street Journal plus 350 basis points, as adjusted monthly, and compounded quarterly. Interest was paid upon maturity of the loan. The debt discount was amortized to interest expense using an effective interest rate method. The effective interest rate of the Revised Duggan February Note and Zanganeh Note was 8.9% and the effective interest rate of the Revised Duggan September Note was 11.3%.

On September 16, 2024, the Company used some of the proceeds raised from the September 2024 Private Placement (see Note 13 for further details) to repay $75,500 in principal on the Revised Duggan September Note. On October 1, 2024, the Company repaid the remaining outstanding balance of the Revised Duggan September Note in full, resulting in principal payments of $24,500 and accrued cash interest of $7,305.

As of December 31, 2025 and 2024, the Company had no debt. During the year ended December 31, 2025, the Company incurred no interest expense. During the year ended December 31, 2024, the Company incurred interest expense of $8,686 related to the Revised Duggan September Note.
Related Party Transactions
Leases

July 25, 2022 First Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On July 25, 2022 the Company entered into a first amendment, dated July 19, 2022, to its existing sublease agreement with Maky Zanganeh and Associates, Inc. (“MZA”), an entity owned by Maky Zanganeh, consisting of 4,500 square feet of office space at 2882 Sand Hill Road, Menlo Park, California. The existing sublease term, which was set to expire on September 30, 2022, was extended for a period of thirty-nine months from October 1, 2022 through December 31, 2025. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. The agreement was further amended to include additional space, as noted below under the August 2, 2024 Third Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc. During the years ended December 31, 2025, 2024 and 2023, payments of $834, $795, and $762, respectively, were made pursuant to the first and third amendments to the Sublease Agreement.

July 29, 2022 Second Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On July 29, 2022, the Company entered into a second amendment to its existing sublease agreement with MZA, described above. The second amendment was effective as of August 1, 2022 and expires on December 31, 2025. The second amendment includes an additional 1,277 square feet of office space at 2882 Sand Hill Road, Menlo Park, California. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the years ended December 31, 2025, 2024 and 2023, payments of $232, $224 and $218, respectively, were made pursuant to the second amendment to the Sublease Agreement.

April 1, 2024 Miami Sublease Agreements

On April 1, 2024, the Company entered into two sublease agreements of its Miami headquarters location, one with Genius 24C Inc. (“Genius”), an affiliate of the Company’s Co-CEO, Robert W. Duggan (the “Genius Sublease Agreement”) and one with Duggan Investments Research LLC (“Investments Research”), also an affiliate of the Company's Co-CEO, Robert W. Duggan (the “Investments Research Sublease Agreement”). Pursuant to the Genius Sublease Agreement, Genius sublet from the Company 848 square feet of office space in the Miami HQ for a sixty-two month term for total rental payments of approximately $446. Pursuant to the Investments Research Sublease Agreement, Investments Research sublet from the Company 848 square feet of office space in the Miami HQ for a sixty-two month term for total rental payments of approximately $446. During the years ended December 31, 2025 and 2024, the Company recognized $186 and $156, respectively, of sublease income recorded net of operating lease expenses.

August 2, 2024 Third Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On August 2, 2024, the Company entered into a third amendment to its existing sublease agreement with MZA. The third amendment was effective August 1, 2024 and included an additional space of 145 square feet of office space located at 2882
Sand Hill Road, Menlo Park, California. The Company continues to be obligated to pay its proportionate share of the net payable by MZA to the third-party landlord, which is revised to 93.6% as of the effective date, based on the square footage of office space sublet by the landlord.

Promissory Note Payable to Related Parties

Refer to Note 12 for disclosure of the promissory note payable to related parties issued December 6, 2022 and fully repaid as of October 1, 2024.

Akeso Agreements

Upon the closing of the License Agreement, the Board appointed Dr. Yu (Michelle) Xia to serve as a member of the Board pursuant to the terms of the License Agreement. Dr. Xia is the founder of Akeso, and has been the chairwoman, president and CEO of Akeso since its inception in 2012. Furthermore, in connection with the License Agreement, the Company also entered into a Supply Agreement with Akeso, pursuant to which Summit agreed to purchase a certain portion of drug substance for clinical and commercial supply (the “Supply Agreement”). Refer to Note 4 for details on the License Agreement and Second Amendment. In addition to the License and Second Amendment and supply agreements, the Company also entered into various clinical services agreements with Akeso. During the years ended December 31, 2025, 2024 and 2023, the Company incurred research and development expenses of $46,133, $24,635 and $6,207, respectively, under these agreements with Akeso. As of December 31, 2025 and 2024 the Company included in accrued expenses, related to Akeso, $1,215 and $3,956, respectively.

2023 Rights Offering

Refer to Note 13 for a discussion on the 2023 Rights Offering.

Private Placements

October 2023 PIPE

Refer to Note 13 for a discussion on the participation by related parties in October 2023 PIPE.

September 2024 PIPE

Refer to Note 13 for a discussion on the participation by related parties in September 2024 PIPE.

October 2025 PIPE

Refer to Note 13 for a discussion on the participation by related parties in October 2025 PIPE.

Warrants Exercise

In March 2025, Mr. Duggan, the Company’s Co-Chief Executive Officer, exercised 2,936,221 of the 3,985,055 warrants which he received in connection with a private placement completed by the Company with Mr. Duggan and other investors on December 24, 2019, resulting in the purchase of 2,936,221 shares of common stock at an exercise price of $1.58.

On April 8, 2025, Mr. Duggan completed the exercise of the remaining warrants received in the December 24, 2019 private placement, resulting in the purchase of 1,048,834 shares of common stock at an exercise price of $1.58.

In October 2024, the Shaun Zanganeh Irrevocable Trust exercised a warrant to purchase 315,681 shares of Common Stock. Refer to Note 13 for the warrants exercise activity for the year ended December 31, 2025.

Professional Services

During the year ended December 31, 2025, the Company engaged the law firm Wilson Sonsini Goodrich & Rosati P.C. (“WSGR”), where Mr. Kenneth A. Clark, a member of the Board, is a partner. Payments to be made by the Company to WSGR
were approved by the Audit Committee in accordance with its Related Party Transaction Policy. For the year ended December 31, 2025, the Company incurred expenses for legal services rendered by WSGR totaling approximately $1.4 million included in general and administrative expenses.
v3.25.4
Stockholders' Equity
 12 Months Ended
Dec. 31, 2025
Equity [Abstract]  
Stockholders' Equity Stockholders' Equity
Preferred Stock

As of December 31, 2025 and December 31, 2024, the Company had 20,000,000 shares of preferred stock, par value $0.01 authorized and no shares issued and outstanding.

Common Stock

As of December 31, 2025 and December 31, 2024, the Company had authorized 1,000,000,000 shares of common stock, par value $0.01 (the “Common Stock”). As of December 31, 2025 and December 31, 2024, the Company had 775,371,200 shares and 737,626,004 shares of Common Stock issued and outstanding, respectively.

On December 6, 2022, the Company announced the 2023 Rights Offering for its existing shareholders to participate in the purchase of additional shares of its Common Stock for $1.05 per share. The 2023 Rights Offering commenced on February 7, 2023 and the associated subscription rights expired on March 1, 2023. Aggregate gross proceeds from the 2023 Rights Offering were $500,000 from the sale of 476,190,471 shares of the Company’s Common Stock and issuance costs were $619. Mr. Duggan and Dr. Zanganeh fully subscribed to their respective basic subscription rights at a price of $1.05 per share. To satisfy the $395,314 subscription price for the shares subscribed by Mr. Duggan in the 2023 Rights Offering, Mr. Duggan agreed with the Company to extinguish a portion of the amount due and payable to him by the Company at the closing of the 2023 Rights Offering pursuant to the $400,000 Duggan Promissory Note in an amount equal to the subscription price (see also Note 12).

On January 19, 2023, the Company filed Amendment No. 2 to the Restated Certificate of Incorporation (the “Amendment No. 2”) with the Secretary of State of the State of Delaware to increase the number of authorized shares of its Common Stock by 650,000,000 (from 350,000,000 to 1,000,000,000), which became effective on such date.
On March 17, 2023, the Company filed a registration statement on Form S-3 to register for resale the following shares of the Company’s Common Stock at $0.01 par value: (i) 10,000,000 shares of Common Stock issued on January 17, 2023 in connection with the License Agreement (as defined in Note 4) with Akeso pursuant to which the Company issued Akeso such shares; and (ii) the 9,346,434 and 373,857 shares of Common Stock issued in December 2022 to Mr. Duggan and Dr. Zanganeh, respectively, as payment of prepaid interest in connection with the Note Purchase Agreement dated December 6, 2022 between Mr. Duggan, Dr. Zanganeh and the Company. On April 27, 2023, the SEC issued the Company a Notice of Effectiveness for the registration statement on Form S-3.

Mr. Soni entered into a share purchase agreement with the Company to purchase $5,000 of its Common Stock via a private placement. The transaction was effective October 13, 2023 with a closing price of $1.68, resulting in the purchase of 2,976,190 shares of the Company’s Common Stock.

June 2024 PIPE (Private Investment in Public Equity)

On June 3, 2024, the Company entered into a securities purchase agreement (the “Purchase Agreement”) with 667, L.P. and Baker Brothers Life Sciences, L.P., affiliates of Baker Bros. Advisors, L.P., for the sale by the Company in a private placement (the “June 2024 Private Placement”) of 22,222,222 shares (the “Shares”) of Common Stock, at a purchase price of $9.00 per share, for an aggregate purchase price of approximately $200,000.

The closing of the June 2024 Private Placement was June 6, 2024. The Purchase Agreement contained customary representations, warranties and covenants by the Company, customary indemnification obligations of the Company, including for liabilities under the Securities Act of 1933, other obligations of the parties and termination provisions. The representations, warranties and covenants contained in the Purchase Agreement were made only for purposes of the Purchase Agreement and as of specific dates, were solely for the benefit of the parties to such agreements and were subject to limitations agreed upon by the contracting parties.

On June 3, 2024, in connection with the Purchase Agreement, the Company entered into a Registration Rights Agreement with certain investors (the “Registration Rights Agreement”). The Registration Rights Agreement provides, among other things, that the Company will as soon as reasonably practicable, file with the SEC a registration statement registering the resale of the shares. The Company agreed to use its reasonable best efforts to have such registration statement declared effective as soon as practicable after the filing thereof. The Company filed the registration statement on August 6, 2024, which was automatically effective upon filing.

September 2024 PIPE

On September 11, 2024, the Company entered into securities purchase agreements (the “September 2024 Purchase Agreements”) with multiple biotech institutional investors and individual accredited investors, for the sale by the Company in a private placement (the “September 2024 Private Placement”) for an aggregate of 10,352,418 shares of the Company’s Common Stock, par value $0.01 per share of Common Stock, at purchase price of $22.70 per share, which was the closing price of the Common Stock on September 11, 2024, for aggregate gross proceeds to the Company of approximately $235,000, with offering costs of $140.

All of the Company's Section 16 officers participated in the capital raise. A total of $79,000 was raised by the Company's Co-Chief Executive Officer (“CEO”), Executive Chairman and majority stockholder, its CEO and the President and member of the Company's Board of Directors (the “Board”), its Chief Operating Officer (“COO”), Chief Financial Officer (“CFO”), and member of the Board, its Chief Accounting Officer (“CAO”), and a member of the Board, who invested via a controlled entity. The remaining $156,000 was raised with multiple leading biotech institutional investors. Refer to Note 15 Related Party Transactions for further details regarding related parties' participation.

The closing of the September 2024 Private Placement was September 13, 2024. The September 2024 Purchase Agreements contain customary representations, warranties and covenants by the Company, customary indemnification obligations of the Company, including for liabilities under the Securities Act, as amended (the “Securities Act”), other obligations of the parties and termination provisions. The representations, warranties and covenants contained in the September 2024 Purchase
Agreements were made only for purposes of the September 2024 Purchase Agreements and as of specific dates, were solely for the benefit of the parties to such agreements and were subject to limitations agreed upon by the contracting parties.

On September 11, 2024, in connection with the September 2024 Purchase Agreements, the Company entered into Registration Rights Agreements with certain investors (the “September 2024 Registration Rights Agreements”). The September 2024 Registration Rights Agreements provide, among other things, that the Company will as soon as reasonably practicable file with the SEC a registration statement registering the resale of the shares. The Company filed the registration statement on September 19, 2024, which was automatically effective upon filing.

October 2025 PIPE

On October 21, 2025, the Company entered into securities purchase agreements (the “October 2025 Purchase Agreements”) with multiple biotech institutional investors and individual accredited investors, for the sale by the Company in a private placement for an aggregate of 26,682,846 shares of the Company’s Common Stock, par value $0.01 per share of Common Stock, at purchase price of $18.74 per Share, which was the closing price of the Common Stock on October 21, 2025, for aggregate gross proceeds to the Company of approximately $500,037, with immaterial offering costs. The private placement transaction was completed in October 2025.

All of the Company's Section 16 officers participated in the capital raise. The Company's Co-CEO, Executive Chairman and majority stockholder, its Co-CEO and the President and member of the Board, its COO, CFO, and member of the Board, its CAO, and certain non-executive employees and other related persons purchased an aggregate of 14,514,402 shares of Common Stock for gross proceeds of approximately $272,000. Additionally, Akeso purchased 533,617 shares of Common Stock for gross proceeds of approximately $10,000. The remaining $218,037 was raised with multiple leading biotech institutional investors.

The October 2025 Purchase Agreements contain customary representations, warranties and covenants by the Company, customary indemnification obligations of the Company, including for liabilities under the Securities Act, as amended (the “Securities Act”), other obligations of the parties and termination provisions. The representations, warranties and covenants contained in the October 2025 Purchase Agreements were made only for purposes of the October 2025 Purchase Agreements and as of specific dates, were solely for the benefit of the parties to such agreements and were subject to limitations agreed upon by the contracting parties.

On October 21, 2025, in connection with the October 2025 Purchase Agreements, the Company entered into Registration Rights Agreements with the Investors (the “October 2025 Registration Rights Agreements”). The October 2025 Registration Rights Agreements provide, among other things, that the Company will as soon as reasonably practicable, and in any event by no later than December 19, 2025, file with the SEC a registration statement registering the resale of the shares. The Company filed the registration statement on October 29, 2025, which was automatically effective upon filing.

At-the-Market Offering (ATM Offering)

On May 13, 2024, the Company entered into an at-the-market (“ATM”) sales agreement (the “Original Distribution Agreement”) pursuant to which the Company may, subject to the terms and conditions set forth in the agreement offer and sell, from time to time, through or to the agents, acting as agents or principal, shares of the Company's Common Stock, par value $0.01, having an aggregate offering price of up to $90,000. On August 11, 2025, the Company entered into an amendment to the Original Distribution Agreement (as amended, the “Distribution Agreement”), which among other things, increased the aggregate offering price of Common Stock that the Company may offer and sell from time to time through the sales agent under the Distribution Agreement by an additional $360,000.

From the date of the Original Distribution Agreement through December 31, 2025, the Company sold 7,146,432 shares of Common Stock under the ATM at a weighted-average price of $21.09 per share, for gross proceeds of $150,721, with commissions and fees of approximately $3,160. The remaining gross proceeds available under the Distribution Agreement as of December 31, 2025 was approximately $299,279. The Company plans to use the net proceeds from this offering for working capital and general corporate purposes.
Warrants

As of December 31, 2025, the Company had no outstanding warrants. As of December 31, 2024, the Company had outstanding and exercisable warrants of 4,629,988 with a weighted average exercise price of $1.58. During the year ended December 31, 2025, 4,629,988 warrants were exercised with a weighted average exercise price of $1.58.
v3.25.4
Stock-Based Compensation
 12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Stock-Based Compensation Stock-Based Compensation
2016 Long Term Incentive Plan

Upon the effectiveness of the 2020 Stock Incentive Plan (the “2020 Plan”), no additional grants will be made under the 2016 Long Term Incentive Plan, (the “2016 Plan”) and any outstanding awards continue with their original terms.

2020 Stock Award Plan

In September 2020, the Company’s Board of Directors approved the 2020 Stock Incentive Plan, which became effective on September 21, 2020. The 2020 plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards.

A total of 8,000,000 shares of Common Stock were initially reserved for issuance under the 2020 Plan. Additionally, up to 5,000,000 shares of Common Stock, including RSUs can be added to the 2020 Plan for future issuance from options that expire, lapse or are terminated from the 2016 Plan or any other predecessor plans. The number of shares of Common Stock that may be issued under the 2020 Plan will automatically increase on each January 1, beginning in 2021 and continuing for each fiscal year until, and including, the fiscal year ending December 31, 2030, equal to the lesser of (i) 6,400,000 shares of Common Stock, (ii) 4% of the common shares outstanding on the final day of the immediately preceding calendar year and (iii) an amount as determined by the Company’s Board of Directors.

As of December 31, 2025, there are 2,643,200 shares available to be issued under the 2020 Plan. The Company currently grants stock options to employees and directors under the 2020 Stock Incentive Plan (the “2020 Plan”) and formerly, the Company granted stock options under the 2016 Long Term Incentive Plan (the “2016 Plan”). The 2020 Plan is administered by the Compensation Committee of the Company's Board of Directors. The 2020 Plan is intended to attract and retain employees and directors and provide an incentive for these individuals to assist the Company to achieve long-range performance goals and to enable these individuals to participate in the long-term growth of the Company.

Based on the provisions of the 2020 Plan, the number of shares of common stock available for issuance under the 2020 Plan increased by 6,400,000 shares on January 1, 2025. On September 18, 2025, the Board approved an increase of 8,000,000 shares of common stock available for issuance under the 2020 Plan (the “Incremental Pool”), subject to the approval of the holders of a majority of the shares voting at the Company’s stockholder meeting. As of December 31, 2025, there are 3,082,075 shares available to be issued under the Incremental Pool. The Company’s consolidated financial statements have treated the grant date of such stock options as the date Board approval was obtained.

On May 3, 2024, the Board adopted the 2024 Inducement Pool (the “Inducement Pool”), which mirrors the terms of the 2020 Plan, with a total of 2,000,000 shares of Common Stock reserved for issuance under the Inducement Pool. Effective January 22, 2025, the number of shares of common stock available under the Inducement Pool increased by 2,000,000 shares. The Inducement Pool provides for the grant of non-qualified stock options and was approved by the Compensation Committee of the Board without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules.

The Inducement Pool is administered by the Compensation Committee of the Board. In accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules, non-qualified stock options under the Inducement Pool may only be made to an employee who has not previously been an employee of the Company or member of the Board (or any parent or subsidiary of the Company), if he or she is granted such non-qualified stock options in connection with his or her commencement of employment with the Company or a subsidiary and such grant is an inducement material to his or her entering into employment with the Company or such subsidiary. As of December 31, 2025, there were 1,936,452 shares available for grant under the Inducement Pool.
2020 Employee Stock Purchase Plan

The 2020 Employee Stock Purchase Plan (the “2020 ESPP”) was adopted by the Board of Directors and approved by the Company’s shareholders on July 17, 2020 and approved by the predecessor company shareholders on August 19, 2020 and is qualified under Section 423 of the Internal Revenue Code. The 2020 ESPP initially authorized the issuance of up to 1,000,000 shares of Common Stock to participating employees. The number of common shares that may be issued under the 2020 ESPP automatically increases on each fiscal year commencing January 1, 2021 and continuing for each fiscal year until, and including the fiscal year commencing on, January 1, 2030 equal to the lesser of (i) 1,600,000 shares of Common Stock, (ii) 1% of the common shares outstanding on such date and (iii) an amount as determined by the Company’s Board of Directors. As of December 31, 2025, there were 1,743,682 shares available to be issued under the 2020 ESPP.

The 2020 ESPP is comprised of purchase periods of six months in duration and commence immediately preceding the end of the previous offering period, unless otherwise determined by the Board of Directors or Compensation Committee.

Under the 2020 ESPP, eligible employees can purchase shares of Common Stock through payroll deductions of up to 15% of their compensation received during the plan period or such shorter period during which deductions from payroll are made, up to a defined maximum amount. The option price is determined based on the lesser of the closing price of Common Stock on (i) the first business day of the plan period or (ii) the exercise date, or shall be based solely on the closing price of the Common Stock on the exercise date; provided that such option price shall be at least 85% of the applicable closing price. In the absence of a determination by the Board of Directors or the Compensation Committee, the option price is 85% of the lesser of the closing price of the Common Stock on (i) the first business day of the plan period or (ii) the exercise date.

The closing price is the (a) the closing price (for the primary trading session) on the Nasdaq Global Select Market or (b) the average of the closing bid and asked prices in the over-the-counter-market, whichever is applicable, as published in the Wall Street Journal or another source selected by the Board or the Committee.

During the fiscal year ended December 31, 2025 and 2024, 139,459 and 353,578 shares, respectively, were issued under the 2020 ESPP Plan.

Stock Options

The Company estimates the fair value of stock options granted to employees and directors using the Black-Scholes valuation model. Stock options granted under the 2016 and 2020 Plans generally vest over three or four years and expire after ten years. This valuation methodology utilizes several key assumptions as highlighted below.

The assumptions used in the Company’s valuation are summarized as follows, presented on a weighted average basis:
Year Ended December 31,
202520242023
Risk-free interest rate
3.8% - 3.9%
4.2 %4.6 %
Expected term (in years)
2.5 - 6.2
6.24.8
Expected volatility
124.9% -142.5%
107.8 %98.1 %
Expected annual dividends per share— %— %— %
The following table summarizes the Company’s stock option activity for the year ended December 31, 2025:     
Number of share optionsWeighted average exercise price
Weighted average remaining contractual term (years)
Aggregate intrinsic value
Outstanding at December 31, 2024*108,136,310$2.348.6$1,677,748 
Granted*13,297,73219.20
Forfeited(1,015,750)10.12
Exercised(953,564)3.99
Outstanding at December 31, 2025119,464,728$4.147.8$1,618,734 
Vested and expected to vest at December 31, 2025110,536,687$3.867.7$1,527,454 
Exercisable at December 31, 202564,834,314$2.327.4$983,902 

* The stock option activity in the table above includes performance-based options outstanding as of December 31, 2024 of 48,220,320 of which 39,013,976 options were unvested and converted to time-based vesting. During the three months ended March 31, 2025, the company granted 5,475,000 performance-based options which were modified to time-based vesting during the three months ended June 30, 2025.

During the second quarter of 2025, the Compensation Committee of the Board of Directors approved a modification to the Company's outstanding unvested performance-based stock option awards for certain employees and executives that will require only the service-based vesting requirements to continue to be satisfied in order to become fully vested, subject to employee consent. The Company accounted for this change as a Type III modification (improbable-to-probable) in accordance with the requirements of Accounting Standards Codification Topic 718 (ASC 718). As a result, 44,488,976 options were valued on the modification date. The Company is recognizing the newly assessed measurement date fair value of the awards as compensation expense over the remaining vesting period. During the year ended December 31, 2025, the Company recognized expense of $650,959 associated with the modification. As of December 31, 2025, the unrecognized compensation cost associated with the modification was $214,295 and is expected to be expensed over a weighted-average recognition period of approximately 1.6 years.

The weighted-average grant-date fair value of stock options granted during the years ended December 31, 2025, 2024 and 2023 was $17.10, $3.40 and $1.41, per share, respectively. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2025, 2024 and 2023 was $15,212, $863, and $474, respectively. The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock.

As of December 31, 2025, there was $345,387 total unrecognized compensation cost related to unvested stock option grants. The unvested amount is expected to be recognized over a weighted average period of approximately 1.8 years.

Stock-Based Compensation

Stock‑based compensation expense related to stock options is recorded within the consolidated statements of operations and comprehensive loss as follows:

Year Ended December 31,
202520242023
Research and development$218,564 $16,007 $4,408 
General and administrative513,856  34,974  9,700  
Total stock-based compensation$732,420$50,981$14,108
The following table summarizes stock-based compensation expense associated with each of our stock-based compensation arrangements:
Year Ended December 31,
202520242023
Time-based stock options$731,358 $39,349 $12,606 
Performance and market-based stock options —  11,033  1,318  
Employee stock purchase plan1,062599184
Total stock-based compensation$732,420$50,981$14,108
v3.25.4
Related Party Transactions
 12 Months Ended
Dec. 31, 2025
Related Party Transactions [Abstract]  
Related Party Transactions Promissory Note Payable to Related Parties
December 2022 Promissory Notes

On December 6, 2022, the Company entered into a Note Purchase Agreement (the “Note Purchase Agreement”), with Mr. Duggan and Dr. Zanganeh, pursuant to which the Company agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520,000. Pursuant to the Note Purchase Agreement, the Company issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400,000 (the “Duggan February Note”) and $20,000 (the “Zanganeh Note”), respectively, which matured and became due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100,000 (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which was originally due on September 15, 2023. The maturity dates of the December 2022 Notes could have been extended one or more times at the Company’s election, but in no event to a date later than September 6, 2024. In addition, if the Company consummated a public offering, then upon the later to occur of (i) five business days after the Company receives the net cash proceeds therefrom or (ii) May 15, 2023, the Duggan February Note and the Zanganeh Note were to be prepaid by an amount equal to the lesser of (a) 100% of the amount of the net proceeds of such offering and (b) the outstanding principal amount on such Notes.

On January 19, 2023, the Company provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024. Furthermore, on January 19, 2023, the Company and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that the Company may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by Summit in the approximate amount of $500,000, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the rights offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) Duggan September Note following the completion of a capital raising transaction subsequent to the rights offering in an amount equal to the lesser of (A) the net proceeds of such capital raise or (B) the full amount outstanding of the Duggan September Note. Following the issuance of the two new Promissory Notes (the “Revised Duggan February Note” and the “Revised Duggan September Note”, respectively), the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Revised Duggan February Note and the Revised Duggan September Note (together with the Zanganeh Note, the “Notes”).

On February 15, 2023, the $20,000 Zanganeh Note matured and the Company repaid the outstanding principal balance. In connection with the closing of the rights offering in 2023 (the “2023 Rights Offering”), the $400,000 Revised Duggan February Note matured and became due, and the Company repaid all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price of shares subscribed by Mr. Duggan in the 2023 Rights Offering.
The Notes accrued interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the period through February 15, 2023. Such prepaid interest was paid in a number of shares of the Company’s common stock equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time the Company entered into the Note Purchase Agreement, plus $0.01), which was 9,720,291 shares. For all applicable periods following February 15, 2023, interest accrued on the outstanding principal balance of the Notes at the U.S. prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the U.S. prime rate plus 300 basis points, as adjusted monthly. Accrued interest was paid in cash, quarterly in arrears, on each of March 31, June 30, September 30 and December 31. Debt issuance costs associated with the Notes were $44 and were capitalized as part of the carrying value of the promissory notes payable to related parties.

On February 17, 2024, the Revised Duggan February Note was amended to extend the maturity date from September 6, 2024 to April 1, 2025. For all applicable periods commencing February 17, 2024, interest accrued on the outstanding principal balance at the greater of 12% or the U.S. prime interest rate, as reported in the Wall Street Journal plus 350 basis points, as adjusted monthly, and compounded quarterly. Interest was paid upon maturity of the loan. The debt discount was amortized to interest expense using an effective interest rate method. The effective interest rate of the Revised Duggan February Note and Zanganeh Note was 8.9% and the effective interest rate of the Revised Duggan September Note was 11.3%.

On September 16, 2024, the Company used some of the proceeds raised from the September 2024 Private Placement (see Note 13 for further details) to repay $75,500 in principal on the Revised Duggan September Note. On October 1, 2024, the Company repaid the remaining outstanding balance of the Revised Duggan September Note in full, resulting in principal payments of $24,500 and accrued cash interest of $7,305.

As of December 31, 2025 and 2024, the Company had no debt. During the year ended December 31, 2025, the Company incurred no interest expense. During the year ended December 31, 2024, the Company incurred interest expense of $8,686 related to the Revised Duggan September Note.
Related Party Transactions
Leases

July 25, 2022 First Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On July 25, 2022 the Company entered into a first amendment, dated July 19, 2022, to its existing sublease agreement with Maky Zanganeh and Associates, Inc. (“MZA”), an entity owned by Maky Zanganeh, consisting of 4,500 square feet of office space at 2882 Sand Hill Road, Menlo Park, California. The existing sublease term, which was set to expire on September 30, 2022, was extended for a period of thirty-nine months from October 1, 2022 through December 31, 2025. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. The agreement was further amended to include additional space, as noted below under the August 2, 2024 Third Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc. During the years ended December 31, 2025, 2024 and 2023, payments of $834, $795, and $762, respectively, were made pursuant to the first and third amendments to the Sublease Agreement.

July 29, 2022 Second Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On July 29, 2022, the Company entered into a second amendment to its existing sublease agreement with MZA, described above. The second amendment was effective as of August 1, 2022 and expires on December 31, 2025. The second amendment includes an additional 1,277 square feet of office space at 2882 Sand Hill Road, Menlo Park, California. The rent payable under the terms of the sublease is equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up has been applied. During the years ended December 31, 2025, 2024 and 2023, payments of $232, $224 and $218, respectively, were made pursuant to the second amendment to the Sublease Agreement.

April 1, 2024 Miami Sublease Agreements

On April 1, 2024, the Company entered into two sublease agreements of its Miami headquarters location, one with Genius 24C Inc. (“Genius”), an affiliate of the Company’s Co-CEO, Robert W. Duggan (the “Genius Sublease Agreement”) and one with Duggan Investments Research LLC (“Investments Research”), also an affiliate of the Company's Co-CEO, Robert W. Duggan (the “Investments Research Sublease Agreement”). Pursuant to the Genius Sublease Agreement, Genius sublet from the Company 848 square feet of office space in the Miami HQ for a sixty-two month term for total rental payments of approximately $446. Pursuant to the Investments Research Sublease Agreement, Investments Research sublet from the Company 848 square feet of office space in the Miami HQ for a sixty-two month term for total rental payments of approximately $446. During the years ended December 31, 2025 and 2024, the Company recognized $186 and $156, respectively, of sublease income recorded net of operating lease expenses.

August 2, 2024 Third Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.

On August 2, 2024, the Company entered into a third amendment to its existing sublease agreement with MZA. The third amendment was effective August 1, 2024 and included an additional space of 145 square feet of office space located at 2882
Sand Hill Road, Menlo Park, California. The Company continues to be obligated to pay its proportionate share of the net payable by MZA to the third-party landlord, which is revised to 93.6% as of the effective date, based on the square footage of office space sublet by the landlord.

Promissory Note Payable to Related Parties

Refer to Note 12 for disclosure of the promissory note payable to related parties issued December 6, 2022 and fully repaid as of October 1, 2024.

Akeso Agreements

Upon the closing of the License Agreement, the Board appointed Dr. Yu (Michelle) Xia to serve as a member of the Board pursuant to the terms of the License Agreement. Dr. Xia is the founder of Akeso, and has been the chairwoman, president and CEO of Akeso since its inception in 2012. Furthermore, in connection with the License Agreement, the Company also entered into a Supply Agreement with Akeso, pursuant to which Summit agreed to purchase a certain portion of drug substance for clinical and commercial supply (the “Supply Agreement”). Refer to Note 4 for details on the License Agreement and Second Amendment. In addition to the License and Second Amendment and supply agreements, the Company also entered into various clinical services agreements with Akeso. During the years ended December 31, 2025, 2024 and 2023, the Company incurred research and development expenses of $46,133, $24,635 and $6,207, respectively, under these agreements with Akeso. As of December 31, 2025 and 2024 the Company included in accrued expenses, related to Akeso, $1,215 and $3,956, respectively.

2023 Rights Offering

Refer to Note 13 for a discussion on the 2023 Rights Offering.

Private Placements

October 2023 PIPE

Refer to Note 13 for a discussion on the participation by related parties in October 2023 PIPE.

September 2024 PIPE

Refer to Note 13 for a discussion on the participation by related parties in September 2024 PIPE.

October 2025 PIPE

Refer to Note 13 for a discussion on the participation by related parties in October 2025 PIPE.

Warrants Exercise

In March 2025, Mr. Duggan, the Company’s Co-Chief Executive Officer, exercised 2,936,221 of the 3,985,055 warrants which he received in connection with a private placement completed by the Company with Mr. Duggan and other investors on December 24, 2019, resulting in the purchase of 2,936,221 shares of common stock at an exercise price of $1.58.

On April 8, 2025, Mr. Duggan completed the exercise of the remaining warrants received in the December 24, 2019 private placement, resulting in the purchase of 1,048,834 shares of common stock at an exercise price of $1.58.

In October 2024, the Shaun Zanganeh Irrevocable Trust exercised a warrant to purchase 315,681 shares of Common Stock. Refer to Note 13 for the warrants exercise activity for the year ended December 31, 2025.

Professional Services

During the year ended December 31, 2025, the Company engaged the law firm Wilson Sonsini Goodrich & Rosati P.C. (“WSGR”), where Mr. Kenneth A. Clark, a member of the Board, is a partner. Payments to be made by the Company to WSGR
were approved by the Audit Committee in accordance with its Related Party Transaction Policy. For the year ended December 31, 2025, the Company incurred expenses for legal services rendered by WSGR totaling approximately $1.4 million included in general and administrative expenses.
v3.25.4
Commitments and Contingencies
 12 Months Ended
Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies Commitments and Contingencies
Fixed asset purchase commitments
At December 31, 2025 and 2024, the Company had no capital commitments.

Lease commitments
Refer to Note 11 for a discussion of the Company’s lease commitments.

Other commitments
The Company enters into contracts in the normal course of business with various third parties for clinical trials, preclinical research studies and testing, manufacturing and other services and products for operating purposes. Most contracts provide for termination upon notice, and therefore are cancellable contracts. The majority of these commitments are due within one year. As of December 31, 2025, total unconditional purchase obligations, excluding leases commitments, are estimated to be approximately $17,976.

The Company has certain commitments under its agreements with Akeso. The License Agreement also contains certain manufacturing and purchase commitments. As of December 31, 2025, the Company is unable to estimate the amount, timing or likelihood of achieving the milestones, making future product sales or assessing estimated forecasts for manufacturing and supplied materials which these contingent payment obligations relate to.

Legal Proceedings
Litigation Relating to the December 2022 Notes Entered into in Connection with the License Agreement

On March 17, 2025, Rainaldi Revocable Trust, a purported stockholder of the Company, filed a derivative lawsuit in the Delaware Court of Chancery against certain of the Company’s current and former directors and the Company, solely as a nominal defendant, concerning the December 2022 Notes entered into by the Company, Mr. Duggan and Dr. Zanganeh in connection with the License Agreement. The suit asserts claims for breach of fiduciary duty and unjust enrichment and seeks, among other things, unspecified damages, rescission of the shares that Mr. Duggan and Dr. Zanganeh received as part of prepaid interest payments under the December 2022 Notes, as well as attorneys’ fees and costs. Defendants’ Motion to Dismiss the complaint was filed on May 16, 2025. Plaintiff filed the Motion to Certify certain constitutional questions to the Delaware Supreme Court on May 29, 2025. Defendants agreed to a stipulation staying briefing on the Motion to Certify and the Motion to Dismiss pending the Delaware Supreme Court’s decision in another case involving substantially the same constitutional questions. On June 18, 2025, the Court granted such stipulation. Defendants believe that Plaintiff's allegations are without merit and plan to vigorously defend against its claims
v3.25.4
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2025
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
v3.25.4
Insider Trading Policies and Procedures
 12 Months Ended
Dec. 31, 2025
Insider Trading Policies and Procedures [Line Items]  
Insider Trading Policies and Procedures Adopted true
v3.25.4
Cybersecurity Risk Management and Strategy Disclosure
 12 Months Ended
Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]  
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]
We have implemented a risk-based approach to identify and assess the cybersecurity threats that could affect our business and information systems. We use recognized commercially reasonable measures, tools and methodologies designed to manage cybersecurity risk that are tested on a regular cadence. We also monitor and evaluate our cybersecurity posture on an ongoing basis through regular vulnerability scans, penetration tests and third-party reviews. We rely on third-party service providers to provide the systems required to effectively run our clinical trials and endeavor to require third-party service providers that have access to personal, confidential or proprietary information to implement and maintain cybersecurity practices. Specific controls that are used in appropriate portions of our environment include endpoint threat detection and response, identity and access management, privileged access management, logging and monitoring involving the use of security information and event management, multi-factor authentication, firewalls and intrusion detection and prevention, and vulnerability and patch management. Our cybersecurity risk management processes are integrated into our enterprise risk management program.

To manage our material risks from cybersecurity threats and to protect against, detect, and prepare to respond to cybersecurity incidents, we endeavor to:

•Monitor emerging data protection laws and implement changes to our processes to comply;
•Conduct annual cybersecurity management and incident training for employees that process sensitive data;
•Conduct onboarding and cybersecurity training for all employees on an ongoing basis;
•Conduct regular phishing email simulations for all employees; and
•Carry cybersecurity risk insurance meant to provide protection against the potential losses arising from a cybersecurity incident.

In addition, we engage several third-party consultants in connection with our risk assessment and risk management, and we have established separate processes and procedures to oversee and identify cybersecurity risks associated with third parties. All third parties involved in our cybersecurity risk assessments and risk management are required to provide reports designed to allow us to monitor and assess such third parties’ security controls.

Our incident response plan coordinates the activities that we and our third-party cybersecurity provider take to respond and recover from cybersecurity incidents, which include processes to triage, assess severity, investigate, escalate, contain, and remediate an incident, as well as to comply with legal obligations and attempt to mitigate brand and reputational damage. We have business continuity plans that we periodically review and update in line with our evolving applications architecture.
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block]
We have implemented a risk-based approach to identify and assess the cybersecurity threats that could affect our business and information systems. We use recognized commercially reasonable measures, tools and methodologies designed to manage cybersecurity risk that are tested on a regular cadence. We also monitor and evaluate our cybersecurity posture on an ongoing basis through regular vulnerability scans, penetration tests and third-party reviews. We rely on third-party service providers to provide the systems required to effectively run our clinical trials and endeavor to require third-party service providers that have access to personal, confidential or proprietary information to implement and maintain cybersecurity practices. Specific controls that are used in appropriate portions of our environment include endpoint threat detection and response, identity and access management, privileged access management, logging and monitoring involving the use of security information and event management, multi-factor authentication, firewalls and intrusion detection and prevention, and vulnerability and patch management. Our cybersecurity risk management processes are integrated into our enterprise risk management program.

To manage our material risks from cybersecurity threats and to protect against, detect, and prepare to respond to cybersecurity incidents, we endeavor to:

•Monitor emerging data protection laws and implement changes to our processes to comply;
•Conduct annual cybersecurity management and incident training for employees that process sensitive data;
•Conduct onboarding and cybersecurity training for all employees on an ongoing basis;
•Conduct regular phishing email simulations for all employees; and
•Carry cybersecurity risk insurance meant to provide protection against the potential losses arising from a cybersecurity incident.

In addition, we engage several third-party consultants in connection with our risk assessment and risk management, and we have established separate processes and procedures to oversee and identify cybersecurity risks associated with third parties. All third parties involved in our cybersecurity risk assessments and risk management are required to provide reports designed to allow us to monitor and assess such third parties’ security controls.

Our incident response plan coordinates the activities that we and our third-party cybersecurity provider take to respond and recover from cybersecurity incidents, which include processes to triage, assess severity, investigate, escalate, contain, and remediate an incident, as well as to comply with legal obligations and attempt to mitigate brand and reputational damage. We have business continuity plans that we periodically review and update in line with our evolving applications architecture.
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 provides oversight to our cybersecurity efforts to ensure effective governance in assessing and managing risks associated with cybersecurity threats.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]
Our cybersecurity leadership team is responsible for assessing and managing cybersecurity risks and is made up of experienced professionals with an extensive background in information security, risk management, and incident response. This team is led by our Head of Information Technology. The Head of Information Technology is a senior technology strategist and thought leader with over two decades of experience in the bio pharma, life sciences, and high-tech sectors.
status updates on various projects intended to enhance the overall cybersecurity posture of the Company, and information about the prevention, detection, mitigation and remediation of any cybersecurity incidents, as appropriate.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] Our Head of Information Technology provides periodic updates to senior management and quarterly updates to the Board of Directors regarding our cybersecurity program, including information about cyber risk management governance, status updates on various projects intended to enhance the overall cybersecurity posture of the Company, and information about the prevention, detection, mitigation and remediation of any cybersecurity incidents, as appropriate.
Cybersecurity Risk Role of Management [Text Block]
Our cybersecurity leadership team is responsible for assessing and managing cybersecurity risks and is made up of experienced professionals with an extensive background in information security, risk management, and incident response. This team is led by our Head of Information Technology. The Head of Information Technology is a senior technology strategist and thought leader with over two decades of experience in the bio pharma, life sciences, and high-tech sectors.

Our Board of Directors provides oversight to our cybersecurity efforts to ensure effective governance in assessing and managing risks associated with cybersecurity threats. Our Head of Information Technology provides periodic updates to senior management and quarterly updates to the Board of Directors regarding our cybersecurity program, including information about cyber risk management governance, status updates on various projects intended to enhance the overall cybersecurity posture of the Company, and information about the prevention, detection, mitigation and remediation of any cybersecurity incidents, as appropriate.
Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]
Our cybersecurity leadership team is responsible for assessing and managing cybersecurity risks and is made up of experienced professionals with an extensive background in information security, risk management, and incident response. This team is led by our Head of Information Technology. The Head of Information Technology is a senior technology strategist and thought leader with over two decades of experience in the bio pharma, life sciences, and high-tech sectors.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]
Our cybersecurity leadership team is responsible for assessing and managing cybersecurity risks and is made up of experienced professionals with an extensive background in information security, risk management, and incident response. This team is led by our Head of Information Technology. The Head of Information Technology is a senior technology strategist and thought leader with over two decades of experience in the bio pharma, life sciences, and high-tech sectors.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block] Our Head of Information Technology provides periodic updates to senior management and quarterly updates to the Board of Directors regarding our cybersecurity program, including information about cyber risk management governance, status updates on various projects intended to enhance the overall cybersecurity posture of the Company, and information about the prevention, detection, mitigation and remediation of any cybersecurity incidents, as appropriate.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
v3.25.4
Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Basis of Presentation
Basis of Presentation
The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Reclassification Certain reclassifications have been made to the prior years’ financial statements to conform to current year presentation.
Use of Estimates
Use of Estimates

The preparation of these financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of income and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments, including those related to accrued research and development expenses, stock-based compensation, and income taxes. Management bases its estimates and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.
Principles of Consolidation
Principles of Consolidation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. GAAP and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. The consolidated financial statements reflect the accounts of Summit Therapeutics Inc. and its wholly owned subsidiaries. Intercompany balances and transactions are eliminated in consolidation.
Foreign Currency Translation
Foreign Currency Translation
The financial statements of the Company’s subsidiaries with functional currencies other than the U.S. dollar are translated into U.S. dollars using period-end exchange rates for assets and liabilities, historical exchange rates for stockholders’ equity and weighted average exchange rates for operating results. Translation gains and losses are included in accumulated other comprehensive (loss) income in stockholders’ equity. Foreign currency transaction gains and losses are included in other income, net in the consolidated statements of operations and comprehensive loss.
Net Loss Per Share
Net Loss Per Share

Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period. Diluted net loss per share is computed by dividing the diluted net loss by the weighted-average number of common shares outstanding for the period, including potentially dilutive common shares. The dilutive effect of share options and warrants are determined under the treasury stock method using the average market price for the period. In addition, the assumed proceeds under the treasury stock method include the average unrecognized compensation expense of stock options and warrants that are in-the-money.
Goodwill
Goodwill

Goodwill represents the excess of the consideration transferred over the fair value of net assets acquired. Goodwill is assigned to reporting units at the time of acquisition or when there is a change in the reporting structure and bases that allocation on which reporting units will benefit from the acquired assets and liabilities. Reporting units are defined as operating segments or one level below an operating segment, referred to as a component. Typically acquisitions related to a single reporting unit do not require the allocation of goodwill to multiple reporting units. If the net assets obtained in an acquisition are assigned to multiple reporting units, the goodwill is distributed to the respective reporting units as part of the purchase price allocation process.

The Company assesses goodwill for impairment on an annual basis as of December 31 or more frequently when events and circumstances occur indicating that the recorded goodwill may be impaired. The Company regularly monitors current business conditions and other factors including, but not limited to, adverse industry or economic trends and lower projections of
profitability that may impact future operating results. The process of evaluating the potential impairment of goodwill requires significant judgment. In performing the Company’s annual goodwill impairment test, the Company is permitted to first assess qualitative factors to determine whether it is more likely than not that the fair value of the Company’s reporting unit is less than its carrying amount, including goodwill. In performing the qualitative assessment, the Company considers certain events and circumstances specific to the reporting unit and to the entity as a whole, such as macroeconomic conditions, industry and market considerations, overall financial performance and cost factors when evaluating whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount. The Company is also permitted to bypass the qualitative assessment and proceed directly to the quantitative test. If the Company chooses to undertake the qualitative assessment and concludes that it is more likely than not that the fair value of the reporting unit is less than its carrying amount, the Company would then proceed to the quantitative impairment test. In the quantitative assessment, the Company compares the fair value of the reporting unit to its carrying amount, which includes goodwill. If the fair value exceeds the carrying value, no impairment loss exists. If the fair value is less than the carrying amount, a goodwill impairment loss is measured and recorded.
Leases
Leases

The Company has operating leases for real estate. The Company does not have any finance leases. A contract is or contains a lease when the lessee has the right to control the use of an identified asset. The Company determines if an arrangement is a lease at inception of the contract, which is the date on which the terms of the contract are agreed to and the agreement creates enforceable rights and obligations. The lease term used to calculate the lease liability include options to extend or terminate the lease when it is reasonably certain that the option will be exercised.

At the lease commencement date, the Company measures and recognizes a lease liability and a right-of-use asset in the financial statements. Lease liabilities are recognized based on the present value of the future lease payments over the lease term at commencement date. The right-of use asset is measured by taking the present value of future lease payments, plus any incremental direct costs incurred, less any lease incentives received. As most of the Company’s leases do not provide an implicit rate, the Company uses an estimated incremental borrowing rate based on the lease term and the economic environment of the lease at the lease commencement date, which is then utilized to determine the present value of future lease payments. Lease expense for minimum lease payments are recognized on a straight-line basis over the lease term, with variable lease payments recognized in the periods in which they are incurred.

The Company has existing lease agreements with lease and non-lease components, has elected to account for the lease and non-lease components as a single lease component, and has allocated all of the contract consideration to the lease component only.

Leases with an initial lease term of 12 months or less are not recorded on the balance sheet. The Company recognizes lease expense for its short-term leases on a straight-line basis over the lease term.
Acquired In-Process Research and Development
Acquired In-Process Research and Development

The Company may enter into agreements with collaboration partners for the development and commercialization of its products. These arrangements may include payments contingent on the occurrence of certain events such as development, regulatory or sales-based milestones. The Company considers the unique nature, terms and facts and circumstances of each transaction. The Company considers whether or not the assets acquired have an alternative future use.
The fair value associated with acquired in-process research and development which does not have an alternative future use is expensed and is recorded as research and development expense. Any development or commercial milestone payments are recognized when the achievement of the associated milestone becomes probable and will either be expensed or capitalized depending upon whether or not regulatory approval has been obtained.
Research and Development Costs
Research and Development Costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred to discover, research and develop product candidates, including personnel expenses, stock-based compensation expense, allocated facility-related and depreciation expenses, third-party license fees and external costs of outside vendors engaged to conduct preclinical and clinical development activities and clinical trials as well as to manufacture clinical trial materials. Non-
refundable prepayments for goods or services that will be used or rendered for future research and development activities are recorded as prepaid expenses. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered. Milestone and other payments made to third-parties with respect to in-process research and development, in accordance with the Company’s license, acquisition and other similar agreements are expensed when determined to be probable and estimable.

The Company has entered into various research and development contracts with other companies. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs or prepaid expenses where the payments made exceed the estimated costs. These amounts are determined based on the estimated costs to complete each study or activity, the estimation of the current stage of completion and the invoices received, as well as predetermined milestones which are not reflective of the current stage of development for prepaid expenses. Actual results could differ from the Company’s estimates. In all cases, the full cost of each study or activity is expensed by the time the final report or where applicable, product, has been received. The Company’s historical estimates have not been materially different from the actual costs.
Stock-Based Compensation
Stock-Based Compensation

The Company measures and recognizes compensation expense for all stock option awards based on the estimated fair value of the award on the grant date. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock option awards. Additionally, the Company uses a Monte Carlo simulation model to calculate the estimated fair value on the date of grant related to awards with market-based service conditions. The fair value is recognized as expense, over the requisite service period, which is generally the vesting period of the respective award, on a straight-line basis for each separately vesting portion of the award when the only condition to vesting is continued service. If vesting is subject to a market or performance condition, recognition is based on the derived service period of the award. Expense for awards with performance conditions is estimated and adjusted on a quarterly basis based upon the assessment of the probability that the performance condition will be met. Use of the Black-Scholes option-pricing model requires management to apply judgment under subjective assumptions. These assumptions include:
•Expected term—The expected term of stock options represents the weighted-average period the stock options are expected to be outstanding. The Company uses the simplified method for estimating the expected term as provided by the SEC. The simplified method calculates the expected term as the average of the time-to-vesting and the contractual life of the options.
•Expected volatility—The expected volatility is calculated based on historical volatility of the Company’s share price.
•Risk-free interest rate—The risk-free rate assumption is based on the U.S. Treasury instruments, the terms of which were consistent with the expected term of the Company’s stock options.
•Expected dividend—The expected dividend assumption is based on the Company’s history and expectation of dividend payouts. The Company has not paid and does not intend to pay dividends.

The Company uses a Monte Carlo simulation model to estimate the fair value of Performance and Market-based Stock Options at the date of grant which utilizes multiple input variables to estimate the probability that the market condition will be achieved. Key assumptions used in the model include the risk-free interest rate, which reflects the US Treasury Constant Maturity Yield with a term commensurate with the contractual term of the award, and stock price volatility, which is derived based on the historical volatility of the Company’s stock.

The Company estimates expected forfeitures at the time of grant instead of accounting for forfeitures as they occur. Stock option awards have been granted at fair value to non-employees in connection with research and consulting services provided to the Company. Equity awards generally vest over terms of 3 or 4 years.

The Company classifies stock-based compensation expense in the consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified.
Income Taxes
Income Taxes

The provision for income taxes is determined using the asset and liability approach. Tax laws may require items to be included in tax filings at different times than the items are reflected in the financial statements. A current asset or liability is recognized
for the estimated taxes receivable or payable for the current year. Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. Deferred taxes are initially recognized at enacted tax rates in force at the time of initial recognition and are subsequently adjusted for any enacted changes in tax rates and tax laws. Subsequent changes to deferred taxes originally recognized in equity are recognized in income. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized. The Company has recorded a full valuation allowance against the deferred tax assets in excess of its deferred tax liabilities, as the deferred tax liabilities represent future reversals of existing taxable temporary differences. The Company records interest and penalties related to income tax matters as part of income tax expense.
Concentration of Credit Risk and Other Risks and Uncertainties
Concentration of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash and short-term investments. The Company’s cash is comprised of short-term cash deposits at a variety of financial institutions which the Company believes are of high credit ratings in amounts that may exceed federally insured limits. The Company has not experienced any losses on such accounts. Cash balances maintained during the year have been principally held with U.S.-based and U.K.-based banks. The Company does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships.

The Company relies, and expects to continue to rely, on a number of vendors to conduct its clinical trials and preclinical studies, manufacture drug product and supply clinical trial and preclinical study materials for its development programs. These programs could be adversely affected by a significant interruption in these services or the availability of materials.
Fair Value Measurements
Fair Value Measurements

In accordance with the provisions of fair value accounting, a fair value measurement assumes that the transaction to sell an asset or transfer a liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability and defines fair value based on the exit price model.

The fair value measurement guidance establishes a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance describes three levels of inputs that may be used to measure fair value:

Level 1
Quoted prices in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2
Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 assets and liabilities include debt securities with quoted prices that are traded less frequently than exchange-traded instruments or securities or derivative contracts that are valued using a pricing model with inputs that are observable in the market or can be derived principally from or corroborated by observable market data.

Level 3
Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation.

In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the Company categorizes such assets and liabilities based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset.
Cash and Cash Equivalents
Cash and Cash Equivalents
The Company considers only those investments that are highly liquid, readily convertible to cash and that mature within 90 days or less from date of purchase to be cash equivalents.
Restricted Cash
Restricted Cash
Restricted cash represents amounts which are legally restricted to withdrawal or usage and is presented in the consolidated balance sheet as restricted cash.
Short-term Investments
Short-term Investments

Short-term investments consist of marketable securities with original maturities greater than ninety days from the date of acquisition. The Company classifies marketable securities with original maturities of greater than 90 days and less than one year as short-term, based on the liquid nature of the marketable securities and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of marketable securities as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices or other observable inputs. Unrealized gains and losses are recorded as a component of other comprehensive income (loss). Realized gains and losses are determined on a specific identification basis and are included in other income, net. Amortization and accretion of discounts and premiums are also recorded in other income, net.

When the fair value is below the amortized cost of the asset, an estimate of expected credit losses is made. This estimate is limited to the amount by which fair value is less than amortized cost. The credit-related impairment amount is recognized in the consolidated statements of operations and comprehensive loss and the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in the consolidated statements of operations and comprehensive loss.
Recently Issued Accounting Pronouncements
Recently Issued Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update “ASU” 2023-09, “Improvements to Income Tax Disclosures”, which requires disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024 and allows for adoption on a prospective basis, with a retrospective option. Early adoption is permitted. The Company adopted ASU 2023-09 for the year ended December 31, 2025 using a retrospective approach. The adoption of ASU-2023-09 did not have a material impact on the Company’s consolidated financial statements and related disclosures.
In November 2024, the FASB issued ASU 2024-03, “Disaggregation of Income Statement Expenses”, which requires disclosures about specific types of expenses included in the expense captions presented on the face of the income statement as well as disclosures. The guidance is to be applied prospectively, with the option for retrospective application and is effective for public business entities for fiscal years beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s consolidated financial statements and related disclosures.

In December 2025, the FASB issued ASU 2025-11, “Narrow-Scope Improvements”, which is intended to improve the navigability of the guidance in ASC 270 and clarify when the guidance is applicable. ASU 2025-11 is effective for interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s consolidated financial statements and related disclosures.

Other recent authoritative guidance issued by the FASB (including technical corrections to the FASB ASC), the American Institute of Certified Public Accountants, and the SEC did not or are not expected to have a material impact on the Company’s consolidated financial statements and related disclosures.
v3.25.4
Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Tables)
 12 Months Ended
Dec. 31, 2025
Accounting Policies [Abstract]  
Schedule of restricted cash balances
The Company’s total cash, cash equivalents and restricted cash balances were as follows:
Year Ended December 31,
202520242023
Cash and cash equivalents$225,266 $104,862 $71,425 
Restricted cash316 325 — 
Total cash, cash equivalents and restricted cash$225,582 $105,187 $71,425 
Schedule of cash and cash equivalents
The Company’s total cash, cash equivalents and restricted cash balances were as follows:
Year Ended December 31,
202520242023
Cash and cash equivalents$225,266 $104,862 $71,425 
Restricted cash316 325 — 
Total cash, cash equivalents and restricted cash$225,582 $105,187 $71,425 
v3.25.4
Segment Reporting (Tables)
 12 Months Ended
Dec. 31, 2025
Segment Reporting [Abstract]  
Schedule of significant expenses of the CODM function The CODM function is regularly provided with the following significant segment expenses:
Year Ended December 31,
 202520242023
Oncology clinical trial related costs$266,439 $100,937 $35,224 
Acquired in-process research and development— 15,007 520,915 
Compensation related costs, excluding stock-based compensation75,575 48,295 31,371 
Stock-based compensation732,420 50,981 14,108 
Other expenses (1)
19,990 10,778 8,032 
Total segment expenses
1,094,424 225,998 609,650 
Other income, net14,838 13,369 11,183 
Interest expense— (8,686)(16,461)
Net loss$(1,079,586)$(221,315)$(614,928)

(1) Other expenses include general and administrative expenses excluding compensation and stock-based compensation.
v3.25.4
Other Income, Net (Tables)
 12 Months Ended
Dec. 31, 2025
Other Income and Expenses [Abstract]  
Schedule of other income, net
The following table sets forth the components of other income, net:
Year Ended December 31,
202520242023
Foreign currency (loss) gain$(610)$(97)$613 
Investment income (1)
15,501 13,466 10,403 
Reclassification of cumulative currency translation gain (2)
— — 419 
Other expense, net
(53)— (252)
$14,838 $13,369 $11,183 

(1) Investment income relates to the Company’s money market funds and short-term investments in U.S. treasury securities. Refer to Note 9 for details.

(2) The reclassification of cumulative currency translation gain related to the reclassification of cumulative foreign currency translation gains from accumulated other comprehensive loss due to the dissolution of certain dormant entities.
v3.25.4
Income Tax (Tables)
 12 Months Ended
Dec. 31, 2025
Income Tax Disclosure [Abstract]  
Schedule of components of loss before income taxes
The components of the Company’s loss before income taxes are as follows:
Year Ended December 31,
202520242023
Foreign$(326,729)$(199,040)$(499,810)
United States(752,857)(22,275)(115,118)
Loss before income taxes$(1,079,586)$(221,315)$(614,928)
Schedule of major components of deferred tax assets and liabilities
The major components of deferred tax assets and liabilities are as follows:
Year Ended December 31,
20252024
Deferred tax assets:
Net operating loss carryforward$73,583 $59,413 
Research and development credit carryforward16,092 7,869 
Stock-based compensation32,158 14,001 
Section 174 Research and Development Capitalization11,034 14,167 
Other711 475 
Total deferred tax assets133,578 95,925 
Deferred tax liabilities:
Other(417)(337)
Total deferred tax liabilities(417)(337)
Net deferred tax assets before valuation allowance 133,16195,588
Valuation allowance(133,161)(95,588)
Deferred tax, net$— $— 
Schedule of change in valuation allowance
The change in the valuation allowance was as follows:
Year Ended December 31,
202520242023
Valuation allowance as of beginning of year$(95,588)$(84,751)$(64,016)
Net increases recorded to income tax provision(37,573)(10,837)(20,735)
Valuation allowance as of end of year$(133,161)$(95,588)$(84,751)
Schedule of reconciliation of the effective income tax rate to the statutory rate
A reconciliation of the Company’s effective tax rate to the U.S. federal statutory rate is as follows:
Year Ended December 31,
202520242023
Tax at federal statutory rate(226,702)21.0 %(46,476)21.0 %(129,048)21.0 %
State income tax, net of federal tax benefit—— %(17)— %—— %
Research and development credits(6,828)0.6 %(4,782)2.2 %(2,275)0.4 %
Nontaxable or nondeductible Items
Stock-based compensation134,033(12.4)%(130)0.1 %2,978(0.5)%
Other299— %77— %521(0.1)%
Foreign Tax Effects
Cayman Islands Statutory income tax rate differential
67,969(6.3)%41,570(18.8)%104,282(17.0)%
Other foreign jurisdictions644(0.1)%229(0.1)%678(0.1)%
Changes in unrecognized tax benefits1,357(0.1)%956(0.4)%800(0.1)%
Change in valuation allowance29,228(2.7)%8,573(4.0)%22,064(3.6)%
Total
$— — %$— — %$— — %
Schedule of reconciliation of unrecognized tax benefits
A reconciliation of unrecognized tax benefits from continuing operations is as follows:
Year Ended December 31,
202520242023
Unrecognized tax benefits, beginning of year$2,122 $1,064 $— 
Increases related to prior year tax positions592 122 610 
Increases related to current year tax positions1,189 936 454 
Unrecognized tax benefits, end of year$3,903 $2,122 $1,064 
v3.25.4
Net Loss per Share (Tables)
 12 Months Ended
Dec. 31, 2025
Earnings Per Share [Abstract]  
Schedule of net loss per share
The following table sets forth the computation of basic and diluted net loss per share:
Year Ended December 31,
202520242023
Net loss$(1,079,586)$(221,315)$(614,928)
Basic and diluted weighted average number of shares of common stock outstanding747,702,265 718,541,896 619,646,180 
Basic net loss per share$(1.44)$(0.31)$(0.99)
Diluted net loss per share$(1.44)$(0.31)$(0.99)
Schedule of potentially dilutive securities excluded from the computation of loss per share
The following potentially dilutive securities were excluded from the computation of the diluted net loss per share of common stock for the periods presented because their effect would have been anti-dilutive:
Year Ended December 31,
202520242023
Options to purchase common stock115,614,72868,920,33454,209,289
Warrants—4,629,9885,015,642
Shares expected to be purchased under employee stock purchase plan65,90586,550155,163
Total
115,680,63373,636,87259,380,094
v3.25.4
Fair Value Measurements and Short-Term Investments (Tables)
 12 Months Ended
Dec. 31, 2025
Fair Value Disclosures [Abstract]  
Schedule of assets and liabilities measured at fair value on a recurring basis
The following tables sets forth the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2025 and 2024:
December 31, 2025
Fair Value Hierarchy LevelAmortized CostUnrealized GainUnrealized (Loss)Credit (Loss)Fair Value
Financial assets included within cash and cash equivalents:
Money market fundsLevel 1$163,588 $— $— $— $163,588 
U.S. Government treasury billsLevel 245,300 12 — — 45,312 
Financial assets included within short-term investments:
Certificate of deposit
Level 225,000 — — — 25,000 
U.S. Government treasury billsLevel 2463,022 160 — — 463,182 
Total$696,910 $172 $— $— $697,082 

December 31, 2024
Fair Value Hierarchy LevelAmortized CostUnrealized GainUnrealized (Loss)Credit (Loss)Fair Value
Financial assets included within cash and cash equivalents:
Money market fundsLevel 1$88,599 $— $— $— $88,599 
Financial assets included within short-term investments:
U.S. Government treasury billsLevel 2307,387 100 — — 307,487 
Total$395,986 $100 $— $— $396,086 
v3.25.4
Leases (Tables)
 12 Months Ended
Dec. 31, 2025
Leases [Abstract]  
Schedule of lease expense
The elements of lease expense were as follows:
Year Ended December 31,
202520242023
    Fixed lease costs$3,853 $3,461 $2,214 
    Variable lease costs225 48 83 
Total lease cost$4,078 $3,509 $2,297 
Schedule of future lease payments
Future lease payments under non-cancelable leases as of December 31, 2025 are detailed as follows:
Year Ending December 31,
2026$3,492 
20274,052 
20284,158 
20293,349 
20303,073 
Thereafter9,205 
Total lease payments27,328 
Less: imputed interest6,438 
Total operating lease liabilities$20,890 
Less: Operating lease liabilities, current portion3,388 
Operating lease liabilities, net of current portion$17,502 
v3.25.4
Stock Based Compensation (Tables)
 12 Months Ended
Dec. 31, 2025
Share-Based Payment Arrangement [Abstract]  
Schedule of weighted-average assumptions
The assumptions used in the Company’s valuation are summarized as follows, presented on a weighted average basis:
Year Ended December 31,
202520242023
Risk-free interest rate
3.8% - 3.9%
4.2 %4.6 %
Expected term (in years)
2.5 - 6.2
6.24.8
Expected volatility
124.9% -142.5%
107.8 %98.1 %
Expected annual dividends per share— %— %— %
Schedule of stock option activity
The following table summarizes the Company’s stock option activity for the year ended December 31, 2025:     
Number of share optionsWeighted average exercise price
Weighted average remaining contractual term (years)
Aggregate intrinsic value
Outstanding at December 31, 2024*108,136,310$2.348.6$1,677,748 
Granted*13,297,73219.20
Forfeited(1,015,750)10.12
Exercised(953,564)3.99
Outstanding at December 31, 2025119,464,728$4.147.8$1,618,734 
Vested and expected to vest at December 31, 2025110,536,687$3.867.7$1,527,454 
Exercisable at December 31, 202564,834,314$2.327.4$983,902 

* The stock option activity in the table above includes performance-based options outstanding as of December 31, 2024 of 48,220,320 of which 39,013,976 options were unvested and converted to time-based vesting. During the three months ended March 31, 2025, the company granted 5,475,000 performance-based options which were modified to time-based vesting during the three months ended June 30, 2025.
Schedule of stock-based compensation expense
Stock‑based compensation expense related to stock options is recorded within the consolidated statements of operations and comprehensive loss as follows:

Year Ended December 31,
202520242023
Research and development$218,564 $16,007 $4,408 
General and administrative513,856  34,974  9,700  
Total stock-based compensation$732,420$50,981$14,108
The following table summarizes stock-based compensation expense associated with each of our stock-based compensation arrangements:
Year Ended December 31,
202520242023
Time-based stock options$731,358 $39,349 $12,606 
Performance and market-based stock options —  11,033  1,318  
Employee stock purchase plan1,062599184
Total stock-based compensation$732,420$50,981$14,108
v3.25.4
Organization (Details) - USD ($)
$ in Thousands
 12 Months Ended 20 Months Ended
Oct. 21, 2025
Sep. 11, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2025
Product Information [Line Items]            
Net loss     $ 1,079,586 $ 221,315 $ 614,928  
Net cash used in operating activities     322,930 142,106 76,760  
Accumulated deficit     2,294,159 1,214,573   $ 2,294,159
Cash and cash equivalents     225,266 104,862 $ 71,425 225,266
Short-term investments     488,182 $ 307,487   488,182
Private placement            
Product Information [Line Items]            
Proceeds from issuance of common stock $ 500,037 $ 235,000 500,037      
Distribution Agreement            
Product Information [Line Items]            
Proceeds from issuance of common stock     $ 106,498     $ 150,721
v3.25.4
Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Significant Accounting Policies [Line Items]      
Foreign currency (loss) gain $ (610) $ (97) $ 613
Restricted cash $ 316 $ 325 $ 0
Minimum      
Significant Accounting Policies [Line Items]      
Equity award, vesting period (in years) 3 years    
Maximum      
Significant Accounting Policies [Line Items]      
Equity award, vesting period (in years) 4 years    
v3.25.4
Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Total Cash, Cash Equivalents and Restricted Cash Balances (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Accounting Policies [Abstract]        
Cash and cash equivalents $ 225,266 $ 104,862 $ 71,425  
Restricted cash 316 325 0  
Total cash, cash equivalents and restricted cash $ 225,582 $ 105,187 $ 71,425 $ 648,607
v3.25.4
Segment Reporting - Significant Expense of the CODM Function (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting Information [Line Items]      
Oncology clinical trial related costs [1] $ 537,674 $ 150,777 $ 59,471
Acquired in-process research and development 0 15,007 520,915
Stock-based compensation 732,420 50,981 14,108
Total operating expenses 1,094,424 225,998 609,650
Other income, net 14,838 13,369 11,183
Interest expense 0 (8,686) (16,461)
Net loss (1,079,586) (221,315) (614,928)
Reportable Segment      
Segment Reporting Information [Line Items]      
Oncology clinical trial related costs 266,439 100,937 35,224
Acquired in-process research and development 0 15,007 520,915
Compensation related costs, excluding stock-based compensation 75,575 48,295 31,371
Stock-based compensation 732,420 50,981 14,108
Other expenses 19,990 10,778 8,032
Total operating expenses 1,094,424 225,998 609,650
Other income, net 14,838 13,369 11,183
Interest expense 0 (8,686) (16,461)
Net loss $ (1,079,586) $ (221,315) $ (614,928)
[1] Refer to Note 15 – Related Party Transactions for expenses incurred.
v3.25.4
Segment Reporting - Narrative (Details)
 12 Months Ended
Dec. 31, 2025
segment
Segment Reporting [Abstract]  
Number of reportable segments 1
Number of operating segments 1
v3.25.4
Akeso License and Collaboration Agreement (Details) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 3 Months Ended 12 Months Ended
Mar. 06, 2023
Jan. 31, 2023
Sep. 30, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Jun. 03, 2024
May 13, 2024
Apr. 27, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Common stock par value (in dollars per share)   $ 0.01   $ 0.01 $ 0.01     $ 0.01 $ 0.01
Payments to Akeso for upfront milestone payments       $ 0 $ 15,007 $ 475,015      
Acquired in-process research and development expense       $ 0 $ 15,007 520,915      
Collaborative arrangement, transaction with party to collaborative arrangement                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Collaborative arrangement, upfront payment   $ 500,000              
Cash payment for collaborative arrangement, upfront payment           474,900      
Payments to Akeso for upfront milestone payments     $ 15,000            
Additional potential commercial milestone payments             $ 55,000    
Collaborative arrangement, direct transaction costs           $ 115      
Collaborative arrangement, additional potential milestone payments             4,555,000    
Collaborative arrangement, potential regulatory milestone payments             1,050,000    
Collaborative arrangement, potential commercial milestone payments             $ 3,505,000    
Collaborative arrangement, transaction with party to collaborative arrangement, upfront payment one                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Cash payment for collaborative arrangement, upfront payment   $ 274,900              
Collaborative arrangement, common stock issued in lieu of cash upfront payment (in shares)   10,000,000       10,000,000      
Collaborative arrangement, upfront payment, paid in shares   $ 25,100              
Issuance of common stock in lieu of cash for Akeso upfront payment           $ 45,900      
Collaborative arrangement, transaction with party to collaborative arrangement, upfront payment two                  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                  
Cash payment for collaborative arrangement, upfront payment $ 200,000                
v3.25.4
Other Income, Net (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Other Income and Expenses [Abstract]      
Foreign currency (loss) gain $ (610) $ (97) $ 613
Investment income 15,501 13,466 10,403
Reclassification of cumulative currency translation gain 0 0 419
Other expense, net (53) 0 (252)
Other income, net $ 14,838 $ 13,369 $ 11,183
v3.25.4
Income Tax - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Operating Loss Carryforwards [Line Items]        
Liability for interest and penalties $ 0 $ 0    
Deferred provision for non-United States income taxes 0 0    
Current provision for state income taxes 0 0    
Deferred provision for state income taxes 0 0    
Current provision for federal income taxes 0 0    
Deferred provision for federal income taxes 0 0    
Current provision for non-United States income taxes 0 0    
Deferred tax asset 133,578 95,925    
Unrecognized tax benefits 3,903 2,122 $ 1,064 $ 0
U.S. Federal        
Operating Loss Carryforwards [Line Items]        
Operating loss carryforwards 93,210 44,270    
Tax credit carryforward 15,565      
U.S. State        
Operating Loss Carryforwards [Line Items]        
Operating loss carryforwards 21,335      
Tax credit carryforward 5,002      
U.K.        
Operating Loss Carryforwards [Line Items]        
Operating loss carryforwards $ 211,096 $ 198,653    
v3.25.4
Income Tax - Components of Loss Before Income Taxes (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Tax Disclosure [Abstract]      
Foreign $ (326,729) $ (199,040) $ (499,810)
United States (752,857) (22,275) (115,118)
Loss before income tax $ (1,079,586) $ (221,315) $ (614,928)
v3.25.4
Income Tax - Major Components of Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Deferred tax assets:        
Net operating loss carryforward $ 73,583 $ 59,413    
Research and development credit carryforward 16,092 7,869    
Stock-based compensation 32,158 14,001    
Section 174 Research and Development Capitalization 11,034 14,167    
Other 711 475    
Total deferred tax assets 133,578 95,925    
Deferred tax liabilities:        
Other (417) (337)    
Total deferred tax liabilities (417) (337)    
Net deferred tax assets before valuation allowance 133,161 95,588    
Valuation allowance (133,161) (95,588) $ (84,751) $ (64,016)
Deferred tax, net $ 0 $ 0    
v3.25.4
Income Tax - Valuation Allowance (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Deferred Tax Assets, Valuation Allowance [Roll Forward]      
Valuation allowance as of beginning of year $ (95,588) $ (84,751) $ (64,016)
Net increases recorded to income tax provision (37,573) (10,837) (20,735)
Valuation allowance as of end of year $ (133,161) $ (95,588) $ (84,751)
v3.25.4
Income Tax - Reconciliation of the Effective Income Tax Rate to Statutory Rate (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Amount      
Tax at federal statutory rate $ (226,702) $ (46,476) $ (129,048)
State income tax, net of federal tax benefit 0 (17) 0
Research and development credits (6,828) (4,782) (2,275)
Nontaxable or nondeductible Items      
Stock-based compensation 134,033 (130) 2,978
Other 299 77 521
Foreign Tax Effects      
Changes in unrecognized tax benefits 1,357 956 800
Change in valuation allowance 29,228 8,573 22,064
Total $ 0 $ 0 $ 0
Percent      
Tax at federal statutory rate 21.00% 21.00% 21.00%
State income tax, net of federal tax benefit 0.00% 0.00% 0.00%
Research and development credits 0.60% 2.20% 0.40%
Nontaxable or nondeductible Items      
Stock-based compensation (12.40%) 0.10% (0.50%)
Other 0.00% 0.00% (0.10%)
Foreign Tax Effects      
Changes in unrecognized tax benefits (0.10%) (0.40%) (0.10%)
Change in valuation allowance (2.70%) (4.00%) (3.60%)
Total 0.00% 0.00% 0.00%
CAYMAN ISLANDS      
Foreign Tax Effects      
Foreign Tax Effects $ 67,969 $ 41,570 $ 104,282
Foreign Tax Effects      
Foreign Tax Effects (6.30%) (18.80%) (17.00%)
Other foreign jurisdictions      
Foreign Tax Effects      
Foreign Tax Effects $ 644 $ 229 $ 678
Foreign Tax Effects      
Foreign Tax Effects (0.10%) (0.10%) (0.10%)
v3.25.4
Income Tax - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Unrecognized Tax Benefits [Roll Forward]      
Unrecognized tax benefits, beginning of year $ 2,122 $ 1,064 $ 0
Increases related to prior year tax positions 592 122 610
Increases related to current year tax positions 1,189 936 454
Unrecognized tax benefits, end of year $ 3,903 $ 2,122 $ 1,064
v3.25.4
Net Loss per Share - Computation of Net Loss per Share (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Earnings Per Share [Abstract]      
Net loss $ (1,079,586) $ (221,315) $ (614,928)
Basic weighted average number of shares of common stock outstanding (in shares) 747,702,265 718,541,896 619,646,180
Diluted weighted average number of shares of common stock outstanding (in shares) 747,702,265 718,541,896 619,646,180
Basic net loss per share (in dollars per share) $ (1.44) $ (0.31) $ (0.99)
Diluted net loss per share (in dollars per share) $ (1.44) $ (0.31) $ (0.99)
v3.25.4
Net Loss per Share - Narrative (Details) - $ / shares
Jun. 03, 2024
Mar. 01, 2023
Dec. 06, 2022
Subsidiary, Sale of Stock [Line Items]      
Sale of stock price (in dollars per share) $ 9.00    
Share price (in dollars per share)   $ 1.82  
Rights Offering      
Subsidiary, Sale of Stock [Line Items]      
Sale of stock price (in dollars per share)   $ 1.05 $ 1.05
v3.25.4
Net Loss per Share - Securities Excluded from the Computation of Loss per Share (Details) - shares
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potentially dilutive securities excluded from the computation of diluted loss per share (in shares) 115,680,633 73,636,872 59,380,094
Options to purchase common stock      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potentially dilutive securities excluded from the computation of diluted loss per share (in shares) 115,614,728 68,920,334 54,209,289
Warrants      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potentially dilutive securities excluded from the computation of diluted loss per share (in shares) 0 4,629,988 5,015,642
Shares expected to be purchased under employee stock purchase plan      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potentially dilutive securities excluded from the computation of diluted loss per share (in shares) 65,905 86,550 155,163
v3.25.4
Goodwill (Details)
$ in Thousands, £ in Millions
 1 Months Ended
Dec. 31, 2017
GBP (£)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]      
Recognition of goodwill | £ £ 1.5    
Goodwill   $ 2,001 $ 1,864
Cumulative goodwill impairment charges   $ 0  
v3.25.4
Fair Value Measurements and Short-Term Investments - Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost $ 696,910 $ 395,986
Unrealized Gain 172 100
Unrealized (Loss) 0 0
Credit (Loss) 0 0
Fair Value 697,082 396,086
Level 1 | Money market funds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost 163,588 88,599
Unrealized Gain 0 0
Unrealized (Loss) 0 0
Credit (Loss) 0 0
Fair Value 163,588 88,599
Level 2 | Certificate of deposit    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost 25,000  
Unrealized Gain 0  
Unrealized (Loss) 0  
Credit (Loss) 0  
Fair Value 25,000  
Level 2 | U.S. Government treasury bills    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost 463,022 307,387
Unrealized Gain 160 100
Unrealized (Loss) 0 0
Credit (Loss) 0 0
Fair Value 463,182 $ 307,487
Level 2 | U.S. Government treasury bills    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Amortized Cost 45,300  
Unrealized Gain 12  
Unrealized (Loss) 0  
Credit (Loss) 0  
Fair Value $ 45,312  
v3.25.4
Fair Value Measurements and Short-Term Investments - Narrative (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Fair Value Disclosures [Abstract]    
Cash $ 16,366 $ 16,263
v3.25.4
Research and Development Prepaid Expenses and Accrued Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]    
Prepaid expenses and other current assets $ 3,996 $ 8,338
Accrued research and development expenditure $ 31,498 $ 17,441
v3.25.4
Leases - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 01, 2025
Aug. 18, 2025
Lessee, Lease, Description [Line Items]          
Leased assets obtained in exchange for operating lease liabilities $ 17,056 $ 4,216 $ 4,245    
Total lease payments 27,328        
Operating lease right-of-use assets $ 20,616 $ 7,144      
Weighted average discount rate 7.60% 6.90%      
Weighted average remaining lease term (in years) 6 years 8 months 12 days 2 years 9 months 18 days      
Cash payments related to lease liabilities $ 3,741 $ 2,568      
New Jersey And California          
Lessee, Lease, Description [Line Items]          
Leased assets obtained in exchange for operating lease liabilities 17,056        
Total lease payments $ 23,117        
CALIFORNIA          
Lessee, Lease, Description [Line Items]          
Lease term (in years)       8 years  
NEW JERSEY          
Lessee, Lease, Description [Line Items]          
Lease term (in years)         3 years
FLORIDA          
Lessee, Lease, Description [Line Items]          
Leased assets obtained in exchange for operating lease liabilities   $ 4,216      
v3.25.4
Leases - Lease Cost (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Lease, Cost [Abstract]      
Fixed lease costs $ 3,853 $ 3,461 $ 2,214
Variable lease costs 225 48 83
Total lease cost $ 4,078 $ 3,509 $ 2,297
v3.25.4
Leases - Future Lease Payments (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Leases [Abstract]    
2026 $ 3,492  
2027 4,052  
2028 4,158  
2029 3,349  
2030 3,073  
Thereafter 9,205  
Total lease payments 27,328  
Less: imputed interest 6,438  
Total operating lease liabilities 20,890  
Less: Operating lease liabilities, current portion 3,388 $ 3,765
Operating lease liabilities, net of current portion $ 17,502 $ 3,453
v3.25.4
Promissory Note Payable to Related Parties (Details)
$ / shares in Units, $ in Thousands
 12 Months Ended
Oct. 01, 2024
USD ($)
Sep. 16, 2024
USD ($)
Feb. 17, 2024
Feb. 15, 2023
USD ($)
Jan. 19, 2023
USD ($)
promissory_note
Dec. 06, 2022
USD ($)
$ / shares
shares
Dec. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Related Party Transaction [Line Items]                  
Repayment of related party notes payable $ 24,500 $ 75,500         $ 0 $ 100,000 $ 24,686
Cash paid for interest on related party promissory note $ 7,305           $ 0 8,806 $ 10,650
Note Purchase Agreement | Chief Executive Officer and Chief Executive Officer and President                  
Related Party Transaction [Line Items]                  
Promissory note           $ 520,000      
Interest rate           7.50%      
Prepaid interest, conversion amount (in dollars per share) | $ / shares           $ 0.7913      
Prepaid interest, conversion amount base (in dollars per share) | $ / shares           $ 0.01      
Common stock issued for prepaid interest (in shares) | shares           9,720,291      
Debt issuance costs           $ 44      
Note Purchase Agreement | Chief Executive Officer and Chief Executive Officer and President | Variable rate, three months immediately following February 15, 2023                  
Related Party Transaction [Line Items]                  
Interest rate margin           0.50%      
Note Purchase Agreement | Chief Executive Officer and Chief Executive Officer and President | Variable rate, thereafter                  
Related Party Transaction [Line Items]                  
Interest rate margin           3.00%      
Duggan February Note and Zanganeh Note | Chief Executive Officer and Chief Executive Officer and President                  
Related Party Transaction [Line Items]                  
Period from public offering (in business days)           5 days      
Public offering proceeds threshold percentage           100.00%      
Duggan February Note | Chief Executive Officer                  
Related Party Transaction [Line Items]                  
Promissory note           $ 400,000      
Zanganeh Note | Chief Executive Officer and President                  
Related Party Transaction [Line Items]                  
Promissory note           20,000      
Repayment of related party notes payable       $ 20,000          
Effective interest rate             8.90%    
Duggan September Note | Chief Executive Officer                  
Related Party Transaction [Line Items]                  
Promissory note           $ 100,000      
Revised Duggan February Note And Revised Duggan September Note | Chief Executive Officer                  
Related Party Transaction [Line Items]                  
New note issuances | promissory_note         2        
Revised Duggan February Note | Chief Executive Officer                  
Related Party Transaction [Line Items]                  
Notes payable, maturity triggering event, public offering proceeds threshold         $ 500,000        
Repayment of related party notes payable       $ 400,000          
Interest rate     12.00%            
Interest rate margin     3.50%            
Effective interest rate             8.90%    
Revised Duggan September Note | Chief Executive Officer                  
Related Party Transaction [Line Items]                  
Effective interest rate             11.30%    
Revised Duggan September Note | Related party                  
Related Party Transaction [Line Items]                  
Incurred interest expense               8,686  
Promissory Notes | Related party                  
Related Party Transaction [Line Items]                  
Promissory note             $ 0 $ 0  
Incurred interest expense             $ 0    
v3.25.4
Stockholders' Equity - Preferred Stock and Common Stock (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Oct. 21, 2025
Sep. 11, 2024
Jun. 03, 2024
Oct. 13, 2023
Jan. 19, 2023
Dec. 06, 2022
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
May 13, 2024
Apr. 27, 2023
Mar. 01, 2023
Jan. 31, 2023
Jan. 18, 2023
Subsidiary or Equity Method Investee [Line Items]                            
Preferred stock, shares authorized (in shares)             20,000,000 20,000,000            
Preferred stock par value (in dollars per share)             $ 0.01 $ 0.01            
Preferred stock, shares outstanding (in shares)             0 0            
Preferred stock, shares issued (in shares)             0 0            
Common stock, shares authorized (in shares)         1,000,000,000   1,000,000,000 1,000,000,000           350,000,000
Common stock par value (in dollars per share)             $ 0.01 $ 0.01   $ 0.01 $ 0.01   $ 0.01  
Common stock, shares issued (in shares)             775,371,200 737,626,004            
Common stock, shares outstanding (in shares)             775,371,200 737,626,004            
Sale of stock price (in dollars per share)     $ 9.00                      
Shares issued (in shares)     22,222,222                      
Offering costs             $ 0 $ 0 $ 619          
Increase in common stock, shares authorized (in shares)         650,000,000                  
Proceeds from the issuance of common stock via private placements, net of offering costs [1]             500,037 434,860 5,000          
Chief Executive Officer | Duggan February Note                            
Subsidiary or Equity Method Investee [Line Items]                            
Promissory note           $ 400,000                
Related party                            
Subsidiary or Equity Method Investee [Line Items]                            
Proceeds from issuance of common stock $ 10,000                          
Shares issued (in shares) 533,617                          
Chief Operations Officer                            
Subsidiary or Equity Method Investee [Line Items]                            
Proceeds from the issuance of common stock via private placements, net of offering costs       $ 5,000                    
Rights Offering                            
Subsidiary or Equity Method Investee [Line Items]                            
Sale of stock price (in dollars per share)           $ 1.05           $ 1.05    
Proceeds from issuance of common stock           $ 500,000 0 [1] 0 [1] 104,686 [1]          
Shares issued (in shares)           476,190,471                
Offering costs           $ 619                
Issuance of common stock             0 $ 0 $ 395,314          
Rights Offering | Chief Executive Officer                            
Subsidiary or Equity Method Investee [Line Items]                            
Issuance of common stock           $ 395,314                
S-3 Registration Statement | Chief Executive Officer                            
Subsidiary or Equity Method Investee [Line Items]                            
Number of shares registered for resale (in shares)                     9,346,434      
S-3 Registration Statement | Related party                            
Subsidiary or Equity Method Investee [Line Items]                            
Number of shares registered for resale (in shares)                     10,000,000      
S-3 Registration Statement | Chief Executive Officer and President                            
Subsidiary or Equity Method Investee [Line Items]                            
Number of shares registered for resale (in shares)                     373,857      
Private placement                            
Subsidiary or Equity Method Investee [Line Items]                            
Common stock par value (in dollars per share) $ 0.01 $ 0.01                        
Sale of stock price (in dollars per share) $ 18.74 $ 22.70                        
Proceeds from issuance of common stock $ 500,037 $ 235,000         $ 500,037              
Shares issued (in shares) 26,682,846 10,352,418                        
Offering costs   $ 140                        
Private placement | Chief Operations Officer                            
Subsidiary or Equity Method Investee [Line Items]                            
Sale of stock price (in dollars per share)       $ 1.68                    
Shares issued (in shares)       2,976,190                    
[1] Refer to Note 13 – Stockholders’ Equity for related party transactions.
v3.25.4
Stockholders' Equity - Private Investment in Public Equity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Oct. 21, 2025
Sep. 11, 2024
Jun. 03, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
May 13, 2024
Apr. 27, 2023
Jan. 31, 2023
Subsidiary or Equity Method Investee [Line Items]                  
Shares issued (in shares)     22,222,222            
Sale of stock price (in dollars per share)     $ 9.00            
Sale of stock aggregate price     $ 200,000            
Common stock par value (in dollars per share)       $ 0.01 $ 0.01   $ 0.01 $ 0.01 $ 0.01
Offering costs       $ 0 $ 0 $ 619      
Affiliated entity                  
Subsidiary or Equity Method Investee [Line Items]                  
Shares issued (in shares) 14,514,402                
Sale of stock aggregate price   $ 79,000              
Proceeds from issuance of common stock $ 272,000                
Nonrelated Party                  
Subsidiary or Equity Method Investee [Line Items]                  
Sale of stock aggregate price $ 218,037 $ 156,000              
Related party                  
Subsidiary or Equity Method Investee [Line Items]                  
Shares issued (in shares) 533,617                
Proceeds from issuance of common stock $ 10,000                
Private placement                  
Subsidiary or Equity Method Investee [Line Items]                  
Shares issued (in shares) 26,682,846 10,352,418              
Sale of stock price (in dollars per share) $ 18.74 $ 22.70              
Common stock par value (in dollars per share) $ 0.01 $ 0.01              
Proceeds from issuance of common stock $ 500,037 $ 235,000   $ 500,037          
Offering costs   $ 140              
v3.25.4
Stockholders' Equity - At-the-Market Offering and Warrants (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended 20 Months Ended
Aug. 11, 2025
Jun. 03, 2024
May 13, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2025
Apr. 27, 2023
Jan. 31, 2023
Subsidiary or Equity Method Investee [Line Items]                  
Common stock par value (in dollars per share)     $ 0.01 $ 0.01 $ 0.01   $ 0.01 $ 0.01 $ 0.01
Shares issued (in shares)   22,222,222              
Sale of stock price (in dollars per share)   $ 9.00              
Offering costs       $ 0 $ 0 $ 619      
Warrants outstanding (in shares)       0 4,629,988   0    
Warrant weighted average exercise price (in dollars per share)         $ 1.58        
Exercised (in shares)       4,629,988          
Exercised (in dollars per share)       $ 1.58          
Original Distribution Agreement                  
Subsidiary or Equity Method Investee [Line Items]                  
Sale of stock, aggregate offering price     $ 90,000            
Distribution Agreement                  
Subsidiary or Equity Method Investee [Line Items]                  
Sale of stock, aggregate offering price $ 360,000                
Shares issued (in shares)             7,146,432    
Sale of stock price (in dollars per share)       $ 21.09     $ 21.09    
Proceeds from issuance of common stock       $ 106,498     $ 150,721    
Offering costs             3,160    
Remaining availability under the offering       $ 299,279     $ 299,279    
v3.25.4
Stock Based Compensation - Narrative (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Sep. 21, 2020
Aug. 19, 2020
Jun. 30, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Sep. 18, 2025
Jan. 22, 2025
Jan. 01, 2025
May 03, 2024
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Weighted-average grant date fair value of stock options granted (in dollars per share)       $ 17.10 $ 3.40 $ 1.41        
Aggregate intrinsic value of stock options exercised       $ 15,212 $ 863 $ 474        
Minimum                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Equity award, vesting period (in years)       3 years            
Maximum                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Equity award, vesting period (in years)       4 years            
ESPP                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Number of shares initially reserve for future issuance (in shares)   1,000,000                
Potential number of additional shares that can be added to the plan for future issuance (in shares)   1,600,000                
Maximum percentage of outstanding shares   1.00%                
Number of shares available for grant (in shares)       1,743,682            
Consecutive offering period (in months)   6 months                
Maximum common stock purchase allowable as a percentage of compensation   15.00%                
Purchase price of common stock as a percentage of closing price   85.00%                
Stock issued (in shares)       139,459 353,578          
ESPP | Minimum                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Purchase price of common stock as a percentage of closing price   85.00%                
Employee Stock Option, Performance Based                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Accelerated vesting, number (in shares)     44,488,976              
Accelerated charges       $ 650,959            
Cost not yet recognized due to accelerated vesting, amount       $ 214,295            
Weighted average recognition period (in years)       1 year 7 months 6 days            
Time-based stock options                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Expiration period (in years)       10 years            
Unrecognized compensation expense       $ 345,387            
Unrecognized compensation expense, period of recognition (in years)       1 year 9 months 18 days            
Time-based stock options | Minimum                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Equity award, vesting period (in years)       3 years            
Time-based stock options | Maximum                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Equity award, vesting period (in years)       4 years            
2020 Plan                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Number of shares initially reserve for future issuance (in shares) 8,000,000                  
Number of shares that can be added to the plan upon option expiration (in shares) 5,000,000                  
Potential number of additional shares that can be added to the plan for future issuance (in shares) 6,400,000                  
Maximum percentage of outstanding shares 4.00%                  
Number of shares available for grant (in shares)       2,643,200            
Number of additional shares allowable (in shares)                 6,400,000  
2020 Incremental Pool                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Number of shares available for grant (in shares)       3,082,075            
Number of additional shares allowable (in shares)             8,000,000      
2024 Inducement Pool                    
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]                    
Number of shares initially reserve for future issuance (in shares)                   2,000,000
Number of shares available for grant (in shares)       1,936,452            
Number of additional shares allowable (in shares)               2,000,000    
v3.25.4
Stock Based Compensation - Weighted-Average Assumptions used for Stock Option Awards (Details)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Stock options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate   4.20% 4.60%
Expected term (in years)   6 years 2 months 12 days 4 years 9 months 18 days
Expected volatility   107.80% 98.10%
Expected annual dividends per share   0.00% 0.00%
Time-based stock options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk- free interest rate, minimum 3.80%    
Risk- free interest rate, maximum 3.90%    
Expected annual dividends per share 0.00%    
Time-based stock options | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term (in years) 2 years 6 months    
Expected volatility 124.90%    
Time-based stock options | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term (in years) 6 years 2 months 12 days    
Expected volatility 142.50%    
v3.25.4
Stock Based Compensation - Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Time-based stock options      
Number of share options      
Beginning balance (in shares) 108,136,310 108,136,310  
Granted (in shares)   13,297,732  
Forfeited (in shares)   (1,015,750)  
Exercised (in shares)   (953,564)  
Ending balance (in shares)   119,464,728 108,136,310
Weighted average exercise price      
Beginning balance (in dollars per share) $ 2.34 $ 2.34  
Granted (in dollars per share)   19.20  
Forfeited (in dollars per share)   10.12  
Exercised (in dollars per share)   3.99  
Ending balance (in dollars per share)   $ 4.14 $ 2.34
Stock option activity, additional disclosures      
Weighted average remaining contractual term, options outstanding (in years)   7 years 9 months 18 days 8 years 7 months 6 days
Aggregate intrinsic value, options outstanding   $ 1,618,734 $ 1,677,748
Number of share options, vested and expected to vest (in shares)   110,536,687  
Weighted average exercise price, vested and expected to vest (in dollars per share)   $ 3.86  
Weighted average remaining contractual term, vested and expected to vest (in years)   7 years 8 months 12 days  
Aggregate intrinsic value, vested and expected to vest   $ 1,527,454  
Number of share options, exercisable (in shares)   64,834,314  
Weighted average exercise price, exercisable (in dollars per share)   $ 2.32  
Weighted average remaining contractual term, exercisable (in years)   7 years 4 months 24 days  
Aggregate intrinsic value, exercisable   $ 983,902  
Employee Stock Option, Performance Based      
Number of share options      
Beginning balance (in shares) 48,220,320 48,220,320  
Granted (in shares) 5,475,000    
Ending balance (in shares)     48,220,320
Stock option activity, additional disclosures      
Number of shares unvested and converted (in shares)     39,013,976
v3.25.4
Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Stock-based compensation $ 732,420 $ 50,981 $ 14,108
Time-based stock options      
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Stock-based compensation 731,358 39,349 12,606
Performance and market-based stock options      
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Stock-based compensation 0 11,033 1,318
Employee stock purchase plan      
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Stock-based compensation 1,062 599 184
Research and development      
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Stock-based compensation 218,564 16,007 4,408
General and administrative      
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Stock-based compensation $ 513,856 $ 34,974 $ 9,700
v3.25.4
Related Party Transactions (Details)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended
Oct. 21, 2025
shares
Apr. 08, 2025
$ / shares
shares
Sep. 11, 2024
shares
Aug. 01, 2024
ft²
Jun. 03, 2024
shares
Apr. 01, 2024
USD ($)
ft²
contract
Mar. 31, 2025
$ / shares
shares
Oct. 31, 2024
shares
Dec. 31, 2025
USD ($)
$ / shares
shares
Dec. 31, 2024
USD ($)
$ / shares
Dec. 31, 2023
USD ($)
Jul. 29, 2022
ft²
Jul. 25, 2022
ft²
Related Party Transaction [Line Items]                          
Research and development [1]                 $ 537,674 $ 150,777 $ 59,471    
Accrued liabilities                 $ 32,100 $ 19,554      
Exercised (in shares) | shares                 4,629,988        
Shares issued (in shares) | shares         22,222,222                
Warrant weighted average exercise price (in dollars per share) | $ / shares                   $ 1.58      
Exercised (in dollars per share) | $ / shares                 $ 1.58        
Private placement                          
Related Party Transaction [Line Items]                          
Shares issued (in shares) | shares 26,682,846   10,352,418                    
Related party                          
Related Party Transaction [Line Items]                          
Shares issued (in shares) | shares 533,617                        
Affiliated entity                          
Related Party Transaction [Line Items]                          
Number of sublease contracts to other party | contract           2              
Shares issued (in shares) | shares 14,514,402                        
Co-Chief Executive Officer                          
Related Party Transaction [Line Items]                          
Exercised (in shares) | shares   1,048,834         2,936,221            
Warrant weighted average exercise price (in dollars per share) | $ / shares             $ 1.58            
Exercised (in dollars per share) | $ / shares   $ 1.58                      
Co-Chief Executive Officer | Private placement                          
Related Party Transaction [Line Items]                          
Shares issued (in shares) | shares             3,985,055            
Wilson Sonsini Goodrich & Rosati P.C. (“WSGR”)                          
Related Party Transaction [Line Items]                          
Legal fees                 $ 1,400        
Sublease Agreement, First and Third Amendment | Affiliated entity                          
Related Party Transaction [Line Items]                          
Payments to related party                 834 $ 795 762    
First amendment to sublease | Affiliated entity                          
Related Party Transaction [Line Items]                          
Area of premises subleased (in square feet) | ft²                         4,500
Sublease extension term (in months)                         39 months
Sublease Agreement, Third Amendment | Affiliated entity                          
Related Party Transaction [Line Items]                          
Area of premises subleased (in square feet) | ft²       145                  
Proportionate share of net payable       93.60%                  
Second amendment to sublease | Affiliated entity                          
Related Party Transaction [Line Items]                          
Area of premises subleased (in square feet) | ft²                       1,277  
Payments to related party                 232 224 218    
Genius Sublease Agreement | Affiliated entity                          
Related Party Transaction [Line Items]                          
Number of sublease contracts to other party | contract           1              
Area of premises subleased to other party (in square feet) | ft²           848              
Sublease term to other party (in months)           62 months              
Total sublease rental payments to be received           $ 446              
Investments Research Sublease Agreement | Affiliated entity                          
Related Party Transaction [Line Items]                          
Number of sublease contracts to other party | contract           1              
Area of premises subleased to other party (in square feet) | ft²           848              
Sublease term to other party (in months)           62 months              
Total sublease rental payments to be received           $ 446              
Genius Sublease Agreement And Investments Research Sublease Agreement | Affiliated entity                          
Related Party Transaction [Line Items]                          
Sublease income                 186 156      
Akeso Supply Agreement | Related party                          
Related Party Transaction [Line Items]                          
Research and development                 46,133 24,635 $ 6,207    
Accrued liabilities                 $ 1,215 $ 3,956      
Consulting Agreement | Affiliated entity                          
Related Party Transaction [Line Items]                          
Exercised (in shares) | shares               315,681          
[1] Refer to Note 15 – Related Party Transactions for expenses incurred.
v3.25.4
Commitments and Contingencies (Details) - USD ($)
Dec. 31, 2025
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]    
Capital commitments $ 0 $ 0
Period for which the majority of contractual commitments are to be paid (in years) 1 year  
Contractual commitments $ 17,976,000