Prelude Therapeutics Inc

1. Nature of Operations

Prelude Therapeutics Incorporated (the “Company”) is a precision oncology company built on a foundation of drug discovery excellence to deliver novel precision cancer medicines to underserved patients. Since beginning operations in 2016, the Company has devoted substantially all its efforts to research and development, conducting preclinical and clinical studies, recruiting management and technical staff, administration, and raising capital.

2. Risks and Liquidity

The Company faces a number of risks common to early-stage companies in the biotechnology industry. Principal among these risks are the uncertainties in the development process, development of the same or similar technological innovations by competitors, protection of proprietary technology, dependence on key personnel, compliance with government regulations and approval requirements, and the need to obtain additional financing to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure, and extensive compliance-reporting capabilities. There can be no assurance that the Company’s research and development will be successfully completed, adequate protection for the Company’s technology will be obtained, any products developed will obtain necessary government regulatory approval, or any approved products will be commercially viable. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies.

Since its inception, the Company has incurred operating losses and had an accumulated deficit of$683.1 million as of December 31, 2025. The Company has no product revenue to date and devotes its efforts to research and development. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of its product candidates currently in development.

At December 31, 2025, the Company had cash, cash equivalents, restricted cash and marketable securities totaling $106.4 million and the Company believes these funds will be sufficient to fund its operating expenses and capital expenditure requirements for at least the next twelve months from the filing date of this Annual Report on Form 10-K.

To fund its operating expenses and capital expenditure requirements after that date, the Company plans to seek additional funding through public or private equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into strategic alliances or other arrangements on favorable terms, or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, it 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.

3. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying financial statements have been prepared in accordance with generally accepted accounting principles (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) promulgated by the Financial Accounting Standards Board (“FASB”).

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.

Estimates and assumptions are periodically reviewed, and the effects of the revisions are reflected in the accompanying financial statements in the period they are determined to be necessary. The most significant estimate relates to accrued clinical trial expenses.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist of cash, cash equivalents, and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant credit risk beyond the normal credit risk associated with commercial banking relationships.

Segment Information

Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker ("CODM") is its Chief Executive Officer. The Company views and manages its operations as asingle operating segment. See Note 9 - Segments for further details.

Fair Value of Financial Instruments

Management believes the carrying amounts of the Company’s financial instruments, including cash, restricted cash, accounts payable, and accrued expenses, approximate fair value due to the short-term nature of these instruments.

Cash, Cash Equivalents and Restricted cash

The Company’s cash equivalents include short-term highly liquid investments with an original maturity of 90 days or less when purchased and are carried at fair value in the accompanying balance sheets.

Restricted cash comprises a letter of credit for the benefit of the landlord in connection with the Company’s Chestnut Run Lease. See Note 8 - Commitments for further details.

The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the balance sheet that total to the amounts shown in the statement of cash flows:

Marketable Securities

The Company’s marketable securities consist of investments in corporate debt securities and United States ("U.S") government debt securities that are classified as available-for-sale. The securities are carried at fair value with the unrealized gains and losses, net of tax, included in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses as well as credit losses, if any, on marketable securities are included in the Company’s statements of operations. The Company classifies marketable securities that are available for use in current operations as current assets on the balance sheets.

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation expense is recognized using the straight-line method over the estimated useful life of the asset, ranging from 5-7 years as follows:

Leasehold improvements are amortized over the shorter of the estimated useful life of the assets or the remaining lease term.

Expenditures for repairs and maintenance of assets are charged to expense as incurred, while major betterments are capitalized. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in the statements of operations.

The Company reviews long-lived assets, such as property and equipment, for impairment when events or changes in circumstances indicate the carrying amount of the assets may not be recoverable. If indicators of impairment are present, the assets are tested for recoverability by comparing the carrying amount of the assets to the related estimated future undiscounted cash flows that the assets are expected to generate. If the expected cash flows are less than the carrying value of the asset, then the asset is considered to be impaired and its carrying value is written down to fair value, based on the related estimated discounted future cash flows.

Leases

The Company accounts for leases in accordance with ASC Topic 842, Leases. The Company's lease for office and laboratory space located in Wilmington, DE is classified as an operating lease. The lease results in an operating right-of-use (ROU) asset, a current operating lease liability, and a non-current operating lease liability in the balance sheet and has a remaining lease term of approximately 11 years. Leases with a term of 12 months or less are considered short-term and a ROU asset and lease obligation are not recognized.

ROU assets represent the right to use an underlying asset for the lease term and the lease liabilities represent an obligation to make lease payments arising from the lease, measured at the present value of the lease payments not yet paid discounted using the discount rate for the lease established at the lease commencement date. The operating lease ROU asset also includes any prepaid lease payments made. Lease expense is recognized over the expected lease term on a straight-line basis.

Comprehensive loss

Comprehensive loss includes net loss and certain changes in stockholders’ equity that are excluded from net loss. The Company’s comprehensive loss for the years ended December 31, 2025 and 2024 comprised net loss and unrealized gain or loss on marketable securities.

Revenue Recognition

The Company recognizes revenue under Accounting Standard Codification 606 –Revenue from Contracts with Customers("ASC 606"). Under ASC 606, the Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods or services. The Company's revenue recognition analysis consists of the following steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations; and (v) recognition of revenue as it satisfies each performance obligation.

The Company evaluates all promised goods and services within a customer contract and determines which goods and services are separate performance obligations. This evaluation includes an assessment of whether the good or service is capable of being distinct and whether the good or service is separable from other promises in the contract.

The transaction price is determined based on the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligations when (or as) the performance obligations are satisfied. The Company recognizes a liability when the Company has received payment but has not yet satisfied the related performance obligations. See note 8 for a full discussion of the Company's revenue contracts. The following table summarizes the changes in deferred revenue:

Stock-Based Compensation

The Company measures share-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards.

Estimating the fair value of share-based awards requires the input of subjective assumptions, including, for stock options, the expected life of the options and stock price volatility. The Company accounts for forfeitures for stock option awards as they occur. The Company uses the Black-Scholes option pricing model to value its stock option awards. The assumptions used in estimating the fair value of share-based awards represent management’s estimate and involve inherent uncertainties and the application of management’s judgment. As a result, if factors change and management uses different assumptions, share-based compensation expense could be materially different for future awards.

The expected life of the stock options is estimated using the “simplified method”, as the Company has limited historical information from which to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. The simplified method is the midpoint between the vesting period and the contractual term of the option. For stock price volatility, the Company uses its own historical volatility along with comparable public companies as a basis for its expected volatility to calculate the fair value of option grants. The risk-free rate is based on the U.S. Treasury yield curve commensurate with the expected life of the option.

Grant Income and Research and Development Tax Credits

The Company recognizes grants related to income and Delaware research and development tax credits in other income, net in the statements of operations when the necessary qualifying conditions, as stated in the agreements, are met and all contingencies have been resolved. For the years ended December 31, 2025 and 2024, the Company recorded other income related to these items of $1.2 million and $2.5 million, respectively. The Company recognizes grants related to assets as deferred income which is included in the balance sheet as other liabilities. The deferred income is then recognized as grant income over the useful life of the related assets.

Research and Development

Research and development costs are expensed as incurred. Research and development expenses consist principally of personnel costs, including salaries, stock-based compensation, and benefits of employees, and other operational costs related to the Company’s research and development activities, including allocated facility-related expenses and external costs of outside vendors, such as clinical research organizations ("CROs") and clinical manufacturing organizations, and other direct and indirect costs.

The Company accrues an expense or records a prepaid for preclinical studies and clinical trial activities performed by CROs and vendors based upon estimates of the proportion of work completed. These estimates are determined by reviewing contracts, vendor agreements and purchase orders, and through discussions with internal clinical personnel and external service providers as to the progress or stage of completion of trials or services and the agreed-upon fee to be paid for such services.

Management makes estimates of the Company’s accrued research and development expenses as of each balance sheet date in the Company’s financial statements based on facts and circumstances known to the Company at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Nonrefundable advance payments for goods and services, including fees for process development or manufacturing and distribution of clinical supplies that will be used in future research and development activities, are deferred and recognized as expense in the period that the related goods are consumed or services are performed.

Income Taxes

Income taxes are accounted for under the asset-and-liability method as required by ASC Topic 740, Income Taxes (“ASC 740”). Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period corresponding to the enactment date. Under ASC 740, a valuation allowance is required when it is more likely than not all or some portion of the deferred tax assets will not be realized through generating sufficient future taxable income.

ASC Subtopic 740-10, Accounting for Uncertainty of Income Taxes, (“ASC 740-10”) defines the criterion an individual tax position must meet for any part of the benefit of the tax position to be recognized in financial statements prepared in conformity with GAAP. The Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not such tax position will be sustained on examination by the taxing authorities, based solely on the technical merits of the respective tax position. The tax benefits recognized in the financial statements from such a tax position should be measured based on the largest benefit having a greater than 50% likelihood of being realized upon ultimate settlement with the tax authority. In accordance with the disclosure requirements of ASC 740-10, the Company’s policy on income statement classification of interest and penalties related to income tax obligations is to include such items as a component of income tax expense.

Net Loss Per Share

Basic net loss per share of common stock is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during each period, including pre-funded warrants to purchase shares of common stock. Diluted net loss per share of common stock includes the effect, if any, from the potential exercise of securities, such as stock options, and the effect from unvested restricted stock units which would result in the issuance of incremental shares of common stock. For diluted net loss per share, the weighted-average number of shares of common stock is the same for basic net loss per share due to the fact that when a net loss exists, dilutive securities are not included in the calculation as the impact is anti-dilutive.

The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares of common stock outstanding, as they would be anti-dilutive:

Amounts in the above table reflect the common stock equivalents.

Recently Issued Accounting Pronouncements

Emerging Growth Company Status

The Company is no longer an emerging growth company as of December 31, 2025 and, as a result, is no longer able to take advantage of reduced disclosure and other obligations that are available to emerging growth companies. However, we still qualify as a “smaller reporting company” which allows us to take advantage of many of the same exemptions from disclosure requirements and other obligations.

Recently adopted accounting guidance

In December 2023, the FASB issued ASU Update No. 2023-09, Income Taxes - Improvements to Income Tax Disclosures. ASU 2023-09 requires enhanced income tax disclosures related to the rate reconciliation and income taxes paid information. The Company adopted ASU 2023-09 on January 1, 2025 andincorporated the improved income tax disclosures in Note 12, Income Taxes.

Accounting guidance not yet adopted

In November 2024, the FASB issued ASU Update No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures. ASU 2024-03 requires disclosure, in the notes to the financial statements, of specified information about certain costs and expenses. The amendments in this Update are effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of this standard but does not expect that it will have a material impact on the financial statements and related disclosures.

4. Marketable Securities

The following is a summary of the Company’s marketable securities as of December 31, 2025 and 2024.

The Company’s marketable securities generally have contractual maturity dates of 13 months or less. As of December 31, 2025, the Company had 14 securities with a total fair market value of $33.1 million in an unrealized loss position. The Company believes that any unrealized losses associated with the decline in value of its securities is temporary and is primarily related to the change in market interest rates since purchase and believes that it is more likely than not that it will be able to hold its marketable securities to maturity.

5. Fair Value of Financial Instruments

Fair value is the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value determination in accordance with applicable accounting guidance requires that a number of significant judgments be made. Additionally, fair value is used on a nonrecurring basis to evaluate assets for impairment or as required for disclosure purposes by applicable accounting guidance on disclosures about fair value of financial instruments. Depending on the nature of the assets and liabilities, various valuation techniques and assumptions are used when estimating fair value. The Company follows the provisions of ASC Topic 820, Fair Value Measurement, for financial assets and liabilities measured on a recurring basis. The guidance requires fair value measurements be classified and disclosed in one of the following three categories:

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Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

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Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liabilities.

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Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

The following fair value hierarchy table presents information about the Company’s assets and liabilities measured at fair value on a recurring basis:

6. Property and Equipment

Property and equipment consisted of the following:

7. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following:

8. Commitments

Leases

The Company leases office and laboratory space in Wilmington, Delaware under a noncancelable lease (the “Chestnut Run Lease”). The premises includes approximately 81,000 rentable square feet and has an initial term of 162 months with 3 five-year extension options and certain expansion rights. Neither the option to extend nor the expansion rights were recognized as part of the Company's measurement of the ROU asset and operating lease liability as of December 31, 2025. Under the terms of the Chestnut Run Lease, the landlord provided an allowance towards the cost of completing tenant improvements for the premises. The Company concluded that the improvements resulting from both the landlord's build-out and the tenant improvements are the landlord's assets for accounting purposes. Costs incurred by the Company related to tenant improvements in excess of the landlord's allowance were treated as prepaid rent and increased the right-of-use asset on the commencement date.

In April 2024, the Company entered into a 12 month finance lease for equipment. The final payment under the agreement was made in April 2025.

Lease cost for each year ended December 31, 2025 and 2024, was $4.4 million, including $0.2 million of short-term lease cost.

In November 2025, the Company entered into a sublease agreement with a counterparty to sublease approximately 20,000 square feet of the Chestnut Run Lease. The sublease began in December 2025 and continues through November 2027. The sublessee hasthree options to extend the sublease forone year each.

The Company analyzed the sublease under ASC Topic 842, Leases ("ASC 842"), and concluded the sublease is a separate lease, as the Company was not relieved of the primary obligation under the Chestnut Run Lease. The Company will continue to account for the Chestnut Run Lease as a lessee and in the same manner as prior to the execution of Sublease Agreement. The Company accounted for the sublease agreement as the lessor, and concluded the sublease qualified as an operating lease, as it did not meet the criteria of a sales-type or direct financing lease. The Company's sublease income was immaterial during the year ended December 31, 2025.

Supplemental balance sheet and other information related to our operating and finance leases as of December 31, 2025 and 2024 were as follows:

Supplemental cash flow information related to our leases for the twelve months ended December 31, 2025 and 2024 were as follows:

As of December 31, 2025 future minimum annual lease payments for operating lease are as follows:

The Company paid a security deposit in the form of a letter of credit of $4.0 million which is included in the accompanying balance sheet as restricted cash. The letter of credit was reduced during the third quarter of 2025 and as of December 31, 2025 the balance was $3.2 million. The security deposit may be reduced to $0.5 million over time in accordance with the terms of the Chestnut Run Lease.

In connection with the Company’s expansion of operations in the State of Delaware, the Company was approved for two grants from the State of Delaware in 2021 and 2022 totaling $3.4 million for the development of lab space. The Company has met the minimum requirements stated in the grant agreement in order to not be required to pay back any portion of the $3.4 million disbursed unless the Company leaves the State of Delaware within five years of disbursement. The Company deferred the recognition of these grant funds as they relate to capitalized costs and has classified them as long-term liabilities in the accompanying balance sheet. The Company recognizes the grant funds in other income over the length of the lease term. During the years ended December 31, 2025 and 2024, the Company recognized $0.2 million of other income related to this grant.

Employment Agreements

The Company entered into employment agreements with key personnel providing for compensation and severance in certain circumstances, as defined in the respective employment agreements.

401(k) Defined Contribution Plan

The Company sponsors a 401(k) defined‑contribution plan covering all employees. Participants are permitted to contribute up to 100% of their eligible annual pretax compensation up to an established federal limit on aggregate participant contributions. The Company provides a match with a maximum amount of 3% of the participant’s compensation. During the years ended December 31, 2025 and 2024 the Company made matching contributions of $0.7 million and $0.8 million, respectively.

Exclusive Option Agreement

On November 3, 2025, the Company entered into an Exclusive Option Agreement (the “Option Agreement”) with Incyte to acquire the Company’s mutative selective JAK2V617F JH2 inhibitor program (the “Program”) for patients with myeloproliferative neoplasms.

Under the Option Agreement, Incyte received an exclusive option to acquire the Company’s entire right, title, and interest in and to certain assets, properties, and rights related to the Program, including the Company’s library of preclinical candidates (collectively, the “Transferred Assets”) by way of an Asset Purchase Agreement (the "APA"). The Company is continuing to advance the Program. At any time commencing on the effective date of the Option Agreement until the later of (a) 30 days after the Company’s delivery of the investigational new drug ("IND") ready data package or (b) 15 months after the effective date of the Option Agreement (which 15 month period shall automatically toll for the Company to deliver the IND-ready package but such tolling will not exceed 3 months unless otherwise agreed by the parties) (the “Option Period”), Incyte may elect to exercise its exclusive option to acquire the Program and associated assets from the Company pursuant to the APA for $100 million. The Company received an initial upfront payment of $35 million in cash from the Option Agreement. Under the APA, the Company would be eligible to receive up to $775 million in additional clinical and regulatory milestones, and single digit royalties on global net sales. Combined, total potential cash payments from the transaction could reach up to $910 million.

Concurrently with the Option Agreement, the Company entered into a securities purchase agreement with Incyte (the “Securities Purchase Agreement”), pursuant to which Incyte purchased 6,250,000 shares (the “Shares”) of the Company’s non-voting common stock at a price of $4.00 per share for gross proceeds of $25.0 million. Pursuant to the Company’s amended and restated certificate of incorporation and subject to the non-voting common stock beneficial ownership limitation, Incyte may elect to convert the Shares into voting shares and in December 2025, Incyte converted 4,372,124 ofthe Shares into voting shares, making them a related party under SEC regulations. Because the Option Agreement and Securities Purchase Agreement were entered into at the same time and negotiated as single commercial package, the Company accounted for the agreements as a single contract under ASC 606. Based on this exercise, the consideration in the Option Agreement plus any excess consideration paid over the fair value of the equity issued to Incyte is a component of transaction price. In determining the fair value of the common stock issued to Incyte, the Company considered the closing price of the common stock on the date of the transaction, which was $3.98 per share, which resulted in a premium paid by Incyte of $0.02 per share, or $0.1 million (“Equity Premium”). The remaining $24.9 million was recorded as an issuance of common stock in stockholders’ equity.

The Company will continue to own and develop all Transferred Assets. If the option is exercised during the Option Period and the parties enter into and close the transaction set forth in the APA, Incyte will own all Transferred Assets subject to the Company’s right, in its sole discretion and cost, to continue to conduct development activities during the Option Period to nominate and select development candidate(s) for the Program. If Incyte elects to not exercise its option to acquire the Program, all Transferred Assets would remain in the sole ownership and control of the Company.

The Company first evaluated whether the arrangement meets the definition of a derivative or contains any embedded derivatives under ASC 815, Derivatives and Hedging. Although the arrangement includes underlying IP‑related value, it qualifies for the scope exception as prescribed by ASC 815-10-15-59(b). The Company next evaluated whether the arrangement represents a funded research and development arrangement under ASC 730, Research and Development. The payments received by Prelude are non-refundable, and there is no contractual requirement, guarantee, or other provision that would require the Company to repay any of the funds received from Incyte. The Company also concluded that any presumption that there is an obligation to repay the funds received due to the subsequent related party relationship with Incyte is overcome, and therefore the agreements are not within the scope of ASC 730-20. The Company also concluded that the agreements are not within the scope of ASC 808, Collaborative Arrangements. The Company assessed the Option Agreement in accordance with ASC 606, Revenue from Contracts with Customer, and concluded that Incyte is a customer in the context of the Option Agreement. The Option Agreement includes the transfer of the following goods or services: (i) to conduct research and development activities related to the Program and (ii) Incyte's exclusive option to acquire the Company’s entire right, title, and interest in and to certain assets, properties, and rights related to the Program. The Company determined that the exclusive option granted was not a material right and, thus, not a performance obligation.

The Company determined that the transaction price totaled $35.1 million, which includes the $35 million upfront cash payment received and the Equity Premium. The Company allocated $35.1 million to its performance obligations to conduct research and development activities related to the Program. The Company will recognize revenue related to the Option Agreement over time as theperformance obligations are satisfied using an inputs approach, by applying actual expenses against total budgeted costs. As of December 31, 2025, $32.4 million of the upfront payment was included in deferred revenue within the balance sheets which the Company estimates will be recognized within thirteen months from year-end. The Company recognized $2.6 million in revenue related to the Option Agreement during the year ended December 31, 2025.

Research Collaboration Agreement

In 2023, the Company entered into a multi-year, multi-program agreement with AbCellera Biologics Incorporated ("AbCellera") to jointly discover, develop, and commercialize novel degrader antibody conjugates (“DACs”) for up to five programs (the "Collaboration Agreement"). Under the terms of the agreement, AbCellera will lead manufacturing activities and the Company will lead clinical development and global commercialization, subject to AbCellera’s option to co-promote any resulting commercial products in the United States. The Company concluded that the Collaboration Agreement with AbCellera will be accounted for under the scope of ASC 808, Collaborative Arrangements, as both parties will actively participate in joint operating activities and are exposed to significant risks and rewards. Costs related to the AbCellera collaboration were not material for the years ended December 31, 2025 and 2024.

In August 2025 the Company amended its collaboration with AbCellera (the "Amended Agreement"), and in October 2025, the Company further expanded the collaboration ("the Expanded License Agreement"). The Amended Agreement and Expanded License Agreement provided AbCellera a non-exclusive license to use certain of the Company’s degrader payloads to independently discover, develop and commercialize a select number of DACs against undisclosed antibody targets. The agreements also entailed other changes to overall resource allocation and collaboration governance. For the newly licensed DAC programs, AbCellera received world-wide rights to lead and fully control the licensed programs at its sole cost and expense and the Company is not responsible for any additional financial responsibilities or go forward development costs associated with those programs. The Company received an upfront non-refundable payment from AbCellera of $6.5 million upon signing the Amended Agreement and an upfront non-refundable payment of $6.0 million upon signing of the Expanded License Agreement. For the additional licensed DACs, the Company is also eligible to receive customary downstream milestones and single digit royalties on future product sales. The original Collaboration Agreement, whereunder the companiescan jointly discover, develop, and commercialize novel DACs for up to five programs remains in effect.

The Company assessed the Amended Agreement signed in accordance with ASC 606, Revenue from Contracts with Customer, and concluded that AbCellera is a customer in the context of the Amended Agreement. The Amended Agreement required the Company to transfer certain intellectual property and related know-how to AbCellera which represented the only performance obligation in the Amended Agreement and was satisfied at a point in time, when the intellectual property and related know-how were transferred to AbCellera during the third quarter of 2025. Accordingly, the Company recognized revenue of $6.5 million during the year ended December 31, 2025 related to the Amended Agreement.

The Company assessed the Expanded Agreement signed in accordance with ASC 606 and concluded that AbCellera is a customer in the context of the Expanded Agreement. The Company determined the promised goods and services included discovering degrader payloads and granting the licenses to the payloads to AbCellera for them to use to research, develop, and commercialize products related to each of the initial targets mutually agreed upon. Each of these licenses is distinct, as AbCellera can derive benefit from each license independent of any other payload. Accordingly, the license to each of the payloads selected by AbCellera represents a separate performance obligation. The delivery of the licenses were the only performance obligations identified in the Expanded Agreement. The transaction price was determined to consist of the upfront payment of $6.0 million. The Company allocated the transaction price equally across the licenses, as the estimated standalone selling price of each license was equal. Each performance obligation will be fully satisfied at the point in time when the license is transferred to AbCellera. For the year ended December 31, 2025, the Company recognized revenue of $3.0 million in the statement of operations related to the licenses that were transferred to AbCellera during the year. As of December 31, 2025, the remaining $3.0 million of the upfront payment was included in deferred revenue within the balance sheets. The Company estimates the remaining performance obligations will be completed in the second half of 2026.

License Agreement

In May 2024, the Company and Pathos AI, Inc. ("Pathos") entered into a license agreement under which the Company granted to Pathos an exclusive, sublicensable, world-wide license to its selective, brain-penetrant PRMT5 inhibitor, PRT811. Under the terms of the license agreement, the Company received a $3.0 million upfront, non-refundable payment. The agreement also included a near term $4.0 million payment due to the Company upon the earlier of 180 days following the effective date of the license agreement or the execution of a quality agreement between the parties pursuant to which the Company will transfer title to certain quantities of Active Pharmaceutical Ingredient (“API”). In addition, the Company may receive potential developmental milestone payments up to $37.0 million, potential sales milestone payments up to $100 million and a range of high single-digit to low double-digit royalties on PRT811 global net sales.

The Company assessed the license agreement with Pathos in accordance with ASC 606 and concluded that Pathos is a customer. The license agreement with Pathos includes the transfer of the following goods or services: (i) exclusive license to PRT811, (ii) transfer of licensed know-how and materials (i.e. datasets, regulatory and manufacturing documents, etc.), (iii) participation in a Joint Communication Committee ("JCC"), and (iv) execution of a quality agreement pursuant to which the Company will transfer title to certain API. The Company evaluated all of the promised goods or services within the contract and determined which goods and services were separate performance obligations. The Company determined that Pathos could not benefit from the license separately from the related know-how and materials, and accordingly, they represent one combined performance obligation. The execution of a quality agreement pursuant to which the Company will transfer title to certain API was identified as a separate performance obligation. The Company also determined the participation in the JCC is immaterial in the context of the license agreement as the Company has no decision-making ability through its participation in the JCC.

The transaction price was allocated to the performance obligations based upon their relative standalone selling prices, which were estimated for (i) the exclusive license and know-how and materials at $3.0 million using an adjusted market approach and (ii) execution of a quality agreement pursuant to which the Company transferred title to certain API at $4.0 million using a cost plus margin approach.

With respect to the accounting principles identified above, each performance obligation was recognized at a point in time. The Company determined that the performance obligation for the license and transfer of related know-how and materials was fully satisfied when the license was granted and key know-how and materials were transferred to Pathos as that was the point at which Pathos can fully use and benefit from the license to PRT811. The performance obligation for the execution of a quality agreement pursuant to which the Company transferred title to certain API was satisfied when the legal titleto the API was transferred. During 2024, the Company satisfied both performance obligations, resulting in $7.0 million of revenue recognized in the statement of operations for the year ended December 31, 2024.

Other Research and Development Arrangements

The Company enters into agreements with CROs to assist in the performance of research and development activities. Expenditures to CROs will represent a significant cost in clinical development for the Company.

9. Segments

The Company currently operates asone operating business segment focused on developing innovative medicines in areas of high unmet need for cancer patients. The Company's determination that it operates as a single segment is consistent with the financial information regularly reviewed by the chief operating decision maker ("CODM") for purposes of evaluating performance, allocating resources, and planning and forecasting for future periods.

The accounting policies of the segment are the same as those described in the summary of significant accounting policies. The CODM assesses performance for the segment based on net loss, which is reported on the statement of operations and comprehensive loss as net loss. The measure of segment assets is reported on the balance sheet as total assets.

To date, the Company has not recognized any revenue from product sales, and the Company does not expect to generate any revenue from product sales in the foreseeable future. Net loss is used to monitor budget versus actual results. Monitoring budgeted versus actual results is used in assessing performance of the segment and to make decisions about the allocation of resources, along with cash forecast models.

The following tables summarizes the significant expense categories regularly reviewed by the CODM for the years ended December 31, 2025, and 2024. Included in Other are programs such as PRT2527, PRT1419, and PRT3645.

10. Common Stock

The Company has two classes of common stock: “voting common stock” and “non-voting common stock.”The holders of the voting common stock are entitled to one vote for each share of voting common stock held at all meetings of stockholders. Exceptas otherwise required by law, the holders of non-voting common stock shall not be entitled to vote at any meetings of stockholders (or written actions in lieu of meetings) and the shares of non-voting common stock shall not be included in determining the number of shares voting or entitled to vote on any matter. Unless required by law, there shall be nocumulative voting. Any holder of non-voting common stock may elect to convert each share of non-voting common stock into one fully paid and non-assessable share of voting common stock at any time by providing written notice to the Company; provided that as a result of such conversion, such holder, together with its affiliates and any members of a Schedule 13(d) group with such holder, would not beneficially own in excess of 9.99% of the Company’s common stock immediately prior to and following such conversion, unless otherwise as expressly provided for in the Company’s restated certificate of incorporation. However, this ownership limitation may be increased (not to exceed 19.99%) or decreased to any other percentage designated by such holder of non-voting common stock upon 61 days’ notice to the Company.

Pre-funded warrants

There were 1,300,000 pre-funded warrants exercised during the year ended December 31, 2025. There wereno pre-funded warrants exercised during the year ended December 31, 2024. As of December 31, 2025, there were 19,532,188 pre-funded warrants outstanding.

Shelf Registration Statements

In May 2024, the Company filed a shelf registration statement (the "2024 Shelf Registration Statement") with the SEC for the issuance of common stock, preferred stock, debt securities, warrants, subscription rights and units up to an aggregate amount of $400 million. The 2024 Shelf Registration statement was declared effective on June 10, 2024. As of December 31, 2025, there was $400.0 million remaining under the 2024 Shelf Registration Statement.

Open Market Sales Agreement

In March 2023, in connection with filing a prospectus supplement to its 2021 Shelf Registration Statement, the Company entered into an Open Market Sales Agreement (the "Sales Agreement") with Jefferies LLC, as the sales agent, pursuant to which the Company may offer and sell shares of its common stock having an aggregate offering amount of up to $75.0 million. In November 2024, the 2021 Shelf Registration Statement expired with respect to the shares to be sold under the Sales Agreement. Accordingly, the Company will need to register the $75.0 million of common stock that may be issued and sold pursuant to the Sales Agreement on a subsequent registration statement before any future sales are permitted. The Company will pay Jefferies LLC a commission rate of up to 3.0% of the aggregate gross proceeds from the sale of any shares of common stock pursuant to the Sales Agreement. At December 31, 2025, there was $75.0 million remaining under the Sales Agreement.

11. Stock-Based Compensation

The Company hastwo equity incentive plans: the 2016 Equity Incentive Plan, as amended, and the 2020 Equity Incentive Plan. New awards can only be granted under the 2020 Equity Incentive Plan (the “Plan”) and as of December 31, 2025,7,449,465 shares were available for future grants. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the Plan shall automatically increase on January 1st of each year and continuing forten years beginning on January 1, 2021, in an amount equal tofive percent of the total number of shares of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the Company's board of directors or compensation committee to determine a lesser number of shares shall be added for such year. On January 1, 2026,3,147,681 shares were added to the Plan. The Plan provides for the granting of common stock, incentive stock options, nonqualified stock options, restricted stock awards, restricted stock units and/or stock appreciation rights to employees, directors, and other persons, as determined by the Company’s board of directors. The Company’s stock options vest based on the terms in each award agreement, generally over four-year periods with 25% of options vesting afterone year and then monthly thereafter, and have a term often years.

The Company measures stock-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. The Company recorded stock-based compensation expense in the following expense categories in its accompanying statements of operations:

Stock Options

The following table summarizes stock option activity for the Plan in the years indicated:

The aggregate intrinsic value of options exercised was immaterial during the years ended December 31, 2025 and 2024. At December 31, 2025, the aggregate intrinsic value of outstanding options and exercisable options was $7.5 million and $2.0 million, respectively.

The following table summarizes information about stock options outstanding and exercisable at December 31, 2025 under the Plan:

The weighted-average grant date fair value of options granted was $0.83 and $3.25 per share for the years ended December 31, 2025 and 2024, respectively. The Company recorded stock-based compensation expense of $11.6 million and $20.8 million for the years ended December 31, 2025 and 2024, respectively, related to stock options. As of December 31, 2025, the total unrecognized compensation expense related to unvested stock option awards was $9.5 million, which the Company expects to recognize over a weighted-average period of 1.8 years.

The fair value of each option was estimated on the date of grant using the weighted average assumptions in the table below:

Restricted Stock Units

The Company issues restricted stock units (“RSU”) to employees that generally vest over afour-year period with 25% of awards vesting after one year and then quarterly thereafter. Any unvested shares will be forfeited upon termination of services.

The following table summarizes activity related to RSU stock-based payment awards:

The Company recorded stock-based compensation expense of $0.2 million and $0.3 million for the years ended December 31, 2025 and 2024, respectively, related to RSUs. At December 31, 2025 the total unrecognized expense related to the RSUs was $0.2 million, which the Company expects to recognize over a weighted-average period of 2.5 years.

Employee Stock Purchase Plan

The Company has an Employee Stock Purchase Plan (the “ESPP”), which as of December 31, 2025 had 2,308,269 shares of common stock reserved for future issuance. The number of shares of the Company’s common stock that may be issued pursuant to rights granted under the ESPP shall automatically increase on January 1st of each year and continuing forten years beginning in 2021, in an amount equal toone percent of the total number of shares of all classes of the Company’s common stock outstanding on December 31st of the preceding calendar year, subject to the discretion of the Company's board of directors or compensation committee to determine a lesser number of shares shall be added for such year. On January 1, 2026,629,536 shares were added to the ESPP.

Under the ESPP, eligible employees can purchase the Company’s common stock through accumulated payroll deductions at such times as are established by the Company's compensation committee. Eligible employees may purchase the Company’s common stock at 85% of the lower of the fair market value of the Company’s common stock on the first day of the offering period or on the last day of the offering period. Eligible employees may contribute up to 15% of their eligible compensation. Under the ESPP, a participant may not accrue rights to purchase more than $25,000 worth of the Company’s common stock for each calendar year in which such right is outstanding.

The ESPP is considered compensatory under the FASB stock compensation rules. Accordingly, share-based compensation expense is determined based on the option’s grant-date fair value as estimated by applying the Black Scholes option-pricing model and is recognized over the withholding period. The Company recognized share-based compensation expense of $0.1 million and $0.2 million for the years ended December 31, 2025 and 2024, respectively, related to the ESPP.

12. Income Taxes

For the years ended December 31, 2025 and 2024, the Company recorded a provision for income taxes of $0.

The Company's loss before income taxes in the United States ("U.S.") for the years ended December 31, 2025 and 2024 was$99.5 million and$127.2 million, respectively. The Company hasno foreign operations.

The Company adopted ASU 2023-09 prospectively in the 2025 reporting period. The prior year rate reconciliation presentation has not been recast and is, therefore, not comparable to the current year presentation. A reconciliation of the U.S. federal statutory income tax rate to the Company's effective tax rate pursuant to the disclosure requirements of ASU 2023-09 is as follows (in millions, except for percentages):

(1) Greater than 50% of the state and local taxes, net of federal income tax effect, is attributable to the State of Delaware.

The tax effects of temporary differences that gave rise to significant portions of the deferred tax assets and liabilities were as follows:

The deferred tax assets, net of valuation allowance of $4.7 million and $5.0 million as of December 31, 2025 and 2024, respectively, primarily consists of net operating loss, tax credit carryforwards and capitalized research and development expenses for income tax purposes. As required by the 2017 Tax Cuts and Jobs Act, effective January 1, 2022, the Company's research and development expenditures were capitalized, resulting in a deferred tax asset. As amended by the One Big Beautiful Bill Act (OBBBA), effective July 2025, the Company’s current year US research and development expenditures were deducted resulting in a reduction of the capitalized R&D deferred tax asset. Due to the Company's history of operating losses, the Company recorded a valuation allowance on its net deferred tax assets by increasing the valuation allowance by $29.3 million and $35.0 million during theyears ended December 31, 2025 and 2024, respectively, as it was more likely than not that such tax benefits will not be realized.

The following table summarizes carryforwards of federal and state net operating losses (“NOL”) and research tax credits:

At December 31, 2025, the Company had federal net operating loss (NOL) carryforwards for income tax purposes of approximately $432.6 million and federal tax credit carryforwards of $28.2 million. The NOL carryforwards begin expiring in 2036 for federal and Delaware state income tax purposes; however, all federal, Delaware state, and Kansas state NOL carryforwards generated subsequent to January 1, 2018, can be carried forward indefinitely. The NOL carryforwards begin expiring in 2037 and 2042 for Tennessee and Massachusetts, respectively. As of December 31, 2025, the Company also had federal and Delaware research and development tax credit carryforwards of $28.2 million and $43 thousand, respectively, that will begin to expire in 2039 and 2031, respectively, unless previously utilized.

The NOL and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. NOL and tax credit carryforwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant stockholders over a three-year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code, respectively, as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. To date, the Company has not performed an analysis to determine whether ownership changes have occurred since inception. Delaware state NOLs may also be limited.

As of December 31, 2025, the Company hadno accrued interest or penalties related to uncertain tax positions andno amounts have been recognized in the Company’s statement of operations. Due to NOL and tax credit carry-forwards that remain unutilized, income tax returns for all tax years remain subject to examination by the taxing jurisdictions. The NOL carryforwards remain subject to review until utilized.

During the years ended December 31, 2025 and 2024, the Company didnot have any significant income taxes paid.

13. Workforce Reduction

During 2025, the Company reduced its workforce by approximately 27% of full-time employees to align its resources with its ongoing clinical and preclinical programs. The one-time severance costs related to the workforce reductions were $1.3 million, of which $1.2 million and $0.1 million are included within research and development and general and administrative expense, respectively, in the accompanying statement of operations.

The following table summarizes the activity recorded in connection with the reduction in workforce for the year ended December 31, 2025 within accrued expenses and other current liabilities on the balance sheet: