Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2025
Accounting Policies [Abstract]
Description of the Business	Description of the Business IGM Biosciences, Inc. (the Company) was incorporated in the state of Delaware in August 1993 under the name Palingen, Inc. and the name was subsequently changed to IGM Biosciences, Inc. in 2010. The Company formerly had headquarters in Mountain View, California. In April and May 2025, the Company terminated all lease agreements and is currently a remote-only company and therefore does not have principal executive offices. Historically, IGM Biosciences, Inc. was a biotechnology company focused on the development of IgM antibodies for the treatment of cancer and autoimmune and inflammatory diseases. Prior to September 30, 2024, the Company consolidated two wholly owned subsidiaries. To simplify the corporate structure, the Company’s board of directors approved the merger (Subsidiary Merger) of the subsidiaries with and into the Company, with the Company being the surviving corporation, effective August 30, 2024. Because the Subsidiary Merger was a reorganization of entities under common control, the net assets were transferred from its subsidiaries at historical carrying value and the effects of the transaction were applied retrospectively as if the Subsidiary Merger had occurred at the earliest date presented in the Company’s financial statements in accordance with Accounting Standard Codification (ASC) Topic 250, Accounting changes and error corrections (Topic 250). The Subsidiary Merger did not have an impact on the financial statements as the Company's financials have historically been presented on a consolidated basis. On July 1, 2025, the Company entered into an Agreement and Plan of Merger (the Merger Agreement) with Concentra Biosciences, LLC, a Delaware limited liability company (Concentra), and Concentra Merger Sub V, Inc, a Delaware corporation and a wholly owned subsidiary of Concentra (Merger Sub). The Merger Agreement provides for, among other things: (i) the acquisition of all of the Company’s outstanding shares of common stock, par value $0.01 per share (the Common Stock), by Concentra through a tender offer (the Offer), for a price per share of the Common Stock of (A) $1.247 in cash (the Cash Amount), subject to applicable tax withholding and without interest, plus (B) one contingent value right (a CVR) (such amount being the CVR Amount and the Cash Amount plus the CVR Amount, collectively being the Offer Price) and (ii) after completion of the Offer and subject to the satisfaction or waiver of certain conditions set forth in the Merger Agreement, the merger of Merger Sub into the Company (the Merger) with the Company surviving the Merger. If the Merger is effected, the Common Stock will be delisted from The Nasdaq Stock Market LLC and the Company’s obligation to file periodic reports under the Securities Act of 1934, as amended (the Exchange Act), will terminate, and the Company will be privately held. If the Merger is not completed and another strategic alternative is not identified, the Company’s Board of Directors may decide to pursue a dissolution or liquidation. There can be no assurance that the Merger will be completed as it is subject to various closing conditions. See Note 14 – Subsequent Events for additional information.
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP), as defined by the Financial Accounting Standards Board (FASB), and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2024 has been derived from the audited financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments which are necessary for a fair statement of the Company’s financial information. The interim results of operations for the three and six months ended June 30, 2025 are not necessarily indicative of the results to be expected for the year ending December 31, 2025 or for any other interim period or for any other future year. The accompanying interim unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2024, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 6, 2025.
Liquidity	Liquidity With the exception of the current period in which the Company recognized the remaining deferred revenue due to the termination of the collaboration agreement with Sanofi (see Note 7 – Sanofi Agreement for additional discussion on the agreement and termination), the Company has incurred net operating losses and negative cash flows from operations since its inception and had an accumulated deficit of $972.3 million as of June 30, 2025. As of June 30, 2025, the Company had cash, cash equivalents, and marketable securities of $104.3 million. Management believes that the existing financial resources are sufficient to continue operating activities at least one year past the issuance date of these condensed financial statements. The Company has historically financed its operations primarily through the sale of common stock and pre-funded warrants in its public offerings and private placement, the sale of convertible preferred stock and issuance of unsecured promissory notes in private placements, and funding received from our collaboration partners. To date, none of the Company’s product candidates have been approved for sale, and the Company has not generated any product revenue since inception. Management expects expenses and operating losses to decrease for the foreseeable future, and the Company’s net losses may fluctuate significantly from period to period, depending on the outcome of the Merger and depending on whether the Company decides to pursue any future product development efforts if the Merger is not completed. The Company’s prospects are subject to risks, expenses and uncertainties frequently encountered by companies in the biotechnology industry as discussed below. While the Company has been able to raise multiple rounds of financing, there can be no assurance that in the event the Company requires additional financing, such financing will be available on terms which are favorable or at all. Failure to raise sufficient capital when needed or generate sufficient cash flow from operations would impact the ability to pursue business strategies and could require the Company to delay, scale back or discontinue one or more product development programs, or other aspects of the Company's business objectives. As discussed above and in Note 14 – Subsequent Events, the Company has entered into a Merger Agreement with Concentra and Merger Sub, which, if effected would result in the full termination of the Company's current and ongoing operations.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed financial statements and accompanying notes. Such management estimates include, but are not limited to, those related to revenue recognition, marketable securities, manufacturing accruals, accrued research and development expenses, stock-based compensation, operating lease right-of-use (ROU) assets and liabilities, valuation of long-lived assets, income tax uncertainties and the valuation of deferred tax assets. The Company bases its estimates on its historical experience and also on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates. The most significant estimates and assumptions that management considers in the preparation of our financial statements relate to revenue recognition, accrued research and development costs, impairment of long-lived assets, and leases.
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 a concentration of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company invests in money market funds, U.S. treasury securities, corporate bonds, commercial paper, and U.S. government agency securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash, cash equivalents, and restricted cash, and bond issuers to the extent recorded on the balance sheets. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. government and its agencies, highly rated banks, and corporate issuers, subject to certain concentration limits and restrictions on maturities. The Company has not experienced any material losses on its deposits of cash, cash equivalents, and marketable securities.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash and cash equivalents. Cash equivalents consist primarily of amounts invested in money market funds and commercial paper and are stated at fair value. As of December 31, 2024, restricted cash consisted of the remaining unused portion of a grant received from a non-profit organization. As of June 30, 2025, the grant expired, and the Company no longer has any restricted cash.
Marketable Securities	Marketable Securities The Company’s marketable securities have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. treasury securities, U.S. government agency securities, corporate bonds, and commercial paper. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the condensed balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive income. The cost of marketable securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income. All available-for-sale securities are considered available to support current operations and are classified as current assets. The Company presents any credit losses identified as an allowance rather than as a reduction in the amortized cost of the available-for-sale securities. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in other income (expense) in the condensed statements of operations. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in other income. Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive income, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in other income in the condensed statements of operations. For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded to prepaid expenses and other current assets on the condensed balance sheets.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are depreciated using the straight-line method over the shorter of the lease term or the estimated useful economic lives of the related assets. Assets are held in construction in progress until placed in service, upon which date, we begin to depreciate these assets. Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization are removed from the condensed balance sheets and the resulting gain or loss are recorded to the condensed statements of operations. Repairs and maintenance are charged to the condensed statements of operations as incurred. As of June 30, 2025, all identified equipment has been sold or otherwise disposed.
Leases	Leases The Company determines if an arrangement is a lease at inception. In addition, the Company determines whether leases meet the classification criteria of a finance or operating lease at the lease commencement date considering: (1) whether the lease transfers ownership of the underlying asset to the lessee at the end of the lease term, (2) whether the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise, (3) whether the lease term is for a major part of the remaining economic life of the underlying asset, (4) whether the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset, and (5) whether the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. Operating leases are included in operating lease ROU assets and lease liabilities in the Company’s condensed balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date if the rate implicit in the lease is not readily determinable. The Company determines the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to the Company. The determination of the Company’s incremental borrowing rate requires management judgment including the development of a synthetic credit rating and cost of debt as the Company currently does not carry any debt. The Company believes that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in the estimated amounts to vary. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease cost is recognized on a straight-line basis over the expected lease term. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease cost primarily relates to common area maintenance charges. Lease agreements that include lease and non-lease components are accounted for as a single lease component. Lease agreements with a noncancelable term of less than 12 months are not recorded on the Company’s condensed balance sheets. During the three months ended June 30, 2025, the Company terminated all building leases located in Mountain View, California, with all leased spaces vacated as of June 30, 2025. The Company derecognized the remaining lease liabilities and operating lease ROU assets associated with the terminated leases. Additionally, the Company shortened the term of a lease located in Doylestown, Pennsylvania through the exercise of an early termination option. The Doylestown lease was fully paid and vacated as of June 30, 2025, resulting in the remeasurement and derecognition of the lease liability and operating lease ROU asset during the quarter. See Note 10 – Impairment and Disposal of Long-Lived Assets for further details of the lease terminations.
Impairment of Long-Lived Assets	Impairment and Disposal of Long-Lived Assets At each reporting period, the Company evaluates the carrying amount of its long-lived assets, which include property and equipment, operating lease right-of-use assets and other long-lived assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets might not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset or asset group and its eventual disposition are less than its carrying amount. Impairment, if any, is measured as the amount by which the carrying amount of a long-lived asset exceeds its fair value and is allocated to the group impacted on a relative fair value basis. As a result of the January 2025 Restructuring and the April 2025 Restructuring, the Company has continued to reduce costs and align the remaining facilities and equipment with current and projected business needs, which gave rise to triggering events indicating that the value of the Company's assets may not be recoverable. During the three months ended June 30, 2025, there were impairment and disposal of long-lived asset charges of $31.9 million, including $25.9 million related to the termination of all building leases and write-off of leasehold improvements and $6.0 million related to the sale and disposal of equipment and other costs. During the six months ended June 30, 2025, there were impairment and disposal of long-lived asset charges of $53.8 million, including $21.9 million of impairment charges recognized during the first quarter of 2025, and $31.9 million related to the termination of all building leases and the write-off of leasehold improvements and the sale and disposal of equipment and other costs in the second quarter of 2025. These charges are included in impairment and disposal of long-lived assets in the accompanying condensed statements of operations. There was no impairment and disposal of long-lived assets during the three and six months ended June 30, 2024 (see Note 10 – Impairment and Disposal of Long-Lived Assets for additional information).
Fair Value Measurement	Fair Value Measurement The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the condensed financial statements on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows: Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date. 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 3—Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Financial instruments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, or historical pricing trends of a security relative to its peers.
Revenue Recognition	Revenue Recognition For arrangements or transactions between participants determined to be within the scope of ASC Topic 606, Revenue from Contracts with Customers (Topic 606) the Company performs the following steps to determine the appropriate amount of revenue to be recognized as the Company fulfills its obligations: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company has entered into and may enter into additional collaboration agreements in the future under which it may obtain upfront payments, milestone payments, royalty payments, profit sharing, and other fees. Promises under these arrangements may include intellectual property licenses, research and development services, and the participation in joint committees. At contract inception, the Company assesses the goods or services promised and enforceable in a contract with a customer and identifies those distinct goods and services that represent a performance obligation. In assessing whether a promised good or service is distinct, and therefore a performance obligation, the Company considers factors such as the nature of the research, stage of development of the targets, manufacturing and commercialization capabilities of the customer and the availability of the associated expertise in the general marketplace. The Company also considers the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, the Company combines that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. Promised goods and services that are not material in the context of the contract are not considered performance obligations. Additional goods or services that are exercisable at a customer’s discretion, including substitution rights, are assessed to determine if they provide a material right to the customer and if so, they are considered performance obligations. The transaction price is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. Non-refundable upfront payments are considered fixed consideration and included in the transaction price. If an arrangement includes development, regulatory or commercial milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. The Company includes the amount of estimated variable consideration, including milestones, in the transaction price to the extent that it is probable that a significant reversal of cumulative revenue recognized will not occur. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and if the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied. If it is determined that multiple performance obligations exist, the transaction price is allocated at the inception of the agreement to all identified performance obligations based on the relative standalone selling prices (SSP), unless the consideration is variable and meets the criteria to be allocated entirely to one or more, but not all, performance obligations in the contract. The relative SSP for each deliverable is estimated using objective evidence if it is available. If SSP is not directly observable the Company estimates the SSP at an amount that would result in the allocation of the transaction price in an amount that depicts the amount of consideration to which the entity expects to be entitled in exchange for transferring the promised goods or services to the customer, using methods such as the expected cost plus margin approach. Once the transaction price has been allocated to a performance obligation using the applicable methodology, it is not subject to reassessment for subsequent changes in standalone selling prices. Collaboration revenue is recognized when, or as, the Company satisfies a performance obligation. The Company recognizes revenue over time by measuring the progress toward complete satisfaction of the relevant performance obligation using an appropriate input method based on the nature of the good or service promised to the customer. After contract inception, the transaction price is reassessed at every period end and updated for changes such as resolution of uncertain events. Management may be required to exercise considerable judgment in estimating revenue to be recognized. Judgment is required in identifying performance obligations, estimating the transaction price, including variable consideration, estimating the standalone selling prices of identified performance obligations, and applying the input method for revenue recognition, including the estimated budgets for each performance obligation. Amounts received prior to satisfying the revenue recognition criteria are recorded as deferred revenue in the Company’s condensed balance sheets. If the related performance obligation is expected to be satisfied within the next twelve months this will be classified in current liabilities. Amounts recognized as revenue prior to receipt are recorded as contract assets in the Company’s condensed balance sheets. If the Company expects to have an unconditional right to receive consideration in the next twelve months, this will be classified in current assets. A net contract asset or liability is presented for each contract with a customer. Contract modifications occur when the price and/or scope of an arrangement changes. If the modification consists of adding new distinct goods or services in exchange for consideration that reflects standalone selling prices of these goods and services, the modification is accounted for as a separate contract with the customer. Otherwise, if the remaining goods and services are distinct from those previously provided, the existing contract is considered terminated, and the remaining consideration is allocated to the remaining goods and services as if this was a newly signed contract. If the remaining goods and services are not distinct from those previously provided, the effects of the modification are accounted for in a manner similar to the effect of a change in the estimated measure of progress, with cumulative catch-up in revenue recorded at the time of the modification. If some of the remaining goods and services are distinct from those previously provided and others are not, the Company applies principles consistent with the objectives of the modification guidance to account for the effects of the modification. On May 5, 2025, the Company received a notice of termination pursuant to which Sanofi elected to terminate the Sanofi Agreement, at will, in its entirety, effective June 5, 2025 (see Note 7 – Sanofi Agreement for additional discussion on the agreement and termination).
Collaborative Arrangements	Collaborative Arrangements The Company analyzes its agreements to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (Topic 808). These assessments are performed throughout the life of the arrangements based on changes in the responsibilities of all parties in the arrangement.
Research and Development Expenses	Research and Development Expenses The Company expenses research and development costs as they are incurred. Research and development expenses consist primarily of: (i) personnel expenses, including salaries, benefits and stock-based compensation expense, for personnel in the Company’s research and development functions; (ii) fees paid to third parties such as contractors, consultants and contract research organizations (CROs) for conducting clinical trials, and other costs related to clinical and preclinical testing; (iii) costs related to acquiring and manufacturing research and clinical trial materials, including under agreements with third parties such as contract manufacturing organizations (CMOs), and other vendors; (iv) costs related to the preparation of regulatory submissions; (v) expenses related to laboratory supplies and services; (vi) fees under license agreements where no alternative future use exists; and (vii) depreciation of equipment and facilities expenses. During the three and six months ended June 30, 2025, the Company incurred reduced research and development costs following the termination of the collaboration agreement with Sanofi, and in connection with the implementation of the Company's plans under the April 2025 Restructuring (see Note – 7 Sanofi Agreement for additional discussion on the agreement and termination and Note 9 – Restructuring Charges for additional discussion around the restructuring).
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing, which are significant components of research and development expenses. A substantial portion of the Company’s research and development activities is conducted by third-party service providers, CROs and CMOs. The Company’s contracts with CROs generally include pass-through fees such as laboratory supplies and services, regulatory expenses, investigator fees, travel costs and other miscellaneous costs, including shipping and printing fees. The Company’s contracts with the CMOs generally include fees such as initiation fees, reservation fees, verification run costs, materials and reagents expenses, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, or stage of completion or actual timeline (start-date and end-date) of the services and the agreed-upon fees to be paid for such services. In the event the Company makes advance payments, the payments are recorded as a prepaid expense and recognized as the services are performed. As actual costs become known, the Company adjusts its accruals. Although the Company does not expect its estimates to be materially different from amounts actually incurred, such estimates for the status and timing of services performed relative to the actual status and timing of services performed may vary and could result in the Company reporting amounts that are too high or too low in any particular period. The Company’s accrual is dependent, in part, upon the receipt of timely and accurate reporting from CROs and other third-party vendors. Variations in the assumptions used to estimate accruals including, but not limited to, the number of patients enrolled, the rate of patient enrollment and the actual services performed, may vary from the Company’s estimates, resulting in adjustments to clinical trial expenses in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect its financial condition and results of operations. Through June 30, 2025, there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses.
Acquired In-Process Research and Development Expenses	Acquired In-Process Research and Development Expenses The Company has entered into agreements (see Note 5 – License Agreements) with third parties to acquire the rights to develop and potentially commercialize certain products. Such agreements generally require an initial payment by the Company when the contract is executed. The purchase of license rights for use in research and development activities, including product development, are expensed as incurred and are classified as research and development expense. Additionally, the Company may be obligated to make future royalty payments in the event the Company commercializes the technology and achieves a certain sales volume. In accordance with ASC Topic 730, Research and Development (Topic 730), expenditures for research and development, including upfront licensing fees and milestone payments associated with products not yet been approved by the FDA, are charged to research and development expense as incurred. Future contract milestone and/or royalty payments will be recognized as expense after the achievement of the milestone and the corresponding milestone payment is legally due.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees, non-employees and directors based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period. The grant date fair value of restricted stock units is estimated based on the closing stock price of the Company’s common stock on the date of grant. The grant date fair value of stock options granted to employees and directors is estimated using the Black-Scholes option-pricing model. The Company accounts for forfeitures as they occur. The Company accounts for any changes in the terms or conditions of an award as a modification in accordance with ASC 718, Compensation - Stock Compensation (Topic 718). In calculating the incremental compensation cost of a modification, the fair value of the modified award is compared to the fair value of the original award measured immediately before its terms or conditions were modified. The fair value of each purchase right under the employee stock purchase plan (ESPP) is estimated at the beginning of the offering period using the Black-Scholes option pricing model and recorded as expense over the service period using the straight-line method.
Income Taxes	Income Taxes The Company accounts for income taxes using the liability method, whereby deferred tax asset and liability account balances are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company provides a valuation allowance when it is more likely than not that some portion, or all of the Company’s deferred tax assets will not be realized. The Company accounts for income tax contingencies using a benefit recognition model. If it considers that a tax position is more likely than not to be sustained upon audit, based solely on the technical merits of the position, it recognizes the benefit. The Company measures the benefit by determining the amount that is greater than 50% likely of being realized upon settlement, presuming that the tax position is examined by the appropriate taxing authority that has full knowledge of all relevant information. The Company is subject to taxation in the United States federal jurisdiction, and various state jurisdictions. The net operating loss and research and development credit carryforwards that are available for utilization in future years may be subject to examination by federal and state tax authorities. The Company’s policy is to recognize interest expense and penalties related to income tax matters as a component of income tax expense. As of June 30, 2025, there were no significant accruals for interest related to unrecognized tax benefits or tax penalties.
Comprehensive Loss	Comprehensive Income (Loss) Comprehensive income (loss) represents the net income (loss) for the period and other comprehensive loss. Other comprehensive loss reflects certain gains and losses that are recorded as a component of stockholders’ equity and are not reflected in the condensed statements of operations. The Company’s other comprehensive loss consists of changes in unrealized gains and losses on available-for-sale securities.
Net Loss Per Share	Earnings (Loss) Per Share Basic earnings (loss) per share is calculated by dividing the net income (loss) by the weighted-average number of shares of common stock (including non-voting common stock and pre-funded warrants) outstanding during the period, without consideration for all other common stock equivalents. Shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing earnings (loss) per share because the shares may be issued for little or no consideration, are fully vested, and are exercisable after the original issuance date. Diluted earnings per share reflects the potential dilution that could occur if stock options or other contracts to issue common stock were exercised or converted into common stock. Diluted loss per share is the same as basic loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented.
Recently Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In October 2023, the FASB issued Accounting Standards Update (ASU) 2023-06, Disclosure Improvements - Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative, which will impact various disclosure areas. The amendments in ASU 2023-06 will be effective on the date the related disclosures are removed from Regulation S-X or Regulation S-K by the SEC, and will no longer be effective if the SEC has not removed the applicable disclosure requirement by June 30, 2027. The Company is currently evaluating the impacts of this standard on its related disclosures. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which amends the guidance in ASC 740, Income Taxes. The ASU is intended to improve the transparency of income tax disclosures by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation and (2) income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. The ASU's amendments are effective for public business entities for annual periods beginning after December 15, 2024. Entities are permitted to early adopt the standard for annual financial statements that have not yet been issued or made available for issuance. Adoption is permitted either prospectively or retrospectively. The Company will adopt this ASU on a prospective basis. The Company is currently evaluating the impact of this standard but does not expect any material impacts on its condensed financial statements and related disclosures.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2025

IGM Biosciences, Inc. (the Company) was incorporated in the state of Delaware in August 1993 under the name Palingen, Inc. and the name was subsequently changed to IGM Biosciences, Inc. in 2010.

The Company formerly had headquarters in Mountain View, California. In April and May 2025, the Company terminated all lease agreements and is currently a remote-only company and therefore does not have principal executive offices. Historically, IGM Biosciences, Inc. was a biotechnology company focused on the development of IgM antibodies for the treatment of cancer and autoimmune and inflammatory diseases.

Prior to September 30, 2024, the Company consolidated two wholly owned subsidiaries. To simplify the corporate structure, the Company’s board of directors approved the merger (Subsidiary Merger) of the subsidiaries with and into the Company, with the Company being the surviving corporation, effective August 30, 2024.

Because the Subsidiary Merger was a reorganization of entities under common control, the net assets were transferred from its subsidiaries at historical carrying value and the effects of the transaction were applied retrospectively as if the Subsidiary Merger had occurred at the earliest date presented in the Company’s financial statements in accordance with Accounting Standard Codification (ASC) Topic 250, Accounting changes and error corrections (Topic 250). The Subsidiary Merger did not have an impact on the financial statements as the Company's financials have historically been presented on a consolidated basis.

On July 1, 2025, the Company entered into an Agreement and Plan of Merger (the Merger Agreement) with Concentra Biosciences, LLC, a Delaware limited liability company (Concentra), and Concentra Merger Sub V, Inc, a Delaware corporation and a wholly owned subsidiary of Concentra (Merger Sub). The Merger Agreement provides for, among other things: (i) the acquisition of all of the Company’s outstanding shares of common stock, par value $0.01 per share (the Common Stock), by Concentra through a tender offer (the Offer), for a price per share of the Common Stock of (A) $1.247 in cash (the Cash Amount), subject to applicable tax withholding and without interest, plus (B) one contingent value right (a CVR) (such amount being the CVR Amount and the Cash Amount plus the CVR Amount, collectively being the Offer Price) and (ii) after completion of the Offer and subject to the satisfaction or waiver of certain conditions set forth in the Merger Agreement, the merger of Merger Sub into the Company (the Merger) with the Company surviving the Merger. If the Merger is effected, the Common Stock will be delisted from The Nasdaq Stock Market LLC and the Company’s obligation to file periodic reports under the Securities Act of 1934, as amended (the Exchange Act), will terminate, and the Company will be privately held. If the Merger is not completed and another strategic alternative is not identified, the Company’s Board of Directors may decide to pursue a dissolution or liquidation. There can be no assurance that the Merger will be completed as it is subject to various closing conditions. See Note 14 – Subsequent Events for additional information.

Basis of Presentation

The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP), as defined by the Financial Accounting Standards Board (FASB), and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2024 has been derived from the audited financial statements at that date but does not include all of the information required by GAAP for complete financial statements. These unaudited interim condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments which are necessary for a fair statement of the Company’s financial information. The interim results of operations for the three and six months ended June 30, 2025 are not necessarily indicative of the results to be expected for the year ending December 31, 2025 or for any other interim period or for any other future year.

The accompanying interim unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2024, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 6, 2025.

Liquidity

With the exception of the current period in which the Company recognized the remaining deferred revenue due to the termination of the collaboration agreement with Sanofi (see Note 7 – Sanofi Agreement for additional discussion on the agreement and termination), the Company has incurred net operating losses and negative cash flows from operations since its inception and had an accumulated deficit of $972.3 million as of June 30, 2025. As of June 30, 2025, the Company had cash, cash equivalents, and marketable securities of $104.3 million. Management believes that the existing financial resources are sufficient to continue operating activities at least one year past the issuance date of these condensed financial statements. The Company has historically financed its operations primarily

through the sale of common stock and pre-funded warrants in its public offerings and private placement, the sale of convertible preferred stock and issuance of unsecured promissory notes in private placements, and funding received from our collaboration partners. To date, none of the Company’s product candidates have been approved for sale, and the Company has not generated any product revenue since inception. Management expects expenses and operating losses to decrease for the foreseeable future, and the Company’s net losses may fluctuate significantly from period to period, depending on the outcome of the Merger and depending on whether the Company decides to pursue any future product development efforts if the Merger is not completed. The Company’s prospects are subject to risks, expenses and uncertainties frequently encountered by companies in the biotechnology industry as discussed below. While the Company has been able to raise multiple rounds of financing, there can be no assurance that in the event the Company requires additional financing, such financing will be available on terms which are favorable or at all. Failure to raise sufficient capital when needed or generate sufficient cash flow from operations would impact the ability to pursue business strategies and could require the Company to delay, scale back or discontinue one or more product development programs, or other aspects of the Company's business objectives. As discussed above and in Note 14 – Subsequent Events, the Company has entered into a Merger Agreement with Concentra and Merger Sub, which, if effected would result in the full termination of the Company's current and ongoing operations.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed financial statements and accompanying notes. Such management estimates include, but are not limited to, those related to revenue recognition, marketable securities, manufacturing accruals, accrued research and development expenses, stock-based compensation, operating lease right-of-use (ROU) assets and liabilities, valuation of long-lived assets, income tax uncertainties and the valuation of deferred tax assets. The Company bases its estimates on its historical experience and also on assumptions that it believes are reasonable; however, actual results could significantly differ from those estimates. The most significant estimates and assumptions that management considers in the preparation of our financial statements relate to revenue recognition, accrued research and development costs, impairment of long-lived assets, and leases.

Concentration of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash, cash equivalents, and marketable securities. The Company invests in money market funds, U.S. treasury securities, corporate bonds, commercial paper, and U.S. government agency securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash, cash equivalents, and restricted cash, and bond issuers to the extent recorded on the balance sheets. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. government and its agencies, highly rated banks, and corporate issuers, subject to certain concentration limits and restrictions on maturities. The Company has not experienced any material losses on its deposits of cash, cash equivalents, and marketable securities.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash and cash equivalents. Cash equivalents consist primarily of amounts invested in money market funds and commercial paper and are stated at fair value. As of December 31, 2024, restricted cash consisted of the remaining unused portion of a grant received from a non-profit organization. As of June 30, 2025, the grant expired, and the Company no longer has any restricted cash.

Marketable Securities

The Company’s marketable securities have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. treasury securities, U.S. government agency securities, corporate bonds, and commercial paper. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the condensed balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive income. The cost of marketable securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other income. All available-for-sale securities are considered available to support current operations and are classified as current assets. The Company presents any credit losses identified as an allowance rather than as a reduction in the amortized cost of the available-for-sale securities.

For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in other income (expense) in the condensed statements of operations. If neither criteria is met, the Company evaluates whether the decline in fair value is related to credit-related factors or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Credit-related impairment losses, limited by the amount that the fair value is less than the amortized cost basis, are recorded through an allowance for credit losses in other income.

Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit factors are recognized in accumulated other comprehensive income, net of tax as a separate component of stockholders’ equity, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in other income in the condensed statements of operations.

For purposes of identifying and measuring credit-related impairments, the Company’s policy is to exclude applicable accrued interest from both the fair value and amortized cost basis of the related security. The Company has elected to write-off uncollectible accrued interest receivable balances in a timely manner, which is defined by the Company as when interest due becomes 90 days delinquent. The accrued interest write-off will be recorded by reversing interest income. Accrued interest receivable is recorded to prepaid expenses and other current assets on the condensed balance sheets.

Property, Plant and Equipment

Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is determined using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are depreciated using the straight-line method over the shorter of the lease term or the estimated useful economic lives of the related assets. Assets are held in construction in progress until placed in service, upon which date, we begin to depreciate these assets.

Upon retirement or sale of the assets, the cost and related accumulated depreciation and amortization are removed from the condensed balance sheets and the resulting gain or loss are recorded to the condensed statements of operations. Repairs and maintenance are charged to the condensed statements of operations as incurred. As of June 30, 2025, all identified equipment has been sold or otherwise disposed.

Leases

The Company determines if an arrangement is a lease at inception. In addition, the Company determines whether leases meet the classification criteria of a finance or operating lease at the lease commencement date considering: (1) whether the lease transfers ownership of the underlying asset to the lessee at the end of the lease term, (2) whether the lease grants the lessee an option to purchase the underlying asset that the lessee is reasonably certain to exercise, (3) whether the lease term is for a major part of the remaining economic life of the underlying asset, (4) whether the present value of the sum of the lease payments and residual value guaranteed by the lessee equals or exceeds substantially all of the fair value of the underlying asset, and (5) whether the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term.

Operating leases are included in operating lease ROU assets and lease liabilities in the Company’s condensed balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses its incremental borrowing rate based on the information available at the lease commencement date if the rate implicit in the lease is not readily determinable. The Company determines the incremental borrowing rate based on an analysis of corporate bond yields with a credit rating similar to the Company.

The determination of the Company’s incremental borrowing rate requires management judgment including the development of a synthetic credit rating and cost of debt as the Company currently does not carry any debt. The Company believes that the estimates used in determining the incremental borrowing rate are reasonable based upon current facts and circumstances. Applying different judgments to the same facts and circumstances could result in the estimated amounts to vary. The operating lease ROU assets also include adjustments for prepayments and accrued lease payments and exclude lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease cost is recognized on a straight-line basis over the expected lease term. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease cost primarily relates to common area maintenance charges. Lease agreements that include lease and non-lease components are accounted for as a single lease component. Lease agreements with a noncancelable term of less than 12 months are not recorded on the Company’s condensed balance sheets.

During the three months ended June 30, 2025, the Company terminated all building leases located in Mountain View, California, with all leased spaces vacated as of June 30, 2025. The Company derecognized the remaining lease liabilities and operating lease ROU assets associated with the terminated leases. Additionally, the Company shortened the term of a lease located in Doylestown,

Pennsylvania through the exercise of an early termination option. The Doylestown lease was fully paid and vacated as of June 30, 2025, resulting in the remeasurement and derecognition of the lease liability and operating lease ROU asset during the quarter. See Note 10 – Impairment and Disposal of Long-Lived Assets for further details of the lease terminations.

Impairment of Long-Lived Assets

Impairment and Disposal of Long-Lived Assets

At each reporting period, the Company evaluates the carrying amount of its long-lived assets, which include property and equipment, operating lease right-of-use assets and other long-lived assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets might not be fully recoverable. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of the asset or asset group and its eventual disposition are less than its carrying amount. Impairment, if any, is measured as the amount by which the carrying amount of a long-lived asset exceeds its fair value and is allocated to the group impacted on a relative fair value basis.

As a result of the January 2025 Restructuring and the April 2025 Restructuring, the Company has continued to reduce costs and align the remaining facilities and equipment with current and projected business needs, which gave rise to triggering events indicating that the value of the Company's assets may not be recoverable. During the three months ended June 30, 2025, there were impairment and disposal of long-lived asset charges of $31.9 million, including $25.9 million related to the termination of all building leases and write-off of leasehold improvements and $6.0 million related to the sale and disposal of equipment and other costs. During the six months ended June 30, 2025, there were impairment and disposal of long-lived asset charges of $53.8 million, including $21.9 million of impairment charges recognized during the first quarter of 2025, and $31.9 million related to the termination of all building leases and the write-off of leasehold improvements and the sale and disposal of equipment and other costs in the second quarter of 2025. These charges are included in impairment and disposal of long-lived assets in the accompanying condensed statements of operations. There was no impairment and disposal of long-lived assets during the three and six months ended June 30, 2024 (see Note 10 – Impairment and Disposal of Long-Lived Assets for additional information).

Fair Value Measurement

The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the condensed financial statements on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:

Level 1—Observable inputs, such as quoted prices in active markets for identical assets or liabilities at the measurement date.

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 3—Unobservable inputs which reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value.

Financial instruments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, or historical pricing trends of a security relative to its peers.

Revenue Recognition

For arrangements or transactions between participants determined to be within the scope of ASC Topic 606, Revenue from Contracts with Customers (Topic 606) the Company performs the following steps to determine the appropriate amount of revenue to be recognized as the Company fulfills its obligations: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation.

The Company has entered into and may enter into additional collaboration agreements in the future under which it may obtain upfront payments, milestone payments, royalty payments, profit sharing, and other fees. Promises under these arrangements may include intellectual property licenses, research and development services, and the participation in joint committees.

At contract inception, the Company assesses the goods or services promised and enforceable in a contract with a customer and identifies those distinct goods and services that represent a performance obligation. In assessing whether a promised good or service is distinct, and therefore a performance obligation, the Company considers factors such as the nature of the research, stage of development of the targets, manufacturing and commercialization capabilities of the customer and the availability of the associated

expertise in the general marketplace. The Company also considers the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, the Company combines that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. Promised goods and services that are not material in the context of the contract are not considered performance obligations. Additional goods or services that are exercisable at a customer’s discretion, including substitution rights, are assessed to determine if they provide a material right to the customer and if so, they are considered performance obligations.

The transaction price is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. Non-refundable upfront payments are considered fixed consideration and included in the transaction price.

If an arrangement includes development, regulatory or commercial milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. The Company includes the amount of estimated variable consideration, including milestones, in the transaction price to the extent that it is probable that a significant reversal of cumulative revenue recognized will not occur. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and if the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied.

If it is determined that multiple performance obligations exist, the transaction price is allocated at the inception of the agreement to all identified performance obligations based on the relative standalone selling prices (SSP), unless the consideration is variable and meets the criteria to be allocated entirely to one or more, but not all, performance obligations in the contract. The relative SSP for each deliverable is estimated using objective evidence if it is available. If SSP is not directly observable the Company estimates the SSP at an amount that would result in the allocation of the transaction price in an amount that depicts the amount of consideration to which the entity expects to be entitled in exchange for transferring the promised goods or services to the customer, using methods such as the expected cost plus margin approach. Once the transaction price has been allocated to a performance obligation using the applicable methodology, it is not subject to reassessment for subsequent changes in standalone selling prices.

Collaboration revenue is recognized when, or as, the Company satisfies a performance obligation. The Company recognizes revenue over time by measuring the progress toward complete satisfaction of the relevant performance obligation using an appropriate input method based on the nature of the good or service promised to the customer. After contract inception, the transaction price is reassessed at every period end and updated for changes such as resolution of uncertain events.

Management may be required to exercise considerable judgment in estimating revenue to be recognized. Judgment is required in identifying performance obligations, estimating the transaction price, including variable consideration, estimating the standalone selling prices of identified performance obligations, and applying the input method for revenue recognition, including the estimated budgets for each performance obligation.

Amounts received prior to satisfying the revenue recognition criteria are recorded as deferred revenue in the Company’s condensed balance sheets. If the related performance obligation is expected to be satisfied within the next twelve months this will be classified in current liabilities. Amounts recognized as revenue prior to receipt are recorded as contract assets in the Company’s condensed balance sheets. If the Company expects to have an unconditional right to receive consideration in the next twelve months, this will be classified in current assets. A net contract asset or liability is presented for each contract with a customer.

Contract modifications occur when the price and/or scope of an arrangement changes. If the modification consists of adding new distinct goods or services in exchange for consideration that reflects standalone selling prices of these goods and services, the modification is accounted for as a separate contract with the customer. Otherwise, if the remaining goods and services are distinct from those previously provided, the existing contract is considered terminated, and the remaining consideration is allocated to the remaining goods and services as if this was a newly signed contract. If the remaining goods and services are not distinct from those previously provided, the effects of the modification are accounted for in a manner similar to the effect of a change in the estimated measure of progress, with cumulative catch-up in revenue recorded at the time of the modification. If some of the remaining goods and services are distinct from those previously provided and others are not, the Company applies principles consistent with the objectives of the modification guidance to account for the effects of the modification. On May 5, 2025, the Company received a notice of termination pursuant to which Sanofi elected to terminate the Sanofi Agreement, at will, in its entirety, effective June 5, 2025 (see Note 7 – Sanofi Agreement for additional discussion on the agreement and termination).

Collaborative Arrangements

The Company analyzes its agreements to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (Topic 808). These assessments are performed throughout the life of the arrangements based on changes in the responsibilities of all parties in the arrangement.

Research and Development Expenses

The Company expenses research and development costs as they are incurred. Research and development expenses consist primarily of: (i) personnel expenses, including salaries, benefits and stock-based compensation expense, for personnel in the Company’s research and development functions; (ii) fees paid to third parties such as contractors, consultants and contract research organizations (CROs) for conducting clinical trials, and other costs related to clinical and preclinical testing; (iii) costs related to acquiring and manufacturing research and clinical trial materials, including under agreements with third parties such as contract manufacturing organizations (CMOs), and other vendors; (iv) costs related to the preparation of regulatory submissions; (v) expenses related to laboratory supplies and services; (vi) fees under license agreements where no alternative future use exists; and (vii) depreciation of equipment and facilities expenses.

During the three and six months ended June 30, 2025, the Company incurred reduced research and development costs following the termination of the collaboration agreement with Sanofi, and in connection with the implementation of the Company's plans under the April 2025 Restructuring (see Note – 7 Sanofi Agreement for additional discussion on the agreement and termination and Note 9 – Restructuring Charges for additional discussion around the restructuring).

Accrued Research and Development Expenses

The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing, which are significant components of research and development expenses. A substantial portion of the Company’s research and development activities is conducted by third-party service providers, CROs and CMOs. The Company’s contracts with CROs generally include pass-through fees such as laboratory supplies and services, regulatory expenses, investigator fees, travel costs and other miscellaneous costs, including shipping and printing fees. The Company’s contracts with the CMOs generally include fees such as initiation fees, reservation fees, verification run costs, materials and reagents expenses, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, or stage of completion or actual timeline (start-date and end-date) of the services and the agreed-upon fees to be paid for such services. In the event the Company makes advance payments, the payments are recorded as a prepaid expense and recognized as the services are performed.

As actual costs become known, the Company adjusts its accruals. Although the Company does not expect its estimates to be materially different from amounts actually incurred, such estimates for the status and timing of services performed relative to the actual status and timing of services performed may vary and could result in the Company reporting amounts that are too high or too low in any particular period. The Company’s accrual is dependent, in part, upon the receipt of timely and accurate reporting from CROs and other third-party vendors. Variations in the assumptions used to estimate accruals including, but not limited to, the number of patients enrolled, the rate of patient enrollment and the actual services performed, may vary from the Company’s estimates, resulting in adjustments to clinical trial expenses in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect its financial condition and results of operations. Through June 30, 2025, there have been no material differences from the Company’s estimated accrued research and development expenses to actual expenses.

Acquired In-Process Research and Development Expenses

The Company has entered into agreements (see Note 5 – License Agreements) with third parties to acquire the rights to develop and potentially commercialize certain products. Such agreements generally require an initial payment by the Company when the contract is executed. The purchase of license rights for use in research and development activities, including product development, are expensed as incurred and are classified as research and development expense. Additionally, the Company may be obligated to make future royalty payments in the event the Company commercializes the technology and achieves a certain sales volume. In accordance with ASC Topic 730, Research and Development (Topic 730), expenditures for research and development, including upfront licensing fees and milestone payments associated with products not yet been approved by the FDA, are charged to research and development expense as incurred. Future contract milestone and/or royalty payments will be recognized as expense after the achievement of the milestone and the corresponding milestone payment is legally due.

Stock-Based Compensation

The Company accounts for stock-based compensation by measuring and recognizing compensation expense for all share-based awards made to employees, non-employees and directors based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over the requisite service period, which is generally the vesting period. The grant date fair value of restricted stock units is estimated based on the closing stock price of the Company’s common stock on the date of grant. The grant date fair value of stock options granted to employees and directors is estimated using the Black-Scholes option-pricing model. The Company accounts for forfeitures as they occur. The Company accounts for any changes in the terms or conditions of an award as a modification in accordance with ASC 718, Compensation - Stock Compensation (Topic 718). In calculating the incremental compensation cost of a modification, the fair value of the modified award is compared to the fair value of the original

award measured immediately before its terms or conditions were modified. The fair value of each purchase right under the employee stock purchase plan (ESPP) is estimated at the beginning of the offering period using the Black-Scholes option pricing model and recorded as expense over the service period using the straight-line method.

Income Taxes

The Company accounts for income taxes using the liability method, whereby deferred tax asset and liability account balances are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company provides a valuation allowance when it is more likely than not that some portion, or all of the Company’s deferred tax assets will not be realized.

The Company accounts for income tax contingencies using a benefit recognition model. If it considers that a tax position is more likely than not to be sustained upon audit, based solely on the technical merits of the position, it recognizes the benefit. The Company measures the benefit by determining the amount that is greater than 50% likely of being realized upon settlement, presuming that the tax position is examined by the appropriate taxing authority that has full knowledge of all relevant information. The Company is subject to taxation in the United States federal jurisdiction, and various state jurisdictions. The net operating loss and research and development credit carryforwards that are available for utilization in future years may be subject to examination by federal and state tax authorities. The Company’s policy is to recognize interest expense and penalties related to income tax matters as a component of income tax expense. As of June 30, 2025, there were no significant accruals for interest related to unrecognized tax benefits or tax penalties.

Comprehensive Loss

Comprehensive Income (Loss)

Comprehensive income (loss) represents the net income (loss) for the period and other comprehensive loss. Other comprehensive loss reflects certain gains and losses that are recorded as a component of stockholders’ equity and are not reflected in the condensed statements of operations. The Company’s other comprehensive loss consists of changes in unrealized gains and losses on available-for-sale securities.

Net Loss Per Share

Earnings (Loss) Per Share

Basic earnings (loss) per share is calculated by dividing the net income (loss) by the weighted-average number of shares of common stock (including non-voting common stock and pre-funded warrants) outstanding during the period, without consideration for all other common stock equivalents. Shares of common stock into which the pre-funded warrants may be exercised are considered outstanding for the purposes of computing earnings (loss) per share because the shares may be issued for little or no consideration, are fully vested, and are exercisable after the original issuance date. Diluted earnings per share reflects the potential dilution that could occur if stock options or other contracts to issue common stock were exercised or converted into common stock. Diluted loss per share is the same as basic loss per share, since the effects of potentially dilutive securities are antidilutive given the net loss for each period presented.

Recently Adopted Accounting Pronouncements

Recently Issued Accounting Pronouncements

In October 2023, the FASB issued Accounting Standards Update (ASU) 2023-06, Disclosure Improvements - Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative, which will impact various disclosure areas. The amendments in ASU 2023-06 will be effective on the date the related disclosures are removed from Regulation S-X or Regulation S-K by the SEC, and will no longer be effective if the SEC has not removed the applicable disclosure requirement by June 30, 2027. The Company is currently evaluating the impacts of this standard on its related disclosures.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which amends the guidance in ASC 740, Income Taxes. The ASU is intended to improve the transparency of income tax disclosures by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation and (2) income taxes paid disaggregated by jurisdiction. It also includes certain other amendments to improve the effectiveness of income tax disclosures. The ASU's amendments are effective for public business entities for annual periods beginning after December 15, 2024. Entities are permitted to early adopt the standard for annual financial statements that have not yet been issued or made available for issuance. Adoption is permitted either prospectively or retrospectively. The Company will adopt this ASU on a prospective basis. The Company is currently evaluating the impact of this standard but does not expect any material impacts on its condensed financial statements and related disclosures.