Immuneering Corp

NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

Note 1 –Organization and Nature of Business

Immuneering Corporation, a Delaware corporation (“Immuneering” or the “Company”), was incorporated in 2008. Immuneering is a clinical-stage oncology company seeking to develop medicines for broad populations of cancer patients, with an initial aim to therapeutically address patients harboring RAS and/or RAF mutations. The Company aims to achieve broad activity through Deep Cyclic Inhibition® ("DCI") of the mitogen-activated protein kinase ("MAPK") pathway, impacting cancer cells while sparing healthy cells. Immuneering’s lead product candidate atebimetinib (also referred to as IMM-1-104) is in a Phase 1/2a clinical trial in patients with advanced solid tumors harboring RAS or RAF mutations. The Company is developing atebimetinib as a once-daily oral therapy through DCI of the MAPK pathway at the level of mitogen-activated protein kinase kinase ("MEK"). The Company’s development pipeline also includes early-stage programs.

On October 30, 2019, Immuneering formed a wholly owned subsidiary, Immuneering Securities Corporation (“ISC”), a Massachusetts securities corporation, for the sole purpose of buying, selling and holding securities on the Company’s behalf.

On December 22, 2021, the Company acquired all outstanding shares of capital stock of BioArkive, Inc. (“BioArkive”), a California corporation, which as a result became a wholly owned subsidiary.

Immuneering, ISC and BioArkive are collectively referred to as the “Company” throughout these interim condensed consolidated financial statements.

The Company is subject to a number of inherent risks associated with any biotechnology company that has substantial expenditures for research and development. These risks include, but are not limited to, the need to obtain adequate additional funding, possible failure of clinical trials or other events demonstrating lack of clinical safety or efficacy of its product candidates, dependence on key personnel, reliance on third-party service providers for manufacturing drug product and conducting clinical trials, the ability to successfully secure its proprietary technology, and risks related to the regulatory approval and commercialization of a product candidate. There can be no assurance that the Company’s research and development programs will be successful. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees, advisors, and consultants.

On August 3, 2021, the Company completed its initial public offering (“IPO”) pursuant to which it issued and sold 8,625,000 shares of its Class A common stock, inclusive of 1,125,000 shares of its Class A common stock sold pursuant to the full exercise of the underwriters’ option to purchase additional shares. The aggregate net proceeds received by the Company from the IPO were $120,318,750, after deducting underwriting discounts and commissions, but before deducting offering costs payable by the Company, which were $2,124,317.

On August 10, 2022, the Company entered into an Equity Distribution Agreement (the "2022 Sales Agreement") with Piper Sandler & Co (the "Sales Agent"), to sell shares of its common stock with aggregate gross proceeds of up to $50 million, from time to time, through an “at the market” equity offering program (the "2022 ATM Program"). The Company sold 327,355 shares of common stock under the 2022 ATM Program, at a weighted average price per share of $4.27, for aggregate gross proceeds of $1.4 million ($1.3 million net of offering expenses) during the three months ended September 30, 2025. The Company sold 5,164,159 shares of common stock under the 2022 ATM program, at a weighted average price per share of $3.03, for aggregate gross proceeds of $15.6 million ($15.0 million net of offering expenses) during the nine months ended September 30, 2025. The Company sold 1,318,752 shares of common stock under the 2022 ATM Program, at a weighted average price per share of $3.38, for aggregate gross proceeds of $4.5 million ($4.2 million net of offering expenses) during the three and nine months ended September 30, 2024.

On April 20, 2023, the Company completed an underwritten follow-on equity offering, pursuant to which it issued and sold 2,727,273 shares of its Class A common stock $0.001 par value per share at an offering price of $11.00 per share. The aggregate net proceeds received by the Company from the offering were $28,200,003, after deducting underwriting discounts and commissions, but before deducting offering costs payable by the Company of $203,768.

On August 13, 2025, the Company entered into an Equity Distribution Agreement (the "2025 Sales Agreement") with the Sales Agent, to sell shares of its common stock with aggregate gross proceeds of up to $100 million, from time to time, through an “at the market” equity offering program (the "2025 ATM Program"). In connection with the September 2025 Offering (as defined below), the Company: (i) reduced the maximum aggregate offering price for sales of shares of common stock pursuant to at-the-market transactions under the 2025 ATM Program by $1,250,007 (the "Reduced Amount"), resulting in a new maximum aggregate offering price of up to $98,749,993 under the 2025 ATM Program, and (ii) suspended the 2025 ATM Program and terminated the continuous offering under the 2025 ATM Program, in each case, as to the Reduced Amount. The Company didnot sell any shares of common stock under the 2025 ATM Program during the three and nine months ended September 30, 2025 or September 30, 2024, respectively.

On August 21, 2025, the Company entered into a Securities Purchase Agreement (the "August 2025 Purchase Agreement") with the purchasers party thereto, pursuant to which the Company agreed to sell securities to such purchasers in a private placement (the “August 2025 Private Placement”). The August 2025 Purchase Agreement provided for the sale and issuance by the Company to the purchasers of: (i) an aggregate of 5,251,349 shares of its common stock at a purchase price of $3.95 per share, (ii) for certain purchasers, in lieu of common stock, an aggregate of 1,077,764 pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to the same number of shares of its common stock, and (iii) an aggregate of 2,848,096 warrants (the “Purchase Warrants”) to purchase up to the same number of shares of its common stock. The Pre-Funded Warrants were issued for a purchase price equating to $3.949 per Pre-Funded Warrant (which was the per share purchase price for the common stock issued in the August 2025 Private Placement, less the $0.001 per share unfunded exercise price for each Pre-Funded Warrant); see "Note 12 - Subsequent Events" for additional information related to the cashless exercise of the Pre-Funded Warrants. The Purchase Warrants were issued with an exercise price of $5.50 per share; as of September 30, 2025, no Purchase Warrants had been exercised. As of September 30, 2025, the Company had received aggregate net proceeds of $23.4 million from the August 2025 Private Placement, after deducting placement expenses of $1.6 million. The August 2025 Private Placement closed on August 26, 2025.

On September 24, 2025, the Company entered into a Securities Purchase Agreement (the "September 2025 Purchase Agreement") with Aventis Inc. ("Aventis"), a wholly owned subsidiary of Sanofi, a French société anonyme, pursuant to which the Company agreed to sell securities to Aventis in a private placement (the “September 2025 Private Placement”). The September 2025 Purchase Agreement provided for the sale and issuance by the Company to Aventis of an aggregate of 2,708,559 shares of its common stock at a purchase price of $9.23 per share. The Company received aggregate net proceeds of $23.3 million from the September 2025 Private Placement, after deducting placement agent discounts and commissions, but before deducting placement costs payable by the Company, which were estimated to be approximately $0.2 million. The September 2025 Private Placement closed on September 26, 2025.

On September 26, 2025, the Company completed an underwritten follow-on equity offering, pursuant to which it issued and sold 18,959,914 shares of its Class A common stock at an offering price of $9.23 per share (the "September 2025 Offering"), with Leerink Partners LLC and Oppenheimer & Co. Inc. acting as underwriters. The aggregate net proceeds received by the Company from the September 2025 Offering were $164.1 million, after deducting underwriting discounts and commissions, but before deducting offering costs payable by the Company, which were estimated to be approximately $0.4 million.

To date, the Company has funded its operations through service revenues (which have since ceased), and with proceeds from the sale of its capital stock, warrants to purchase stock, and convertible notes. The Company has incurred recurring losses over the past several years and as of September 30, 2025, the Company had an accumulated deficit of $268.7 million. The Company expects to continue to generate operating losses for the foreseeable future. The future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company’s inability to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurances that additional funding will be available on terms acceptable to the Company, or at all. If the Company is unable to raise additional funds when needed, it may be required to delay, reduce the scope of, or eliminate development programs, which may adversely affect its business and operations. Management considered whether or not there are conditions or events, in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern, and concluded that there are none as it estimates that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months from the issuance date of these unaudited condensed consolidated financial statements.

Note 2 -Summary of Significant Accounting Policies

Basis of Presentation

The interim condensed consolidated financial statements have been prepared in accordance with accounting standards set by the Financial Accounting Standards Board (“FASB”). The FASB sets generally accepted accounting principles (“GAAP”) to ensure the interim condensed consolidated financial statements are consistently reported. References to GAAP issued by the FASB in these footnotes are to the FASB ASC. The interim condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

There have been no material changes to the accounting policies of the Company as those set forth in Note 2 to the audited consolidated financial statements contained in the Annual Report on Form 10-K for the fiscal year ended December 31, 2024.

Unaudited Interim Financial Information

The unaudited interim condensed consolidated financial statements of the Company have been prepared in accordance with GAAP and in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with GAAP have been omitted from the unaudited interim condensed consolidated financial statements, as is permitted by such rules and regulations. While we believe that the disclosures presented are adequate in order to make the information not misleading, these unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes for the year ended December 31, 2024.

It is management’s opinion that these financial statements include all normal and recurring adjustments necessary for a fair presentation of the Company’s financial position, operating results and cash flows. Net loss for any interim period is not necessarily indicative of future or annual results.

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, liabilities, revenues and expenses during the reporting periods. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets, liabilities and the recording of expenses that are not readily apparent from other sources. Significant estimates reflected in these interim condensed consolidated financial statements include but are not limited to: the accrued research and development expenses, the determination of fair value of stock-based awards, and the impairment of goodwill and intangible assets. Actual results may differ materially and adversely from these estimates.

Goodwill

Goodwill represents the excess of the fair value of the acquiree over the recognized basis of the net identifiable assets acquired and includes the future economic benefits from other assets that could not be individually identified and separately recognized. Goodwill is not amortized, but instead is periodically reviewed for impairment and an impairment charge is recorded in the periods in which the recorded carrying value of goodwill exceeds its fair value.

On a quarterly basis, the Company performs a review of its business to determine if events or changes in circumstances have occurred which could have a material adverse effect on the fair value of the Company and its goodwill. If such events or changes in circumstances were deemed to have occurred, the Company would perform an impairment test of goodwill as of the end of the quarter and record any noted impairment loss. The Company performs its annual impairment test during the fourth quarter of each fiscal year.

There wereno impairments identified for the year ended December 31, 2024 or for the three and nine months ended September 30, 2025.

Deferred Offering Costs

The Company capitalizes certain legal, professional, and other third-party charges related to ongoing equity financings as deferred offering costs until fully consummated. These costs are to be recorded as a reduction of the offering’s proceeds which are recorded to additional paid-in capital within stockholders’ equity. Should the Company choose not to initiate such financing, the deferred offering costs would be immediately expensed as operating expenses.

Deferred offering costs associated with the Sales Agreement are reclassified to additional paid-in capital on a pro-rata basis when the Company completes offerings under the Sales Agreement. Any remaining deferred costs will be expensed to the statement of operations should the planned offering be abandoned. The Company had approximately $0.2 million of deferred offering costs as of September 30, 2025 and $0.5 million as of December 31, 2024.

Common Stock Warrants

The Company accounts for warrants issued as a separable unit in connection with sale of common stock as either liability or equity in accordance with Accounting Standards Codification (“ASC”) 480-10, Accounting for Certain Financial Instruments with Characteristics of both Liabilities and Equity (“ASC 480-10”) or ASC 815-40, Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock (“ASC 815-40”). Under ASC 480-10, warrants are considered liabilities if they are mandatorily redeemable and they require settlement in cash or other assets, or a variable number of shares. If warrants do not meet liability classification under ASC 480-10, the Company considers the requirements of ASC 815-40 to determine whether the warrants should be classified as liability or equity. If warrants do not require liability classification under ASC 815-40 or other applicable generally accepted accounting principles in the United States of America (“U.S. GAAP”) the warrants should be classified as equity.

The proceeds received from the sale of equity classified warrants and shares of common stock in a bundled transaction are allocated based on the relative fair values of warrants and shares with no changes in fair value of warrants recognized after the issuance date.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss by the weighted average number of shares of common stock and pre-funded warrants outstanding during the period, without consideration for potentially dilutive securities. The pre-funded warrants are included as outstanding shares in the computation as the exercise price is negligible and the pre-funded warrants are fully vested and exercisable. Diluted net loss per share is the same as basic net loss per share for the periods presented since the effects of potentially dilutive securities are antidilutive given the net loss of the Company.

Recently Issued But Not Yet Adopted Accounting Pronouncements and Legislation

From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. The Company is an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, as amended (the “JOBS Act”). The JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. Thus, an emerging growth company can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. The Company elected to avail itself of this extended transition period and, as a result, the Company will not be required to adopt certain new or revised accounting standards on the relevant dates on which adoption of such standards is required for other public companies.

In November 2024, the FASB issued Accounting Standards Update ("ASU") No. 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40) (“ASU 2024-03”). The guidance in ASU 2024-03 aims to improve disclosures around an entity's expenses. Upon adoption, companies will be required to disclose in the notes to the financial statements a disaggregation of certain expense categories included within the expense captions on the face of the income statement. The standard is effective for fiscal years beginning after December 15, 2026 and interim periods in fiscal years beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating this standard's potential impact on its consolidated financial statements and related disclosures.

On July 4, 2025, the U.S. government enacted The One Big Beautiful Bill Act of 2025 which includes, among other provisions, changes to the U.S. corporate income tax system including the allowance of immediate expensing of qualifying research and development expenses and permanent extensions of certain provisions within the Tax Cuts and Jobs Act. The

Company is currently evaluating the future impact of these tax law changes on its consolidated financial statements and disclosures.

Note 3 –Marketable Securities

The Company's marketable securities are classified as available-for-sale pursuant to ASC 320, Investments – Debt and Equity Securities and are recorded at fair value. Unrealized gains (losses) are included as a component of accumulated other comprehensive loss in the condensed consolidated balance sheets and statements of stockholders’ equity and a component of total comprehensive loss in the condensed consolidated statements of comprehensive loss, until realized. The Company assesses its available-for-sale marketable securities for impairment on a quarterly basis.

The Company's marketable securities portfolio historically contains investments in U.S. Treasury, other U.S. government-backed securities, and commercial paper. The Company reviews its portfolio based on the underlying risk profile of the securities and does not expect there to be a loss on these investments. The Company also regularly reviews the securities in an unrealized loss position and evaluates the current expected credit loss by considering factors such as historical experience, market data, issuer-specific factors, and current economic conditions.

There were no marketable securities as of September 30, 2025 and December 31, 2024, respectively. There wereno impairments recorded during the three and nine months ended September 30, 2025 or September 30, 2024. Realized gains and losses are included in other income (expense) on the condensed consolidated statements of operations.

During the three and nine months ended September 30, 2025 and 2024, the Company recognizedno year-to-date credit loss related to its short-term investments, and hadno allowance for credit loss recorded as of September 30, 2025 or December 31, 2024.

Note 4 –Fair Value Measurements

We record cash equivalents and marketable securities at fair value. ASC 820, Fair Value Measurements and Disclosures, establishes a fair value hierarchy for those instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and our own assumptions (unobservable inputs). The hierarchy consists of three levels:

Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities.

Level 2 – Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, directly or indirectly, for substantially the full term of the asset or liability.

Level 3 – Unobservable inputs that reflect our own assumptions about the assumptions market participants would use in pricing the asset or liability in which there is little, if any, market activity for the asset or liability at the measurement date.

The following table summarizes our cash equivalents measured at fair value on a recurring basis as of September 30, 2025:

There have been no changes to the valuation methods during the nine months ended September 30, 2025. There were no transfers between Level 1 and Level 2 and we hadno financial assets or liabilities that were classified as Level 3 at any point during the nine months ended September 30, 2025.

Cash equivalents and marketable securities have been initially valued at the transaction price and subsequently, at the end of each reporting period, valued utilizing third-party pricing services or other observable market data. The pricing services utilize industry standard valuation models, including both income and market-based approaches, and observable market inputs to determine value. After completing our valuation procedures, we did not adjust or override any fair value measurements provided by the pricing services as of September 30, 2025 and December 31, 2024.

The following table summarizes our cash equivalents measured at fair value on a recurring basis as of December 31, 2024:

Note 5 –Property and Equipment, net

Property and equipment, net consisted of the following:

Depreciation and amortization expense totaled $78,841 and $88,949 for the three months ended September 30, 2025 and 2024, respectively. Depreciation and amortization expense totaled $248,628 and $269,691 for the nine months ended September 30, 2025 and 2024, respectively.

Note 6 –Accrued Expenses

Accrued expenses consisted of the following:

Note 7 -Common Stock

The Company had 200,000,000 authorized shares of Class A common stock, $0.001 par value per share as of September 30, 2025 and December 31, 2024 of which 63,483,397 and 31,050,448 were issued and outstanding, respectively. The holders of Class A common stock are entitledone vote for each share of common stock. Dividends may be paid when, and if, declared by the Board of Directors, subject to the limitations, powers and preferences granted to the Preferred Stockholders and on a proportionate basis with holders of Class B common stock.

The Company had 20,000,000 authorized shares of Class B common stock, $0.001 par value per share as of September 30, 2025 and December 31, 2024, of whichno shares have been issued nor are outstanding. The holders of Class B common stock haveno voting rights. Dividends may be paid when, and if, declared by the Board of Directors, subject to the limitations, powers and preferences granted to the preferred stockholders and on a proportionate basis with holders of Class A common stock.

Equity Offerings

2022 Shelf Registration Statement

On August 10, 2022, the Company filed a Registration Statement on Form S-3 (File No. 333-266738) (the “2022 Shelf Registration Statement”) with the SEC in relation to the registration of common stock, preferred stock, debt securities, warrants and/or units or any combination thereof in the aggregate amount of up to $200 million for a period of up tothree years from the date of its effectiveness on August 19, 2022.

On August 10, 2022, the Company also entered into the 2022 Sales Agreement with the Sales Agent to sell shares of the Company’s Class A common stock, par value $0.001 per share, with aggregate gross sales proceeds of up to $50 million, from time to time, through the 2022 ATM Program under the 2022 Shelf Registration Statement. Subject to the terms and conditions of the 2022 Sales Agreement, the Sales Agent may sell the shares by methods deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act, including sales made through the Nasdaq Global Market, on any other existing trading market for the common stock, to or through a market maker, or, if expressly authorized by the Company, in privately negotiated transactions. The Company or Sales Agent could terminate the 2022 Sales Agreement upon notice to the other party and subject to other conditions. The Company paid the Sales Agent a commission equal to 3.0% of the gross proceeds of any Common Stock sold through the Sales Agent under the 2022 Sales Agreement and provided the Sales Agent with customary indemnification rights. The Company sold 327,355 shares of common stock under the 2022 ATM Program, at a weighted average price per share of $4.27, for aggregate gross proceeds of $1.4 million ($1.3 million net of offering expenses) during the three months ended September 30, 2025. The Company sold 5,164,159 shares of common stock under the 2022 ATM program, at a weighted average price per share of $3.03, for aggregate gross proceeds of $15.6 million ($15.0 million net of offering expenses) during the nine months ended September 30, 2025. The Company sold 1,318,752 shares of common stock under the 2022 ATM Program, at a weighted average price per share of $3.38, for aggregate gross proceeds of $4.5 million ($4.2 million net of offering expenses) during the three and nine months ended September 30, 2024.

Issuance costs incurred related to the 2022 Sales Agreement are recorded as deferred offering costs and are classified as long-term assets on the balance sheet. The deferred offering costs for the 2022 ATM Program were written off in August 2025, after the 2022 Shelf Registration Statement and the 2022 ATM Program expired, the 2022 Sales Agreement was terminated, and the Company entered into the 2025 Sales Agreement related to the 2025 ATM Program. The Company had approximately $0.5 million of deferred offering costs as of December 31, 2024 associated with the 2022 Sales Agreement.

2025 Shelf Registration Statement

On August 13, 2025, the Company filed a Registration Statement on Form S-3 (File No. 333-289589) (the “2025 Shelf Registration Statement”) with the SEC in relation to the registration of common stock, preferred stock, debt securities, warrants and/or units or any combination thereof in the aggregate amount of up to $300 million for a period of up tothree years from the date of its effectiveness on August 20, 2025.

On August 13, 2025, the Company also entered into the 2025 Sales Agreement with the Sales Agent to sell shares of the Company’s Class A common stock, par value $0.001 per share, with aggregate gross sales proceeds of up to $100 million, from time to time, through the 2025 ATM Program under the 2025 Shelf Registration Statement. Subject to the terms and conditions of the 2025 Sales Agreement, the Sales Agent may sell the shares by methods deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act, including sales made through the Nasdaq Global Market, on any other existing trading market for the common stock, to or through a market maker, or, if expressly authorized by the Company, in privately negotiated transactions. The Company or Sales Agent may terminate the 2025 Sales Agreement upon notice to the other party and subject to other conditions. The Company will pay the Sales Agent a commission up to 3.0% of the gross proceeds of any Common Stock sold through the Sales Agent under the 2025 Sales Agreement and has provided the Sales Agent with customary indemnification rights. The Company didnot sell any shares of Class A common stock under the 2025 ATM Program during the three and nine months ended September 30, 2025 or September 30, 2024, respectively. In connection with the September 2025 Offering, the Company: (i) reduced the maximum aggregate offering price for sales of shares of common stock pursuant to at-the-market transactions under the 2025 ATM Program by $1,250,007 (or the Reduced Amount, as defined above), resulting in a new maximum aggregate offering price of up to $98,749,993 under the 2025 ATM Program, and (ii) suspended the 2025 ATM Program and terminated the continuous offering under the 2025 ATM Program, in each case, as to the Reduced Amount. As of September 30, 2025, the Company had aggregate gross sales proceeds capacity of $98.7 million remaining under the 2025 ATM Program.

Issuance costs incurred related to the 2025 Sales Agreement are recorded as deferred offering costs and are classified as long-term assets on the balance sheet at September 30, 2025. The Company had approximately $0.2 million of deferred offering costs as of September 30, 2025 associated with the 2025 Sales Agreement.

August 2025 Private Placement

On August 21, 2025, the Company entered into the August 2025 Purchase Agreement with the purchasers party thereto, pursuant to which the Company agreed to sell securities to such purchasers in the August 2025 Private Placement. The August 2025 Purchase Agreement provided for the sale and issuance by the Company to the purchasers of: (i) an aggregate of 5,251,349 shares of its common stock at a purchase price of $3.95 per share, (ii) for certain purchasers, in lieu of common stock, an aggregate of 1,077,764 Pre-Funded Warrants to purchase up to the same number of shares of its common stock, and (iii) an aggregate of 2,848,096 Purchase Warrants to purchase up to the same number of shares of its common stock. The Pre-Funded Warrants were issued for a purchase price equating to $3.949 per Pre-Funded Warrant (which was the per share purchase price for the common stock issued in the August 2025 Private Placement, less the $0.001 per share unfunded exercise price for each Pre-Funded Warrant); see "Note 12 - Subsequent Events" for additional information related to the cashless exercise of the Pre-Funded Warrants. The Purchase Warrants were issued with an exercise price of $5.50 per share; as of September 30, 2025, no Purchase Warrants had been exercised. As of September 30, 2025, the Company had received aggregate net proceeds of $23.4 million from the August 2025 Private Placement, after deducting placement expenses of $1.6 million. The August 2025 Private Placement closed on August 26, 2025.

Also on August 21, 2025, in connection with the August 2025 Purchase Agreement, the Company entered into a Registration Rights Agreement (the “Registration Rights Agreement”) with the purchasers in the August 2025 Private Placement. Pursuant to the Registration Rights Agreement, the Company agreed to prepare and file a registration statement with the SEC for purposes of registering the resale of the common stock and the shares of common stock issuable upon exercise of the Pre-Funded Warrants and Purchase Warrants (collectively, the “Warrant Shares”) purchased by the purchasers in the August 2025 Private Placement, and any shares of common stock issued as a dividend or other distribution with respect to, in exchange for or in replacement of such common stock or Warrant Shares. On September 3, 2025, the Company filed a Registration Statement on Form S-3 (File No. 333-289997) (the “2025 Resale Registration Statement”) with the SEC in relation to the registration for re-sale of the common stock and Warrant Shares from the August 2025 Private Placement. The SEC declared the 2025 Resale Registration Statement effective on September 8, 2025.

The Purchase Warrants have an exercise price of $5.50 per share of common stock, are exercisable immediately following their issuance, and will expire on September 8, 2030. The Purchase Warrants contain standard adjustments to the exercise price including for stock splits, stock dividends or distributions, certain other dividends or distributions and certain reorganizations. The Purchase Warrants also include certain rights upon the occurrence of a “fundamental transaction” (as described in the Purchase Warrants).

The foregoing and other related summaries contained herein do not purport to be complete and are qualified in their entirety by reference to the August 2025 Purchase Agreement, the Registration Rights Agreement, the Pre-Funded Warrants and the Purchase Warrants, which are filed as Exhibits 10.3, 10.4, 4.1 and 4.2, respectively, to this Quarterly Report on Form 10-Q.

The proceeds received from the sale of equity classified warrants and shares of common stock in a bundled transaction are allocated based on the relative fair values of warrants and shares of common stock with no changes in fair value of warrants recognized after the issuance date.

The Purchase Warrants and Pre-Funded Warrants were classified as a component of stockholders’ equity within additional paid-in-capital and were recorded at the issuance date using a relative fair value allocation method. The Purchase Warrants and Pre-Funded Warrants are equity classified because they are freestanding financial instruments that are legally detachable and separately exercisable from the equity instruments, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, permit the holders to receive a fixed number of common shares upon exercise, are indexed to the Company’s common stock and meet the equity classification criteria. In addition, such Purchase Warrants do not provide any guarantee of value or return. The Company valued the Purchase Warrants at issuance using the Black-Scholes valuation model and allocated proceeds from the sale proportionately to the common stock and Purchase Warrants, of which approximately $3.7 million was allocated to the Purchase Warrants and recorded as a component of additional paid-in-capital.

As of September 30, 2025, the Company had (i)2,848,096 Purchase Warrants issued and outstanding at an exercise price of $5.50 per share to purchase shares of the Company's common stock, and (ii)1,077,764 Pre-Funded Warrants issued and outstanding at an exercise price of $0.001 per share to purchase shares of the Company's common stock. On October 6, 2025, certain purchasers from the August 2025 Private Placement exercised an aggregate of 1,077,764 Pre-Funded Warrants previously issued to them pursuant to the August 2025 Purchase Agreement. Each such exercise was made pursuant to the cashless exercise provision of the applicable Pre-Funded Warrant, such that an aggregate of 166 shares of common stock were withheld in lieu of a cash payment of the $0.001 exercise price for each Pre-Funded Warrant, and the exercising purchasers were issued an aggregate of 1,077,598 shares of common stock. See "Note 12 - Subsequent Events" for additional information related to the cashless exercise of the Pre-Funded Warrants.

September 2025 Aventis (Sanofi) Private Placement

On September 24, 2025, the Company entered into the September 2025 Purchase Agreement with Aventis, pursuant to which the Company agreed to sell securities to Aventis in the September 2025 Private Placement. The September 2025 Purchase Agreement provided for the sale and issuance by the Company to Aventis of an aggregate of 2,708,559 shares of its common stock at a purchase price of $9.23 per share. The Company received aggregate net proceeds of $23.3 million from the September 2025 Private Placement, after deducting placement agent discounts and commissions, but before deducting placement costs payable by the Company, which were estimated to be approximately $0.2 million. The September 2025 Private Placement closed on September 26, 2025.

Pursuant to the September 2025 Purchase Agreement, the Company also agreed to (i) notify Aventis within three business days of the Company engaging in discussions with any third party regarding, or the Company’s board of directors authorizing the Company to pursue or initiate a process to pursue, any transaction that would be reasonably expected to result in a change of control of the Company or an affiliate of the Company (a “Change of Control”) or any other license, sale, assignment, transfer, grant or other disposition of the Company’s or an affiliate of the Company’s rights to research, develop, manufacture, commercialize, or otherwise exploit atebimetinib (a “Covered Transaction” and, collectively, a “Strategic Transaction Process”), (ii) provide Aventis the opportunity to participate in such Strategic Transaction Process subject to customary confidentiality and other undertakings on substantially the same procedural terms and timeframe as other participants, and (iii) for a period of 120 days following the date of the September 2025 Purchase Agreement, not enter into any Covered Transaction or commence, continue, or otherwise engage in any discussions, or negotiate with any third party, to enter into any Covered Transaction (provided that this provision shall not limit the entry by the Company into, or any engagement in discussion or negotiations with any third party regarding, a Change of Control transaction). These provisions contain customary confidentiality restrictions and limitations on disclosure obligations, and will terminate upon the earlier of: (a) such time as Aventis and its affiliates no longer hold at least 50% of the securities purchased from the Company pursuant to the September 2025 Purchase Agreement, (b) 90 days after the public release of the topline results of the overall survival of the Phase 3 clinical trial of atebimetinib in pancreatic cancer, (c) the liquidation, dissolution or winding-up of the affairs of the Company, or the consummation of any Change of Control or any other deemed liquidation event of the Company and (d) such time as all development activities with respect to atebimetinib have been terminated.

In addition, pursuant to the September 2025 Purchase Agreement, Aventis agreed (i) until the date that is six months after the closing date of the September 2025 Private Placement, to be subject to customary lock-up restrictions with respect to sales of shares of the Company’s Common Stock (or similar transactions with the same economic effect), subject to certain customary exceptions, (ii) until the first anniversary of the closing date of the September 2025 Private Placement, to be subject to stand-still restrictions with respect to acquisitions of shares of the Company’s Common Stock and similar activities, subject to certain customary exceptions and fall-away provisions, and (iii) until the first anniversary of the closing date of the September 2025 Private Placement or such earlier time as the stand-still restrictions shall have fallen away, vote with respect to all voting securities of the Company as to which it is entitled to vote in accordance with the recommendation of a majority of the Company’s board of directors.

The foregoing and other related summaries contained herein do not purport to be complete and are qualified in their entirety by reference to the September 2025 Purchase Agreement, which is filed as Exhibit 10.5 to this Quarterly Report on Form 10-Q.

September 2025 Offering

On September 26, 2025, the Company completed the September 2025 Offering, pursuant to which it issued and sold 18,959,914 shares of its Class A common stock at an offering price of $9.23 per share, with Leerink Partners LLC and Oppenheimer & Co. Inc. acting as underwriters. The aggregate net proceeds received by the Company from the September 2025 Offering were $164.1 million, after deducting underwriting discounts and commissions, but before deducting offering costs payable by the Company, which were estimated to be approximately $0.4 million.

Note 8 -Net Loss Per Share Attributable to Common Stockholders

Basic and diluted net loss per share attributable to common stockholders was calculated at September 30, 2025 and September 30, 2024 as follows:

The weighted average number of common shares used in the basic and diluted net loss per common share calculations includes the weighted-average pre-funded warrants outstanding during the period as they are exercisable at any time for nominal cash consideration. There were 1,077,764 Pre-Funded Warrants outstanding at September 30, 2025.

The following table sets forth the potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive (in common stock equivalent shares) at September 30, 2025 and September 30, 2024:

Note 9 –Stock-Based Compensation

During 2015, the Company established the Long Term Incentive Plan (“Incentive Plan”), under which incentive stock options, nonqualified stock options, restricted stock or other awards may be awarded to employees, directors or consultants of the Company. The options typically vest over afour-year period. Upon the effectiveness of the Company’s 2021 Incentive Award Plan (the “2021 Plan”), the Company ceased granting awards under the Incentive Plan. However, the Incentive Plan continues to govern awards outstanding thereunder.

On July 23, 2021, the Company’s Board of Directors adopted, and on July 23, 2021 its stockholders approved, the 2021 Plan, which became effective on July 29, 2021. The 2021 Plan provides for the grant of incentive stock options, stock appreciation rights, restricted stock awards, restricted stock units, and other stock-based awards. The number of shares reserved for issuance under the 2021 Plan was initially equal to 2,590,000 plus an annual increase on the first day of each calendar year, beginning on January 1, 2022 and ending on and including January 1, 2031, equal to the lesser of (i)4% of the aggregate number of shares of Class A common stock outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares of Class A common stock as determined by the Board of Directors. No more than 15,350,000 shares of Class A common stock may be issued under the 2021 Plan upon the exercise of incentive stock options. Shares issued under the 2021 Plan may be authorized but unissued shares, shares purchased on the open market or treasury shares. If an award under the 2021 Plan expires, lapses or is terminated, exchanged for or settled in cash, surrendered, repurchased, cancelled without having been fully exercised/settled or forfeited, any unused shares subject to the award will, as applicable, become or again be available for new grants under the 2021 Plan. In addition, shares subject to stock options issued under the Incentive Plan may become available for issuance under the 2021 Plan to the extent such stock options are canceled, forfeited, exchanged, settled in cash or otherwise terminated. As of September 30, 2025, there were 969,941 shares available for future issuance under the 2021 Plan.

On July 23, 2021, the Company’s Board of Directors adopted, and on July 23, 2021 its stockholders approved, the 2021 Employee Stock Purchase Plan (the “2021 ESPP”), which became effective on July 29, 2021. A total of 250,000 shares of Class A common stock were initially reserved for issuance under this plan. The number of shares of Class A common stock that may be issued under the 2021 ESPP will automatically increase on the first day of each calendar year, beginning on January 1, 2022 and ending on and including January 1, 2031, equal to the lesser of (i)1% of the shares of Class A common stock outstanding on the final day of the immediately preceding calendar year and (ii) such smaller number of shares of Class A common stock as determined by the Board of Directors, provided that not more than 3,340,000 shares of Class A common stock may be issued under the 2021 ESPP. As of September 30, 2025, there were 849,697 shares of common stock reserved for future issuance under the 2021 ESPP and 530,911 shares had been granted or purchased under the 2021 ESPP.

On May 21, 2024 (the “Effective Date”), based upon the recommendation of the Compensation Committee of the Company's Board of Directors, the Board of Directors approved an option repricing, in accordance with the 2021 Plan, which repricing was effected on the Effective Date. The repricing applied to options to purchase shares of the Company’s Class A common stock with an exercise price per share greater than $3.01 that were held by then current employees and certain non-employee service providers under the 2021 Plan (the “Eligible Options”), including E.B. Brakewood, the Company’s Chief Business Officer, and Michael Bookman, the Company's Chief Legal Officer.

Options held by Benjamin Zeskind, Ph.D., the Company’s President and Chief Executive Officer, Brett Hall, Ph.D., the Company's Chief Scientific Officer, and the non-employee members of the Board were not eligible for the repricing.

As a result of the option repricing, as of the Effective Date, the exercise price of all Eligible Options was reduced to $3.01 per share, which represented approximately two times the closing trading price of the Company’s Class A common stock on the Nasdaq Global Market on the Effective Date; however, the exercise price for repriced options would revert to the original exercise price for any exercise occurring prior to June 30, 2025 (the "Retention Period"), unless there was a change of control of the Company or the option holder’s employment has been terminated (i) by the Company without cause or (ii) by reason of death or disability. The repriced options otherwise remain subject to their existing terms and conditions as set forth in the 2021 Plan and applicable award agreements. As of the Effective Date, outstanding options to purchase 2,986,354 shares were deemed Eligible Options and were repriced such that the exercise price per share for such outstanding options was reduced to $3.01 per share. There were no changes to the number of shares, the vesting schedule or the expiration date of the Eligible Options.

The effect of the option repricing resulted in a total incremental non-cash stock-based compensation expense of $0.6 million, which was calculated using the Black-Scholes option-pricing model, of which $0.2 million of the incremental non-cash stock-based compensation expense is associated with vested repriced options and will be recognized on a straight-line basis through the 13-month Retention Period. The remaining $0.4 million of the incremental non-cash stock-based compensation expense is associated with unvested repriced options and will be recognized as follows: (a) if the Retention Period is greater than the remaining original vesting period of the repriced option, the incremental cost will be amortized on a straight-line basis through the Retention Period end date or (b) if the Retention Period is less than the remaining original vesting term of the repriced option, the incremental cost will be amortized on a straight-line basis over the remaining original vesting period.

During the three and nine months ended September 30, 2025, the Company recognized incremental stock-based compensation expense of $32 thousand and $193 thousand, respectively, associated with the repricing which is included in general and administrative and research and development expense in the condensed consolidated statement of operations and comprehensive loss. During the three and nine months ended September 30, 2024, the Company recognized incremental stock-based compensation expense totaling $84 thousand and $120 thousand, respectively, associated with the repricing which is included in general and administrative and research and development expense in the condensed consolidated statement of operations and comprehensive loss.

On March 20, 2025, the Company’s Board of Directors adopted the Immuneering Corporation 2025 Employment Inducement Award Plan (the "Inducement Award Plan"), without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Stock Market LLC listing rules. The Inducement Award Plan provides for the grant of non-qualified stock options, stock appreciation rights, restricted stock awards, restricted stock units, and other stock-based awards. The number of shares reserved for issuance under the Inducement Award Plan was initially equal to 500,000 shares. Shares issued under the Inducement Award Plan may be authorized but unissued shares, shares purchased on the open market or treasury shares. If an award under the Inducement Award Plan expires, lapses or is terminated, exchanged for or settled in cash, surrendered, repurchased, cancelled without having been fully exercised/settled or forfeited, any unused shares subject to the award will, as applicable, become or again be available for new grants under the Inducement Award Plan. As of September 30, 2025, there were 382,000 shares available for future issuance under the Inducement Award Plan.

The Company recognized stock-based compensation expense of $1,456,080 and $4,673,290 during the three and nine months ended September 30, 2025, respectively. During the three and nine months ended September 30, 2024, the Company recognized stock-based compensation expense of $1,640,116 and $4,776,623, respectively. As of September 30, 2025, compensation expense remaining to be recognized for outstanding stock options was $7,761,498 and to be recognized over a weighted-average period of 2.42 years.

The fair value of options granted is calculated on the grant date using the Black-Scholes option valuation model. Prior to the Company’s IPO on August 3, 2021, the Company wasa private company and thus lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own publicly traded stock price. For the nine months ended September 30, 2025, the Company granted 2,362,294 shares of stock options at a weighted-average grant date fair value of $1.99.

The Company used the following assumptions in its application of the Black-Scholes option pricing model for grants during the nine months ended September 30, 2025 and 2024:

The following table summarizes the stock option activity during the nine months ended September 30, 2025:

For the three and nine months ended September 30, 2025 and 2024, the Company recognized share-based compensation expense on the accompanying condensed consolidated statements of operations as follows:

Note 10 –Commitments and Contingencies

Operating Leases

The Company leases 38,613 square feet of office and laboratory space in San Diego, California, under a lease that terminates on April 30, 2032. As of September 30, 2025, the right-of-use asset balance associated with this lease was $3,411,693.

The Company currently also leases office space in Cambridge, Massachusetts and New York, New York, pursuant to short-term arrangements. The Cambridge lease is currently on a month-to-month basis, requiring one month’s notice before termination. In September 2025, the Company executed a one year lease for the existing office space in Cambridge with a term that commences on December 1, 2025 and ends on November 30, 2026. The New York lease was most recently renewed on October 1, 2025 to extend the lease term through September 30, 2026. These lease agreements include or included payments for lease and non-lease components. The Company has elected to not separate such components and these payments were recognized as rent expense.

As of September 30, 2025, total future minimum lease payments for its short-term leases in Cambridge, Massachusetts, and New York, New York were $32,426 due in 2025 and $140,136 due in 2026.

Future minimum lease payments for operating leases with initial or remaining terms in excess of one year at September 30, 2025 were as follows:

Quantitative information regarding the Company’s leases for the nine months ended September 30, 2025 and 2024 is as follows:

As the Company’s leases typically do not provide an implicit rate, the Company uses an estimate of its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments.

Litigation

From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities and may be exposed to litigation in connection with its product candidates and operations. The Company’s policy is to assess the likelihood of any adverse judgments or outcomes related to legal matters, as well as ranges of probable losses. When it is probable that future expenditures will be made and can be reasonably estimated the Company will accrue a liability for such matters. Significant judgement is required to determine both probability and estimated amount. The Company is not aware of any material legal matters.

Clinical Research Contracts

The Company may enter into contracts in the normal course of business with contract research organizations for clinical trials, with contract manufacturing organizations for clinical supplies, and with other vendors for preclinical studies, supplies and other services for the Company’s operating purposes. These contracts generally provide for termination with a 30-day notice.

Note 11 –Segments

An operating segment is identified as a component of an enterprise about which separate discrete financial information is available for evaluation by the Chief Operating Decision Maker ("CODM") in making decisions, including regarding resource allocation and assessing performance. The Company’s Chief Executive Officer is its CODM.

The Company's CODM uses consolidated single-segment (one) financial information for purposes of: allocating resources, evaluating performance, making operating decisions, setting incentive targets, and planning and forecasting for future periods. The Company's CODM makes such decisions based on consolidated net loss. This measure is used to monitor budget versus actual results to evaluate the performance of the segment. Managing and allocating resources on a consolidated basis enables the CODM to assess the overall level of resources available and how to deploy these resources across functions and operations (including research and development) that align with the Company’s strategic goals. All of the Company’s long-lived assets are held in the United States.

The following table is representative of the significant expense categories regularly provided to the CODM when managing the Company’s single reporting segment.

(1) Includes direct research and development expenses.

(2) Includes general and administrative expenses, in addition to facilities and other research and development expenses.

(3) Includes interest income and other (income) expense.

Note 12 – Subsequent Events

October 2025 Pre-Funded Warrant Exercise

On October 6, 2025, certain purchasers from the August 2025 Private Placement exercised an aggregate of 1,077,764 Pre-Funded Warrants previously issued to them pursuant to the August 2025 Purchase Agreement. Each such exercise was made pursuant to the cashless exercise provision of the applicable Pre-Funded Warrant, such that an aggregate of 166 shares of common stock were withheld in lieu of cash payment of the $0.001 exercise price for each Pre-Funded Warrant share, and the exercising purchasers were issued an aggregate of 1,077,598 shares of common stock (the "October 2025 Cashless Exercise"). Following the October 2025 Cashless Exercise, no Pre-Funded Warrants remained issued and outstanding.