Quarterly Report for Quarter Ending September 30, 2025 (Form 10-Q)

Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion and analysis of our financial condition and results of operations should be read together with our unaudited condensed consolidated financial statements and related notes appearing elsewhere in this Quarterly Report on Form 10-Q and with our audited consolidated financial statements and related notes for the year ended December 31, 2024 included in our Annual Report on Form 10-K. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report on Form 10-Q, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the "Risk Factors" section of this Quarterly Report on Form 10-Q and our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, our actual results could differ materially from the results described in, or implied by, the forward-looking statements contained in the following discussion and analysis.

Overview

Tango Therapeutics was founded with a clear mission: to discover the next wave of targeted therapies in oncology by addressing the specific genetic alterations that drive cancer. We develop new drugs directed at tumor suppressor gene loss in defined patient populations with high unmet medical need. Tumor suppressor gene loss remains a largely unaddressed target space specifically because these genetic events cannot be directly targeted. Our novel small molecules are designed to be selectively active in cancer cells with specific genetic alterations, killing those cancer cells while sparing normal cells. We also are extending this target space beyond the classic, cell-autonomous effects of tumor suppressor gene loss to include the discovery of novel targets that reverse tumor suppressor gene mediated immune evasion which prevents the immune system from recognizing and killing cancer cells. We believe our approach will provide the ability to deliver deep, durable target inhibition with favorable tolerability and safety profiles, thus potentially maximizing clinical benefit.

We are currently developing two MTAP-deleted selective PRMT5 inhibitors: vopimetostat (TNG462) for non-CNS cancers, including pancreatic and lung cancer, and TNG456, our next-generation, brain-penetrant PRMT5 inhibitor, for CNS cancers, including GBM.

In October 2025, we reported positive data from the ongoing Phase 1/2 clinical trial of vopimetostat in patients with MTAP-deleted selective cancers, demonstrating clinical activity across multiple cancer types with a favorable safety and tolerability profile to date. The cutoff date for the analysis was September 1, 2025 and included all evaluable patients at active doses (200 mg QD and above). Overall response rates were calculated in all tumor-evaluable patients enrolled more than 6 months prior to the efficacy analysis. Median progression free survival (mPFS) was calculated in all patients who received a first scan (~8 weeks).

Across all MTAP-deleted tumor types, there were 94 tumor evaluable patients. We observed an ORR (objective response rate) of 27% and mPFS of 6.4 months. In the 29 patients with second line (2L) MTAP-deleted pancreatic cancer, mPFS was 7.2 months. In patients with 2L pancreatic cancer that were enrolled more than 6 months prior to the data cutoff and were tumor evaluable (n=8), the ORR was 25%, more than double that observed in historical chemotherapy studies (~10%), supporting the planned initiation of a pivotal trial in this patient population in 2026. In the histology selective cohort with 37 evaluable late line patients, we observed a 49% ORR and mPFS of 9.1 months. The histology selective cohort excludes pancreatic and lung cancer patients, as those indications were enrolled in separate cohorts and are being developed independently. Sarcoma patients are also excluded from this analysis, as no activity was observed in this indication (ORR 0%), which will not be pursued in future development. As of September 1, 2025, 41 patients with 2L+ lung cancer were enrolled in the Phase 1/2 clinical trial at active doses, 12 of whom were enrolled more than 6 months prior to the analysis. Emerging data from the lung cohort are consistent with expectations, and we anticipate providing a safety and efficacy update in 2026.

Additionally, vopimetostat demonstrated a favorable safety and tolerability profile with no drug-related dose discontinuations and ~8% dose reduction in patients dosed at 250 mg QD as of the data cutoff date. We have FDA agreement on 250 mg QD as the go-forward dose.

The company has engaged Malte Peters, M.D., Mark Winderlich, Ph.D., and Philippe Serrano, Pharm.D., as consultants to support the company on key initiatives related to initiation of the planned pivotal study in second line pancreatic cancer, anticipated to start in 2026, and advancing our late-stage development capabilities. Dr. Peters, who also serves on the Tango Board of Directors, Dr. Winderlich and Mr. Serrano have significant late-stage clinical development, biostatistics and regulatory expertise, having brought multiple oncology products to market. They will aid the company in its upcoming engagement with the U.S. FDA and future regulatory strategy.

In June 2025, the first patient was treated in the combination clinical trial that is evaluating vopimetostat with the RAS(ON) multi-selective inhibitor, daraxonrasib, and RAS(ON) G12D-selective inhibitor, zoldonrasib (Revolution Medicines). In the first

cohort in the trial (n=7), both combinations have been well-tolerated to date with exposures in the active range for all compounds and early signs of activity. We believe this ongoing clinical trial has the potential to support a first line pancreatic cancer pivotal study in MTAP-deleted/RAS mutated patients.

In May 2025, the first patient was treated with TNG456 in the dose escalation portion of the Phase 1/2 clinical trial to evaluate the safety, pharmacokinetics, pharmacodynamics and antitumor activity of TNG456 as a monotherapy. The trial is currently enrolling patients with MTAP-deleted solid tumors, with a focus on GBM. Preclinical data for TNG456 showed favorable potency and MTAP selectivity and sufficient brain penetrance to potentially have meaningful efficacy in GBM.

TNG260 is a first-in-class CoREST inhibitor, which in preclinical studies reversed the immune evasion effect of STK11 loss-of-function mutations. TNG260 had a favorable safety, tolerability and pharmacokinetic profile in dose escalation. In November 2025, we announced that forty-one patients with STK11-mutant, locally advanced or metastatic solid tumors were enrolled in three dose escalation cohorts of the Phase 1/2 clinical trial. 21/41 patients were evaluable at active doses. The maximum tolerated dose (MTD) was 80 mg QD. Patients with checkpoint inhibitor resistant STK11 mutant/KRAS wild-type NSCLC receiving clinically active doses of TNG260 plus pembrolizumab had a mPFS of 27 weeks (n=5), more than double the standard of care PFS of ~10 weeks. There was no evidence of activity in other STK11 mutant cancers. 80 mg QD TNG260 was selected for dose optimization, which is ongoing for patients with advanced STK11 mutant/KRAS wild type NSCLC, representing ~10% of lung adenocarcinoma annually in the US (~10,000 patients).

TNG961 is a development candidate targeting HBS1L in FOCAD-deleted solid tumors. FOCAD deletion occurs in 20-40% of all MTAP-deleted cancers. FOCAD deletion is common in NSCLC, occurring in ~5% of these patients. 20-40% of cancers with MTAP deletion have a coincident FOCAD deletion on chromosome 9, and cancers with FOCAD deletion are dependent on HBS1L for mRNA processing, thus protein synthesis. By degrading HBS1L and disrupting the HBS1L/PELO complex, TNG961 causes tumor regression in FOCAD-deleted preclinical models of multiple histologies.

Financial Overview

Since the Company's inception, we have focused primarily on organizing and staffing our company, business planning, raising capital, discovering product candidates, securing related intellectual property, and conducting research and development activities for our programs. To date, we have funded our operations primarily through equity financings and from the proceeds received from our collaboration agreement with Gilead. Since inception, we have raised an aggregate of $166.9 million of gross proceeds from the sale of our preferred shares, $342.1 million in gross proceeds through the closing of the Business Combination and simultaneous financing transactions, $237.1 million through our collaboration with Gilead, and $348.0 million of gross proceeds through (i) $80.0 million from the private placement of common shares and pre-funded warrants to purchase common shares in August 2023, (ii) $43.0 million from our "at-the-market" stock offering program in January 2024 and (iii) $225.0 million in aggregate gross proceeds from the underwritten offering and concurrent private placement of common shares and pre-funded warrants to purchase common shares in October 2025.

We expect that our existing cash, cash equivalents and marketable securities on hand as of September 30, 2025 of $152.8 million, in addition to $212.0 million in aggregate net proceeds from our underwritten offering and concurrent private placement of common shares and pre-funded warrants to purchase common shares in October 2025, will enable us to fund our operating expenses and capital expenditure requirements into 2028. Since inception, we have incurred significant operating losses. For the nine months ended September 30, 2025 and 2024, our net losses were $62.8 million and $92.6 million, respectively. We had an accumulated deficit of $564.4 million as of September 30, 2025. We expect to continue to incur significant and increasing expenses and operating losses for the foreseeable future, as we advance our product candidates through preclinical and clinical development and seek regulatory approvals, manufacture drug product and drug supply, and maintain and expand our intellectual property portfolio. We also expect to hire additional personnel, pay for accounting, audit, legal, regulatory and consulting services, and pay costs associated with maintaining compliance with Nasdaq listing rules and the requirements of the U.S. Securities and Exchange Commission, director and officer liability insurance, investor and public relations activities and other expenses associated with operating as a public company. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our preclinical studies, our clinical trials, and our expenditures on other research and development activities.

We do not have any product candidates approved for sale and have not generated any revenue from product sales. We will not generate revenue from product sales unless and until we successfully complete clinical development and obtain regulatory approval for our product candidates, if ever. In addition, if we obtain regulatory approval for our product candidates and do not enter into a third-party commercialization partnership, we expect to incur significant expenses related to developing our commercialization capability to support product sales, marketing, manufacturing and distribution activities. As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until we can generate

significant revenue from product sales, if ever, we expect to finance our operations through a combination of public or private equity offerings and debt financings or other sources, such as potential collaboration agreements, strategic alliances and licensing arrangements. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed on acceptable terms, or at all. Our failure to raise capital or enter into such agreements as, and when needed, could have a negative effect on our business, results of operations and financial condition.

Because of the numerous risks and uncertainties associated with pharmaceutical development, we are unable to predict the timing or amount of increased expenses or when or if we will be able to achieve or maintain profitability. Even if we are able to generate revenues from the sale of our therapies, we may not become profitable. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and be forced to reduce our operations.

At-the-Market Stock Offering

In September 2022, we entered into a sales agreement (the Sales Agreement) with Jefferies LLC (Jefferies), which permits us to sell from time to time, at our option, up to an aggregate of $100.0 million of shares of our common stock through Jefferies, as sales agent. Sales of the common stock, if any, will be made by methods deemed to be "at-the-market" stock offerings. The Sales Agreement will terminate upon the earliest of: (a) the sale of $100.0 million of shares of our common stock or (b) the termination of the Sales Agreement by us or Jefferies. To date, the Company has sold 4,001,200 shares of common stock under this program for gross proceeds of $43.0 million.

Revenue

To date, we have not recognized any revenue from product sales, and we do not expect to generate any revenue from the sale of products in the next several years. If our development efforts for our product candidates are successful and result in regulatory approval, or license agreements with third parties, we may generate revenue in the future from product sales. However, there can be no assurance as to when we will generate such revenue, if at all.

Collaboration Agreements with Gilead Sciences

In October 2018, we entered into a collaboration agreement (the 2018 Gilead Agreement) with Gilead Sciences, Inc. (Gilead). Pursuant to the terms of the 2018 Gilead Agreement, we received an initial upfront payment of $50.0 million. The upfront payment was initially recorded as deferred revenue on our balance sheet and is recognized as revenue as or when the performance obligation under the contract is satisfied. In August 2020, the 2018 Gilead Agreement was expanded into a broader collaboration via an amended and restated research collaboration and license agreement (the Gilead Agreement). Pursuant to the terms of the Gilead Agreement, we received an upfront payment of $125.0 million. Consistent with the treatment of the previously received upfront payment, this upfront payment was recorded as deferred revenue on our balance sheet and is recognized as revenue as or when the performance obligation under the contract is satisfied. In 2020 and 2021, Gilead elected to extend two programs for research extension fees totaling $24.0 million, which was added to our estimate of the transaction price to total $199.0 million. In June 2024, Gilead licensed a program for a $12.0 million fee, which was recognized as license revenue in the second quarter of 2024.

In August 2025, the Company and Gilead mutually agreed to truncate the research term of the collaboration and license agreement from seven to five years, concluding the research portion of the collaboration. There is no financial penalty to the Company as a result, no licensed programs are being returned to the Company, all ongoing work at Gilead on licensed programs will continue and agreements for all future milestones and royalties remain in effect. The Company has no future research obligations and the remaining unrecognized deferred revenue balance as of June 30, 2025 of $53.8 million has been recognized as revenue in the third quarter of 2025.

As of September 30, 2025, all $199.0 million has been recognized as collaboration revenue related to the upfront and research option-extension payments from the Gilead Agreements.

During the three months ended September 30, 2025 and 2024, we recognized $53.8 million and $11.6 million, respectively, and during the nine months ended September 30, 2025 and 2024, we recognized $62.4 million and $25.9 million, respectively, of collaboration revenue associated with the Gilead agreements based on performance completed during each period.

Refer to Note 2 and Note 3 to our unaudited condensed consolidated financial statements and related notes appearing elsewhere in this Quarterly Report on Form 10-Q and our audited consolidated financial statements and related notes for the year

ended December 31, 2024 included in our Annual Report on Form 10-K for additional information regarding our revenue recognition accounting policy and our collaboration agreement with Gilead.

Operating Expenses

Research and Development Expenses

Research and development expenses consist primarily of costs incurred for our drug discovery efforts and the development of our product candidates. We expense research and development costs as incurred, which include:

Costs for certain activities are recognized based on an evaluation of the progress to completion of specific tasks using data such as information provided to us by our vendors and analyzing the progress of our preclinical studies or other services performed. Significant judgment and estimates are made in determining the accrued expense balances at the end of any reporting period.

Our direct external research and development expenses consist primarily of fees paid to CROs and outside consultants in connection with our preclinical and clinical development and manufacturing activities. Our direct external research and development expenses also include fees incurred under license agreements. We track these external research and development costs on a program-by-program basis once we have identified a product candidate.

We do not allocate employee costs or costs associated with our target discovery efforts, laboratory supplies, and facilities, including depreciation or other indirect costs, to specific programs because these costs are deployed across multiple programs and, as such, are not separately classified. We characterize research and development costs incurred prior to the identification of a product candidate as discovery costs. We use internal resources primarily to conduct our research and discovery activities as well as for managing our preclinical, development and manufacturing activities.

The following table summarizes our research and development expenses:

*In November 2024, we announced we stopped enrollment in the TNG908 Phase 1/2 trial due to insufficient brain exposure for GBM clinical activity and portfolio prioritization. Expenses beyond November 2024 related to previously enrolled patients and close-out clinical trial costs.

**In May 2024, we announced the discontinuation of TNG348, a USP1 inhibitor, due to toxicity observed in the dose escalation portion of our Phase 1/2 clinical trial. Expenses beyond May 2024 related to close-out clinical trial costs.

The successful development of our product candidates is highly uncertain. We plan to substantially increase our research and development expenses for the foreseeable future as we continue the development of our product candidates and manufacturing processes and conduct discovery and research activities for our preclinical programs. We cannot determine with certainty the timing of initiation, the duration or the completion costs of current or future preclinical studies and clinical trials of our product candidates or the timing of regulatory filings in connection with clinical trials or regulatory approval, due to the inherently unpredictable nature of preclinical and clinical development. Clinical and preclinical development timelines, the probability of success and development costs can differ materially from expectations. We anticipate that we will make determinations as to which product candidates to pursue and how much funding to direct to each product candidate on an ongoing basis in response to the results of ongoing and future preclinical studies and clinical trials, regulatory developments and our ongoing assessments as to each product candidate's commercial potential. Our clinical development costs have, and are expected to continue to increase significantly with the commencement and continuation of our current and planned clinical trials, including our planned combination clinical trials. We anticipate that our expenses will increase substantially, particularly due to the numerous risks and uncertainties associated with developing product candidates, including the uncertainty of:

Any changes in the outcome of any of these variables with respect to the development of our product candidates in preclinical and clinical development could mean a significant change in the costs and timing associated with the development of these product candidates. We may never succeed in achieving regulatory approval for any of our product candidates. We may obtain unexpected results from our clinical trials. We may elect to discontinue, delay or modify clinical trials of some product candidates or focus on other product candidates.

General and Administrative Expenses

General and administrative expenses consist primarily of employee related costs, including salaries, bonuses, benefits, stock-based compensation and other related costs. General and administrative expense also includes professional services, including legal, accounting and audit services and other consulting fees as well as facility costs not otherwise included in research and development expenses, insurance and other general administrative expenses.

We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support our continued research activities and development of our product candidates. We also anticipate that we will incur increased accounting, audit, legal, regulatory, compliance and director and officer insurance costs as well as investor and public relations expenses associated with operating as a public company.

Other Income, Net

Interest Income

Interest income consists of income earned and losses incurred in connection with our investments in money market funds, U.S. Treasury bills and U.S. government agency bonds.

Other Income, Net

Other income, net consists of miscellaneous income and expense unrelated to our core operations.

Benefit from (provision for) Income Taxes

Our benefit from (provision for) income tax consists of an estimate for U.S. federal and state income taxes based on enacted rates, as adjusted for allowable credits, deductions, uncertain tax positions, changes in deferred tax assets and liabilities and changes in tax law. We recorded an insignificant benefit from (provision for) income taxes for each of the three and nine months ended September 30, 2025 and 2024.

Results of Operations

Comparison of the three months ended September 30, 2025 and 2024

The following table summarizes our results of operations for the three months ended September 30, 2025 and 2024:

Collaboration Revenue

Collaboration revenue of $53.8 million and $11.6 million for the three months ended September 30, 2025 and 2024, respectively, was derived from the Gilead collaboration. All remaining deferred revenue from the upfront and research option-extension payments under the Gilead collaboration were recognized as collaboration revenue during the three months ended September 30, 2025 as a result of the truncation of the collaboration agreement, which concluded all research activities.

Research and Development Expenses

Research and development expense was $30.8 million for the three months ended September 30, 2025 compared to $33.3 million for the three months ended September 30, 2024. The decrease of $2.5 million was primarily driven by a $2.0 million decrease due to the discontinuation of the TNG908 clinical program and lower discovery program expenses. This decrease was partially offset by increased spend related to the advancement of the vopimetostat and TNG456 clinical programs.

General and Administrative Expenses

General and administrative expense was $8.9 million for the three months ended September 30, 2025 compared to $11.2 million for the three months ended September 30, 2024. The decrease of $2.3 million was primarily due to decreases in personnel-related costs, including share-based compensation expense, as well as a decrease in external legal and patent costs.

Interest Income

Interest income was $1.1 million for the three months ended September 30, 2025 compared to $1.8 million for the three months ended September 30, 2024, with the decrease primarily attributable to a decrease in our marketable securities balance in 2025 as compared to 2024.

Other Income, Net

Other income, net was $0.7 million for the three months ended September 30, 2025 compared to other income, net of $2.0 million for the three months ended September 30, 2024, with the decrease attributed to lower accretion from investments purchased at a discount.

Benefit from (provision for) Income Taxes

Benefit from income taxes was less than $0.1 million for the three months ended September 30, 2025 compared to a provision for income taxes of less than $0.1 million for the three months ended September 30, 2024. The tax benefit and provision are insignificant in each of the periods ended September 30, 2025 and 2024.

Comparison of the nine months ended September 30, 2025 and 2024

The following table summarizes our results of operations for the nine months ended September 30, 2025 and 2024:

Collaboration Revenue

Collaboration revenue of $62.4 million and $25.9 million for the nine months ended September 30, 2025 and 2024, respectively, was derived from the Gilead collaboration. All remaining deferred revenue from the upfront and research option-extension payments under the collaboration were recognized as collaboration revenue during the nine months ended September 30, 2025 as a result of the truncation of the collaboration agreement which concluded all research activities.

License Revenue

License revenue was $0 and $12.1 million for the nine months ended September 30, 2025 and 2024, respectively. The revenue recognized during the second quarter of 2024 was primarily due to licensing a program to Gilead for $12.0 million during the period.

Research and Development Expenses

Research and development expense was $100.1 million for the nine months ended September 30, 2025 compared to $110.0 million for the nine months ended September 30, 2024. The decrease of $9.9 million was primarily driven by a $12.1 million decrease due to the discontinuation of the TNG908 and TNG348 clinical programs, a $2.7 million decrease in TNG260 clinical trial costs and lower discovery program expenses. This decrease was partially offset by increased spend related to the advancement of the vopimetostat, TNG456 and TNG961 clinical programs.

General and Administrative Expenses

General and administrative expense was $31.7 million for the nine months ended September 30, 2025 compared to $32.7 million for the nine months ended September 30, 2024. The decrease of $1.0 million was primarily due to a decrease in personnel-related costs, including share-based compensation expense.

Interest Income

Interest income was $4.0 million for the nine months ended September 30, 2025 compared to $6.1 million for the nine months ended September 30, 2024, with the decrease primarily attributable to a decrease in our marketable securities balance in 2025 as compared to 2024.

Other Income, Net

Other income, net was $2.7 million for the nine months ended September 30, 2025 compared to other income, net of $6.1 million for the nine months ended September 30, 2024, with the decrease attributed to lower accretion from investments purchased at a discount.

Provision for Income Taxes

Provision for income taxes was $0.1 million for the nine months ended September 30, 2025 compared to $0.2 million for the nine months ended September 30, 2024. The tax provision is insignificant in each of the periods ended September 30, 2025 and 2024.

Liquidity and Capital Resources

Sources of Liquidity

Since our inception, we have generated recurring net losses. We have not yet commercialized any products and we do not expect to generate revenue from sales of any products for several years, if at all. To date, we have funded our operations primarily through equity financings and from the proceeds received from our collaboration agreement with Gilead. Since inception, we have raised an aggregate of $166.9 million of gross proceeds from the sale of our preferred shares, $342.1 million in gross proceeds from the Business Combination and simultaneous financing transactions, $237.1 million through our collaboration with Gilead, and $348.0 million of gross proceeds through (i) the $80.0 million private placement of common shares and pre-funded warrants to purchase common shares in August 2023, (ii) the $43.0 million from our "at-the-market" stock offering program in January 2024 and (iii) $225.0 million in gross proceeds from the underwritten offering and concurrent private placement of common shares and pre-funded warrants to purchase common shares in October 2025. As of September 30, 2025, we had cash and cash equivalents and marketable securities of $152.8 million.

On October 23, 2025, we announced the pricing of an underwritten offering and a concurrent private placement with a select group of institutional and accredited healthcare specialist investors for the issuance of a total of 22,755,438 shares of common stock at a price of $8.66 per share and pre-funded warrants to purchase 3,226,458 shares of common stock at a purchase price of $8.659 per pre-funded warrant, resulting in aggregate gross proceeds of $225.0 million. The pre-funded warrants have an exercise price of $0.001 per share of common stock, are immediately exercisable and will remain exercisable until exercised in full. After deducting expenses related to the offering and private placement of $13.0 million, net proceeds were $212.0 million. Both transactions closed on October 24, 2025. Net proceeds will be used to advance our pipeline and for working capital and other general corporate purposes.

Funding Requirements

We expect that our existing cash, cash equivalents and marketable securities on hand as of September 30, 2025 of $152.8 million, in addition to $212.0 million in aggregate net proceeds from our underwritten offering and concurrent private placement of common shares and pre-funded warrants to purchase common shares in October 2025, will enable us to fund our operating expenses and capital expenditure requirements into 2028. We have based this estimate on assumptions that may prove to be wrong, and we could expend our capital resources sooner than we expect.

Cash Flows

Comparison of the nine months ended September 30, 2025 and 2024

The following table summarizes our cash flows for each of the nine month periods presented:

Operating Activities

Net cash used in operating activities was $109.2 million for the nine months ended September 30, 2025 compared to net cash used in operating activities of $94.9 million for the nine months ended September 30, 2024. The increase in net cash used in operating activities for the nine months ended September 30, 2025 was primarily due to a decrease in operating assets and liabilities, including a deferred revenue decrease driven by the truncation of the Gilead collaboration in August of 2025, which was partially offset by a decrease in net loss.

Investing Activities

Net cash provided by investing activities was $94.9 million for the nine months ended September 30, 2025 compared to net cash provided by investing activities of $34.1 million for the nine months ended September 30, 2024. The change was primarily due to a decrease in purchases of marketable securities as compared to the nine months ended September 30, 2024, which was partially offset by a decrease in sales and maturities of marketable securities as compared to the nine months ended September 30, 2024.

Financing Activities

Net cash provided by financing activities was $3.1 million for the nine months ended September 30, 2025 compared to net cash provided by financing activities of $46.7 million for the nine months ended September 30, 2024. The cash provided by financing activities for the nine months ended September 30, 2025 consisted of $3.1 million in net proceeds received from the exercises of stock options and ESPP purchases. The cash provided by financing activities for the nine months ended September 30, 2024 consisted of the $41.7 million in net proceeds received from our "at-the-market" stock offering program in January 2024, as well as the cash provided from the exercises of stock options and ESPP purchases.

Contractual Obligations and Commitments

The following table summarizes our contractual obligations at September 30, 2025 and the effects that such obligations are expected to have on our liquidity and cash flows in future periods:

The commitment amounts in the table above primarily reflect the minimum payments due under our amended operating lease for office and laboratory space at our 201 Brookline Avenue, Boston, Massachusetts location. These commitments are also recognized as operating lease liabilities in our balance sheet at September 30, 2025. Refer to Note 7 to our audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2024 for additional discussion of the lease.

Purchase Obligations

In the normal course of business, we enter into contracts with third parties for preclinical studies, clinical operations, manufacturing and research and development supplies. These contracts generally do not contain minimum purchase commitments and generally provide for termination with limited notice, and therefore are cancellable contracts. These payments are not included in the table above as the amount and timing of such payments are not known as of September 30, 2025.

License Agreement Obligations

We have also entered into a license agreement under which we may be obligated to make milestone and royalty payments. We have not included future milestone or royalty payments under the agreement in the table above since the payment obligations are contingent upon future events, such as achieving certain development, regulatory, and commercial milestones or generating product sales. As of September 30, 2025 and December 31, 2024, we were unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. Refer to Note 8 of our audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2024 for a description of our license agreement.

Critical Accounting Policies and Significant Judgments and Estimates

Our consolidated financial statements have been prepared in accordance with U.S. GAAP. The preparation of these consolidated financial statements requires us to make judgments and estimates that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances and at the time these estimates are made, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Some of the judgments and estimates we make can be subjective and complex. Our actual results may differ from these estimates under different assumptions or conditions. On an ongoing basis, we evaluate our judgments and estimates in light of changes in circumstances, facts, and experience. The effects of material revisions in estimates, if any, will be reflected in the consolidated financial statements prospectively from the date of change in estimates.

While our significant accounting policies are described in more detail in Note 2 to our audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2024, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our financial statements.

Revenue Recognition

The terms of our collaboration agreements may include consideration such as non-refundable up-front payments, license fees, research extension fees, and clinical, regulatory and sales-based milestones and royalties on product sales.

We recognize revenue under ASC Topic 606, Revenue from Contracts with Customers, or ASC 606, which applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. ASC 606 provides a five-step framework whereby revenue is recognized when control of promised goods or services is transferred to a customer at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To determine revenue recognition for arrangements that we determine are within the scope of the revenue standard, we perform the following five steps: (i) identify the promised goods or services in the contract; (ii) determine whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measure the transaction price, including the constraint on variable consideration; (iv) allocate the transaction price to the performance obligations; and (v) recognize revenue when (or as) we satisfy each performance obligation. We only apply the five-step model to contracts when collectability of the consideration to which we are entitled in exchange for the goods or services we transfer to the customer is determined to be likely. At contract inception, once the contract is determined to be within the scope of ASC 606, we assess whether the goods or services promised within each contract are distinct and, therefore, represent a separate performance obligation. Goods and services that are determined not to be distinct are combined with other promised goods and services until a distinct bundle is identified. We then allocate the transaction price (the amount of consideration we expect to be entitled to from a customer in exchange for the promised goods or services) to each performance obligation and recognize the associated revenue when (or as) each performance obligation is satisfied. Our estimate of the transaction price for each contract includes all variable consideration to which we expect to be entitled.

We recognize the transaction price allocated to license payments as revenue upon delivery of the license to the customer and resulting ability of the customer to use and benefit from the license, if the license is determined to be distinct from the other performance obligations identified in the contract. If the license is considered to not be distinct from other performance obligations, we utilize judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied (i) at a point in time, but only for licenses determined to be distinct from other performance obligations in the contract, or (ii) over time; and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from license payments. We evaluate the measure of progress each reporting period and, if necessary, adjust the measure of performance and related revenue recognition.

We evaluate whether it is probable that the consideration associated with each milestone payment will not be subject to a significant reversal in the cumulative amount of revenue recognized. Amounts that meet this threshold are included in the transaction price using the most likely amount method, whereas amounts that do not meet this threshold are considered constrained and excluded from the transaction price until they meet this threshold. Milestones tied to regulatory approval, and therefore not within our control, are considered constrained until such approval is received. Upfront and ongoing development milestones under our collaboration agreements are not subject to refund if the development activities are not successful. At the end of each subsequent reporting period, we re-evaluate the probability of a significant reversal of the cumulative revenue recognized for the milestones, and, if necessary, adjust the estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenues from collaborators in the period of adjustment. We exclude sales-based milestone payments and royalties from the transaction price until the sale occurs (or, if later, until the underlying performance obligation to which some or all of the royalty has been allocated has been satisfied or partially satisfied), because the license to our intellectual property is deemed to be the predominant item to which the royalties relate as it is the primary driver of value.

ASC 606 requires us to allocate the arrangement consideration on a relative standalone selling price basis for each performance obligation after determining the transaction price of the contract and identifying the performance obligations to which that amount should be allocated. The relative standalone selling price is defined in ASC 606 as the price at which an entity would sell a promised good or service separately to a customer. If other observable transactions in which we have sold the same performance obligation separately are not available, we are required to estimate the standalone selling price of each performance obligation. Key assumptions to determine the standalone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success.

Whenever we determine that multiple promises to a customer are not distinct and comprise a combined performance obligation that includes services, we recognize revenue over time using the cost-to-cost input method, based on the total estimated cost to fulfill the obligation. Significant management judgment is required in determining the level of effort required under an arrangement and the period over which we are expected to complete our performance obligations under an arrangement.

Consideration that does not meet the requirements to satisfy the above revenue recognition criteria is a contract liability and is recorded as deferred revenue in the consolidated balance sheets. We have recorded short-term and long-term deferred revenue on our consolidated balance sheets based on our best estimate of when such revenue will be recognized. Short-term deferred revenue consists of amounts that are expected to be recognized as revenue in the next 12 months. Amounts that we expect will not be recognized within the next 12 months are classified as long-term deferred revenue.

In certain instances, the timing of and total costs of satisfying these obligations under our collaboration agreement can be difficult to estimate. Accordingly, our estimates may change in the future. If these estimates and judgments change over the course of these agreements, it may affect the timing and amount of revenue that we will recognize and record in future periods.

Under ASC 606, we will recognize revenue when we fulfill our performance obligations under the agreements with customers. As the required performance obligation is satisfied, we will recognize revenue for the portion satisfied and record a receivable for any fees that have not been received. Amounts are recorded as short-term collaboration receivables when our right to consideration is unconditional. A contract liability is recognized when a customer prepays consideration or owes payment to an entity in advance of our performance according to a contract. We do not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. We expense incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that we would have recognized is one year or less or the amount is immaterial.

Accrued Research and Development Expenses

As part of the process of preparing our consolidated financial statements, we are required to estimate our accrued research and development expenses. This process involves estimating the level of service performed and the associated cost incurred for the

service when we have not yet been invoiced or otherwise notified of actual costs. The majority of our service providers invoice us in arrears for services performed, on a pre-determined schedule or when contractual milestones are met; however, some require advance payments, which would be recorded as a prepaid expense in other assets, or if there is the right of offset, offset against our liability balance with the counterparty. We make estimates of our accrued expenses as of each balance sheet date in the consolidated financial statements based on facts and circumstances known to us at that time. At each period end, we corroborate the accuracy of these estimates with the service providers and make adjustments, if necessary.

We record the expense and accrual related to research and development activities performed by our vendors based on our estimates of the services received and efforts expended considering a number of factors, including our knowledge of the progress towards completion of the research and development activities; invoicing to date under the contracts; communication from the vendors of any actual costs incurred during the period that have not yet been invoiced; and the costs included in the contracts and purchase orders. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the expense. In accruing service fees, we estimate the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate, we adjust the accrual or prepaid expense accordingly. Although we do not expect our estimates to be materially different from amounts actually incurred, our understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period. To date, there have not been any material adjustments to our prior estimates of accrued research and development expenses.

Recently Adopted Accounting Pronouncements

A description of recently issued and adopted accounting pronouncements that may potentially impact our financial position, results of operations or cash flows is disclosed within Note 2 of our unaudited condensed consolidated financial statements and related notes appearing elsewhere in this Quarterly Report on Form 10-Q and also in Note 2 to our audited consolidated financial statements and related notes in our Annual Report on Form 10-K for the year ended December 31, 2024.