Tango Therapeutics, Inc. Commitments Disclosure

8. Commitments and Contingencies

License and Other Agreements

Sesame Therapeutics, Inc.

In August 2023, the Company received an inconsequential equity stake in Sesame Therapeutics, Inc. (Sesame), a related party, in exchange for providing lab space and resources for the early phases of company development. The Company concluded that the common stock investment should be accounted for as an equity investment. Sesame's common stock is not exchange-traded and does not have a readily determinable fair value. Therefore, the Company accounts for the common stock investment under the measurement alternative for equity investments that do not have a readily determinable fair value. During 2025, an observable price change event occurred, resulting in the $0.5 million increase in fair value recognized related to the common stock investment as a result of the application of the measurement alternative. As of December 31, 2025, the cost of the investment in Sesame’s common stock was $0.5 million, including immaterial transaction costs, and was recorded as an equity investment within Other assets on the consolidated balance sheets.

In June 2024, the Company and Sesame entered into a license agreement pursuant to which the Company granted Sesame a non-exclusive license to certain know-how associated with preclinical research (the Sesame Agreement). Pursuant to the Sesame Agreement, the Company received a $0.1 million upfront, non-refundable payment in June 2024.

Under the terms of the Sesame Agreement, the Company is eligible to receive up to $25.9 million in potential future clinical, regulatory, and commercial milestone event payments. The Company is also eligible to receive low single-digit tiered royalties on net sales of any product covered by a licensed patent.

The Company evaluated the Sesame Agreement under ASC 606. The Company identified the following promises under the agreement: (1) the non-exclusive license and (2) the initial know-how transfer, and determined that the promises were immaterial as the upfront license payment at contract inception was an inconsequential payment amount. The initial upfront license payment was recorded as license revenue on the consolidated statements of operations and comprehensive loss during the period ended June 30, 2024.

All potential future milestone payments are considered to be variable consideration and have been excluded from the transaction price. Revenue for all potential clinical and regulatory milestone achievements will be recognized when the related milestones are achieved or when it becomes probable that a significant reversal in the amount of revenue recognized relating to the milestone event will not occur. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. Additionally, revenue related to potential sales milestones and royalties from the sales of the licensed products will be recognized when the related sales occur.

In August 2025, the Company and Sesame entered into a use and occupancy sub-lease of office and laboratory space at 201 Brookline Avenue in Boston, Massachusetts. The sub-lease has a term of 17-months with an option to extend for one additional six-month period. Total sub-lease payments from Sesame to the Company will approximate $0.4 million over the term of the sub-lease agreement.

Due to common relationships amongst members of management and the boards of directors, the transaction above with Sesame is a related party transaction.

Medivir AB

In March 2020, the Company entered into a License Agreement (the Medivir Agreement) with Medivir AB (Medivir), pursuant to which the Company obtained an exclusive license to all patents, know-how and other intellectual property associated with a preclinical-stage research program. Pursuant to the Medivir Agreement, the Company made an upfront payment of $0.4 million.

Under the terms of the Medivir Agreement, the Company is obligated to pay Medivir in connection with development, regulatory and commercial activities. The Company has agreed to make certain milestone payments of $1.4 million in the aggregate for the first licensed product that achieves specified clinical milestones, plus $25.0 million for the first licensed product that achieves specified regulatory approval and sales milestones, in each case, in either of the first two specified genetic contexts and $0.7 million in the aggregate if that first licensed product achieves specified clinical milestones, plus

$5.0 million if that first licensed product achieves specified regulatory and sales milestones for a third genetic context or the second licensed product achieves such specified development, regulatory and sales milestones in either of the first two specified genetic contexts. The Company has the right to reduce these milestone payments by a specified amount in the event the licensed product is not covered by Medivir’s patents or if payments are due to a third party for a license under such third party’s intellectual property rights. The Company is also obligated to pay Medivir a low single-digit royalty on net sales of any product covered by a licensed patent. The Medivir Agreement expires on the date of expiration of all royalty obligations. Either party may terminate the Medivir Agreement earlier upon an uncured material breach of the other party.

Upfront fees paid pursuant to the Medivir License Agreement were recorded to research and development expense.

In May 2024, we made the decision to discontinue further development of TNG348, the basis of our USP1 program, due to liver toxicity experienced by patients in the dose escalation portion of the Phase1/2 clinical trial. In February 2026, the Medivir Agreement was terminated.

Consulting Agreement

In October 2025, the Company and Malte Peters, M.D. entered into a consulting agreement to support the Company's work on key initiatives related to the 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 served on the Tango Board of Directors, has significant late-stage clinical development expertise, having brought multiple oncology products to market. In exchange for his consulting services, Dr. Peters will receive compensation of (i) $36,000 per calendar month and (ii) an equity grant of 150,000 non-qualified stock options. Due to Dr. Peters maintaining a position on the Board of Directors at the time of the consulting agreement execution, the compensation related to the agreed-upon consulting services is deemed a related party transaction. Dr. Peters was appointed as the Company’s President and Chief Executive Officer on January 8, 2026.

Clinical Trial Collaboration and Supply Agreements

In November 2024, the Company and Revolution Medicines, Inc. (RevMed) entered into a Clinical Trial Collaboration and Supply Agreement (CTCSA). The agreement provides that RevMed will supply daraxonrasib (RMC-6236), a RAS(ON) multi-selective inhibitor, and zoldonrasib (RMC-9805), a RAS(ON) G12D-selective inhibitor, at no cost to the Company for use in trials that will include vopimetostat and each of these RAS(ON) inhibitors. The Company will be the sponsor of any combination trials and bear associated costs. Each company will retain commercial rights to its respective compounds, and the agreement is mutually non-exclusive. Due to common relationships amongst members of management and the boards of directors, this transaction is a related party transaction.

Given the differentiated profile of vopimetostat enabling the potential for efficacious and tolerable RAS inhibitor combinations, in March 2026, we entered into a CTCSA with Erasca, Inc., or Erasca, to evaluate vopimetostat in combination with Erasca’s pan-RAS molecular glue, ERAS-0015. Under the terms of the agreement, Tango is the sponsor of the trial and Erasca is supplying ERAS-0015 at no cost. Each company will retain commercial rights to its respective compound, and the agreement is mutually non-exclusive.

Other Funding Commitments

As of December 31, 2025, the Company had ongoing preclinical and clinical studies. The Company enters into contracts in the normal course of business with contract research organizations in connection with preparation and operation of clinical trials, professional consultants for expert advice and other vendors for clinical supply manufacturing or other preclinical and clinical services. These contracts are generally cancellable, with notice, at the Company's option and do not have significant cancellation penalties.

Guarantees

The Company enters into certain agreements with other parties in the ordinary course of business that contain indemnification provisions. These typically include agreements with directors and officers, business partners, contractors, landlords, construction companies, contract research organizations, clinical trial sites, and other parties. Under these provisions, the Company generally indemnifies, defends and holds harmless the indemnified party for losses suffered or incurred by the indemnified party under the terms of the contract, including as a result of the Company’s activities. These indemnification provisions generally survive termination of the underlying agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification provisions is unlimited. However, to

date the Company has not incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. As a result, the estimated fair value of these obligations is minimal.

Litigation

The Company, from time to time, may be party to litigation arising in the ordinary course of business. The Company was not subject to any material legal proceedings as of December 31, 2025, and no material legal proceedings are currently pending or threatened. Because of uncertainties related to claims, proceedings and litigation, assessments of potential liabilities are based on the Company's best estimates based on information available at the time of the assessment. On a periodic basis, as additional information becomes available, or based on specific events such as the outcome of litigation, court decisions or settlement of claims (and offers of settlement), the Company may reassess the potential liability related to these matters and may revise these estimates, which could result in a material adverse effect on the operating results of the Company. Costs associated with involvement in legal proceedings are expensed as incurred. The outcome of any such proceedings, regardless of the merits, is inherently uncertain. If the Company were to be unable to prevail in any such proceedings, the consolidated financial position, results of operations, and future cash flows of the Company may be materially impacted.