Xilio Therapeutics, Inc.

In March 2024, Xilio Development entered into a license agreement (the "License Agreement") with Gilead Sciences, Inc. ("Gilead"), pursuant to which it granted Gilead an exclusive global license to develop and commercialize efarindodekin alfa, the Company’s masked IL-12 product candidate, and specified other molecules directed to IL-12. Xilio Development is responsible for conducting clinical development for efarindodekin alfa through an initial Phase 2 clinical trial. Following the delivery by Xilio Development of a specified clinical data package for efarindodekin alfa related to the Phase 1 clinical trial and the initial Phase 2 clinical trial, Gilead can elect to transition responsibilities for the development and commercialization of efarindodekin alfa to Gilead, subject to the terms of the License Agreement and payment by Gilead of a $75.0 million transition fee.

In connection with the execution of the License Agreement, in March 2024, the Company also entered into a stock purchase agreement with Gilead. Under the stock purchase agreement, Gilead purchased $25.0 million of the Company’s common stock and prefunded warrants inthree private placements, consisting of an aggregate of 650,387 shares of common stock and prefunded warrants to purchase up to an aggregate of 712,514 shares of its common stock. The prefunded warrants are exercisable any time at an exercise price of $0.0014 per share, subject to Gilead not being deemed a beneficial owner of greater than 19.9% of the Company’s common stock upon the exercise of the prefunded warrants.

The Company has received $72.5 million in payments under the Gilead agreements, consisting of the $30.0 million upfront cash payment under the License Agreement, $25.0 million in gross proceeds from private placements under the stock purchase agreement anda $17.5 million development milestone. As of March 31, 2026, the Company is eligible to receive up to $575.0 million in additional contingent payments, which consist of a $75.0 million transition fee if Gilead exercises its option for the IL-12 program and up to $500.0 million in specified development, regulatory and sales-based milestones after opt-in. In addition, the Company is eligible to receive tiered royalties ranging from high single digits to mid-teens on annual global net product sales.

The Company considered the ASC 606 criteria for combining contracts and determined the License Agreement and the stock purchase agreement should be combined into a single contract because they were negotiated and entered into in contemplation of one another. The Company concluded the initial private placement and the additional private placements do not represent freestanding financial instruments as such instruments are not legally detachable due to contractual transfer restrictions. The Company accounted for the common stock issued to Gilead in the initial private placement based on the fair market value of the common stock on the date of issuance. The fair market value of the common stock issued to Gilead in the initial private placement was $4.4 million, based on the closing price of the Company’s common stock on the date of issuance, resulting in a $9.1 million premium. The Company determined that the premium paid by Gilead for the common stock purchased in the initial private placement should be attributed to the transaction price of the License Agreement.

The Company determined that the License Agreement represents a contract with a customer within the scope of ASC 606 and identifiedtwo promises under the License Agreement: (i) the exclusive licenses granted to Gilead related to the Company’s IL-12 program and (ii) the provision by Xilio Development and its affiliates of development services related to ongoing and planned clinical trials for efarindodekin alfa through an initial Phase 2 clinical trial. The Company determined that the exclusive license and development services were not capable of being distinct on the basis that the development services to be provided by Xilio Development are specialized in nature, specifically with respect to its specialized expertise related to efarindodekin alfa, the IL-12 program and the Company’s proprietary platform for masked biologics. Accordingly, the Company concluded that there is a single identified combined performance obligation consisting of the exclusive license and the development services.

For purposes of ASC 606, the transaction price of the License Agreement at the outset of the arrangement was determined to be $39.1 million, which consisted of the upfront cash payment of $30.0 million under the License Agreement and the $9.1 million premium on the sale of common stock to Gilead in the initial private placement, which was allocated to the single combined performance obligation. The Company used the most likely amount method to estimate variable consideration. During the year ended December 31, 2025, the overall transaction price was adjusted to include the achievement of the $17.5 million development milestone in the third quarter of 2025. All additional contingent payments are fully constrained as of March 31, 2026, as the achievement of the milestones underlying such contingent payments are uncertain and highly susceptible to factors outside of the Company’s control. Accordingly, all such additional contingent payments are excluded from the transaction price. The Company reevaluates the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur and may adjust the transaction price as necessary. Sales-based royalties, including milestone payments based on the level of sales, were also excluded from the transaction price, as the license is deemed to be the predominant item to which the royalties relate. The Company plans to recognize such revenue at the later of (i) when the related sales occur or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

Revenue associated with the combined performance obligation is recognized as services are provided as control is transferred over time. The Company measures progress based on the amount of costs incurred relative to the total costs expected to fulfill the combined performance obligation. In management’s judgment, this input method is the best measure of progress towards satisfying the combined performance obligation and reflects a faithful depiction of the transfer of goods and services.

During the three months ended March 31, 2026 and 2025, the Company recognized collaboration and license revenue of $4.7 million and $2.2 million, respectively, under the License Agreement and the stock purchase agreement with Gilead. As of March 31, 2026, the Company recorded deferred revenue under the License Agreement and the stock purchase agreement of $22.0 million, of which $15.5 million was recorded as a current liability on the Company’s condensed consolidated balance sheet. The deferred revenue is expected to be recognized as collaboration and license revenue through at least 2027 depending on the timing of certain clinical development activities.

Summary of Contract Assets and Liabilities

The following table presents changes in the balances of the Company's contract liabilities: