Description of Business and Liquidity and Going Concern	12 Months Ended
Dec. 31, 2023
Description of Business and Liquidity and Going Concern
Description of Business and Liquidity and Going Concern	1. Description of Business, Liquidity and Going Concern Description of Business Xilio Therapeutics, Inc. (“Xilio” or the “Company”) is a clinical-stage biotechnology company dedicated to discovering and developing tumor-activated immuno-oncology (“I-O”) therapies with the goal of significantly improving outcomes for people living with cancer without the systemic side effects of current I-O treatments. The Company was incorporated in Delaware in June 2020, and its headquarters are located in Waltham, Massachusetts. Liquidity and Going Concern Since its inception, the Company has devoted substantially all of its financial resources and efforts to research and development activities. As of December 31, 2023, the Company had an accumulated deficit of $325.5 million and has incurred significant operating losses, including net losses of $76.4 million and $88.2 million for the years ended December 31, 2023 and 2022, respectively. The Company expects its operating losses and negative operating cash flows to continue for the foreseeable future as it continues to advance its product candidates through clinical trials, maintains the infrastructure necessary to support these activities and continues to incur costs associated with operating as a public company. As of December 31, 2023, the Company had cash and cash equivalents of $44.7 million. The Company anticipates that its cash and cash equivalents as of December 31, 2023, together with (i) the $30.0 million upfront payment under the exclusive license agreement with Gilead Sciences, Inc. (“Gilead”), (ii) the approximately $13.5 million in proceeds from the initial private placement with Gilead, which closed on March 28, 2024, and (iii) the approximately $11.3 million in gross proceeds from the Company’s private placement, which is expected to close on April 2, 2024 (subject to customary closing conditions), and after giving effect to (a) one-time costs and anticipated future cost savings associated with the Company’s strategic portfolio reprioritization and workforce reduction announced in March 2024 and (b) the repayment in the first quarter of 2024 of the outstanding loan balance under the Company’s loan and security agreement with Pacific Western Bank (“PacWest”), will be sufficient to fund the Company’s operating expenses and capital expenditure requirements into the second quarter of 2025. For further information regarding these transactions and other subsequent events, please see Note 14, Subsequent Events. However, the Company has based this estimate on assumptions that may prove to be wrong, and the Company could exhaust its available capital resources sooner than it anticipates. In addition, since these amounts may not be sufficient to fund its operations for at least twelve months from the date of issuance of the consolidated financial statements, there is substantial doubt about the Company’s ability to continue as a going concern. To continue to fund the operations of the Company, management has developed plans, which in the near term primarily consist of raising additional capital through one or more of the following: additional equity or debt financings; additional collaborations, partnerships or licensing transactions; or other sources. However, there can be no assurance that the Company will be able to complete any such transaction on acceptable terms or otherwise, and the Company may be unable to obtain sufficient additional capital. If the Company is not able to secure sufficient additional capital in the near term, the Company may in the future need to implement additional cost reduction strategies, which could include delaying, limiting, further reducing or eliminating both internal and external costs related to its operations and research and development programs. The accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.

Description of Business and Liquidity and Going Concern

12 Months Ended

Dec. 31, 2023

Description of Business and Liquidity and Going Concern

Description of Business and Liquidity and Going Concern

1. Description of Business, Liquidity and Going Concern

Description of Business

Xilio Therapeutics, Inc. (“Xilio” or the “Company”) is a clinical-stage biotechnology company dedicated to discovering and developing tumor-activated immuno-oncology (“I-O”) therapies with the goal of significantly improving outcomes for people living with cancer without the systemic side effects of current I-O treatments. The Company was incorporated in Delaware in June 2020, and its headquarters are located in Waltham, Massachusetts.

Liquidity and Going Concern

Since its inception, the Company has devoted substantially all of its financial resources and efforts to research and development activities. As of December 31, 2023, the Company had an accumulated deficit of $325.5 million and has incurred significant operating losses, including net losses of $76.4 million and $88.2 million for the years ended December 31, 2023 and 2022, respectively. The Company expects its operating losses and negative operating cash flows to continue for the foreseeable future as it continues to advance its product candidates through clinical trials, maintains the infrastructure necessary to support these activities and continues to incur costs associated with operating as a public company. As of December 31, 2023, the Company had cash and cash equivalents of $44.7 million. The Company anticipates that its cash and cash equivalents as of December 31, 2023, together with (i) the $30.0 million upfront payment under the exclusive license agreement with Gilead Sciences, Inc. (“Gilead”), (ii) the approximately $13.5 million in proceeds from the initial private placement with Gilead, which closed on March 28, 2024, and (iii) the approximately $11.3 million in gross proceeds from the Company’s private placement, which is expected to close on April 2, 2024 (subject to customary closing conditions), and after giving effect to (a) one-time costs and anticipated future cost savings associated with the Company’s strategic portfolio reprioritization and workforce reduction announced in March 2024 and (b) the repayment in the first quarter of 2024 of the outstanding loan balance under the Company’s loan and security agreement with Pacific Western Bank (“PacWest”), will be sufficient to fund the Company’s operating expenses and capital expenditure requirements into the second quarter of 2025. For further information regarding these transactions and other subsequent events, please see Note 14, Subsequent Events. However, the Company has based this estimate on assumptions that may prove to be wrong, and the Company could exhaust its available capital resources sooner than it anticipates. In addition, since these amounts may not be sufficient to fund its operations for at least twelve months from the date of issuance of the consolidated financial statements, there is substantial doubt about the Company’s ability to continue as a going concern.

To continue to fund the operations of the Company, management has developed plans, which in the near term primarily consist of raising additional capital through one or more of the following: additional equity or debt financings; additional collaborations, partnerships or licensing transactions; or other sources. However, there can be no assurance that the Company will be able to complete any such transaction on acceptable terms or otherwise, and the Company may be unable to obtain sufficient additional capital. If the Company is not able to secure sufficient additional capital in the near term, the Company may in the future need to implement additional cost reduction strategies, which could include delaying, limiting, further reducing or eliminating both internal and external costs related to its operations and research and development programs.

The accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.