Xilio Therapeutics, Inc., a clinical-stage biotechnology company, develops immunotherapies to improve the immune system of cancer patients. Its checkpoint inhibitor program includes XTX101, a clinical-stage, tumor-selective anti-CTLA-4 mAb that is in Phase 1/2 clinical trials in patients with solid tumors. The company also develops cytokine programs, which comprises XTX202, a modified form of IL-2; XTX301, an IL-12 product candidate; and XTX401, an IL-15 product candidate that are masked with a protein domain to prevent binding activity until cleaved off by tumor microenvironment (TME)-associated proteases. Xilio Therapeutics, Inc. was founded in 2016 and is headquartered in Waltham, Massachusetts.