Xilio Therapeutics, Inc. is a clinical-stage biotechnology company. The Company is engaged in 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. It is using its proprietary platform to build a pipeline of novel, tumor-activated I-O molecules that are designed to optimize the therapeutic index by localizing anti-tumor activity within the tumor microenvironment, including tumor-activated cytokines, antibodies, bispecific and immune cell engagers. Its pipeline products include Vilastobart (XTX101), XTX301, XTX501, and tumor-activated bispecific molecules and immune cell-engaging molecules. XTX101 is an investigational tumor-activated, Fc-enhanced, high-affinity binding anti-CTLA-4 monoclonal antibody. XTX301, a tumor-activated, engineered interleukin 12, or IL-12, therapy.