Xilio Therapeutics, Inc. announced initial safety, pharmacokinetic (PK), pharmacodynamic (PD) and anti-tumor activity data from its ongoing Phase 1/2 clinical trial evaluating XTX202, an investigational tumor-activated, engineered, beta-gamma IL-2, in late line patients with advanced solid tumors. The data were presented at the Society for Immunotherapy of Cancer (SITC) 38th Annual Meeting in San Diego, CA being held on November 1-5, 2023. Clinical Development Plans for XTX202: XTX202 recently cleared dose level seven (4.0 mg/kg) in Phase 1 mon otherapy dose-escalation, and Xilio recently opened enrollment at a second dose level of 4.0 mg/kg in the ongoing Phase 2 monotherapy trial for XTX202.

Based on the initial monotherapy data for XTX202, Xilio also plans to explore opportunities for strategic partnerships to evaluate XTX202 as a combination therapy. As previously reported, Xilio anticipates achieving the following milestones in 2023: Activate clinical trial sites for the Phase 1 dose escalation portion of the clinical trial evaluating XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in the fourth quarter of 2023; Report preliminary Phase 1 safety data for XTX202, a tumor-activated, engineered IL-12, into the third dose level in the fourth quarter of 20 23. In addition, subject to obtaining sufficient additional capital, Xilio announced plans to: Complete Phase 1 combination dose escalation and select a recommended Phase 2 dose for XTX101 in combination with atezolIZumab in the second quarter of 2024; Subject to the results of Phase 1 combination dose escalation, initiate a Phase 2 trial for XTX101 in combination With atezolizumab In approximately 20 patients with MSS CRC in the third quarter of 2024; Report initial Phase 2 data for XTX101 in combinationwith atezolizumabin approximately 20 patients with MSSRC in the fourth quarter of 2024 and in approximately 20 additional patients (40 patients total) in the first quarter of 2025; Report Phase 2 monotherapy data for XTX101 in approximately 20 patients treated at the 4.0 mg/kg dose with metastatic RCC or unresectable or metastatic melanoma in the second quarter of 2024.

Report Phase 1 safety and PK/PD data for XTX301 in advanced solid tumors in the second half of 2024.