Xilio reports initial monotherapy safety and anti-tumor activity data for XTX202

Xilio Therapeutics announced initial safety, pharmacokinetic, pharmacodynamic 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, or SITC, 38th Annual Meeting in San Diego, CA being held on November 1-5. “The newly reported data from our Phase 1/2 clinical trial for XTX202 expands the evidence across our programs supporting clinical validation of our tumor-activated technology. We observed a disease control rate of 50% at higher doses and 31% across all dose levels in a variety of advanced and IO refractory solid tumors, including cold tumors. Importantly, treatment-related adverse events were primarily Grade 1-2 with no evidence of vascular leak syndrome reported at any dose level, and two patients are continuing on treatment for more than one year, highlighting XTX202’s potential for long-term tolerability at high doses,” said Katarina Luptakova, M.D., Chief Medical Officer of Xilio. “In addition, an analysis of an on-treatment biopsy from a patient receiving 2.8 mg/kg of XTX202 demonstrated evidence of activation in the tumor with minimal active drug in peripheral circulation and also suggests that monotherapy doses at or above 2.8 mg/kg are approaching the optimal range to engage CD8+ T effector cell and NK cell expansion while continuing to avoid stimulation of regulatory T cells. Overall, these encouraging data support continued evaluation of XTX202 at a dose of 4.0 mg/kg in our Phase 2 trial of patients with metastatic renal cell carcinoma and unresectable or metastatic melanoma and the exploration of opportunities for combination therapy.”