XTX202

XTX202 is an investigational, tumor-activated, engineered interleukin-2 (IL-2) molecule with beta-gamma bias designed to selectively activate immune responses within the tumor microenvironment. The drug is engineered to be pharmacologically inactive in circulation and becomes activated by matrix metalloproteases (MMPs) that are enriched in tumors. Upon activation, XTX202 potently stimulates CD8+ effector T cells and natural killer (NK) cells without stimulating regulatory T cells, aiming to enhance anti-tumor immunity while minimizing systemic toxicity such as vascular leak syndrome. The IL-2 domain of XTX202 is modified to reduce binding to the high-affinity IL-2 receptor (IL-2Rα), further limiting regulatory T cell activation. Clinical trials have shown dose-dependent disease control rates in patients with advanced solid tumors—including renal cell carcinoma and melanoma—with a favorable safety profile and no evidence of vascular leak syndrome at doses up to 4 mg/kg administered intravenously every three weeks[1][2][3][5][6][7].