XTX701

XTX701 is an investigational, preclinical, masked, multi-specific T-cell engager (TCE) designed to target prostate-specific membrane antigen (PSMA) and six-transmembrane epithelial antigen of the prostate 1 (STEAP1) while engaging CD3 on T cells. Developed by Xilio Therapeutics, the molecule features a masked CD3-binding domain to minimize peripheral T-cell activation and on-target, off-tumor toxicity, alongside a built-in CD2 co-stimulatory domain to enhance T-cell activation, expansion, and durability of response. XTX701 is being developed for the treatment of metastatic castration-resistant prostate cancer (mCRPC), where PSMA and STEAP1 are collectively expressed in approximately 95% of cases. Investigational New Drug (IND)-enabling studies are ongoing, with an IND submission planned for the fourth quarter of 2027.