vilastobart + atezolizumab

Vilastobart + atezolizumab is an investigational combination therapy comprising vilastobart (formerly XTX101), a tumor-activated, Fc-enhanced anti-CTLA-4 monoclonal antibody, and atezolizumab, a monoclonal antibody targeting PD-L1 (Tecentriq). Vilastobart is engineered to remain inactive systemically and become activated by proteases in the tumor microenvironment, where it blocks CTLA-4, leading to immune checkpoint inhibition and selective depletion of CTLA-4 high regulatory T cells through Fc receptor engagement and antibody-dependent cell-mediated cytotoxicity (ADCC). Atezolizumab blocks PD-L1, preventing it from binding PD-1 and B7-1, thereby releasing additional brakes on anti-tumor T cell activity. The combination is specifically being investigated in metastatic microsatellite stable colorectal cancer (MSS CRC) and other advanced solid tumors, with aims to improve efficacy and reduce immune-related toxicities compared to traditional anti-CTLA-4 therapies[2][3][4][6][7].

Other names

vilastobartatezolizumab