Phase 2 VVD-133214 WRN helicase covalent inhibitor + pembrolizumab (PD-1 antibody) in MSI/dMMR CRC

This randomized, open-label Phase 2 study tests whether adding VVD-133214 (RO7589831)—a first-in-class, covalent allosteric inhibitor of Werner helicase (WRN)—can improve outcomes versus pembrolizumab alone in previously untreated advanced/metastatic, unresectable MSI-high and/or dMMR colorectal adenocarcinoma. The experimental arms give two VVD-133214 dose levels plus pembrolizumab; the control arm is pembrolizumab monotherapy (Merck/MSD), a PD-1–blocking antibody that reinvigorates anti-tumor T cells. VVD-133214 was discovered by Vividion Therapeutics (a Bayer company) and developed with/alongside Roche; the scientific bet is synthetic lethality, since MSI/dMMR tumors have a selective dependency on WRN to tolerate replication stress and DNA damage. Today, first-line care for MSI-H/dMMR metastatic CRC is PD-1–based immunotherapy (pembrolizumab or nivolumab ± ipilimumab), but a meaningful subset has primary resistance or later progression—this trial asks whether WRN blockade can deepen and/or broaden checkpoint responses in the front-line setting.