Fierce-21: Phase II study of vofatmab (B-701), a selective inhibitor of FGFR3, as salvage therapy in metastatic urothelial carcinoma (mUC).

409 Background: Patients (pts) with mUC who have failed platinum-based chemotherapy have a poor prognosis. About 20% of them usually respond to immune checkpoint inhibitors (ICI). Also, 20% of pts with mUC harbor FGFR3 mutations or fusions (M/F), and this feature may be associated with lower sensitivity to ICI. Vofatamab (B-701) is a fully human monoclonal antibody against FGFR3 that blocks activation of the wildtype and genetically activated...