In the FGFR3::TACC3-V555M xenograft model, a 77% inhibition of tumor growth was observed with TYRA-300 while a 12% tumor growth inhibition was observed with erdafitinib….TYRA-300 is currently under development for patients with FGFR3-altered urothelial carcinoma. TYRA-300 retains efficacy in the presence of a gatekeeper resistance mutation.