This study met its primary objective, with a 40% confirmed response rate after continuous daily treatment with 8 mg or 9 mg of oral erdafitinib. These findings showed that among patients with locally advanced and unresectable or metastatic urothelial carcinoma with certain FGFR alterations, erdafitinib had promising antitumor activity.

Three PRs (two confirmed and one unconfirmed) were seen in patients with urothelial cancer who had received more than four lines of prior treatment, including a patient with FGFR3-TACC3 who stayed on treatment (at 9 mg daily) for about 10 months, a patient with FGFR2-BICC1/FGFR2-CASP7 (FGFR2-BICC1 was more frequent than FGFR2-CASP7, per polymerase chain reaction assay) who continued to be on study drug (9 mg daily) at 12 months, and another patient with FGFR3-TACC3 who continued to be on the study drug (12-mg intermittent dose) at 3 months.