FORT-1: Phase II/III Study of Rogaratinib Versus Chemotherapy in Patients With Locally Advanced or Metastatic Urothelial Carcinoma Selected Based on <i>FGFR1</i>/<i>3</i> mRNA Expression.

Abstract

Rogaratinib, an oral pan-fibroblast growth factor receptor (FGFR1-4) inhibitor, showed promising phase I efficacy and safety in patients with advanced urothelial carcinoma (UC) with <i>FGFR1-3</i> mRNA overexpression. We assessed rogaratinib efficacy and safety versus chemotherapy in patients with <i>FGFR</i> mRNA-positive advanced/metastatic UC previously treated with platinum chemotherapy. FORT-1 (ClinicalTrials.gov identifier: NCT03410693) was a phase II/III, randomized, open-label trial. Patients with <i>FGFR1</i>/<i>3</i> mRNA-positive locally advanced or metastatic UC with ≥ 1 prior platinum-containing regimen were randomly assigned (1:1) to rogaratinib (800 mg orally twice daily, 3-week cycles; n = 87) or chemotherapy (docetaxel 75 mg/m², paclitaxel 175 mg/m², or vinflunine 320 mg/m² intravenously once every 3 weeks; n = 88). The primary end point was overall survival, with objective response rate (ORR) analysis planned following phase II accrual. Because of comparable efficacy between treatments, enrollment was stopped before progression to phase III; a full interim analysis of phase II was completed. ORRs were 20.7% (rogaratinib, 18/87; 95% CI, 12.7 to 30.7) and 19.3% (chemotherapy, 17/88; 95% CI, 11.7 to 29.1). Median overall survival was 8.3 months (95% CI, 6.5 to not estimable) and 9.8 months (95% CI, 6.8 to not estimable; hazard ratio, 1.11; 95% CI, 0.71 to 1.72; <i>P</i> = .67). Grade 3/4 events occurred in 37 (43.0%)/4 (4.7%) patients and 32 (39.0%)/15 (18.3%), respectively. No rogaratinib-related deaths occurred. Exploratory analysis of patients with <i>FGFR3</i> DNA alterations showed ORRs of 52.4% (11/21; 95% CI, 29.8 to 74.3) for rogaratinib and 26.7% (4/15; 95% CI, 7.8 to 55.1) for chemotherapy. To our knowledge, these are the first data to compare FGFR-directed therapy with chemotherapy in patients with <i>FGFR</i>-altered UC, showing comparable efficacy and manageable safety. Exploratory testing suggested <i>FGFR3</i> DNA alterations in association with <i>FGFR1</i>/<i>3</i> mRNA overexpression may be better predictors of rogaratinib response.