Pemigatinib in previously treated Chinese patients with locally advanced or metastatic cholangiocarcinoma carrying FGFR2 fusions or rearrangements: A phase II study

OBJECTIVE: This study evaluated the antitumor activity and safety of pemigatinib in previously treated Chinese patients with advanced cholangiocarcinoma and fibroblast growth factor receptor 2 (FGFR2) fusions or rearrangements. BACKGROUND: Pemigatinib provided clinical benefits for previously treated patients with cholangiocarcinoma carrying FGFR2 fusions or rearrangements and was approved for this indication in multiple countries. METHODS: In this ongoing, multicenter, single‐arm, phase II study, adult patients with locally advanced or metastatic cholangiocarcinoma carrying centrally confirmed FGFR2 fusions or rearrangements who had progressed on ≥1 systemic therapy received 13.5 mg oral pemigatinib once daily (3‐week cycle; 2 weeks on, 1 week off) until disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoint was objective response rate (ORR) assessed by an independent radiology review committee. RESULTS: As of January 29, 2021, 31 patients were enrolled. The median follow‐up was 5.1 months (range, 1.5–9.3). Among 30 patients with FGFR2 fusions or rearrangements evaluated for efficacy, 15 patients achieved partial response (ORR, 50.0%; 95% confidence interval [CI], 31.3–68.7); 15 achieved stable disease, contributing to a disease control rate of 100% (95% CI, 88.4–100). The median time to response was 1.4 months (95% CI, 1.3–1.4), the median duration of response was not reached, and the median progression‐free survival was 6.3 months (95% CI, 4.9–not estimable [NE]). Eight (25.8%) of 31 patients had ≥grade 3 treatment‐emergent adverse events. Hyperphosphatemia, hypophosphatasemia, nail toxicities, and ocular disorders were mostly <grade 3, except for 2 events ≥grade 3. CONCLUSIONS: The encouraging antitumor activity and favorable safety profile support the use of pemigatinib as a treatment in previously treated Chinese patients with cholangiocarcinoma and FGFR2 rearrangements.