Pemigatinib in Chinese patients with advanced/metastatic or surgically unresectable cholangiocarcinoma including FGFR2 fusion or rearrangement: Updated data from an open-label, single-arm, multicenter phase II study (CIBI375A201 study).

Abstract

e16183 Background: Pemigatinib is a selective FGFR inhibitor that showed effectiveness and tolerability in patients with cholangiocarcinoma with FGFR2 fusion or rearrangement. However, pemigatinib has not been investigated in Chinese population with cholangiocarcinoma (CCA). Initial efficacy and safety data were previously presented (G-M. Shi et al. ESMO 2021; NCT04256980). Here, we report updated follow-up results from the phase II study. Methods: Patients aged 18 years or older with recurrent or metastatic CCA that failed at least one prior systemic therapy were enrolled. In Part 1, 3 subjects were enrolled regardless of the FGFR2 status and were treated at 9 mg pemigatinib. The other 31 subjects with documented FGFR2 fusion or rearrangement were enrolled in Part 2 and received 13.5 mg pemigatinib. From 2/26/2020 to 12/20/2021, all the subjects in both parts were orally given pemigatinib QD on a 2 weeks on/1 week off schedule until disease progression, unacceptable toxicity, withdrawal of consent, or physician decision. The primary efficacy end point was ORR assessed by independent radiological review committee (IRRC) per RECIST V1.1 in 31 patients enrolled in Part 2. Results: As of the data cutoff date (Dec 20th, 2021), with a median follow up of 12.6 (11.8, 14.2) months, among 30 efficacy evaluable subjects with 1 participant excluded due to inadequate FGFR2 aberrant frequency, the updated confirmed objective response rate (ORR) was 60% (95% CI: 42.5%, 77.5%) per RECIST 1.1. The median DOR was 8.3 months (95% CI: 6.5, 11.2), and with 8 pts still maintaining tumor control of partial response. The updated median PFS was 9.1 months (95% CI: 7.8, 11.0). The DCR was also 100% (95% CI: 100%, 100%). All 34 subjects were included for safety analysis. As of data cutoff the safety profile was consistent with the primary analysis, with no new safety signals or concerns identified. With the longer follow up time, the frequency of grade 3 or higher TRAEs was increased to 26.5%. One patient experienced TRAE leading to treatment discontinuation, while no TRAE leading to death was observed or reported. TEAEs leading to dose interruption or dose reduction occurred in 23.5% and 14.7% of patients, respectively. Conclusions: Pemigatinib was high response rate and manageable tolerability in Chinese patients with recurrent or metastatic cholangiocarcinoma with FGFR2 fusion or rearrangement. Editorial acknowledgement: Guoming Shi and Xiaoyong Huang contributed equally to this work. Clinical trial information: NCT04256980.