LAUSR

Background: Futibatinib, an irreversible FGFR1-4 inhibitor, is indicated for the treatment of adult patients with previously treated, unresectable, locally advanced or metastatic intrahepatic cholangiocarcinoma harboring FGFR2 gene fusions or other rearrangements. As the primary elimination pathway for futibatinib is hepatic metabolism, we conducted a phase 1 study to evaluate the effect of hepatic impairment (HI) on futibatinib pharmacokinetics (PK) and safety in healthy adults. Methods: A single oral dose of 20 mg futibatinib was administered to adult subjects with mild (Child-Pugh score, 5-6), moderate (7-9), or severe (10-15) HI. Control healthy subjects were matched to each HI cohort according to age, body mass index, and sex. Intensive PK samples were collected up to 72 hours post-dose. Exposure measures (AUC0-inf, AUC0-t, and Cmax) in subjects with HI were compared with matching control cohorts and with the overall healthy-control cohort. Relationships between plasma PK and HI were examined graphically via scatter/regression plots of PK parameters versus baseline Child-Pugh score, bilirubin, albumin, international normalized ratio, and aspartate aminotransferase. Results: Overall, 38 subjects were enrolled (mild HI, n = 8; moderate HI, n = 8; severe HI, n = 6; healthy controls, n = 16). Following the administration of futibatinib, no trend was observed between the severity of HI and the extent of futibatinib exposure increase. Compared with matched controls, AUC0-inf increased by 21%, 20% and 18%, and Cmax by 43%, 15%, and 10% in subjects with mild, moderate, and severe HI, respectively. Changes in exposure were not considered clinically relevant as geometric mean ratios were within 80-125% bioequivalence limits, except for Cmax in subjects with mild HI (43%). Futibatinib PK parameters and HI measures did not appear to be associated based on visual inspection or statistical evaluation of regression plots (p-values all > 0.05). No subjects discontinued from the study due to treatment-emergent adverse events (TEAEs). Overall, two (12.5%) subjects in the healthy-control cohort reported one Grade 1 TEAE each (dyspepsia and headache) and two (25.0 %) subjects in the mild HI cohort each reported one Grade 1 TEAE (toothache and headache). All TEAEs were considered related to treatment. No subjects with moderate/severe HI reported TEAEs. Conclusions: No clinically meaningful differences in the systemic plasma exposure of futibatinib were observed based on the severity of HI. Single oral doses of futibatinib were well tolerated among subjects with varying degrees of HI and matched healthy adult subjects in this study. The data suggest that dose adjustment may not be necessary in patients with HI receiving futibatinib 20 mg QD for its approved indication. Citation Format: Ling Gao, Ikuo Yamamiya, Mark Pinti, Juan Carlos Rondón, Thomas Marbury, Gareth Tomlinson, Lukas Makris, Nanae Hangai, Volker Wacheck. Phase 1, open-label, single-dose study to evaluate the effect of hepatic impairment on the pharmacokinetics and safety of futibatinib in adult subjects [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT192.