Primary results of phase 2 FOENIX-CCA2: The irreversible FGFR1-4 inhibitor futibatinib in intrahepatic cholangiocarcinoma (iCCA) with FGFR2 fusions/rearrangements

[[abstract]]Background FGFR2 fusions occur in ~15% of patients (pts) with iCCA, a rare cancer with a poor prognosis. Futibatinib, a highly selective, irreversible FGFR1-4 inhibitor, has shown activity across tumor types, including iCCA, in a phase 1 study. The pivotal phase 2 FOENIX-CCA2 trial (NCT02052778) is evaluating futibatinib in iCCA harboring FGFR2 fusions/rearrangements. Here, we report the first efficacy, safety, and quality of life (QoL) data for the complete FOENIX-CCA2 population. Methods Eligible pts had unresectable/metastatic iCCA with an FGFR2 fusion/rearrangement and progressive disease (PD) after ≥1 prior treatment (tx; excluding FGFR inhibitors). Pts received futibatinib 20 mg QD until PD/intolerability. The primary endpoint was objective response rate (ORR) per RECIST v1.1 by independent central review (target ORR: 20%). Secondary endpoints included duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), safety, and patient-reported outcomes (PROs). Subgroup analyses were performed by pt characteristic and molecular alteration. Results Among 103 pts (56% female), 53% had received ≥2 prior tx. FGFR2 fusions were present in 78% (23% had FGFR2-BICC1 fusions) and FGFR2 rearrangements in 22%. At data cutoff (Oct 1, 2020), 72 pts (70%) had discontinued tx. The study met its primary objective with a confirmed ORR of 41.7% (43/103). Responses were durable, with a median (m) DOR of 9.7 mo and 72% of responses ≥6 mo. DCR was 82.5%. mPFS was 9.0 mo; mOS was 21.7 mo, with a 12-mo OS rate of 72%. ORR was consistent across pt demographic subgroups (≥65 y: 65.2%; 2 prior tx: 38.7%). Common tx-related AEs (TRAEs) were hyperphosphatemia (85%), alopecia (33%), and dry mouth (30%). The most frequent grade 3 TRAE, hyperphosphatemia (30%), resolved with adequate management (median 7 d). Retinal disorders (all grade 1-2) were reported in 8% of pts. TRAEs were managed with dosing interruptions (50%)/reductions (54%); 2 pts discontinued tx due to TRAEs. No tx-related deaths occurred. ORRs were consistent in pts with dosing interruptions (40.2%) or reductions (46.8%). PROs were stable through 11.0 mo of tx. In exploratory biomarker analyses, ORR was consistent in pts with FGFR2 fusions (43.8%) and other FGFR2 rearrangements (34.8%) and in pts with BICC1 (41.7%) and non-BICC1 (44.6%) fusion partners. Notably, no obvious differences in ORR were observed in pts with co-occurring genetic alterations, including TP53 comutations (ORR, 38.5% [5/13]). Additional biomarker data will be presented. Conclusions Futibatinib resulted in frequent, durable objective responses in pts with iCCA harboring FGFR2 fusion/rearrangements, regardless of pt baseline characteristic, molecular alteration, or comutation. AEs were manageable with dosing modifications that did not impact response. QoL was maintained