Background: Futibatinib, a covalently binding FGFR1–4 inhibitor, showed a 42% objective response rate with a 9.7 mo median duration of response in pts with advanced intrahepatic cholangiocarcinoma (iCCA) and FGFR2 fusions/rearrangements in the phase 2 FOENIX-CCA2 trial. Futibatinib treatment (tx) was safe and tolerable with a predictable and manageable side effect profile. This pooled retrospective analysis examined mgmt of futibatinib-associated AEs in pts with advanced tumors, including iCCA. Methods: Pts from a global phase 1/2 study (NCT02052778) and a Japanese phase 1 study (JapicCTI-142552) who received futibatinib 20 mg QD (recommended dose) were included. Futibatinib dose modifications and supportive medications (meds) for AE mgmt were analyzed for futibatinib-associated AEs of clinical interest (group terms: hyperphosphatemia, hepatic AEs, retinal disorders, nail disorders, rash, palmar plantar erythrodysesthesia [PPE], cataract). The Kaplan-Meier method was used for time-to-resolution (TTR) analysis. Results: As of October 1, 2020, 318 pts with advanced solid tumors (60% CCA; 98% with ≥1 prior tx) had received ≥1 futibatinib 20 mg QD dose (median tx duration, 3.6 mo). Table includes incidence and mgmt of key AEs of clinical interest. Hyperphosphatemia was the most frequent cause of futibatinib dose modifications; 85% and 30% of pts with hyperphosphatemia received phosphate binders and/or phosphaturic agents, respectively, with no obvious TTR differences. Other common supportive meds included analgesics (in 55% of pts with nail disorders; 71% with PPE) and corticosteroids (37% of pts with rash). Retinal disorders occurred in 8% of pts (all grade [gr] 1-2 and resolved). Cataract, a late-onset AE on continued tx, occurred in 12 (4%; 4 [1%] gr ≥3) pts, leading to dose modifications in 3 pts. One pt underwent cataract surgery and resumed futibatinib tx the next day. Discontinuations due to tx-related AEs were rare (2.5%) and included 1 pt each with retinal detachment, onycholysis, and cataract. Conclusions: This analysis of AE mgmt showed a consistent and manageable safety profile for futibatinib in pts with pretreated advanced tumors. Commonly observed AEs with futibatinib were well managed with dose adjustments and supportive meds and rarely led to tx discontinuation. Clinical trial information: NCT02052778/JapicCTI-142552.

NE, not estimable ^aGr ≥3 resolved to gr <3 ^bGr 2 resolved to gr <2