Updated results of a phase IIa study to evaluate the clinical efficacy and safety of erdafitinib in Asian advanced cholangiocarcinoma (CCA) patients with FGFR alterations.

4117 Background: Patients (pts) with advanced CCA who progressed on or after first line chemotherapy have no approved treatment options. Fibroblast growth factor receptor (FGFR) gene alterations are observed in many tumor types including 14-17% in CCA. Erdafitinib, an orally bioavailable, selective pan-FGFR kinase inhibitor, has shown clinical activity against solid tumors with FGFR alterations. Methods: LUC2001 is an open-label, multicenter, Ph2a study in advanced CCA pts with FGFR alterations (FoundationOne), who progressed after ≥ 1 prior treatment. The primary endpoint is objective response rate (ORR; RECIST 1.1). The secondary endpoints are disease control rate (DCR), progression free survival (PFS), duration of response (DOR), safety and pharmacokinetics (PK). Disease is evaluated every 8 weeks until disease progression (PD). Results: As of 3 Dec 2018, 222 CCA pts were molecularly screened; 34 had FGFR alterations, of whom 14 (8 FGFR2 fusion, 3 FGFR2 mutation, 1 FGFR3 fusion, 2 FGFR3 mutation) were dosed 8 mg once daily with up titration option. Median age was 51.5 years. 13/14 and 12/14 pts had prior platinum or gemcitabine based therapy respectively, 7/14 pts got re-treated with platinum or gemcitabine based therapy, and 9/14 pts had ≥2 prior lines of therapy. Median number of treatment cycles was 5.0 (range: 1; 22) and treatment duration was 4.83 (range: 0.5; 20.3) months. In 12 evaluable pts, there were 6 confirmed partial response (PR), 4 stable disease (SD) and 2 PD; ORR (CR+PR) was 6/12 (50.0%), DCR (CR+PR+uCR+uPR+SD) was 10/12 (83.3%); median DOR was 6.83 months (95% CI: 3.65; 12.16); median PFS was 5.59 months (95% CI: 1.87, 13.67). In 10 evaluable FGFR2+ pts, ORR was 6/10 (60.0%); DCR was 10/10(100%); median PFS was 12.35 months (95% CI: 3.15, 19.38). The most common TEAEs ( > 30%) were hyperphosphatemia, dry mouth, stomatitis, and dry skin. 9 pts had ≥ Grade 3 AEs (8 Grade 3,1 Grade 5), of which 7 drug related. TEAE led to treatment 1 discontinuation, 6 dose reductions and 1 death (not drug related). The results of PK and PK/PD relationship were consistent with other erdafitinib studies in different ethnic background pts. Conclusions: Asian advanced CCA pts with FGFR alterations treated with erdafitinib had encouraging efficacy and acceptable safety profile similar to experience in other tumor types and populations. Clinical trial information: NCT02699606.