Erdafitinib in Asian patients with advanced solid tumors: an open-label, single-arm, phase IIa trial

Abstract Background FGFR genomic aberrations occur in approximately 5–10% of human cancers. Erdafitinib has previously demonstrated efficacy and safety in FGFR -altered advanced solid tumors, such as gliomas, thoracic, gastrointestinal, gynecological, and other rare cancers. However, its efficacy and safety in Asian patients remain largely unknown. We conducted a multicenter, open-label, single-arm phase IIa study of erdafitinib to evaluate its efficacy in Asian patients with FGFR -altered advanced cholangiocarcinoma, non-small cell lung cancer (NSCLC), and esophageal cancer. Methods Patients with pathologically/cytologically confirmed, advanced, or refractory tumors who met molecular and study eligibility criteria received oral erdafitinib 8 mg once daily with an option for pharmacodynamically guided up-titration to 9 mg on a 28-day cycle, except for four NSCLC patients who received erdafitinib 10 mg (7 days on/7 days off) as they were recruited before the protocol amendment. The primary endpoint was investigator-assessed objective response rate per RECIST v1.1. Secondary endpoints included progression-free survival, duration of response, disease control rate, overall survival, safety, and pharmacokinetics. Results Thirty-five patients (cholangiocarcinoma: 22; NSCLC: 12; esophageal cancer: 1) were enrolled. At data cutoff (November 19, 2021), the objective response rate for patients with cholangiocarcinoma was 40.9% (95% CI, 20.7–63.6); the median progression-free survival was 5.6 months (95% CI, 3.6–12.7) and median overall survival was 40.2 months (95% CI, 12.4–not estimable). No patient with RET/FGFR -altered NSCLC achieved objective response and the disease control rate was 25.0% (95% CI, 5.5–57.2%), with three patients with stable disease. The single patient with esophageal cancer achieved partial response. All patients experienced treatment-emergent adverse events, and grade ≥ 3 treatment-emergent adverse events were reported in 22 (62.9%) patients. Hyperphosphatemia was the most frequently reported treatment-emergent adverse event (all-grade, 85.7%). Conclusions Erdafitinib demonstrated efficacy in a population of Asian patients in selected advanced solid tumors, particularly in those with advanced FGFR -altered cholangiocarcinoma. Treatment was tolerable with no new safety signals. Trial registration This trial is registered with ClinicalTrials.gov (NCT02699606); study registration (first posted): 04/03/2016.