Efficacy and safety of infigratinib in patients with refractory advanced gastric or gastroesophageal junction adenocarcinoma harboring FGFR2 gene amplification: a single-arm, multicenter phase 2 trial.

BACKGROUND

FGFR2 has garnered attention as a promising therapeutic target for gastric cancer (GC) because of its role in GC progression. Infigratinib, an FGFR1-3 selective tyrosine kinase inhibitor, has shown potential in preclinical GC models.

METHODS

Infigratinib was evaluated in a phase 2 trial for patients with FGFR2-amplified GC or gastroesophageal junction (GEJ) adenocarcinoma who had failed two or more lines of systemic treatment for locally advanced or metastatic disease. A total of 21 patients received 125 mg of infigratinib orally once daily on a "3 weeks on, 1 week off" schedule.

RESULTS

Infigratinib showed preliminary antitumor activity in this molecularly selected population, as reflected by a confirmed objective response rate of 23.8% (95% CI, 8.2-47.2) with median progression-free survival of 3.4 months and median overall survival of 6.7 months. The most common grade 3-4 adverse events were elevated aspartate aminotransferase, decreased white blood cell count, and neutropenia. No treatment-related deaths occurred. Exploratory genomic analyses identified alterations in individual patients with disease progression that may be associated with resistance; however, these findings were based on a limited number of cases and should be interpreted as hypothesis-generating.

CONCLUSIONS

The findings support continued investigation of FGFR-targeted strategies in FGFR2-amplified GC/GEJ adenocarcinoma, while underscoring the need for larger studies, refined biomarker selection, and deeper characterization of resistance mechanisms.

TRIAL REGISTRATION: NCT05019794, Registered 28 July 2021, https://clinicaltrials.gov/study/NCT05019794 .