1527P - Efficacy and safety of infigratinib in locally advanced or metastatic gastric cancer or gastroesophageal junction adenocarcinoma patients with FGFR2 gene amplification

Background

The FGFR/FGF cascade is a complex intracellular pathway that controls cellular proliferation, tumor growth, angiogenesis, and dissemination. It is implicated in various human cancers including gastric cancer (GC). The FGFR2-amplification in a proportion ranging from 9% to 1.2% worldwide in GC patients. However, previous studies have demonstrated FGFR2-amplification may have poor PFS and OS survival in GC patients. Infigratinib (BGJ398) is a selective ATP-competitive, FGFR1–3 selective oral TKI. We present the data generated from the LB1001-201 trial (NCT05019794) Cohort 1 to evaluate the efficacy and safety of infigratinib monotherapy in previously systemic second-line treated patients harbouring FGFR2 gene amplification.

Methods

Population and eligibility criteria - Failed on prior 2^nd -lines treatment or above, locally advanced or metastatic GC/EGJ. FGFR2 gene amplification positive was confirmed via central FISH testing. Adequate organ function and laboratory values. MAPK-MEK or selective FGFR inhibitor treatment-naive. Procedures and treatment - Tumor biopsy or FFPE samples will be tested at the central lab for FGFR2 gene amplification orally infigratinib (125mg, QD) for 3 weeks on, 1 week off in each 28-day cycle; Dose adjustment will be based on drug-related AEs and severity per protocol demanded. Outcomes and assessments - ORR and DCR: Descriptive statistics were used, and an accurate 95% CI was provided. Time-to-event endpoints were summarized using K-M analyses. Safety endpoints were analyzed using frequency and percentage distribution in patients who received at least one dose of infigratinib.

Results

cORR 25.0% (95%CI 8.7, 49.1), DCR 80.0% (95%CI 56.3, 94.3), mDoR 3.8 months (mos) (3.6, NE). mPFS 3.3 mos (95%CI 2.3, 4.5), mOS 8.0 mos (95%CI 4.1, NE). 15/19 patients with tumor shrinkage, the maximum from baseline was -78.5%. ≥ Grade 3 TRAE was 42.9%, most were recoverable. No drug-induced death was reported.

Conclusions

Infigratinib in GC/GEJ patients with FGFR2 gene amplification has shown an inspiring clinical improvement, with acceptable tolerance, which is a potential first TKI regimen that precisely targeting in this population.

Clinical trial identification

NCT05019794.

Editorial acknowledgement

Legal entity responsible for the study

Shanghai LianBio Development Co., Ltd.

Funding

Shanghai LianBio Development Co., Ltd.

Disclosure

All authors have declared no conflicts of interest.