136MO - Bemarituzumab (bema)+FOLFOX6 as first-line treatment in patients with FGFR2b overexpressing locally advanced or metastatic gastric/gastroesophageal junction cancer (G/GEJC): East Asia subgroup of FIGHT final analysis

Background

Despite decline in incidence and improvement in mortality rates for advanced G/GEJC in Asia, outcomes remain quite poor. As novel biomarkers emerge, they may reveal more opportunities to improve outcomes in advanced G/GEJC via targeted therapeutics. The global, randomized, phase 2, double-blind FIGHT study (NCT03694522) suggested that bema can improve PFS and OS in patients (pts) with FGFR2b+ (any 2+/3+ IHC staining and/or FGFR2 amplification by ctDNA) advanced or metastatic G/GEJC. Here, we present the outcomes for Asian pts from Japan, China, South Korea, and Taiwan.

Methods

89 East Asian pts (57.4% of total) were enrolled in FIGHT; all received FOLFOX6. 45 received bema (15mg/kg) and 44 received placebo (pbo) once Q2W and 7.5mg/kg bema or pbo on C1D8. Of these, 29 and 31, respectively, had FGFR2b overexpression in ≥10% of tumor cells with any 2+/3+ staining intensity by IHC (FGFR2b+ ≥10%).

Results

At 24mo of follow-up (data cutoff 13 May 2022), bema+mFOLFOX6 showed improved median PFS (95% CI) of 12.9mo (8.8-17.9) vs 8.2mo (5.6-10.3) for pbo+mFOLFOX6 (HR 0.50, 95% CI 0.29-0.87); median OS (95% CI) was also improved at 24.7mo (13.8-33.1) vs 12.9mo (9.3-21.4) (HR 0.56, 95% CI 0.32-0.96). ORR was 48.9% vs 34.1%. Treatment benefit was more pronounced in patients with FGFR2b+ ≥10%: PFS HR 0.28 (95% CI 0.13-0.57), OS HR 0.43 (95% CI 0.22-0.86). Observed safety within this subgroup was consistent with those in the global study. Corneal treatment-emergent adverse events (TEAEs) occurred in 68.2% (n=30) bema and 13.6% (n=6) pbo pts. Study drug was discontinued for any-grade corneal TEAEs not resolved within 28 days; 56.7% (17/30) of pts with a corneal TEAE discontinued bema.

Conclusions

In East Asian pts (N=89) with FGFR2b+ advanced or metastatic G/GEJC, bema+mFOLFOX6 continued to show clinically meaningful outcomes over pbo+mFOLFOX6 after 24mo of follow-up. The efficacy and safety results from the East Asian subgroup were consistent with those of the global FIGHT final analysis.

Clinical trial identification

NCT03694522.

Editorial acknowledgement

Medical writing assistance was provided by Tim Peoples, MA, ELS, contractor to Amgen Inc.

Legal entity responsible for the study

Amgen Inc.

Funding

Five Prime Therapeutics, Inc.

Disclosure

Y. Kang: Financial Interests, Personal, Advisory Board: ALX Oncology, Zymeworks, Amgen, Novartis, Macrogenics, Daehwa, Blueprint, Surface Oncology, BMS, Merck, Roche, Liscure. K. Lee: Financial Interests, Personal, Advisory Board: BMS (Korea), Bayer (Korea), Daiichi Sankyo (Korea), Merck Sharp & Dohme (Korea), Metafines, Vifor pharma (Korea), Astellas (Korea); Financial Interests, Personal, Invited Speaker: Boryung Co.; Financial Interests, Institutional, Local PI: ABLBIO, ALX Oncology, Amgen, Arcus Biosciences, Astellas Pharma, AstraZeneca, BeiGene, Bolt therapeutics, Daiichi Sankyo, Exelixis, Genexine, Green Cross Corp, InventisBio, LSK BioPharma, Leap therapeutics, Macrogenics, MedPacto, Merck KGaA, Merck Sharp & Dohme, Oncologie, Ono pharmaceutical, Pfizer, Pharmacyclics, Y-BIOLOGICS, Seagen, Taiho Pharmaceutical, Trishula therapeutics, Zymeworks,; Non-Financial Interests, Personal, Leadership Role, SMC chair of ASPEN-06 study: ALX Oncology. J. Li: Financial Interests, Personal, Speaker’s Bureau: AstraZeneca, Lilly. L. Bai: Financial Interests, Personal, Speaker, Consultant, Advisor: Lilly, Pfizer, SynCoreBio, Bristol Myers Squibb. C.P.K. Chan: Financial Interests, Personal, Full or part-time Employment, Employee: Amgen; Financial Interests, Personal, Stocks or ownership, Stockholder: Amgen. A. Yusuf: Financial Interests, Personal, Full or part-time Employment, Employee: Amgen; Financial Interests, Personal, Stocks or ownership, Stockholder: Amgen. A. Zahlten-Kuemeli: Financial Interests, Personal, Full or part-time Employment, Employee: Amgen; Financial Interests, Personal, Stocks or ownership, Stockholder: Amgen. K. Taylor: Financial Interests, Personal, Full or part-time Employment, Employee: Amgen; Financial Interests, Personal, Stocks or ownership, Stockholder: Amgen. K. Yamaguchi: Financial Interests, Personal, Invited Speaker: Taiho Pharm; Financial Interests, Personal, Advisory Board: Daiichi Sankyo, Bristol Mayers Squibbb, Ono Pharm, Eli Lilly Japan; Financial Interests, Institutional, Funding: Taiho Pharm. All other authors have declared no conflicts of interest.