Nivolumab Combined with Chemotherapy in FGFR2 and PD-L1 Co-Expressing Metastatic Gastric Cancer: A Prospective Phase 2 NIVOFGFR2 Study.

Background: Immunotherapy is increasingly significant in treating metastatic gastric cancer. This prospective phase 2 study investigates the efficacy and safety of combining nivolumab with chemotherapy in patients with metastatic gastric cancer co-expressing FGFR2 and PD-L1.

Methods: Eligible patients were aged 18 years or older, with previously untreated HER-2 negative, PD-L1 positive, and FGFR2 positive metastatic gastric adenocarcinoma. Patients received nivolumab (360 mg every 3 weeks) in combination with chemotherapy (CAPOX: capecitabine 1000 mg/m twice daily on days 1-14 and oxaliplatin 130 mg/m on day 1, every 3 weeks). Tumor assessments were conducted using RECIST v1.1 every 8 weeks for 48 weeks, then every 12 weeks. The primary endpoint was the 1-year progression-free survival (PFS) rate. Secondary endpoints included median PFS, overall survival (OS), objective response rate (ORR), and grade ≥ 3 adverse events (AEs).

Results: From June 2022 to October 2023, 194 patients were assessed for eligibility, with 23 patients enrolled and treated. At a median follow-up of 17.3 months, the 1-year PFS rate was 30.4%, with a median PFS of 6.0 months (95% CI, 4.3-7.7). The median OS was 15.1 months (95% CI, 13.2-16.8). The ORR was 21.7%, with one complete response and four partial responses. Grade 3 or higher TRAEs were reported in 34.8% of patients, primarily associated with chemotherapy. No treatment-related deaths occurred.

Conclusions: While the primary endpoint of improved 1-year PFS rate was not met, the study offers valuable insights into the potential benefits of combining nivolumab with chemotherapy in FGFR2 and PD-L1 co-expressing metastatic gastric cancer. Future research should optimize patient selection, assess combined immunotherapy and targeted anti-FGFR2 therapy, and further investigate the role of subsequent treatments to maximize therapeutic benefits.