Envafolimab plus lenvatinib and paclitaxel shows activity in advanced gastric cancer after first-line progression.

BACKGROUND: This single-center, open-label, exploratory trial aimed to investigate the efficacy and safety of envafolimab combined with lenvatinib and chemotherapy in previous treated advanced G/GEJ adenocarcinoma. METHODS: Eligible patients with HER2-negative, microsatellite stable (MSS) advanced G/GEJ adenocarcinoma who had progressed after first-line treatment were enrolled in this phase II trial. Patients without previously receiving PD-1/PD-L1 inhibitors were enrolled in Group A, and those who progressed on the first-line PD-1 inhibitors were included in Group B. Patients in both groups received envafolimab (200 mg, subcutaneous injection (sc), days 1 and 15, Q4W) combined with lenvatinib and albumin-bound paclitaxel (100 mg/m, IV, days 1, 8 and 15, Q4W, up to 6 cycles) until disease progression, unacceptable toxicity, or refusal of continuation. The primary endpoint was objective response rate (ORR). RESULTS: A total of 30 patients were included for safety and efficacy analysis. As of data cutoff (Sep 14, 2024), the median follow-up was 17.0 months (IQR: 8.0-18.8) in Group A. The ORR was 60.0%, and the DCR was 100.0%. The mPFS was 8.2 months (95% CI 6.1-10.4) with mOS of 14.8 months (95% CI 7.4-22.2). With a median follow-up of 9.0 months (IQR: 6.1-16.2) in Group B, the ORR was 46.7%, and the DCR was 100.0%. The mPFS was 5.9 months (95% CI 3.8-8.1), and the mOS was 11.5 months (95% CI 3.1-19.9). The overall incidence of adverse events (AEs) of any grade was 100%. While Group A showed numerically better outcomes than Group B, there was no statistically significant difference in PFS (P = 0.629) or OS (P = 0.873) between the two groups. CONCLUSIONS: Second-line envafolimab-based combination therapy demonstrated promising effects in previously treated advanced GC, particularly in those who have not previously received ICIs.