Maintenance Capecitabine Plus Ramucirumab After First-Line Chemotherapy in Patients With Advanced Esophagogastric Adenocarcinoma: Results From the Randomized PLATFORM Study.

PURPOSE

PLATFORM is an adaptive phase II study assessing maintenance therapies in advanced esophagogastric adenocarcinoma (OGA). We evaluated the role of capecitabine plus a vascular endothelial growth factor receptor 2 inhibitor ramucirumab (cape-ram) in these patients.

METHODS

Human epidermal growth factor receptor 2 (HER2)-negative patients with advanced OGA with stable or responding disease after 18 weeks of induction platinum-based chemotherapy were randomly assigned 1:1 to surveillance or cape-ram. The primary end point was progression-free survival (PFS), and key secondary end points were overall survival (OS) and safety. Recruitment to the cape-ram arm closed prematurely because of industry support withdrawal. A one-sided log-rank test with a 2.5% significance level was considered significant.

RESULTS

Between April 2019 and November 2022, 25 surveillance and 22 cape-ram patients were contemporaneously randomly assigned. Median follow-up was 24.4 months. Compared with surveillance, cape-ram significantly prolonged PFS (hazard ratio [HR], 0.33 [95% CI, 0.17 to 0.63], < .001; median PFS: 2.5 months with surveillance versus 5.5 months with cape-ram; 6-month PFS rate: 4% [95% CI, 0.3% to 17.0%] 42.9% [95% CI, 21.9% to 62.3%], respectively) and OS (HR, 0.51 [95% CI, 0.26 to 1.00], = .023; median OS: 7.1 months with surveillance 14.4 months with cape-ram; median OS from start of induction chemotherapy was 12.1 months 19.5 months, respectively). Of 10 cape-ram patients with measurable disease, 1 had an incremental partial response. Grade ≥3 adverse events (AEs) were seen in 32% surveillance and 57% cape-ram patients. Six cape-ram patients had grade 3 treatment-related AEs, and no new safety signals were identified.

CONCLUSION

Maintenance cape-ram after induction chemotherapy for patients with HER2-negative OGA significantly improved survival compared with surveillance. To our knowledge, this is the first randomized maintenance study demonstrating survival benefit and provides support for maintenance treatment.