Maintenance capecitabine after first-line platinum-based chemotherapy in advanced oesophagogastric adenocarcinoma: final analysis from the PLATFORM trial.

BACKGROUND

PLATFORM is an adaptive phase II trial assessing maintenance therapies in advanced oesophagogastric adenocarcinoma (OGA). We evaluated maintenance capecitabine in patients with disease control after first-line chemotherapy.

METHODS

HER2-negative patients with advanced OGA who had response or stable disease after 18 weeks of first-line chemotherapy were randomised (1:1) to surveillance or capecitabine. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS) and safety.

RESULTS

Between May 2015 and May 2024, 266 patients were randomised (129 surveillance, 137 capecitabine). Median follow up was 70.7 months. Capecitabine significantly improved PFS (HR 0.69; 95% CI 0.54-0.89; p = 0.002), with median PFS of 5.0 vs 2.8 months. One-year PFS rates were 19.9% vs 6.8%; and two-year rates 8.1% vs 4.3%. No OS difference was observed (median OS: 10.5 vs 10.0 months; HR 0.87; 95% CI 0.67-1.12; p = 0.143). One and two-year OS rates were similar (1-year: 44.1% vs 45.7%; 2-year: 18.8% vs 16.8%). Grade ≥3 adverse events were more frequent with capecitabine (46% vs 29%), with 21% experiencing grade 3 treatment related events.

DISCUSSION: Maintenance capecitabine significantly prolonged PFS compared to surveillance, meeting the primary endpoint and supporting its use to extend disease control in advanced OGA.