Maintenance durvalumab after first-line platinum-based chemotherapy in advanced oesophago-gastric (OG) adenocarcinoma: Results from the PLATFORM trial.

• DOI: 10.1200/jco.2021.39.15_suppl.4015
• Publication Date: 2021-06-02T14:06:35Z
• Authors: Caroline Fong; Bijal Patel; Clare Peckitt; Elli Bourmpaki; Katharina von Loga; Ruwaida Begum; Michael Davidson; Gayathri Anandappa; Catherine Cafferkey; David J. Watkins; Sheela Rao; Tom Waddell; Jonathan Wadsley; Fareeda Coxon; Tom Roques; Carys Morgan; Charlotte Rees; Naureen Starling; Ian Chau; David Cunningham
• Keywords: Durvalumab; Clinical endpoint; Progression-free survival

4015 Background: PLATFORM is a prospective, open-label, multicentre, adaptive phase II trial assessing maintenance therapy in patients (pts) with OG adenocarcinoma after platinum-based first-line induction chemotherapy. HER2 negative pts were initially randomised 1:1:1:1:1 to surveillance (A1), capecitabine (A2), durvalumab (A3), rucaparib (A4) and + ramucirumab (A5) added later as per design. Here we report the primary analysis of vs. surveillance. Methods: Pts upon achieving response or stable disease following 18 weeks chemotherapy stratified by region, extent performance status. A1 had 4 weekly visits A3 received 10mg/kg iv Q2W. Target accrual was 154 pts/arm; however, closed prematurely cessation industry support. The endpoint progression-free survival (PFS) from randomisation post progression according RECIST 1.1 criteria, death. Secondary endpoints time treatment failure (TTF), objective rate (ORR), overall (OS) toxicity. Survival analyses PD-L1 using combined positive score (CPS, Ventana SP263 assay) conducted. Results: A total 205 concurrently into (n = 100) 105). At data cut-off (02 Feb 2021), median follow up 24.2 months [95% confidence interval (CI) 21.6-36.8]. There no significant difference PFS between [median PFS: 3.2 4.7 (hazard ratio (HR) 0.79 (95% CI 0.59-1.06, p 0.122) respectively]. Median OS 11.4 11.3 (HR 0.92, 95% 0.66-1.27, 0.60) respectively TTF detected both arms (median TTF: 3.5 0.69-1.23, 0.558)]. ORR 6% 2 complete n partial responses) whereas radiological responses seen A1. results available for 76 77 A3. comparable subgroups CPS thresholds ≥1, ≥5 ≥10. safety population consisted 199 (A1: 98 A3: 101 pts). Grade ≥3 treatment-related adverse events reported 18% new signals identified. Conclusions: Although advantage not compared surveillance, subset who demonstrated incremental responses. Exploratory expression associated improved outcomes. Clinical information: NCT02678182.