Final Survival Outcomes With Ramucirumab Plus Erlotinib Versus Placebo Plus Erlotinib in Patients With Untreated EGFR-Mutated Metastatic NSCLC: RELAY Japanese Subset

Introduction Significant improvement in progression-free survival (PFS; primary end point) was reported in the phase 3 RELAY study with ramucirumab (RAM) plus erlotinib (ERL) versus placebo (PL) in untreated EGFR -mutated NSCLC (hazard ratio [HR] = 0.59, 95% confidence interval [CI]: 0.46–0.76, p < 0.0001), including in the Japanese subset. We report updated PFS and final overall survival (OS) for the Japanese subset. Methods Patients (no central nervous system metastases) were randomized 1:1 (stratification included EGFR leucine to arginine substitution [L858R]/exon 19 deletion [ex19del]) to ERL (150 mg/d) with RAM (10 mg/kg; n=106) or PL (n = 105) intravenously every 2 weeks. The study was not powered for OS. Results At final OS data cutoff (median follow-up = 48.2 mo), PFS benefit was sustained with RAM plus ERL versus PL plus ERL (median [m] PFS: 19.4 versus 11.2 mo; HR=0.69, 95% CI: 0.51–0.93); the mOS was 54.3 and 46.0 months (HR = 0.91, 95% CI: 0.65–1.26), respectively. In L858R (n = 110) and ex19del (n = 100) subgroups, the mOS was 54.3 versus 43.2 months (HR = 0.63, 95% CI: 0.40–0.99) and 53.9 versus 62.1 months (HR = 1.40, 95% CI: 0.86–2.28), respectively. T790M rates post-progression were 52.0% versus 51.1%, respectively. Osimertinib as subsequent therapy was received by 61.0% versus 55.2% patients (L858R: 58.2% versus 48.1%; ex19del: 65.3% versus 62.7%); the median (range) osimertinib treatment duration was 16.8 (0.7–58.3) versus 20.1 (2.1–77.2) months. Safety was consistent with known RAM and ERL profiles, with no increased toxicity over time. Conclusions The Japanese subset reported that RAM plus ERL improved PFS, and a mOS greater than 50 months was achieved. OS differed by EGFR mutation type, with an indication of benefit for patients with L858R.