Phase I Study of the Efficacy and Safety of Ramucirumab in Combination with Osimertinib in Advanced T790M-positive EGFR-mutant Non-small Cell Lung Cancer

Purpose: We report the final analysis of JVDL (NCT02789345), which examined the combination of the EGFR tyrosine kinase inhibitor (TKI) osimertinib plus the VEGFR2-directed antibody ramucirumab in patients with T790M-positive EGFR-mutant non-small cell lung cancer (NSCLC). Patients and Methods: This open-label, single-arm phase I study enrolled patients with EGFR T790M-positive NSCLC, who had progressed following EGFR TKI but were third-generation EGFR TKI-naive. A dose-limiting toxicity (DLT) period with as-needed dose deescalation was followed by an expansion cohort. Patients received daily oral osimertinib and intravenous ramucirumab every 2 weeks until progression or discontinuation. Results: Twenty-five patients were enrolled. No DLTs were observed. Median follow-up time was 25.0 months. Common grade 3 or higher treatment-related adverse events (TRAE) were hypertension (8%) and platelet count decreased (16%); grade 5 TRAE (subdural hemorrhage) occurred in I patient. Patients with (N = 10) and without central nervous system (CNS) metastasis (N = 15) had similar safety outcomes. Five patients remain on treatment. Objective response rate (ORR) was 76%. Median duration of response was 13.4 months [90% confidence interval (CI): 9.6-21.2]. Median progression-free survival (PFS) was 11.0 months (90% CI: 55-19.3). Efficacy was observed in patients with and without CNS metastasis (ORR 60% and 87%; median PFS 10.9 and 14.7 months, respectively). Exploratory biomarker analyses in circulating tumor DNA suggested that on-treatment loss of EGFR Exon 19 deletion or L858R mutations, detectable at baseline, correlated with longer PFS, but on-treatment loss of 1790M did not. Emergent genetic alterations postprogression included C797S, MET amplification, and EGFR amplification. Conclusions: Ramucirumab plus osimertinib demonstrated encouraging safety and antitumor activity in T790M-positive EGFR-mutant NSCLC.