Efficacy, Safety, and Influence on the Tumor Microenvironment of Neoadjuvant Pembrolizumab plus Ramucirumab for PD-L1-Positive NSCLC: A Phase II Trial (EAST ENERGY)

Abstract

Purpose: Angiogenesis inhibitors are known to modify tumor immunity. Combination of angiogenesis inhibitors with immune checkpoint inhibitors has shown efficacy against many types of cancers, including non-small cell lung cancer (NSCLC). We investigated the feasibility of neoadjuvant therapy with pembrolizumab and ramucirumab, a VEGFR-2 antagonist for patients with PD-L1-positive NSCLC, and its influence on the tumor microenvironment.

Patients and methods: Patients with pathologically proven, PD-L1-positive, clinical stage IB to IIIA NSCLC were eligible. Patients received two cycles of pembrolizumab (200 mg/body) and ramucirumab (10 mg/kg) every 3 weeks. Surgery was scheduled 4 to 8 weeks after the last dose. The primary endpoint was the major pathologic response rate by a blinded independent pathologic review. The sample size was 24 patients. Exploratory endpoints were evaluated to elucidate the effects of neoadjuvant therapy on the tumor microenvironment.

Results: The 24 eligible patients were enrolled between July 2019 and April 2022. The major pathologic response rate was 50.0% (90% confidence interval, 31.9%-68.1%). Six patients showed pathologic complete response. Grade 3 adverse events (AE) occurred in nine patients (37.5%), including three immune-related AEs (acute tubulointerstitial nephritis in two cases and polymyalgia rheumatica in one case). There were no grade 4 or 5 AEs. The transcriptome and multiplex IHC results suggested that tumors with greater CD8+ T-cell infiltration and higher expression of effector molecules at the baseline could show better sensitivity to treatment.

Conclusions: This new neoadjuvant combination of pembrolizumab plus ramucirumab was feasible, and anti-VEGF agents may enhance the effects of immune checkpoint inhibitors.