Efficacy, Safety, and Influence on Tumor Microenvironment of Neoadjuvant Pembrolizumab plus Ramucirumab for PD-L1 Positive NSCLC: A Phase 2 Trial (EAST ENERGY).

Purpose: Angiogenesis inhibitors are known to modify tumor immunity. Combination of angiogenesis inhibitors with immune checkpoint inhibitors (ICIs) 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 vascular endothelial growth factor (VEGF) receptor-2 antagonist for patients with PD-L1-positive NSCLC and its influence on the tumor microenvironment (TME).
Patients and Methods: Patients with pathologically proven NSCLC with PD-L1-positive, clinical stage IB-IIIA were eligible. Patients received two cycles of pembrolizumab (200 mg/body) and ramucirumab (10 mg/kg) every three weeks. Surgery was scheduled 4 to 8 weeks after the last dose. The primary endpoint was the major pathologic response (MPR) rate by a blinded independent pathology review. The sample size was 24 patients. Exploratory endpoints were evaluated to elucidate the effects of neoadjuvant therapy on TME.
Results: The 24 eligible patients were enrolled between July 2019 and April 2022. The MPR rate was 50.0% (90% confidence interval, 31.9-68.1%). Six patients showed pathological complete response. Grade 3 adverse events (AEs) occurred in 9 patients (37.5%), including 3 immune-related AEs (acute tubulointerstitial nephritis in 2 cases and polymyalgia rheumatica in one). There were no grade 4 or 5 AEs. The transcriptome and multiplexed immunohistochemistry 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 ICIs.