IMpower132: Atezolizumab plus platinum-based chemotherapy vs chemotherapy for advanced NSCLC in Japanese patients

Abstract

IMpower132 explored the safety and efficacy of atezolizumab plus pemetrexed and platinum-based chemotherapy as first-line treatment for advanced non-small-cell lung cancer (NSCLC). Key eligibility criteria for the phase 3, open-label, IMpower132 study included age ≥18 y, histologically or cytologically confirmed advanced non-squamous NSCLC per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, Eastern Cooperative Oncology Group performance status of 0/1, and no prior systemic treatment for stage IV NSCLC. Patients received atezolizumab (1200 mg) plus pemetrexed (500 mg/m2) and cisplatin (75 mg/m2) or carboplatin (area under the concentration curve, 6 mg/mL/min) (APP arm) or chemotherapy alone (PP arm). The co-primary study endpoints were overall survival (OS) and investigator-assessed progression-free survival (PFS) per RECIST 1.1 in the intention-to-treat population. A subgroup analysis was conducted in Japanese patients. In the Japanese subgroup (n = 101), median OS was 30.8 (95% CI, 24.3 to not estimable) mo in the APP arm (n = 48) and 22.2 (95% CI, 15.7-30.8) mo in the PP arm (n = 53; hazard ratio [HR], 0.63 [95% CI, 0.36-1.14]). PFS was 12.8 (95% CI, 8.6-16.6) mo in the APP arm vs 4.5 (95% CI, 4.1-6.7) mo in the PP arm (HR, 0.33 [95% CI, 0.21-0.58]). Grade 3/4 treatment-related adverse events (TRAEs) occurred in 68.8% of APP arm patients and 44.2% of PP arm patients. Consistent with global study results, atezolizumab plus pemetrexed and platinum-based chemotherapy improved efficacy and was well tolerated in Japanese patients with advanced NSCLC despite a higher incidence of grade 3/4 TRAEs.