Phase II study of pemetrexed and cisplatin plus cetuximab followed by pemetrexed and cetuximab maintenance therapy in patients with advanced nonsquamous non-small cell lung cancer

Abstract

ObjectivesThe aim was to determine if combined pemetrexed, cisplatin, and cetuximab was efficacious and safe as first-line treatment in advanced nonsquamous non-small cell lung cancer (NSCLC). Patients and methodsIn this single-arm, multicenter clinical trial, patients with Stage IIIB/IV nonsquamous NSCLC received first-line therapy consisting of pemetrexed (500mg/m2) and cisplatin (75mg/m2) on Day 1 (21-day cycles) plus weekly cetuximab (400mg/m2 loading dose, then 250mg/m2) for 4–6 cycles. Non-progressing patients received maintenance therapy consisting of pemetrexed and cetuximab as above until disease progression. All patients received vitamin supplementation, dexamethasone, and antihistamine prophylaxis. The primary endpoint was objective response rate (ORR). Secondary endpoints were progression-free survival (PFS), 1-year survival rate, translational research (TR) and safety. ResultsOf the 113 patients receiving study drug, 109 were protocol-qualified. All patients completed ≥1 cycle of induction, and 51 (45%) and 49 (43%) patients completed ≥1 cycle of maintenance with pemetrexed and cetuximab, respectively. The ORR (n=109) was 38.5% (80% confidence interval [CI], 32.3–45.1%), all partial responses. Median PFS was 5.8 (80% CI, 4.4–6.7) months. One-year survival rate was 45% (80% CI, 39–51%). In exploratory analyses, there was some preliminary evidence of potential prognostic relationships with efficacy outcomes for epidermal growth factor receptor and thyroid transcription factor-1 protein expression, but not for KRAS mutation or for thymidylate synthase or folate receptor-alpha protein expression. Seventy-three (64.6%) patients had study drug-related Grade 3/4 adverse events (AEs). Drug-related serious AEs were reported in 31 (27.4%) patients. There were 3 (2.7%) potentially drug-related deaths on-study or within 30 days of follow up. ConclusionPemetrexed, cisplatin, and cetuximab appeared efficacious and tolerable in advanced nonsquamous NSCLC patients. The TR outcomes are hypothesis-generating given the study's size and nonrandomized nature.