Adenocarcinoma has an excellent outcome with pemetrexed treatment in Korean patients: A prospective, multicenter trial

Objective This prospective multicenter study conducted by the Korean Cancer Study Group evaluated the efficacy and safety of pemetrexed in Korean patients with advanced non-small cell lung cancer (NSCLC) who had prior chemotherapy.Patients and methods: Patients with stage IIIB or IV NSCLC in whom prior chemotherapy failed received pemetrexed 500 mg/m2 every 3 weeks with folic acid and vitamin B12 supplementation until disease progression or the development of intolerable toxicity. Eighty-one patients were enrolled.Results The overall response rate for 78 evaluable patients was 5.1% [95% confidence interval (CI) 1.4–12.6; partial response 4/78, no complete response]. The disease control rate including complete, partial response and stable disease was 46.2% (36/78, 95% CI 34.8–57.8). With a median 8.7 months follow-up, the median time to progression was 3.1 months (95% CI 1.17–5.03) and the median overall survival (OS) was 7.8 months (95% CI 5.19–10.35). The median OS for patients with adenocarcinoma histology was 18.7 months compared to 6.1 months for non-adenocarcinoma. In a multivariate analysis, Eastern Cooperative Oncology Group performance status 0–1 [hazards ratio (HR) = 0.331, 95% CI 0.135–0.814] and adenocarcinoma (HR = 0.504, 95% CI 0.283–0.899) were independent factors for prolongation of overall survival.Conclusions Pemetrexed monotherapy has promising efficacy in patients with advanced NSCLC as a second-line therapy with less hematologic and non-hematologic toxicity, especially in those with adenocarcinoma histology.