Phase II study of pemetrexed-gemcitabine combination in patients with advanced-stage non-small cell lung cancer

Cisplatin is one of the most active agents for the treatment of non-small cell lung cancer (NSCLC). It is also known for significant toxicity, which makes it unsuitable for certain patients. Our purpose was to evaluate the efficacy and toxicity of a promising cisplatin-free combination, gemcitabine plus pemetrexed, in NSCLC.

Chemo-naive patients with inoperable NSCLC were eligible for this study. Gemcitabine (1250 mg/m2) was given intravenously on days 1 and 8, followed by intravenous pemetrexed (500 mg/m2) on day 8. After inclusion of 13 patients, folic acid and vitamin B12 supplementation was added to lower pemetrexed-induced toxicity. Quality of life was assessed with the Lung Cancer Symptom Scale.

Sixty patients enrolled; 58 were evaluable for response. All patients had a World Health Organization performance status of 0 or 1. Eighty-seven percent had stage IV disease. Nine patients had a confirmed partial response [overall response rate, 15.5%; 95% confidence interval (CI), 7.3-27.4%]. Twenty-nine (50.0%) patients had stable disease. Median overall survival was 10.1 months (95% CI, 7.9-13.0 months), with a 1- and 2-year overall survival of 42.6% (95% CI, 30.0-55.3%) and 18.5% (95% CI, 7.9-29.1%). Median progression-free survival was 5.0 months. Median response duration was 3.3 months. There were no deaths attributed to treatment. Common Toxicity Criteria grade 3/4 toxicities were neutropenia (61.7%), febrile neutropenia (16.7%), fatigue (23.3%), and elevations of aspartate aminotransferase (15.0%) and alanine aminotransferase (20.0%).

This combination had good tolerance and achieved promising overall survival with extended 1- and 2-year survival rates. This cisplatin-free regimen warrants further evaluation in randomized trials.