Phase II study of Edatrexate in stage III and IV non-small-cell lung cancer.

A total of 49 patients with advanced, previously untreated non-small-cell lung cancer (NSCLC) were treated with a new antifolate, Edatrexate (10-ethyl-10-deaza-aminopterin; 10-EdAM). Patients received 80 mg/m2 weekly for 12 weeks, and responders received a further 6 cycles at 2-week intervals. Dose reductions were carried out for haematological toxicity and mucositis. Response was assessed prior to each treatment according to WHO criteria. Among the 45 evaluable patients, 6 [13.3%; 95% confidence interval (CI), 6%-26%] achieved a partial response (PR) and 9 (20%; 95% CI, 11%-34%) showed a minor response (MR; 25%-50% reduction in the sum of 2 perpendicular tumour diameters). In those receiving four or more cycles of treatment, the PR and MR rates were 17.6% and 26.4%, respectively. The resultant toxicity mainly constituted skin rash, mucositis and myelosuppression. Edatrexate is active against NSCLC and produces toxicity profile similar to that of methotrexate.