Pirarubicin (THP) (Roger Bellon Laboratory, France) is a new anthracycline under clinical development. In order to assess the efficacy and toxicity of the drug in small-cell lung carcinoma (SCLC), we have undertaken this trial in front-line therapy in patients with metastatic disease, PS less than 3 and at least one evaluable lesion. Responses were assessed after two cycles of THP (60 mg/m2 i.v. bolus every 3-4 weeks) and a further cross over to VP16 + CDDP (three cycles) was systematic whatever the response to THP. This crossover was performed after only one cycle in case of obvious progression. From June 1988 to April 1990, 32 patients were enrolled: 6 were ineligible (4 non-SCLC, 2 M0), 26 patients were fully evaluable for THP and 18 patients for VP16-CDDP. The characteristics of the patients were as follows: mean age 57.4 years (38-71); T4: 54%; T3: 27%; T2: 19%; N3: 62%; N2: 35%; No: 4%. The efficacy was as follows 1 complete response and 2 partial responses (confirmed by endoscopy); 12 patients received only one cycle because of obvious progression; the overall response rate is 12% (95% confidence interval 0-24%). The patient who had complete response after pirarubicin remained in CR after VP16-CDDP, whereas the 2 patients who had partial response achieved CR for one and PR for the other; among the 15 who did not respond 1 CR and 7 PR were observed. The only significant toxicity of THP was granulopenia without infection. THP seems to be an effective anthracycline in SCLC, and the study is continuing. A response could be reached in 50% of the nonresponders with standard therapy and 10 of 24 patients (42%) finally responded. Therefore, this schedule for testing new drugs in metastatic SCLC appears ethically acceptable.