Recombinant interferon alpha-2a in combination with dacarbazine in the treatment of metastatic malignant melanoma: analysis of long-term responding patients.

Thirty-four evaluable patients with metastatic malignant melanoma were entered into a phase-II study designed to assess the response rate and analyze the long-term therapeutic efficacy of recombinant interferon (rIFN) alpha-2a and dacarbazine. Patients received 14 days of daily subcutaneous r-IFN alpha-2a (3 x 10(6) IU/day), followed by 9 x 10(6) IU on alternate days, as long as objective response lasted, in combination with i.v. dacarbazine started on day 7 (400 mg/m2) and repeated every 21 days (dacarbazine doses were escalated to 800 mg/m2). In 11 patients, 6 complete (17.6%) and 5 partial (14.7%) responses were seen, with an overall response rate of 32.3% (95% confidence interval: 16%-48%). The median survival time of the responding patients was significantly better than that of patients with progressive disease (P = 0.01) and the median response time of the patients showing complete response was longer than that of the partially responding patients (14 and 7 months respectively, P = 0.06).