Phase II trial of biochemotherapy with interferon alpha, dacarbazine, cisplatin and tamoxifen in metastatic melanoma: a Southwest Oncology Group trial

The therapeutic benefit of adding interferon cc (IFN alpha) to established single-agent and combination chemotherapy regimens for the treatment of met astatic melanoma has not been proven. We designed the present study to esti mate the response rate of IFNa, dacarbazine, cisplatin and tamoxifen in pat ients who had not been treated with systemic therapy for advanced disease. Using a schedule similar to that which had previously been shown to favor I FN alpha plus dacarbazine over dacarbazine alone, we treated patients with an "induction" regimen of IFN alpha, 15 mU m(-1) day(-1) intravenously 5 da ys/week for 3 weeks. Following induction, schedules of IFN alpha, 5 mU m(-2 ) day(-1) subcutaneously three times a week, and tamoxifen, 10 mg orally tw ice a day, were begun. Dacarbazine, 250 mg m(-2) day(-1) and cisplatin 33 m g m(-2) day(-1) for 3 consecutive days were repeated every 4 weeks, and sub cutaneous IFN alpha and oral tamoxifen were continued until the discontinua tion of chemotherapy. We treated 25 patients (18 men and 7 women, median ag e 52 years) and observed only 1 objective response (response rate 4%, 95% c onfidence interval 0.1%-20%). The toxicities of the regimen consisted of mo derate myelosuppression and constitutional side-effects. On the basis of th e low antitumor activity of this regimen, we do not recommend it for furthe r study or for use as standard therapy of metastatic melanoma.