PURPOSE: Temozolomide is an imidazotetrazine with a mechanism of action similar to dacarbazine and equivalent activity in melanoma. It is well tolerated and is a candidate for combination chemotherapy and schedule manipulation. In this study, we combined temozolomide with interferon alfa-2b and, separately, with thalidomide, and we administered temozolomide alone in a compressed schedule. The objectives of this randomized phase II, two-center study were to determine response rates, overall survival, and tolerability of the regimens in patients with advanced metastatic melanoma. PATIENTS AND METHODS: One hundred eighty-one patients with metastatic melanoma were randomly assigned to receive up to six 4-weekly cycles consisting of temozolomide 200 mg/m2 every 8 hours for five doses, or temozolomide 200 mg/m2 daily for days 1 to 5 plus interferon alfa-2b 5 MU (million International Units) subcutaneously three times a week, or temozolomide 150 mg/m2 (increased after one cycle to 200 mg/m2) daily on days 1 to 5 plus thalidomide 100 mg daily days 1 to 28. RESULTS: The treatment arms were well balanced for known prognostic factors. Median survival was 5.3 months for 8-hourly temozolomide, 7.7 months for temozolomide/interferon, and 7.3 months for temozolomide/thalidomide; and 1-year survivals were 18%, 26%, and 24%, respectively. Response or disease stabilization occurred in 20% of patients (95% confidence interval [CI], 10% to 33%) given 8-hourly temozolomide, 21% (95% CI, 12% to 33%) given temozolomide/interferon, and 25% (95% CI, 15% to 38%) given temozolomide/thalidomide. Grade 3 or 4 nonhematologic toxicities were similar in each arm except for infection, which was more frequent with 8-hourly temozolomide. There were fewer instances of grade 3 or 4 myelotoxicity with temozolomide/thalidomide. CONCLUSION: Of the three regimens tested, the combination of temozolomide and thalidomide seems the most promising for future study.