Sixty-two patients with biopsy-proven, measurable disseminated malignant melanoma received either the combination IFN-alpha 2A with BCNU (30 patients) or the combination cimetidine with BCNU (32 patients) in parallel noncomparative Phase II trials. From patients receiving IFN-alpha 2A plus BCNU, we observed a 7% response rate: 1 complete response (CR) and 1 partial response (PR) (soft tissue disease with durations of 6.9 and 11.5+ months, respectively). Median time to progression (MTP) was 1.8 months and median survival time (MST) was 3.8 months. Myelosuppression and a flu-type illness were the most common toxicities. From patients receiving cimetidine plus BCNU, the response rate was 16%: 4 PRs (soft tissue disease, 3.8 months; visceral, 2.1, 4.0+, and 9.7 months) and 1 CR (soft tissue, 14.3+ months). MTP and MST were 1.9 and 5.5 months, respectively. Myelosuppression and nausea/vomiting were the most common side effects. Although each of these regimens had great conceptual allure, neither offered any durable impact on the natural history of disseminated malignant melanoma. Nevertheless, alternative combinations of biological response modifiers (BRMs) and BRMs with biochemical modulators or cytotoxic agents may provide some useful alternatives for further clinical investigations.