Patients (30) with disseminated malignant melanoma received i.v. recombinant leukocyte A interferon (rIFN-.alpha.A), 12 .times. 106 U/m2, 3 times weekly for a planned treatment duration of 3 mo. This dose was selected in view of prior phase II data indicating that 50 .times. 106 U/m2 3 times weekly produced excessive toxicity. In this current trial 3 objective partial regressions (20%) were observed among the 15 better-risk patients (performance score 0, 1 and no prior chemotherapy) with times to disease progression of 1.9, 9.6 and 12.9+ mo. There were also 3 regressions (1 complete and 2 partial) among the 15 poor-risk patients (performance score 2, 3 or prior chemotherapy) with progression times of 3, 3.2 and 96+ mo. For all patients, the median survival time was 4.2 mo. One half of the patients were observed to have progressive disease with 1 mo. of commencing treatment. Responding metastatic lesions were limited to soft tissue, although 1 patient also had a partial response of a lung nodule. The most substantial toxicities were moderate-to-severe myalgias (27%), nausea (33%), anorexia (47%) and fatigue (50%). Among the 22 patients with weight loss, the median was 2.3 kg (range, 0.6-8.4 kg). Hematologic and hepatic toxicity was transient and of little clinical significance. rIFN-.alpha.A in the dose and schedule used is clinically tolerable and has antitumor activity in malignant melanoma. The response rate was similar to results observed in a previous study of a higher dose regimen.
