Preliminary observations of immunomodulatory activity of lymphoblastoid interferon-alpha administered every other day or weekly

Patients with metastatic malignant melanoma were treated with a purified, natural mixture of lymphoblastoid interferon-alpha. Patients were randomized to receive 15 X 10(6) U/m2 every other day for 2 weeks, in cycles separated by a variable rest period of at least 1 week, or to receive 5 X 10(6) U/m2 weekly. The first schedule was an intensive treatment regimen, at or near the maximum tolerated dose; the second was intended to provide maximum opportunity for augmented natural, antitumor immunity to be expressed. A preliminary evaluation of the modulation of natural killing, antibody-dependent cellular cytotoxicity, and monocyte-mediated tumor growth inhibition in the first nine patients entered into the trial is presented. Increased activity in the three assays was frequently seen in the 2-3 days after interferon administration; the peak was usually short-lived, and no sustained increases were observed. There was a tendency for more frequent augmentation in patients on the weekly schedule, and augmentation of monocyte-mediated tumor growth inhibition was more readily apparent than increases in the other activities. No tumor responses were observed and no correlation of tumor response with immunomodulation was possible.