Treatment of multiple myeloma with recombinant interferon alfa-2a.

A Phase II study of interferon alfa-2a was conducted in 64 patients with multiple myeloma (42 IgG, 16 IgA, 5 Bence-Jones type, and 1 IgD) in a multi-institutional cooperative trial. Partial remission was obtained in 10 (21.3%) of 47 evaluable patients, and minor responses in 5 (10.6%) of 47. Remission was reached at 22 to 89 days (median, 29 days) after the initiation of interferon alfa-2a and lasted 4 to 55 weeks (median, 8 weeks). Side effects were noted in more than two-thirds of patients, and included fever (58%), malaise (20%), anorexia (52%), nausea-vomiting (26%), lethargy (2%), and myelosuppression (56%). They were all reversible on discontinuation of interferon alfa-2a. Antibody to interferon alfa-2a was detected in 1 of 20 patients tested during the course of treatment. Thus, interferon alfa-2a was effective in multiple myeloma, producing unequivocal response in 21.3% of patients without unacceptable side effects.