The treatment of hairy cell leukemia with alpha 2b-interferon: experience with 27 patients treated more than one year.

Thirty-six patients with progressive hairy cell leukemia were treated with recombinant alpha 2b-interferon injected subcutaneously 2 X 10(6) IU/m2, three times a week. Twenty-seven patients completed 12 months of therapy and were randomized either to receive 6 months of continued interferon or to go off treatment. At the time of randomization, two patients had achieved a complete response, 22 a partial response, and three a minimal response. Three patients have relapsed, one while receiving interferon during the randomization period and two who were off therapy for 6 months. The outpatient regimen of interferon administration was well tolerated, with the principal acute toxicities being fever and an influenza-like syndrome and the major long-term toxicity being mild-moderate fatigue.