Recombinant beta-serine-interferon in hairy cell leukemia compared prospectively with results with recombinant...

Ten patients with hairy cell leukemia (HCL) requiring therapy were treated with recombinant beta-serine-interferon (rIFN-beta ser) (90 x 10(6) units [U] subcutaneously three times a week). Eight patients were evaluable for response and nine for toxicity. Five patients (63%) showed normalization of peripheral blood counts, and an additional two patients (25%) showed improvement in at least one hematologic variable. Persistent hairy cells were detected in the bone marrow of all patients at the completion of therapy. All patients experienced influenza-like symptoms which were not dose limiting and which resolved with continued therapy. Erythema and induration at interferon injection sites developed in five patients (56%); one required dose reduction and another was removed from the study for this reason. Data from matched historical controls treated with recombinant alpha-interferon are presented for comparison. We conclude that rIFN-beta ser has activity in HCL.