Treatment of hairy cell leukemia with recombinant alpha-interferon.

Thirty patients with hairy cell leukemia were treated with recombinant interferon alpha-A (rIFN alpha A; Roferon-A); seven were previously untreated. Nine complete and 17 partial remissions were documented by bone marrow core biopsies. All patients' peripheral blood hematologic indexes either improved or normalized. Twelve of 13 patients with retroperitoneal or mediastinal adenopathy obtained remissions of tumor masses. All seven patients with splenomegaly showed prompt reduction in the size of the spleen to normal size. The incidence of complete remissions was significantly higher (P = .02) in previously untreated patients (5 of 7) than in those in whom splenectomy had been performed (4 of 23), a result presumed to be related to the pretreatment tumor burden. rIFN alpha A was well tolerated; mild fatigue was the most frequent complaint. In most patients, tumor remissions resulted in an improved quality of life: they eliminated the need for transfusing blood products and reduced the incidence of infections, and immune deficits were apparently restored in some of the patients. We conclude that rIFN alpha A is an effective therapy for all stages of hairy cell leukemia including previously untreated or newly diagnosed patients.