Treatment of hairy cell leukaemia with recombinant alpha interferon.

Eleven patients with progressive hairy cell leukaemia (three nonsplenectomised) were treated with recombinant alpha-2 interferon (Intron-A or Roferon-A) subcutaneously three times per week at a dosage of 3 x 10(6) units. Ten patients completed at least ten weeks of therapy and could be evaluated; one patient died of haemorrhage from severe thrombocytopenia after only three weeks treatment. Nine of the ten patients responded and all of these are regarded as good partial remissions (normalisation of all blood parameters but still discernible hairy cells in the marrow). Responding patients have all been followed for a median of two years and in one case 3 1/2 years since commencement of therapy. The patients are all transfusion independent and free of infection. We conclude that alpha-2 interferon therapy for progressive hairy cell leukaemia is effective therapy in both splenectomised and nonsplenectomised patients.