Recombinant interferon alpha-2b in the treatment of polycythemia vera

We studied the effects of recombinant alpha 2-b interferon (alpha 2-b IFN) in a dose of 3 x 10(6)U intramuscularly three times a week for 1 year in 13 patients affected by polycythemia vera (PV) previously treated with phlebotomy only. Response to treatment was evaluated by reduction of the number of phlebotomies required to retain normal hematocrit value. Ten out of 13 patients (77%) responded to treatment; in 4 of them the exigency of phlebotomy was completely eliminated. In all responders a concomitant decrease of platelet count and splenomegaly was obtained. Treatment was well tolerated and side effects were easily controlled. We conclude that alpha-IFN may represent an attractive therapeutic option in the management of the proliferative stages of PV.