A phase II trial of pegylated interferon alpha -2b therapy for polycythemia vera and essential thrombocythemia

BACKGROUND Conventional interferon- alpha (IFN) is an effective treatment for patients with myeloproliferative disorders. However, many patients discontinue therapy because of side effects. METHODS In this 24-month, Phase II feasibility study of pegylated interferon alpha -2b (PEG-IFN) treatment, a starting dose of 0.5 mu g/kg per week was received by 21 patients with polycythemia vera (PV) and 21 patients with essential thrombocythemia (ET). The treatment objective, a complete platelet response (CR), was a platelet count