Interferon α-2b gains high sustained response therapy for advanced essential thrombocythemia and polycythemia vera with JAK2V617F positive mutation

Objective: This open-label, prospective, observational study aimed to evaluate treatment response, efficacy therapy and safety to IFN alpha-2b for the essential thrombocythemia (ET) and polycythemia vera (PV) with JAK2V617F positive mutation. Method: A total of 123 ET patients received IFN alpha-2b therapy with JAK2V617F positive or negative mutation; and 136 PV patients with JAK2V617P received IFN alpha-2b or hydroxyurea (HU) therapy according to random number assignment (ages 18-65 years old). Result: ET patients receiving IFN alpha-2b with JAK2V617P had a greater advantage in overall hematologic response ( OHR) than JAK2V617F-(83.3% versus 61.4%,P < 0.01). For PV patients with JAK2V617P, IFN had no OHR superiority to HU (70.3% versus 70.8%, > 0.05), but which gained a greater satisfactory molecular response than HU (54.7% versus 19.4%, P < 0.01). IFN significantly decreased the phlebotomy rate, which was better than HU for MPDs patients with OHR than HU (3.6% versus 65.7%, P< 0.01). Furthermore, ET patients with JAK2V617P demonstrated a definite advantage over JAK2V617F-in five-year PFS (75.9% versus 47.6%, P < 0.05). For PV patients with JAK2V617P, IFN alpha.-2b was superior to HU in five-year PFS (66.3% versus 46.7%, P < 0.01). Moreover, IFN alpha-2b also contributed to improved vasomotor symptoms in MPDs, and especially significantly decreased the incidence of distal paresthesias (14.1% versus 37.5%) and erythromelalgia (9.4% versus 29.2%) better than HU (P < 0.01). Meanwhile, IFN did not observe the severe hematological adverse events in patients with PV or ET. Conclusion: The data confirmed that IFN alpha-2b benefited the patients with ET or PV, particularly for JAK2V617P mutation. (C) 2014 Elsevier Ltd. All rights reserved.