Novel Therapies in Polycythemia Vera

Polycythemia vera is a myeloproliferative neoplasm characterized by increased erythrocyte count, thrombotic potential, and transformation to myelofibrosis. Older patients and those who have a history of thrombosis require cytoreductive therapy, most commonly with hydroxyurea. Other currently available therapies include pegylated interferon alfa-2a and the JAK1/2 inhibitor ruxolitinib. However, there are limitations to these agents, including potential detrimental adverse effects. In this review, we will describe current therapeutic options for the treatment of PV and then detail new agents with available clinical trial data. A number of novel investigational therapies including MDM2 inhibitors, histone deacetylase inhibitors, and long-acting pegylated interferon alfa-2b are in various stages of clinical development with encouraging efficacy data. The therapeutic landscape for patients with PV is expanding. Novel agents are in development that not only reduce the thrombotic potential but also act directly on the malignant PV clone with the intention of significantly modifying disease progression.