Advances in Treatment for Polycythemia Vera and Essential Thrombocythemia / 대한내과학회지

ABSTRACT

Although there have been substantial advances in confirming diagnoses and defining the molecular characteristics of polycythemia vera (PV) and essential thrombocythemia (ET), treatments for these conditions remain elementary. The main goal is still mainly focused on reducing the risk of thrombosis. The prevention of hemorrhage, leukemia transformation, and progression to myelofibrosis has yet to be established. To reduce the risk of thrombosis, risk-adapted treatment is recommended. Phlebotomy is the most important and effective treatment modality for patients with erythrocytosis, while cytoreduction using hydroxyurea, busulfan, or interferon-α is an ancillary treatment for patients at high risk for thrombosis. Anagrelide is used to decrease platelet counts in patients with thrombocytosis by inhibiting the maturation of platelets from megakaryocytes. Recent trials have shown that ruxolitinib, a Janus kinase (JAK) inhibitor, has clinical benefits in patients with polycythemia vera who show an inadequate response, or unacceptable side effects, to therapeutic doses of hydroxyurea. Theoretically, JAK inhibitors may also delay the progression of leukemia transformation and myelofibrosis but there is still no evidence of this. The cost of JAK inhibitors for the treatment of patients with PV/ET is a difficult hurdle for its use as a first-line treatment.