Successful Long-Term Treatment of Philadelphia Chromosome-Negative Myeloproliferative Neoplasms With Combination of Hydroxyurea and Anagrelide

BackgroundResistance or intolerance to either of the 2 favored therapeutic choices for MPN is a common clinical challenge. To overcome this, we report our successful long-term experience with the combination of low-dose HU and AG.Patients and MethodsRetrospective review identified 12 patients with essential thrombocythemia or polycythemia vera using combination therapy.ResultsThe mean duration of treatment 4.25 years. Combination therapy achieved a 45% median platelet count reduction with relatively low daily dose requirements (711 mg HU, 1.38 mg AG). All but 1 patient achieved partial (25%) or complete response (67%) according to European LeukemiaNet criteria. No arterial or venous thrombosis, or bleeding events occurred.ConclusionThis is the longest follow-up experience of an HU and AG combination regimen in MPN. The low-dose combination regimen effectively achieved clinical and laboratory response while simultaneously minimizing dose-related adverse reactions, and should be the preferred therapeutic alternative to third-line agents in MPN patients who are resistant or intolerant to monotherapy.