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

Abstract Background Resistance 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 Methods Retrospective review identified 12 patients with essential thrombocythemia or polycythemia vera using combination therapy. Results The 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. Conclusion This 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.