Real-World Dosing Patterns of Ruxolitinib in Patients With Polycythemia Vera Who Are Resistant to or Intolerant of Hydroxyurea

Many patients with polycythemia vera switch treatment from hydroxyurea to FDA-approved ruxolitinib. This medical chart review of 249 patients investigated reasons for switching treatment and ruxolitinib treatment patterns. Most patients became resistant to hydroxyurea. Half of patients initiated ruxolitinib at the recommended dose, dose modifications were common in the first 6 months, and most patients achieved hematocrit control and continued treatment for extended time frames. Appropriate dosing of ruxolitinib early in treatment is important for effective long-term treatment. Introduction: Approximately one-quarter of patients with polycythemia vera become resistant to and/or intolerant of hydroxyurea. This analysis characterizes reasons patients were switched from hydroxyurea to ruxolitinib and describes ruxolitinib dosing patterns and outcomes in real-world clinical practice. Patients and Methods: This medical chart review of United States community hematology/oncology practices in the Cardinal Health Oncology Provider Extended Network included patients with polycythemia vera who were >= 18 years old, received hydroxyurea for >= 3 months, started ruxolitinib between January 1, 2015 and December 31, 2016, and had >= 2 visits during the subsequent 6 months. Clinical data were collected at predefined intervals from diagnosis to last provider visit. Results: Providers identified 249 patients for inclusion. jcauses of hydroxyurea discontinuation were resistance (78%; frequently for hematocrit >= 45% [79%]) and intolerance (28%; frequently for nausea/vomiting [50%]). Initial ruxolitinib dosing was 10 mg twice daily (recommended dose) in 131 patients (53%). Among these patients, median treatment duration was 29.2 months, 35 (27%) had dose modification (increase, n = 24; decrease, n = 11) and 4 had interruptions within 6 months. The most common reason for dose increase was continued need for phlebotomy (46%); 6 patients had dose reductions owing to reduced platelets. Hematocrit control at initiation and during the first 6 months of ruxolitinib treatment was 15% and 63%, respectively. Conclusion: Most patients initiated ruxolitinib upon hydroxyurea resistance. Approximately half initiated ruxolitinib at the recommended dose, 27% of whom experienced dosing modifications within the first 6 months. After switching to ruxolitinib, most patients achieved hematocrit control and continued treatment for extended time frames. (C) 2021 The Authors. Published by Elsevier Inc.