Ruxolitinib versus standard therapy for the treatment of polycythemia vera

N Engl J Med. 2015 Jan 29;372(5):426-35. doi: 10.1056/NEJMoa1409002.

Abstract

Background: Ruxolitinib, a Janus kinase (JAK) 1 and 2 inhibitor, was shown to have a clinical benefit in patients with polycythemia vera in a phase 2 study. We conducted a phase 3 open-label study to evaluate the efficacy and safety of ruxolitinib versus standard therapy in patients with polycythemia vera who had an inadequate response to or had unacceptable side effects from hydroxyurea.

Methods: We randomly assigned phlebotomy-dependent patients with splenomegaly, in a 1:1 ratio, to receive ruxolitinib (110 patients) or standard therapy (112 patients). The primary end point was both hematocrit control through week 32 and at least a 35% reduction in spleen volume at week 32, as assessed by means of imaging.

Results: The primary end point was achieved in 21% of the patients in the ruxolitinib group versus 1% of those in the standard-therapy group (P<0.001). Hematocrit control was achieved in 60% of patients receiving ruxolitinib and 20% of those receiving standard therapy; 38% and 1% of patients in the two groups, respectively, had at least a 35% reduction in spleen volume. A complete hematologic remission was achieved in 24% of patients in the ruxolitinib group and 9% of those in the standard-therapy group (P=0.003); 49% versus 5% had at least a 50% reduction in the total symptom score at week 32. In the ruxolitinib group, grade 3 or 4 anemia occurred in 2% of patients, and grade 3 or 4 thrombocytopenia occurred in 5%; the corresponding percentages in the standard-therapy group were 0% and 4%. Herpes zoster infection was reported in 6% of patients in the ruxolitinib group and 0% of those in the standard-therapy group (grade 1 or 2 in all cases). Thromboembolic events occurred in one patient receiving ruxolitinib and in six patients receiving standard therapy.

Conclusions: In patients who had an inadequate response to or had unacceptable side effects from hydroxyurea, ruxolitinib was superior to standard therapy in controlling the hematocrit, reducing the spleen volume, and improving symptoms associated with polycythemia vera. (Funded by Incyte and others; RESPONSE ClinicalTrials.gov number, NCT01243944.).

Publication types

  • Clinical Trial, Phase III
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / therapeutic use*
  • Blood Cell Count
  • Female
  • Humans
  • Hydroxyurea / adverse effects
  • Hydroxyurea / therapeutic use
  • Janus Kinases / antagonists & inhibitors*
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Organ Size / drug effects
  • Polycythemia Vera / drug therapy*
  • Pyrazoles / adverse effects
  • Pyrazoles / pharmacology
  • Pyrazoles / therapeutic use*
  • Remission Induction
  • Spleen / drug effects
  • Spleen / pathology
  • Thrombocytopenia / chemically induced

Substances

  • Antineoplastic Agents
  • INCB018424
  • Pyrazoles
  • Janus Kinases
  • Hydroxyurea

Associated data

  • ClinicalTrials.gov/NCT01243944