(ChemotherapyAdvisor) – Patients with myelofibrosis treated with oral ruxolitinib had significant clinical benefit vs. placebo as shown by reduced spleen size, reduction in debilitating myelofibrosis-related symptoms and improved overall survival, results of a study published in the March 1 issue of New England Journal of Medicine has found.
In the double-blind trial, patients with intermediate-2 or high-risk myelofibrosis were randomly assigned to ruxolitinib twice daily (n=155) or placebo (n=154). The primary end point, proportion of patients with a reduction in spleen volume of 35% or more at 24 weeks, was reached in 41.9% of patients in the ruxolitinib group vs. 0.7% in the placebo group (P<0.001).
Patients who received ruxolitinib maintained reduction in spleen volume, with 67.0% of patients who responded continuing to respond 48 weeks or more. Total symptom score improvement of 50% or more at 24 weeks was 45.9% of patients in the ruxolitinib arm vs. 5.3% in the placebo arm (P<0.001). A median follow-up of 51 weeks showed a significant survival advantage for patients who received ruxolitinib: 13 deaths had occurred in the ruxolitinib group (8.4%) vs. 24 deaths in the placebo group (15.6%) (HR=0.50; P=0.04).
In the ruxolitinib arm, 13 deaths occurred vs. 24 in the placebo group (HR=0.50; P=0.04). Rate of discontinuation of ruxolitinib due to adverse events was 11.0% vs. 10.6% for placebo. Anemia and thrombocytopenia were the most common adverse events among patients who received ruxolitinib and led to one patient discontinuing treatment for each event. Two patients, both receiving ruxolitinib, had transformation to acute myeloid leukemia.
(Ed. note: see “Oral Ruxolitinib Reduces Splenomegaly, Disease-Related Symptoms of Myelofibrosis vs. Best Available Therapy,” for results of the Phase 3 study comparing ruxolitinib to best available therapy.)