Ruxolitinib induced a “superior” complete response (CR) rate compared with best available therapy in patients with polycythemia vera (PV) who are resistant or intolerant to hydroxycarbamide, according to a recent study.
Claire Harrison, MD, FRCP, of the Guy’s and St. Thomas’ National Health System Foundation Trust, and colleagues conducted the MAJIC-PV study and published the results in the Journal of Clinical Oncology.
The randomized, phase II trial compared ruxolitinib with best available therapy in 180 patients who were resistant or intolerant to hydroxycarbamide. The study’s primary outcome measure was the CR rate within one year. Its secondary outcomes included duration of response, event-free survival (EFS), symptom response, and molecular response.
Just under half (43%) of patients receiving ruxolitinib achieved a CR, while 26% achieved a CR on the best available therapy (odds ratio, 2.12; 90% CI, 1.25-3.60; P=.02). The duration of the CR was longer in patients receiving ruxolitinib (hazard ratio [HR], 0.38; 95% CI, 0.24-0.61; P<.001).
“Symptom responses were better with ruxolitinib and durable,” Dr. Harrison and colleagues wrote.
Furthermore, EFS was “superior” in patients achieving a CR within one year (HR, 0.41; 95% CI, 0.21-0.78; P=.01) and in those receiving ruxolitinib (HR, 0.58; 95% CI, 0.35-0.94; P=.03), according to the study’s authors.
A serial analysis of the JAK2 V617F variant allele fraction “revealed molecular response was more frequent” with ruxolitinib and was associated with “improved outcomes,” showing significant results in progression-free survival (PFS; P=.001), EFS (P=.001), and overall survival (OS; P=.01), Dr. Harrison and colleagues wrote. It was also associated with clearance of JAK2 V617F stem cells and progenitor cells. Furthermore, they found ASXL1 mutations predicted for adverse EFS (HR, 3.02; 95% CI, 1.47-6.17; P=.003).
“The MAJIC-PV study demonstrates ruxolitinib treatment benefits [patients with PV who are resistant or intolerant to hydroxycarbamide] with superior CR, and EFS as well as molecular response; importantly also demonstrating for the first time, to our knowledge, that molecular response is linked to EFS, PFS, and OS,” Dr. Harrison and colleagues concluded.
Harrison CN, Nangalia J, Boucher R, et al. Ruxolitinib versus best available therapy for polycythemia vera intolerant or resistant to hydroxycarbamide in a randomized trial. J Clin Oncol. 2023. doi:10.1200/JCO.22.01935