October 14, 2024
Author(s): Mary Caffrey
An updated meta-analysis confirms that ruxolitinib, the Janus kinase (JAK) 1/JAK2 inhibitor sold as Jakafi, offers improvements in key measures of efficacy compared with best available therapy (BAT) for patients with polycythemia vera (PV),1 a rare, slow-progressing disorder that causes the blood to make too many red blood cells.
Caused by a genetic mutation, PV is not typically fatal on its own, but it can cause dangerous blood clots and damage to the spleen. In a small number of cases, it progresses to more aggressive forms of blood cancer.
The latest results were reported in the journal APMIS,1 formerly known as Acta Pathologica, Microbiologica, et Immunologica Scandinavica.
The analysis followed a 2020 meta-analysis involving 16 studies that appeared in Blood Advances.2 That analysis included evidence from 4 randomized controlled trials and included 663 patients; the authors estimated a thrombosis incidence of 3.09% per year for ruxolitinib vs 5.51% for BAT, but noted that globally, this did not reach significance (P = .098). “A clinical trial on selected patients at high risk of thrombosis would be warranted, but its feasibility is questionable,” the authors wrote.2
The current analysis examines ruxolitinib’s efficacy and safety compared BAT in 1061 patients with PV and in hydroxyurea-resistant and intolerant patients with PV across 6 studies, with a cutoff of November 2023. The patients included 620 on BAT and 441 on ruxolitinib. According to the investigators:
- Those taking ruxolitinib showed higher hematocrit control (P = .015) and treatment response (P = .04) compared to BAT.
- Patients taking ruxolitinib had significantly improved Myeloproliferative Neoplasms-Symptom Assessment Form scores (MPN-SAF), P < .01.
However, on the safety front, patients with PV treated with ruxolitinib had higher rates of nonmelanoma skin cancer (P < .01), as has been previously documented.