Ruxolitinib Improves Survival for Older Patients With Primary Myelofibrosis

Ruxolitinib (Rx) treatment helps prolong survival for elderly patients with primary myelofibrosis (PMF), according to an abstract presented at the European Hematology Association’s Virtual Congress, indicating that older age does not hinder the treatment’s efficacy.

The findings, coming from nearly a decade’s worth of retrospective data on patients aged at least 65 years, offer real-world evidence on the impact of Rx treatment on survival for the age group.

“Rx is a Janus kinase (JAK) 1/JAK2 inhibitor with established efficacy in improving PMF-related symptoms and survival,” researchers said. “However, while aging is known to correlate with worse prognosis in PMF, real-life studies become essential to demonstrate the efficacy and safety of Rx in older populations.”

Over the study period, progression-free survival (PFS) among 70 patients was 62.7 months and overall survival (OS) was 101.8 months. Comparing outcomes between patients receiving Rx and those not, multivariate analyses showed that the JAK inhibitor improved survival, resulting in superior PFS (hazard ratio [HR] 0.28; 95% CI, 0.05-1.52) and OS (HR 0.05; 95% CI, 0.01-0.48).

Among the patients, 17% received Rx treatment and all of these patients were at the overt fibrotic stage. Severity of disease was similar between the 2 groups, with no significant differences in International Prognostic Scoring System (IPSS), dynamic IPSS (DIPSS), and DIPSS-plus scores.

While the rate of JAK2V617F mutation was comparable between both groups, patients receiving Rx had a higher allele burden. At baseline, the majority of Rx-treated patients had anemia, but there were no significant differences in leucocyte cunts, lactate dehydrogenase, circulating blasts, or constitutional symptoms between the 2 groups.

In univariate analyses, age, anemia, constitutional symptoms, circulating blasts, and intermediate-2/high-risk disease based on IPSS/DIPSS were significantly associated with PFS, while these variables and Grade ≥2 fibrosis were associated with OS.

Reference: Duarte S, Gomes R, Alfonso C, et al. Use of ruxolitinib in elderly patients with primary myelofibrosis. Presented at: EHA 2021; June 9-17, 2021. Abstract EP1121.