Low blood cell counts before treatment may signal higher risk in myelofibrosis
Findings may help guide care before starting ruxolitinib treatment
Written by |
People with myelofibrosis who had low blood cell counts before starting ruxolitinib had shorter overall survival after treatment, according to a new study.
“Cytopenias [low blood cell counts] before the start of ruxolitinib treatment have an unfavorable effect on the outcome and survival of patients with myelofibrosis,” researchers wrote in the study, “Cytopenic Patients with Myelofibrosis—Inferior Response and Outcome to Treatment with Ruxolitinib,” published in the Indian Journal of Hematology and Blood Transfusion.Â
Myelofibrosis is a rare blood cancer that causes fibrosis, or scarring, in the bone marrow. One of the key jobs of the bone marrow is to make new blood cells. As such, a common symptom of myelofibrosis is cytopenia, or low counts of blood cells, including oxygen-carrying red blood cells, infection-fighting white blood cells, and/or clot-promoting platelets.
Ruxolitinib can affect blood cell counts
Ruxolitinib, sold as Jakafi in the U.S., is an approved myelofibrosis treatment that works by blocking JAK signaling pathways that are abnormally active in myelofibrosis. Because ruxolitinib affects blood cell-related signaling, it can also cause or worsen cytopenias as a side effect.
In general, the presence of cytopenia is associated with worse outcomes among people with myelofibrosis. However, it can be hard to tease out whether cytopenia is a consequence of the disease itself or a side effect of treatment. As such, there’s little data on whether cytopenia present before treatment is associated with outcomes different from those of cytopenia that develops during treatment.
In this study, scientists in Serbia reported on outcomes from 57 people with myelofibrosis who were treated with ruxolitinib at their center between 2017 and 2024. Before starting ruxolitinib, just over 60% of patients had cytopenia, meaning it was already present before treatment began. At a follow-up six months after starting ruxolitinib, the number of patients with cytopenia had increased, consistent with the known blood-related side effects of ruxolitinib.
Low blood counts tied to shorter survival
Statistical analyses showed that patients who had cytopenia before starting ruxolitinib had significantly shorter overall survival than those without cytopenia. In the analysis, baseline cytopenia was associated with a nearly 2.7 times higher risk of death.
By contrast, cytopenia after six months of ruxolitinib treatment was not significantly linked to overall survival or event-free survival. “After six months of treatment with ruxolitinib, cytopenias were more prevalent, but without an effect of cytopenia on [overall survival],” the researchers concluded.
The scientists said these data overall suggest that myelofibrosis patients with cytopenia before starting ruxolitinib tend to have worse outcomes, highlighting a need for personalized care to improve outcomes for these patients. They noted the study was limited by its retrospective design and small sample size, though the findings were consistent with larger studies.
