Real-World Use of Ruxolitinib in Patients with Myelofibrosis and Anemia or Thrombocytopenia at Diagnosis

Abstract

Plain Language SummaryMyelofibrosis is a bone marrow cancer. Patients with myelofibrosis experience troublesome symptoms like exhaustion and weakness and may have a painfully enlarged spleen. Because myelofibrosis disrupts the production of blood cells, some patients also have anemia, or too few platelets. For these patients, myelofibrosis tends to be more severe, and they generally die sooner than patients with normal blood cell levels. Ruxolitinib is a treatment for myelofibrosis that improves symptoms and reduces spleen size. One side effect of ruxolitinib is that it can temporarily lower blood cell levels, which may be concerning for patients with low blood cell counts from their disease. More data are needed to understand how best to use ruxolitinib to treat this population. In this study, researchers collected data from doctors who used ruxolitinib to treat patients who had myelofibrosis and low blood cell counts. They collected data on how much ruxolitinib patients were prescribed, if and why patients stopped taking ruxolitinib, and how well ruxolitinib worked to treat myelofibrosis. Patients were studied for nearly 2 years. The researchers found that around a third of patients stopped taking ruxolitinib by the end of the study, but very few did so because of concerns about their blood cell counts. Most patients were able to take ruxolitinib at a high enough dose to be effective, improving spleen size and helping patients feel better. These findings suggest that ruxolitinib can be used to treat myelofibrosis, even in patients with low blood cell counts.