Real-World Data Confirm: Anemia During Ruxolitinib Treatment Is Associated With Worse Outcomes for Patients With Myelofibrosis

In a retrospective, real-world population analysis, patients with myelofibrosis (MF) and anemia who were treated with ruxolitinib had poorer survival outcomes than patients without anemia, independent of whether anemia occurred before or during therapy. Further research is required to determine how to effectively target anemia during MF treatment to guarantee better survival outcomes.

Ruxolitinib is the standard of care for patients with MF; however, it does not address the significant anemia burden experienced by many patients. In clinical trial settings, participants with MF who develop new or worsening anemia have poorer overall survival (OS) while taking ruxolitinib than participants without anemia.¹ Following up on this finding, Andrew Kuykendall, MD, Moffitt Cancer Center, Tampa, Florida, and colleagues performed a retrospective analysis of publicly available data to investigate whether anemia status also affects the survival of patients with MF receiving ruxolitinib in a real-world setting.²

Using the US Flatiron Health database, the investigators compared the survival outcomes of patients with MF treated with ruxolitinib between 2013 and 2023. At baseline, 147 patients had anemia at baseline, and 139 did not. Within 12 weeks of starting treatment with ruxolitinib, 48% of the group with anemia at baseline, and 44% of the group without anemia at baseline presented with new or worsening anemia.

Patients without anemia at baseline who developed new or worsening anemia had significantly longer OS than all other subgroups, individually and combined (hazard ratio [HR], 2.03; 95% CI, 1.32-3.12; P<.01). This effect was most visible for patients with baseline nonanemic MF who developed anemia while receiving ruxolitinib compared with patients who remained free of anemia (HR, 2.17; 95% CI, 1.27-3.70; P<.01).

Overall, in a real-world setting, patients with MF who had anemia when they started taking ruxolitinib   and those who developed anemia during treatment had worse survival than those without anemia during treatment. Further research should focus on treating anemia during MF-targeted therapy.

1. Gupta V, et al. Blood. 2023;142(Supplement 1):5174.
2. Kuykendall, AT, Palandri F, Zhang S, et al. Retrospective real-world analysis of survival outcomes in patients with myelofibrosis and new or worsening anemia treated with ruxolitinib in the United States. Abstract #3804. Presented at the American Society of Hematology Annual Meeting; December 7-10, 2024; San Diego, California.