Patients With Myelofibrosis, Anemia Have Higher Rates of Comorbidities, Severe Thrombocytopenia

A study presented at the Society of Hematologic Oncology 2024 Annual Meeting in Houston, Texas, outlined the characteristics, clinical outcomes, and treatment patterns of patients with myelofibrosis (MF) with and without anemia.

The study, led by Nour Haidar, MD, of Saint Louis Hospital in Paris, France, identified adult patients with an International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis code for MF from the Mass General Brigham Research Patient Data Registry. Of 861 eligible patients, 300 (34.8%) had anemia.

Patient Characteristics

The rates of baseline comorbidities and constitutional symptoms were higher in patients with anemia versus those without (renal disease, 21.0% vs 5.2%; cardiovascular disease, 46.7% vs 23.4%; fever, 10.3% vs 2.3%). Mean platelet counts were lower in patients with anemia (246.1×10⁹/L) versus those without (313.7×10⁹/L). The percentage of patients with severe thrombocytopenia, defined as platelets less than 50×10⁹/L, were 15.3% and 2.7%, respectively.

Over a median follow-up of 2.2 years, the rate of any-grade thrombocytopenia was 41.5% (45.9% for anemic patients, 39.9% for nonanemic patients). The median time to occurrence was 23.4 months (95% CI, 15.0–46.3) in patients with anemia versus 51.8 months (95% CI, 41.3–61.0) in patients without anemia (P=0.009). The rate of leukemic transformation was higher in anemic patients versus nonanemic patients (10.4% vs 8.3%; P=0.342). Three months after baseline, red blood cell transfusions were also higher in anemic patients (4.1 vs 1.3; P<0.001).

Ruxolitinib Treatment Patterns

Some Janus kinase (JAK) inhibitors can exacerbate anemia, the authors noted. Although patients with MF and anemia began ruxolitinib treatment at lower doses partly due to thrombocytopenia, discontinuation and dose reduction of the JAK inhibitor occurred earlier for them than for patients without anemia.

“Anemia and lower dosing were associated with worse [overall survival], highlighting a need for alternative treatment options for this patient population,” the researchers concluded.

This analysis was funded by GSK.

Reference

Hobbs G, Niehoff N, Liu T, et al. Real-world clinical outcomes in patients with myelofibrosis with and without baseline anemia in the Mass General Brigham Integrated Delivery Network. Abstract #MPN-529. Presented at the Society of Hematologic Oncology 2024 Annual Meeting; September 4-7, 2024; Houston, Texas.