The Current Treatment Landscape for Myelofibrosis
Key Takeaways:
- Myelofibrosis (MF) is primarily treated with 1 of 4 Janus kinase (JAK) inhibitors: ruxolitinib, fedratinib, pacritinib, and momelotinib.
- The approved JAK inhibitors have similar rates of efficacy among patients with MF, so treatment decision-making should focus on safety profiles and individual patients’ symptom burden.
- Advancements in MF treatment include effective combination strategies and innovative therapies utilizing new agents, highlighting the importance of new clinical trials focused on improving disease management.
With 4 JAK inhibitors now approved for MF, treatment decisions increasingly depend on matching therapy to individual patient characteristics rather than efficacy alone. A recent review of the evolving MF treatment landscape highlights how platelet counts, anemia, symptom burden, comorbidities, and treatment history can guide selection among ruxolitinib, fedratinib, pacritinib, and momelotinib, while emerging combination regimens and investigational agents may further expand options for patients with difficult-to-manage disease.
Approved JAK Inhibitors
Ruxolitinib, fedratinib, pacritinib, and momelotinib are the main JAK inhibitors approved for the treatment of MF. Although few studies have directly compared these therapies, indirect comparisons observed comparable efficacy among all 4 inhibitors. Therefore, therapy selection should be based on each patient’s symptom profile, blood platelet count, and comorbidities.
Ruxolitinib is the procedural first-line therapy for patients with standard platelet counts. It was the first JAK inhibitor approved for MF treatment and whose efficacy and safety are backed by extensive clinical data. Adverse events (AEs) include anemia and thrombocytopenia.
Fedratinib is a second-line therapy to be used after ruxolitinib failure, mainly among patients who need massive spleen reduction. AEs include nausea, vomiting, diarrhea, and—in rare cases—Wernicke encephalopathy.
Pacritinib is a first-line option for patients with severe thrombocytopenia and can be administered at full dose without worsening symptoms. AEs include anemia and gastrointestinal disturbances such as diarrhea and nausea.
Momelotinib is appropriate for patients with anemia-dominant disease, especially those who depend on transfusions. The primary AE for this inhibitor is peripheral neuropathy.
Additional Therapies
MF treatment could be improved with combination strategies aimed at enhancing disease management. In a prior study, pacritinib plus ruxolitinib demonstrated better efficacy with no substantial increase in toxicity.
Many ongoing clinical trials are assessing the impact of various agents on MF. Luspatercept, monoclonal antibodies, PIM kinase inhibitors, selinexor, and interferon-alpha combinations with JAK inhibitors all represent potential innovations in treatment.
Splenomegaly can also be managed with non-pharmacologic interventions like splenectomy, splenic irradiation, partial splenic artery embolization, and radiofrequency ablation. The use of these treatments is restricted to patients with refractory MF or who are ineligible for JAK inhibitor therapy.
Implications for Managed Care
The researchers call for improvements in early intervention strategies, which could help prevent the development of splenomegaly in patients with MF. The next steps in MF treatment could include more effective combination regimens, improved biomarker testing, and innovative therapies that slow disease progression.
According to the authors, “A phenotype-driven, individualized approach to therapy selection, guided by the patient’s cytopenia profile, symptom burden, transplant candidacy, and available clinical trials, offers the best prospect for optimizing outcomes.”
Reference
Al-Asa'd Y, Quasem N, Alshurafa A, Al-Farsi K, Yassin MA. Management of splenomegaly in patients with myelofibrosis in the era of JAK inhibitors: a comprehensive review. Frontiers Oncol. 2026;16:1851781. doi:10.3389/fonc.2026.1851781
