From the Guidelines
Ruxolitinib is the recommended first-line treatment for myelofibrosis-associated splenomegaly in patients with intermediate-2 or high-risk disease, as well as in those with intermediate-1 risk disease and highly symptomatic splenomegaly. Myelofibrosis often leads to splenomegaly due to extramedullary hematopoiesis, where blood cell production shifts from the bone marrow to the spleen. Management depends on symptom severity and disease progression.
Key Considerations
- For mild splenomegaly without significant symptoms, observation may be appropriate.
- For moderate to severe splenomegaly causing discomfort, early satiety, or cytopenias, JAK inhibitors like ruxolitinib are first-line treatments, typically reducing spleen size by 35-50% within 3-6 months 1.
- Hydroxyurea may be used if JAK inhibitors are contraindicated, particularly in patients with low-risk disease or those with intermediate-1 risk disease without highly symptomatic splenomegaly 1.
Treatment Approach
- Ruxolitinib is recommended for reducing splenomegaly in patients with splenomegaly not responding or intolerant to hydroxyurea 1.
- The treatment approach should be individualized based on disease risk, symptom severity, and patient-specific factors.
- Regular monitoring of blood counts is essential as myelofibrosis can progress to acute leukemia.
- Patients should be evaluated for stem cell transplantation, the only potentially curative option, especially younger patients with high-risk disease features 1.
From the Research
Myelofibrosis and Splenomegaly
- Myelofibrosis is a hematologic malignancy that often presents with splenomegaly, which is characterized by an enlarged spleen due to extramedullary hematopoiesis 2.
- Splenomegaly is a common symptom in myelofibrosis patients, occurring in approximately 80% of newly diagnosed patients 2.
Treatment Options
- JAK inhibitors, such as ruxolitinib, are the mainstay of pharmacologic treatment for splenomegaly in myelofibrosis, and have been shown to reduce spleen size and improve disease-related symptoms 3, 4, 5.
- Ruxolitinib has been demonstrated to be effective in reducing splenomegaly and improving quality of life in patients with myelofibrosis, with a significant reduction in spleen volume observed in clinical trials 3, 4, 5.
- Other JAK inhibitors, such as fedratinib and pacritinib, are also available for the treatment of splenomegaly in myelofibrosis, and may be used in patients who are not eligible for or have become refractory to ruxolitinib 2, 6.
Efficacy and Safety
- The efficacy of ruxolitinib in reducing splenomegaly and improving disease-related symptoms has been consistently demonstrated in clinical trials, with significant reductions in spleen volume and improvements in quality of life observed 3, 4, 5.
- The most common adverse events associated with ruxolitinib are anemia and thrombocytopenia, which can be managed with dose adjustments or transfusions 3, 4, 5.
- Novel therapies, including combination treatments, are being developed to improve the management of splenomegaly in myelofibrosis, and may offer improved efficacy and safety profiles compared to existing treatments 2, 6.