April 17, 2025
Jason Gotlib, MD
Like other hematologic malignancies, the management of myeloproliferative neoplasms (MPNs) reflects a dynamic assessment of the grades of clinical evidence to guide the appropriateness of therapeutic interventions. The National Comprehensive Cancer Network and European LeukemiaNet have synthesized these data into risk-stratified guidelines to provide foundational approaches for diagnosing and treating MPNs.1,2 However, the biologic, clinical, and molecular heterogeneity of MPNs, as well as the unique treatment goals of individuals often leads to a melding of data-driven algorithms with personalized care approaches informed by shared decision-making between patients and their physicians. Although this hybrid heuristic may introduce some imprecision in this era of precision medicine, it also recognizes that treatment decisions are not completely fated by the results of a multigene next-generation sequencing panel. This is a common theme running through the following 6 articles featured in this How I Treat series on MPNs:
- Mary Frances McMullin and Claire N. Harrison, “How I treat patients with low-risk polycythemia vera who require cytoreduction”
- Lucia Masarova and Helen T. Chifotides, “How I individualize selection of JAK inhibitors for patients with myelofibrosis”
- Akriti G. Jain and Aaron T. Gerds, “How I treat anemia in myelofibrosis”
- Deepti H. Radia, “How I diagnose and treat systemic mastocytosis with an associated hematologic neoplasm”
- Andreas Reiter, Georgia Metzgeroth, and Nicholas C. P. Cross, “How I diagnose and treat myeloid/lymphoid neoplasms with tyrosine kinase gene fusions”
- Alexandre Guy, Pierre-Emmanuel Morange, and Chloé James, “How I approach the treatment of thrombotic complications in patients with myeloproliferative neoplasms”
In the first How I Treat article, McMullin and Harrison discuss their approach to the use of cytoreduction in patients with low-risk polycythemia vera (PV).3 For high-risk patients (aged >60 years or history of thrombosis), standard care includes the addition of cytoreduction to the low-risk treatment backbone of low-dose aspirin and phlebotomy. In low-risk PV, progressive splenomegaly, leukocytosis, or thrombocytosis (eg, >1500 × 109/L); high symptom burden (related to PV and/or severe iron deficiency); and persistence of frequent phlebotomy are examples of indications that may justify the use of cytoreduction.1,2 In the last several years, molecular remission, eg, reduction of Janus kinase 2 (JAK2) V617F variant allele fraction, has increasingly animated the conversation between patients and physicians. This shift has likely been accelerated by the encouraging longer-term molecular results with ro-PEG-interferon-α-2b (BESREMi) in the CONTINUOUS-PV/PROUD-PV studies.4,5 Although molecular remission is an intuitively attractive therapeutic goal, it remains to be established whether such deeper responses will ultimately translate into disease modification (eg, reduction in thrombosis, decreased evolution to myelofibrosis [MF] or acute myeloid leukemia, and improved overall survival). Individuals without a conventional indication for cytoreduction (especially younger patients who have a longer survival runway ahead of them), may still wish to seek an active treatment plan. The “if and when” to use cytoreduction in the patient with low-risk PV is a complicated calculus of potential side effects, impact on quality of life, financial toxicity, and a hedge that committing to a long-term treatment program will favorably bend the arc of the disease.