March 20, 2025
Author(s): Seema A. Bhat, MD
Fact checked by: Ashling Wahner, Courtney Flaherty
Seema A. Bhat, MD, a hematologist at The Ohio State University Comprehensive Cancer Center—James; as well as an assistant professor in the Department of Internal Medicine in the Division of Hematology at The Ohio State University, discusses the importance of risk stratification for navigating treatment selection for patients with myeloproliferative neoplasms (MPNs).
Stratifying patients with MPNs into appropriate risk groups is crucial for treatment decision-making, as patients’ individual risk factors strongly factor into selection, Bhat says. Typically, patients with low-risk disease will receive treatments directed at symptom management, whereas cytoreductive agents like hydroxyurea, as well as targeted therapies like JAK inhibitors, are considered for patients with high-risk disease, she explains. Furthermore, allogeneic stem cell transplantation may be a curative treatment option for patients with very high–risk MPNs, she notes.
The revised IPSET Thrombosis Score is used for essential thrombocythemia (ET) risk stratification. Patients are considered to have low-risk polycythemia vera (PV) if they are younger than 60 years of age and have no history of thrombosis; patients are considered to have high-risk PV if they are older than 60 years of age and/or have a thrombosis history.
Four JAK inhibitors are FDA approved for the treatment of patients with MPNs. Ruxolitinib (Jakafi) is indicated for adult patients with intermediate- or high-risk myelofibrosis, including primary myelofibrosis and secondary (post-PV or post-ET) myelofibrosis; as well as adult patients with PV who have had an inadequate response or are intolerant to hydroxyurea. Fedratinib (Inrebic) is approved for adult patients with intermediate-2 or high-risk primary or secondary myelofibrosis. Pacritinib (Vonjo) is indicated for use in adult patients with intermediate- or high-risk primary or secondary myelofibrosis with a platelet count below 50 × 109 /L. Finally, momelotinib (Ojjaara) is approved for adult patients with intermediate- or high-risk primary or secondary myelofibrosis with anemia.