How I treat patients with low-risk PV requiring cytoreduction

Cytoreductive treatments have traditionally been used in patients with polycythemia vera (PV) considered to be at high risk of thrombosis. However, low-risk PV is also associated with adverse outcomes, including thrombosis and disease transformation. Emerging evidence suggests that more patients who require treatment can be identified with improved risk stratification tools. Additionally, the development of more potent and less toxic therapies highlights the need to review current clinical practices in the management of low-risk PV. 

McMullin and Harrison published a case series in Blood describing clinical situations triggering the use of cytoreductive treatment for patients with low-risk PV, including choice of cytoreductive agent and effective treatment monitoring.¹

Key learnings¹

Parameters to consider when assessing the need for cytoreductive treatment in low-risk PV include assessment of symptoms, cardiovascular risk, leukocytosis, frequency of phlebotomy, thrombocytosis, splenomegaly, and molecular risk assessment for JAK2V617F VAF. Other factors, such as pregnancy and surgery, should also be considered where applicable.  

IFNα or HU is the preferred choice of first-line treatment, with an emphasis on IFNα. Emerging data support the use of ruxolitinib as a second-line treatment, particularly in symptom management for low-risk PV.

In young patients with low-risk PV, sequential monitoring of JAK2V617F burden may improve outcomes.

Future evidence of disease modification with cytoreductive treatments may lead to recommendations for initiating cytoreductive treatments in most patients with PV.