Achievements and future outlook for JAK inhibitors in polycythaemia vera

Polycythemia vera (PV) is driven by mutations in JAK2 kinase and subsequent JAK/STAT activation, presentation can range from an asymptomatic state to micro or macrovascular events. Characteristic aquagenic pruritus and fatigue can have a substantial impact on quality of life. Over time, a minority will transform into more aggressive conditions such as post-PV myelofibrosis or acute myeloid leukemia. The JAK1 and 2 inhibitor Ruxolitinib has been approved for the treatment of PV after the failure of first-line therapies. Other JAK inhibitors have not been extensively tested in PV.

In this article, we describe how PV is diagnosed and conventional treatments before moving to cover the status of JAK inhibitors as a therapeutic option for this disease and other novel therapies following a literature review.

Ruxolitinib when used for PV delivers control of blood counts and reduces disease-related symptoms. Recent data have also suggested that treatment with Ruxolitinib can improve event-free survival and may be associated with disease modification. Adverse effects of Ruxolitinib such as the increased risk of infection and squamous cell skin cancers, most likely to be linked to immunosuppression and prior lines of therapies, require careful consideration.