Polycythemia Vera Management Often Does Not Follow Guidelines

Clinicians treating patients with polycythemia vera (PV) do not appear to be using currently available therapies to their full potential, according to a new report.

The study, published in Annals of Hematology, found most patients were started on phlebotomy monotherapy and thrombotic events in were not uncommon.

The study investigators noted that people with PV have life expectancies between 12.4 and 20 years less than their peers. However, a patient’s risk level also varies based on their age and whether they have a history of thrombosis. Those under the age of 60 with no history of thrombosis are generally considered to be “low risk,” they said.

Hematocrit (HCT) levels are also a key indicator or risk. A previous study found patients who were able to keep their HCT levels below 45% had a significantly lower risk of major thrombosis.

“Moreover, in patients with PV who were receiving phlebotomy and/or hydroxyurea treatment, HCT maintenance of 45% to 50% was associated with 4 times the rate of death from cardiovascular causes or major thrombosis compared with patients with HCT maintenance below 45%,” the authors noted.

Current guidelines suggest using phlebotomy as the first-line treatment of low-risk patients, along with low-dose aspirin and the management of cardiovascular risks. Other therapeutic options are available in patients in need of cytoreduction, and cytoreductive therapy is a first-line treatment for high-risk patients, the authors said. Ruxolitinib (Jakafi) is a second-line therapeutic option, the authors added.

They wanted to know how clinicians were handling real-world cases of PV and how that management was affecting patient outcomes. They retrospectively analyzed a medical claims database to identify the medical and pharmacy claims of more than 28,000 people with PV from 2011 through 2019. Patients were included in the study if they had at least 2 PV diagnosis codes, at least 1 year of PV treatment, and at least 1 prescription claim in 2018 and 2019. An HCT subgroup was created for the 4246 patients for whom at least 2 HCT test results were available. The authors used age and thrombotic history to stratify the patients into low- and high-risk groups.

The investigators found phlebotomy monotherapy was the main strategy deployed in both risk groups. Sixty percent of high-risk patients and 83% of the low-risk patients started with phlebotomy monotherapy, and 81% and 74%, respectively, remained on their original therapy after a median follow-up period of 808 days. Thirty percent of high-risk patients received hydroxyurea monotherapy as their first-line therapy.

“Our study shows a significant gap between recommended treatment and actual treatment patterns in a community-dwelling population,” the authors wrote.

Fifty-four percent of the patients in the high-risk group who began with phlebotomy monotherapy had HCT levels above 50% sometimes or all of the time, as did 64% of those in the low-risk group.

Sixteen percent of people in the study (20% of high-risk patients and 8% of low-risk patients) experienced at least 1 thrombotic episode following treatment initiation.

“Our study results are in line with prior research findings which indicate that PV patients experience a high rate of thrombotic events irrespective of treatment pathway, highlighting the need to improve patient management, even though our study design does not establish associations between specific treatment pathways and the risk of thrombotic events,” the investigators said.

Overall, the authors said their data suggest physicians are overreliant on phlebotomy, even though a relatively low percentage of patients are achieving recommended HCT control and a significant number of patients are experiencing thrombotic events.

Reference

Verstovsek S, Pemmaraju N, Reaven NL, et al. Real-world treatments and thrombotic events in polycythemia vera patients in the USA. Ann Hematol. 2023;102(3):571-581. doi:10.1007/s00277-023-05089-6