Despite guidelines that recommend cytoreductive therapy for high-risk patients with polycythemia vera (PV) the majority of these patients do not receive the therapy, according to a study in Experimental Hematology & Oncology. PV increases patients’ mortality risk, largely as a result of elevated rates of cardiovascular disease, thrombotic events and hematologic transformations.

Both the National Comprehensive Cancer Network (NCCN) and the European LeukemiaNet (ELN) recommend assessing patients for risk of thrombotic events. While aspirin and phlebotomy are adequate to manage most low-risk patients, those at greater risk of thrombotic events as well as those with symptomatic thrombocytosis or progressive leukocytosis should receive cytoreductive medication in addition to aspirin and phlebotomy, according to the organizations.

Doctor discussing treatment with patient. Source: Getty

The real world study identified 2,856 adult patients from the Truven Health MarketScan database who had two or more non-diagnostic claims for PV that were at least 30 days apart. The researchers used a pre-index period of January 1 to December 31, 2012 and a post-index period of January 1, 2013 to December 31, 2014.

Of the 2,856 patients, 1,823 were considered high risk and two-thirds were male. High-risk patients had higher pre-index rates of comorbidities than low-risk patients, particularly for hypertension, 65% vs 43.1%; type 2 diabetes, 21.7% vs 10.1%; and congestive heart failure, 6.6% vs 0.6%.

In the pre-index period, 666 high-risk patients and 160 low-risk patients received cytoreductive therapy, primarily hydroxyurea at 94.7% and 87.5%, respectively. Post-index, more than 90% of both groups who began cytoreductive therapy received hydroxyurea, 97.0% of 100 high-risk patients and 91.4% of  35 patients at low risk. Other agents used during both periods studied included anagrelide and interferon.

Overall, the researchers found that just 42% of high-risk patients received cytoreductive therapy. In addition, 18.9% of low risk patients received cytoreductive therapy during either period.

The authors concluded that “despite consistent guideline recommendations for cytoreductive therapy in patients with high-risk PV, this analysis revealed that only a minority of these patients received cytoreductive medication. A notable proportion of high-risk patients with PV would likely benefit from a revised treatment plan that aligns with current guidelines.”