Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by an overproduction of normal red blood cells, white blood cells and platelets that leads to an increased risk of thrombosis. The most prominent feature of polycythemia vera is erythrocytosis which distinguishes it from other myeloproliferative neoplasms.
Patients may benefit from off-label treatment with hydroxyurea (Hydrea, Doxia) and that cytoreductive agent is currently considered the first line of therapy for PV patients. The only approved drug for PV is Jakafi (ruxolitinib), which is indicted for patients with an inadequate response, or are intolerant to, hydroxyurea.
It is estimated that approximately 25% of the ~100,000 patients in the United States with PV develop resistance, or intolerance, to hydroxyurea.
Patients with uncontrolled PV have an increased risk of cardiovascular complications such as stroke, pulmonary embolism, deep vein thrombosis and heart attack.
A new study presented at the 2017 American Society of Clinical Oncology (ASCO) conference indicates many PV patients are not taking hydroxyurea or other cytoreductive medication.
In a retrospective study using the Truven Health MarketScan Database, claims from 2856 patients with PV were examined. Patients had a mean age of 62.5 years (+ 13.5 years) and 63.8% were considered high-risk patients (for thrombosis).
The most commonly-used cytoreductive medications were hydroxyurea (93.6%), anagrelide (7.6%), and interferon (2.4%).
As shown in teh table below, less than half of high-risk patients and less than one-fifth of low-risk patients were receiving cytoreductive medication.
Table 1. Cytoreductive Medication Use in PV Patents
| Risk (N=2856)
| High-risk (n = 1823)
Age < 60 with TE (n = 165)
Age > 69 without TE (n=1145)
Age > 60 with TE (n = 513)
|766 / 1823 (42.0%)
54 / 165 (32.7%)
474 / 1145 (41.4%)
238 / 513 (46.4%)
| Low-risk (n = 1033)
||195 / 1033 (19.9%
These results are concerning and indicates that many PV patients may be unnecessarily at risk for additional cardiovascular events. More studies are necessary to ascertain why cytoreductive medications are not being administered.
Paranagama D, Yu J, Colucci P, et al. Are patients with high-risk polycythemia vera (PV) receiving cytoreductive medications? A retrospective analysis of real-world data. J Clin Oncol
2017;35; (suppl; abstr e18031).