Study to Identify and Describe Predictive Factors for Thromboembolic Events in Patients With High-risk Polycythemia Vera

This is a prospective observational study that will enroll patients with high-risk Polycythemia Vera (PV) with at least one Thromboembolic Event (TE) after diagnosis or up to 2 years prior to diagnosis. This is a non-randomized study, and to ensure a sufficient number of patients in both cohorts, enrollment in each cohort will be terminated once the target of 150 patients has been reached.

Inclusion Criteria: 1. Signed informed consent must be obtained prior to participation in the study. 2. Age ≥18 years. 3. Diagnosis of PV according to WHO 2008 or WHO 2016 and high-risk stratification according to European LeukemiaNet (ELN) classification. 4. At least one TE after diagnosis or up to 2 years prior to diagnosis. 5. Patients on treatment with hydroxyurea at enrollment and for at least 18 months prior to enrollment or those on treatment with ruxolitinib who started treatment up to 18 months before enrollment.