Treatment patterns and outcomes in PV and ET: A nationwide study

Results from a nationwide, population-based study investigating treatment patterns, vascular complications, and survival in 2,604 patients with polycythemia vera (PV) and 3,141 patients with essential thrombocythemia (ET), were recently published in the European Journal of Haematology by Larsson et al.  The rates of arterial and venous events, major bleeding, and all-cause mortality (ACM) were assessed by treatment type.

Key data: Hydroxyurea (HU) was used during follow-up in 42.3% of low-risk PV patients and 29.7% of very low-risk/low-risk ET patients. Patients with high-risk PV treated with interferon (IFN) exhibited the lowest arterial event rate (1.46 per 100 patient-years), while the lowest rates of venous events were in patients treated with HU and radioactive phosphorus-32 (P32; 0.88 per 100 patient-years). Patients with high-risk ET receiving IFN therapy experienced both the lowest arterial and venous event rates (1.55 and 0.44 per 100 patient-years, respectively). Older age and leukocytosis at diagnosis independently predicted thrombosis, bleeding, and ACM in both PV and ET, while HU and IFN were associated with reduced ACM risk.

Key learning: Advanced age and leukocytosis at diagnosis independently predicted thrombosis, bleeding, and ACM risk in both PV and ET, while HU and IFN demonstrated favorable safety profiles, supporting their potential use as first-line therapies in real-world settings.