Hydroxyurea compared with anagrelide in high-risk essential thrombocythemia.

Area of Science:

• Hematology
• Oncology
• Pharmacology

Background:

• Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by elevated platelet counts.
• Patients with ET are at increased risk for vascular events, necessitating effective treatment strategies.
• Risk stratification is crucial for selecting appropriate therapies to prevent thrombotic and hemorrhagic complications.

Purpose of the Study:

• To compare the efficacy and safety of hydroxyurea versus anagrelide in patients with essential thrombocythemia at high risk for vascular events.
• To evaluate the impact of these treatments on arterial thrombosis, venous thrombosis, hemorrhage, and mortality.
• To determine the optimal therapeutic approach for managing ET in high-risk populations.

Main Methods:

• A randomized controlled trial involving 809 patients with essential thrombocythemia.
• Patients received low-dose aspirin combined with either anagrelide or hydroxyurea.
• The primary endpoint was a composite of arterial thrombosis, venous thrombosis, serious hemorrhage, or death from thrombotic/hemorrhagic causes.

Main Results:

• Anagrelide plus aspirin was associated with a higher risk of the primary endpoint compared to hydroxyurea plus aspirin (OR, 1.57; P=0.03).
• Anagrelide increased rates of arterial thrombosis, serious hemorrhage, and transformation to myelofibrosis, but decreased venous thromboembolism.
• Platelet count control was equivalent between groups, but more patients receiving anagrelide withdrew from treatment.

Conclusions:

• Hydroxyurea plus low-dose aspirin is a superior treatment option compared to anagrelide plus low-dose aspirin for high-risk essential thrombocythemia patients.
• Hydroxyurea demonstrates a better safety profile and efficacy in preventing major adverse events in this patient population.
• These findings support hydroxyurea as a preferred first-line therapy for essential thrombocythemia in patients with high vascular event risk.