Thromboreductin® is indicated for the treatment of essential thrombocytemia in patient with high risk when the other cytoreductive therapy is ineffective or intolerated. Thromboreductin® could be option for the high risk patients as the first choice therapy. Treatment decisions are individual for each patient, platelet count, age, clinical signs and history, platelet growth rate after diagnosis, concomitant diseases and risk factors for thromboembolism, and the type of current treatment. Patients with high-risk essential thrombocytemia are characterized by at least one of the following: age above 60 years or platelet count above 1,500 × 109 / l or thrombocytemia 600-1500x109 / l with clinical signs or asymptomatic thrombocytemia with rapid platelet count (above 300 × 109 / l over 3 months) or in patients with a history of thromboembolic or haemorrhagic complications.