A Study of Anagrelide and Hydroxyurea in High-Risk Essential Thrombocythemia Patients

A Phase IIIb, Randomized, Open Label Study to Compare the Safety, Efficacy and Tolerability of Anagrelide Hydrochloride Versus Hydroxyurea in High-Risk Essential Thrombocythaemia Patients.

Essential thrombocythaemia is a disorder of bone marrow, which causes too many platelets to be produced. Platelets are small cells carried around in the blood, which help form blood clots. When patients have too many platelets, there is a risk of blood clots forming unnecessarily and excessive bleeding. The aim of this study is to gain additional information on the safety profile of Anagrelide (Xagrid(r)) and Hydroxyurea (also known as hydroxycarbamide).

Inclusion Criteria:

• Confirmed diagnosis of essential thrombocythaemia - high risk profile
• Previously untreated with a cytoreductive agent
• Females of childbearing potential must have a negative urine pregnancy test prior to entering the study and must agree to use effective birth control for the duration of the study

Exclusion Criteria:

• Diagnosis of any other myeloproliferative disorder
• Any known cause for a secondary thrombocytosis
• Anti-coagulant and anti-aggregant therapies
• Known or suspected heart disease
• Left Ventricular Ejection Fraction < 55%