The purpose of this study is determine whether Anagrelide Retard is non-inferior to
anagrelide immediate release form in treatment of essential thrombocythemia.
Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterised by a sustained
increase in platelet counts above the normal value (> 450 x 109/L) and increased
megakaryopoiesis in the bone marrow, without secondary causes of thrombocytosis.
Anagrelide hydrochloride selectively reduces platelet numbers by inhibiting megakaryocyte
development and maturation in humans, without affecting other cell lineages.
Anagrelide Retard is a new, prolonged release (PR) tablet formulation of anagrelide developed
by AOP Orphan Pharmaceuticals AG. The rationale for developing this new formulation is based
on the assumption of having a better tolerability while maintaining an efficacy comparable to
that of the immediate release formulation.
The effects of Anagrelide Retard and Thromboreductin® will be compared in terms of mean
platelet count measured by a central laboratory/centralized method at 3 time points during
the maintenance phase.