Effect of SPD422 on Platelet Lowering and Safety in Japanese Adults With At Risk Essential Thrombocythaemia

A Phase 3, Open-label, Single-arm Study Evaluating the Effect of SPD422 on Platelet Lowering and Safety in Japanese Adults With At Risk Essential Thrombocythaemia Who Are Intolerant or Refractory to Current Cytoreductive Treatment

The purpose of this study is to investigate how effective and safe SPD422 (Anagrelide Hydrochloride) is in Japanese subjects, diagnosed with Essential Thrombocythemia, who's previously treatment has either not been effective or has caused unacceptable adverse reactions. The study will aim to show that platelet counts can be safely reduced in treated patients to below 600 x 10^9/L after a minimum of three months treatment. To demonstrate an positive effect platelet levels will need to remain below 600 x 10^9/L for at least 4 weeks.

Inclusion Criteria:

• Subjects must have previously been treated with a cytoreductive therapy and been intolerant or refractory to that therapy.

Exclusion Criteria:

• Subjects should not have any other underlying conditions or medications that would confound the study analysis or interact with the study medication.