Conditions: Essential Thrombocythemia (ET)
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 53
Healthy volunteers: no

Brief summary:
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.

Detailed description:

Arms:
arm 1: None

Interventions: intervention 1: Anagrelide Hydrochloride
Intervention descriptions: intervention 1: Subjects will be started at 1.0 mg per day and titrated as necessary.

Protocol document: