Sponsor: Shire

Principal investigator: Gunnar Birgegård

Primary objective: To monitor long term safety of anagrelide (Xagrid)

Status: Ongoing in most European countries. Inclusion stopped April 30 2009.

Research support: Shire

Study design: Observational study of 1000 patients on Xagrid and 2000 patients on other therapies, mainly hydroxycarbamide. Patients are followed for 5+5 years. Clinical outcome of ET therapy with regards to blood counts as well as clinical predefined events are registered every 6 months.

Inclusion criteria: ET patients receiving cytoreductive therapy for ET. Patients can be newly diagnosed or continuing their pre-prescibed medication of ET. Informed consent.

Exclusion criteria: Participation in other studies with experimental agents.

Contact person: Gunnar Birgegård