A Study of Anagrelide Controlled Release (GALE-401) in Patients With High Platelet Counts Due to Bone Marrow Disorders

This is an open-label, single-arm, multicenter, Phase 2 study of anagrelide CR in subjects with an MPN-related thrombocytosis. Eligible subjects will include those who have not been previously treated for thrombocytosis or have not received platelet-lowering therapy for at least 2 weeks prior to study treatment. Each subject will receive anagrelide CR at a starting dose of 0.5 mg b.i.d. (1.0 mg/day), and is anticipated to continue study treatment for at least 24 weeks. Subjects who have achieved clinical benefit in the opinion of the Investigator and who are tolerating the study drug may continue study treatment until they develop unacceptable toxicity or other discontinuation criteria have been met. The primary efficacy endpoint will be the proportion of subjects who achieve a platelet response (CR or PR). The safety and tolerability of study treatment will be assessed by the frequency and severity of adverse events as determined by NCI Common Terminology Criteria for Adverse Events (CTCAE) v 4.03. The PK profile of anagrelide CR will be assessed at the initial (0.5mg b.i.d.) and final titrated dose levels.