Study Evaluating The Safety, Tolerability And Brain Function Of 2 Doses Of PF-0254920 In Subjects With Early Huntington's Disease

A Phase 2, Double-blind Randomized, Sequential Treatment Group, Placebo-controlled Study To Evaluate The Safety, Tolerability And Brain Cortico-striatal Function Of 2 Doses Of Pf-02545920 In Subjects With Early Huntington's Disease

This study will evaluate the Safety, Tolerability and Brain Function of 2 doses of PF-0254920 in Subjects with Early Huntington's Disease.

Inclusion Criteria:

• Must have a diagnosis of Huntington's Disease
• a CAG repeat expansion equal or great than 39
• a Unified Huntington Disease Rating Scale (UHDRS) Total Motor Score equal or greater than 5 and less than 60
• a UHDRS Total Functional Capacity equal or greater than 9

Exclusion Criteria:

• Subjects with evidence or history of severe acute or chronic medical condition or laboratory abnormality, or significant neurological disorder other than HD.
• Treatment with any antipsychotic medication within 5 weeks of enrollment