An Imaging Study to Investigate the Distribution of GW842166X in the Brain.

An Open Label Positron Emission Tomography (PET) Study to Investigate Brain Penetration by [11C]GW842166 in Healthy Subjects

GW842166X is being developed for the treatment and management of inflammatory pain. GW842166X is a CB2 receptor agonist and the mechanism is not fully understood, although it is thought that for the anti-inflammatory action the drug is required to cross inot the brain from the blood. This study aims to look at if the drug crosses into the brain once given orally using an imaging technique called positron emission tomography.

Inclusion Criteria:

• Male aged 50 to 80yrs inclusive at the screening visit.
• subjects with negative HIV and hepatitis B and C test results within 3 months of study start.

Exclusion Criteria:

• A negative Allens test on arm to be used for arterial cannulation.
• Any contraindications to MRI scanning.
• History or presence of hepatic or renal disease.
• Previous involvement in PET or radiological investigations.
• Family history of cancer.
• History of claustrophobia
• Presence of a cardiac pacemaker or any other electronic device or ferromagnetic metal