Brain uptake of GSK1521498 & naltrexone: a PET scan study (version 1)

• Research type

  Research Study

• Full title

  An open-label, non-randomized [11C]carfentanil PET study in healthy male subjects to investigate brain mu-opioid receptor occupancy, pharmacokinetics, and pharmacodynamics of single oral doses of GSK1521498 and naltrexone.

• IRAS ID

  23130

• Contact name

  Steve Warrington

• Eudract number

  2009-010358-37

• ISRCTN Number

  N/A

• Clinicaltrials.gov Identifier

  N/A

• Research summary

  GSK1521498 is a new experimental medicine that might help overweight people to lose weight. We hope it will block sites in the brain (called mu-opioid receptors) that are involved in the pleasurable feelings we get from eating.The study is in 3 parts.Parts 1 & 2: We'll measure how much GSK1521498 attaches (Ó?binds?) to mu-opioid receptors in the brain and for how long, using a PET (positron emission tomography) brain scan. We'll inject a tiny dose of a radioactive tracer. The tracer binds to mu-opioid receptors in the brain, and the PET scan shows where the tracer is.We'll also use an fMRI (functional magnetic resonance imaging) brain scan, to see if GSK1521498 affects how the brain responds when a hungry participant sees pictures of food, and drinks a nice-tasting liquid.Part 3: We'll test naltrexone, a medicine that also binds to mu-opioid receptors. Naltrexone is given to people who??ve stopped taking drugs of abuse called Ó?opiates?, such as heroin. We'll do the same tests in both parts of the study, and compare GSK1521498 and naltrexone. We'll study up to 24 healthy men, aged 25 to 65 years. 12 participants will take up to 3 single doses of GSK1521498, and 12 will take a single dose of naltrexone. Participants will take up to 8 weeks to finish the study. For each PET scan They'll stay on the ward for at least 24 hours. They'll also make outpatient visits.A pharmaceutical company (GlaxoSmithKline) is funding the study.The study will take place at 2 centres in London. We'll recruit healthy participants by: advertising (newspaper, radio, and websites); by word of mouth; from volunteer databases; and via our websites.

• REC name

  London - Brent Research Ethics Committee

• REC reference

  09/H0717/30

• Date of REC Opinion

  26 May 2009

• REC opinion

  Favourable Opinion