NIH's NIAAA To Conduct Clinical Trial Of Gabapentin Enacarbil For AUD
By Cyndi Root
The National Institutes of Health (NIH) announced in a press release that its agency the National Institute on Alcohol Abuse and Alcoholism (NIAAA) will conduct a six-month trial of gabapentin enacarbil (brand name Horizant) in people who have been diagnosed with alcohol use disorder (AUD). XenoPort, a biopharmaceutical company from Santa Clara, California, will supply the study drug. George F. Koob, Ph.D., director of the NIAAA, said, “Prior clinical studies of gabapentin, the active metabolite of the molecule called gabapentin enacarbil, have shown positive results in patients with AUD. We believe that the time is right to conduct a multi-site, well-controlled clinical trial.”
Gabapentin Enacarbil
Gabapentin enacarbil is a prodrug of gabapentin. It is thought to be absorbed into the body through nutrient transport mechanisms. In April 2011, the FDA approved gabapentin enacarbil for the treatment of restless legs syndrome (RLS). A year later, the FDA approved gabapentin enacarbil in 2012 for the management of postherpetic neuralgia in adults. Gabapentin is prescribed to treat epilepsy and pain conditions.
The Scripps Research Institute in La Jolla, California recently found in a clinical study supported by the NIAAA that AUD patients taking gabapentin enacarbil were more likely to stop or refrain from heavy drinking than those taking a placebo. XenoPort scientists have engineered extended-release gabapentin enacarbil tablets to maintain drug levels in the body, making it more likely to be an effective treatment option for AUD patients.
NIAAA Trial
The clinical trial for gabapentin enacarbil in AUD is expected to begin in 2015 and last for six months. About 350 patients will be enrolled in the safety and efficacy trial. Participants will receive either gabapentin enacarbil or a placebo. In Xenoport’s press release, it states that the FDA will meet with XenoPort and the NIAAA in Q4 2014 to discuss the trial’s design. XenoPort hopes to use the results of the trial in a supplemental new drug application (sNDA) for Horizant to help patients with AUD maintain abstinence from alcohol.
Ronald W. Barrett, Ph.D., CEO of XenoPort, said, "Our goal in designing gabapentin enacarbil was to address the pharmacokinetic limitations of gabapentin. We are hopeful that the predictable high bioavailability, rapid titration, and low fluctuating gabapentin blood levels with twice-daily administration associated with Horizant may enable successful treatment of AUD and look forward to working with the NIAAA on this important study."