Meth Addiction: Blocking Meth’s Effects on the Brain

Susan Van Dusen

For more than 30 years, Michael Owens, Ph.D., has sought a way for drug addicts to overcome their addiction and return to a drug-free life.

His research began in the 1980s by studying how to treat the overdose of phencyclidine, or PCP. A decade later, he joined forces with UAMS’ Brooks Gentry, M.D., and together their research has evolved into a highly specific therapy targeting one of the most addictive illegal drugs: methamphetamine.

“PCP was a very prominent drug for a short time, and we still see a rise in usage occasionally. However, the drug that is really causing problems in Arkansas and worldwide is methamphetamine,” said Owens, professor of pharmacology in the UAMS College of Medicine.

A highly addicting central nervous system stimulant, meth is primarily produced in clandestine labs, many of which are based in people’s homes, or obtained through drug smuggling operations.

While laws limiting the sale of starter ingredients for meth have greatly reduced production in Arkansas, three surrounding states are in the top 10 nationwide for meth production. This close proximity to meth hot spots has kept the drug flowing across Arkansas’ state line, where it is responsible for a significant percentage of drug abuse cases.

“Amphetamine abuse accounts for 18.5 percent of patients seeking treatment for substance abuse in Arkansas. Methamphetamine accounts for the vast majority of these cases,” Owens said.

The key to success for Owens’ and Gentry’s new therapy is its ability to remain in the bloodstream for weeks at a time.

“It sits, waiting for meth to be introduced into body. When that happens, it combines rapidly and reduces the rate at which the drug enters the brain, blocking its effects,” Owens said.

If proven effective, it will be the first therapy to reduce meth’s effects for prolonged periods of time, he said.

The results of a phase 1 clinical trial of the medication — named ch-mAb7F9 — were published in the Dec. 15, 2014, issue of the scientific journal mAbs and demonstrated its safety and tolerability in healthy adults.

This is the first drug of its kind the FDA has ever seen.
The next step for Owens, Gentry and their team — including collaborators Misty Stevens, Ph.D., and Melinda Gunnell — is to focus on additional safety testing for people with meth addiction. Because this is a new type of therapy, extra time to determine its safety is an essential part of the development process.

“This is the first drug of its kind the FDA has ever seen. They are very supportive, but also are very cautious,” said Gentry, professor and chairman of the UAMS Department of Anesthesiology.

A grant of $5 million from the National Institutes of Health (NIH) National Institute on Drug Abuse (NIDA) will support production of the monoclonal antibody and fund more safety testing to prepare the team to conduct a phase 2 clinical trial involving meth users, which they hope to begin in about three years.

NIDA has provided the team continual support since the mid-1990s, and even longer for Owens’ early-stage research.

In addition to their work on the monoclonal antibody, the team announced a $9.55 million NIDA grant in early 2015 to continue its study of an antibody vaccine for meth addiction, which would allow the body to develop immunity to the drug’s effects.

“While the monoclonal antibody has an immediate effect, the vaccine could take up to six weeks to generate a response. This could be helpful for someone who isn’t a hardcore user, but still needs help quitting,” Gentry said.

Like the monoclonal antibody, the vaccine wouldn’t interact with other medications, nor would it impact brain function or interfere with psychiatric counseling. The vaccine also would carry a lower price tag than the monoclonal antibody and could last up to nine months in the body.

Assuming the antibody and vaccine receive federal Food and Drug Administration approval, they can be provided as an integral part of a meth user’s complete treatment program, which consists of counseling and possibly other medications to reduce craving.

While Owens and Gentry are clear they aren’t developing a cure for meth addiction, they do see their discoveries opening a door for addicts who are ready to quit.

“The antibody is for people who want help and are willing to change their behavior. It gives you a chance to recover and outlive your disease,” Owens said.