A medication associated with glial cell activation, a phenomenon increasingly being studied for its possible relationship to drug abuse, could eventually prove to offer a breakthrough in the treatment of methamphetamine dependence.
Biopharmaceutical company MediciNova, Inc., last year announced that the medication MN-166 (ibudilast) will be studied in a Phase 2 clinical trial for methamphetamine addiction, in research funded by the National Institute on Drug Abuse (NIDA). The U.S. company licensed the medication from a Japanese company in 2004, first to examine its usefulness in the treatment of the relapsing form of multiple sclerosis.
MN-166 acts on glial cells, and glial cell activation has been gaining attention as a contributing factor in methamphetamine and opioid abuse. Besides the methamphetamine trial, MediciNova also announced late last year that it had initiated enrollment of a Phase 2a trial of MN-166 for heroin and prescription opioid abuse.
In an interview with Addiction Professional last month, MediciNova chief business officer Michael Coffee and chief scientific officer Kirk Johnson said that successful results with a compound for stimulant dependence could help achieve multiple goals: successfully getting recovery-seeking individuals through treatment, helping to prevent relapse, and minimizing the damage that methamphetamine inflicts on the brain, where it can take upwards of a couple of years for healing to occur.
“We’re at the very early stages of our understanding,” says Coffee, referring both to medication-assisted therapies in general and this area of treatment specifically.
Ibudilast has been marketed for years in Japan and Korea, mostly to treat cerebrovascular disorders; Johnson says that in the Asian countries it is used mainly today to treat post-stroke dizziness. While the current drug addiction trials of the medication are focusing on methamphetamine and opioids, Johnson says MN-166 also could prove to have some applicability in the treatment of alcohol dependence and cocaine addiction.
Stimulant addiction has been a particularly elusive subject when it comes to identifying promising findings in medication-assisted treatment research. Historical barriers to success in identifying medication therapies for methamphetamine addiction have included the need to achieve a broader understanding of methamphetamine toxicity, the process of identifying whether viable commercial opportunities indeed exist in this treatment category, and the challenge of designing appropriate clinical studies with methamphetamine addicts in outpatient settings, Johnson says.
The Phase 2 trial for methamphetamine addiction, which will be conducted with the University of California, Los Angeles (UCLA) Department of Family Medicine/Center for Behavioral and Addiction Medicine, will assign 140 treatment-seeking volunteers to either 100 mg a day of MN-166 or placebo for 12 weeks. This dosage level is higher than what is typically used for the current indications for the drug.
A statement from the biopharmaceutical company says, “Half of the trial participants in each treatment group will have a co-diagnosis of HIV as methamphetamine addiction in HIV-positive individuals is a growing issue.”
The primary study outcome will be abstinence from methamphetamine use in the final two weeks of treatment. Researchers also will look at the medication’s effect on neurocognitive performance and its regulation of HIV-related factors such as T-cell counts and sexual behavior.
Principal investigator Keith Heinzerling, MD, medical director of UCLA’s Center for Behavioral and Addiction Medicine, says, “This study has real public health relevance because a medication treatment may improve health outcomes and reduce the public health burden of methamphetamine dependency, especially those with HIV infection, where there is high risk of comorbidity.”