A leading drug development expert with the National Institute on Drug Abuse (NIDA) believes helpful compounds for the treatment of cocaine addiction are not too far off, and says the recent poor performance of one medication in a clinical trial should not discourage the addiction treatment community.
“It should be kept in mind that cocaine addiction is a relatively new problem in our society and that meaningful efforts to discover and develop medications for the treatment of this disorder were only initiated after the crack cocaine epidemic of the 1980s,” says David J. McCann, PhD, acting director of NIDA’s Division of Pharmacotherapies and Medical Consequences of Drug Abuse. McCann points out that NIDA-supported basic research in recent years has made significant inroads in uncovering details about cocaine’s mechanism of action—information that should ultimately prove valuable in medications development.
McCann warns that not too much should be read into recent reports that an initial encouraging trial using the drug vigabatrin in Mexico was followed by a disappointing outcome in a U.S. trial. The data from the latest trial are not out for closer analysis yet, he explains, and he says it would be wrong at this point to classify Catalyst Pharmaceutical Partners’ vigabatrin as a failed option.
“We need to keep in mind that failed trials are quite common in medications development for CNS disorders and that many FDA-approved anxiolytics and antidepressants experienced failed trials along their way to approval,” McCann says.
He adds in regard to vigabatrin, “The preclinical data, the theoretical rationale for efficacy, and the results of the initial efficacy trial in Mexico are just too encouraging to dismiss the drug at this point.”
Over the long term, two other potentially significant therapies for cocaine addiction are a bioengineered cocaine hydrolase enzyme and a selective kappa-opioid receptor antagonist. The enzyme is not yet in clinical trials but appears to be promising at least for addressing cocaine overdose treatment. The kappa-opioid antagonist, known as JDTic, has been associated with blocking stress-induced responses in rodents, and because of its link to stress could have broad applications in addiction treatment, McCann explains. “JDTic could advance to clinical testing before the end of 2009,” he says.