The “fast track” is a relative term in the world of medication approvals. The GABA aminotransferase inhibitor known as vigabatrin has held that status with the Food and Drug Administration (FDA) for the treatment of cocaine addiction since February 2006, but more than four years later it remains unclear as to how close an official approval for that indication might be. Still, significant progress in this effort might not be far off.
Florida-based Catalyst Pharmaceutical Partners, Inc. is about to embark on a $10 million Phase 2B study that is being financed primarily by the National Institute on Drug Abuse (NIDA) and the Department of Veterans Affairs (VA). Company CEO Patrick McEnany says the 200-patient study will examine the effectiveness of vigabatrin vis-à-vis placebo at a number of outpatient sites that will employ observed dosing of the oral medication three times a week.
Vigabatrin is indicated for the adjunctive treatment of treatment-resistant complex partial seizures, and as primary treatment for infantile spasms in West syndrome. McEnany explains that the medication’s effects on GABA and dopamine are thought to block the euphoric effects associated with cocaine exposure.
At this month’s annual meeting of the College on Problems of Drug Dependence, company officials presented an overview of the data they have collected from vigabatrin trials conducted to date. “We’ve learned a great deal about use of vigabatrin for addiction and about the proper clinical trial design,” McEnany says.
He acknowledges a host of challenges associated with arriving at an effective medication treatment for stimulant addiction, ranging from questions about the mechanisms associated with this addiction to concerns over achieving medication compliance in this population. He reiterates the often-cited point that “big pharma” has steered clear of this patient population in its drug development plans, but he adds with confidence, “I really think that that’ll change.”
As have many pharmaceutical executives before him, McEnany emphasizes that his company does not see this medication as a magic bullet for cocaine addiction. It would hope eventually to market the drug as a therapy to be used in conjunction with 12-Step or other treatment. Still, any significant breakthrough in a subset of addiction treatment that has not seen one would be a dramatic event for the field, even if it is one that still may be years away.