Recent studies at Baylor College of Medicine revealed that patients who received an experimental cocaine vaccine are developing antibodies against the drug, but cocaine use has not yet reduced among the study participants. Although there is still work to do in advancing the experimental vaccine, researchers believe there is also positive, important progress, as evidenced by results of the most recent of the two studies, published today in the journal Drug and Alcohol Dependence.
Research on a cocaine vaccine has been in development for more than 30 years. In this study, 300 patients from six sites across the United States were studied. Researchers found that more than 60 percent of the 153 patients who received a cocaine vaccine effectively reached optimal antibody levels commensurate with a therapeutic range. The patients were reported to have increased treatment retention and were able to reach at least two weeks of abstinence. The pessimistic point was that the level of cocaine did not decrease.
The results were compared to a group of 148 people who received placebo and both groups revealed the same amount of cocaine consumption. Both groups had equivalent cocaine use habits, smoking cocaine for an average of 13 days per month before the treatment.
In the first eight weeks of treatment, before the antibody reached therapeutic levels, the ones that received the vaccine registered a level of use higher than the ones that received placebo. Users received the vaccine during weeks one, three, five, nine and 13 with 10 apart from vaccinations.
Researchers said these findings showed an improvement of response in the immune system, although they were disappointed by the final results of cocaine use. BCM researchers are still continuing to work on the experimental vaccine, and are now exploring new ways of attaining higher antibody levels. One of the options is including an inpatient treatment, which researchers believe will increase the period of abstinence.
In a previous study led in 2008, the same researchers found out that the cocaine vaccine “had antibody levels that were sufficiently high enough to block the euphoric effects of cocaine,” according to Dr. Thomas Kosten, professor and the Jay H. Waggoner Endowed Chair in the Menninger Department of Psychiatry and Behavioral Sciences at BCM.
The research was funded by the National Institute on Drug Abuse, from the National Institutes of Health.