Xenova’s cocaine vaccine shows promise
pharmafile | June 15, 2004 | News story | |
Cocaine addicts could be helped by a vaccine currently in development by UK biotech company Xenova, phase II results from one small-scale study showing 75% of patients receiving the vaccination remained drug-free for three months.
In another arm of the trial, 13 cocaine dependent users stopped using the drug and were vaccinated to help them abstain, a small majority succeeding in staying off the drug for three months, with 42% continuing to be cocaine-free after six months.
The vaccine TA-CD works by stimulating the body to produce antibodies which bind to cocaine and block its uptake in the brain helping users stay off the drug or, if they give into the urge, limit its euphoric effects.
Bridget Martell, associate research scientist at Yale University and involved in the TA-CD trials said: "Cocaine dependent users have a serious need for assistance with achieving and maintaining abstinence. We are impressed with these results which, although on a comparatively small number of subjects, are particularly significant as a number of addicts receiving the TA-CD vaccine were able to remain abstinent during the study periods."
Xenova chief executive David Oxlade said the results were encouraging and gave a strong indication of proof of concept, but acknowledged its use in real-life settings could be more problematic.
He told the BBC: "A lot of cocaine addicts have complex social and psychological issues. Once one drug stops working, if these underlying issues aren't addressed, people may move on to another drug that does."
Experts have also suggested that the drug must block the 'high' drug users feel entirely, or risk encouraging addicts to take more and more to reach the same feeling.
There are currently an estimated 475,000 users of powder cocaine and 200,000 crack cocaine addicts in the UK, with deaths from cocaine poisoning rising quickly, often from damage to the cardiovascular system including ruptured blood vessels.
Xenova has a therapeutic vaccine for the treatment of nicotine addiction in phase I, but its lead product is its treatment for high-grade gloma cancer, TransMID, which is in phase III.
