Cocaine vaccine passes key testing hurdle

An anti-cocaine vaccine that prevents the drug from reaching the brain has been successfully tested in non-human primates, scientists say.
Researchers at Weill Cornell Medical College tested their novel anti-cocaine vaccine in primates, bringing them closer to launching human clinical trials.
The study used a radiological technique to demonstrate that the anti-cocaine vaccine prevented the drug from reaching the brain and producing a dopamine-induced high.
"The vaccine eats up the cocaine in the blood like a little Pac-man before it can reach the brain," said the study's lead investigator, Dr Ronald G Crystal, chairman of the Department of Genetic Medicine at Weill Cornell Medical College.

"We believe this strategy is a win-win for those individuals, among the estimated 1.4 million cocaine users in the US, who are committed to breaking their addiction to the drug," he said.
"Even if a person who receives the anti-cocaine vaccine falls off the wagon, cocaine will have no effect," he added.

Crystal said he expects to begin human testing of the anti-cocaine vaccine within a year.
Cocaine, a tiny molecule drug, works to produce feelings of pleasure because it blocks the recycling of dopamine - the so-called "pleasure" neurotransmitter - in two areas of the brain, the putamen in the forebrain and the caudate nucleus in the brain's centre.

When dopamine accumulates at the nerve endings, "you get this massive flooding of dopamine and that is the feel good part of the cocaine high," said Crystal.
The novel vaccine Crystal and his colleagues developed combines bits of the common cold virus with a particle that mimics the structure of cocaine.
When the vaccine is injected into an animal, its body "sees" the cold virus and mounts an immune response against both the virus and the cocaine impersonator that is hooked to it.
"The immune system learns to see cocaine as an intruder. Once immune cells are educated to regard cocaine as the enemy, it produces antibodies, from that moment on, against cocaine the moment the drug enters the body," Crystal said.

The researchers are not sure yet how often the vaccine would be administered in humans to maintain its anti-cocaine effect. One vaccine lasted 13 weeks in mice and seven weeks in non-human primates.
The study was published in the journal Neuropsychopharmacology.