Scientists designing antibodies to shield brain from drugs

     

     MSNBC NEWS SERVICES

     

     Aug. 23 — Designer antibodies may someday be used to immunize people against cocaine and other drugs by blocking the rush that users crave. If these vaccines fulfill their promise, they could revolutionize emergency treatment for PCP and amphetamines and could help people who want to kick the habit. ‘We are able to ‘train’ the immune system into creating specific antibodies which can attach themselves and ultimately stop cocaine from ever reaching its target — the central nervous system.’

     — KIM JANDA

     Scripps Research Institute

     

     CALIFORNIA RESEARCHERS said on Monday they have taken a step closer to creating a vaccine against cocaine’s addictive properties and hope to begin conducting tests on humans later this year.

     Tests in rats show the vaccine can keep the drug from reaching the brain, Kim Janda of the Scripps Research Institute in La Jolla told a meeting of the American Chemical Society in New Orleans.

     The immune system does not naturally respond to cocaine because it is such a small molecule. Janda and colleagues have attached a protein — something the immune system is primed to recognize — to a derivative of cocaine.

     “We are able to ‘train’ the immune system into creating specific antibodies which can attach themselves and ultimately stop cocaine from ever reaching its target — the central nervous system,” Janda said in a statement.

     “Thus, we can create a ‘vaccine’ against cocaine’s addictive properties.”

     The approach might also be used to treat an overdose, Janda said.

     Janda said he hopes tests in humans will start later this year.

     Already, one cocaine vaccine, developed by a biomedical company in Massachusetts, is being tested on people at a Connecticut clinic. So far, only the safety has been tested, and it had virtually no side effects, said Dr. Thomas Kosten, a psychiatry professor at Yale University and chief of psychiatry for the Veteran’s Administration in Connecticut.

     The study was not designed to look at the effectiveness of the vaccine, but a few of the participants reported that cocaine “doesn’t seem to have the bang that it used to have,” Kosten said.

     A cocaine vaccine would target the estimated two million heavy cocaine users in the United States alone.

     The National Institute on Drug Abuse estimates that 10 percent of people who try cocaine go on to become addicted. Surveys show 22 million Americans have tried the drug.

     Another team of scientists told the American Chemical Society meeting it had an antibody-based drug to treat addiction to PCP, known also as phencyclidine or angel dust.

     “Our goal would be to protect against the sudden unexpected urge to use, so that if the patient used it, he wouldn’t get the effects,” said Dr. Michael Owen, a pharmacologist at the University of Arkansas for Medical Sciences who hopes to begin tests this year on a PCP overdose treatment.

     The Associated Press and Reuters contributed to this report.