The Truth About the "New" Coke Vaccine

The Truth About the "New" Coke Vaccine - Page 2

By Walter Armstrong 03/23/11

Scientists are heralding the novel cocaine vaccine as a landmark anti-addiction drug. But how well does it really work?

A shot in the arm for addiction treatment? ThinkStock

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The designers of the TA-CD vaccine solved that problem, displaying an unusual amount of scientific jujitsu. They devised a cocaine-molecule look-alike of much greater size and attached it to a deactivated piece of cholera toxin, which enhances the immune response by tricking antibodies into attacking the fake coke targets. (Why cholera? Because the disease is very rare in Western nations, where most cocaine is consumed, so a natural immunity doesn’t already exist.) The coke-like molecule, with antibodies latched onto it, is now too big to pass through the blood-brain barrier.
Sponge-like, the vaccine, when successful, not only reduces the amount of blow that hits your brain but also slows it down, muting the feel-good effects. The vax cut the levels of cocaine in rats’ brains by as much as 80%, according to Haney.
The study recruited over 100 folks from a methadone program outside New Haven. The majority were crack users; a minority were also addicted to heroin, marijuana, and/or alcohol. Plus, they were taking the clinic’s anti-opioid offering. Add TA-CD to that chemical mix, and teasing out a direct effect of any one drug is a murky matter.
A series of five TA-CD shots were administered to half the group over a period of 12 weeks; the other half got dummy jabs. Urine samples were taken three times a week during the 24-week study to measure cocaine use. The results? “In this study, immunization did not achieve complete abstinence from cocaine use,” Thomas Kosten, MD, a substance-abuse expert at Baylor College of Medicine who pioneered work on TA-CD, told the Post. (He’s evidently also an expert at spin.) “Previous research has shown, however, that a reduction in use is associated with a significant improvement in cocaine abusers’ social functioning and thus is therapeutically meaningful.”
In fact, “complete abstinence” wasn’t remotely on anyone’s agenda. Only 38 percent of the vaccinated group developed enough antibodies to actually blunt the effects of the cocaine, but they did produce a greater proportion (45%) of cocaine-free pee cups than everybody else (35%). So the vaccine worked in 11 out of 55 cases—which means that clients who cut their cocaine use in half were hailed as proof of the drug's success.
But certain negatives were noted in the trials as well. For one, no antibodies at all were produced in one-quarter of the vaccinated folks. The reason for this Haney calls “the million-dollar question.” There were also some amusing crazy-addict anecdotes, showing how the vaccine, even when it works, can backfire. Some volunteers, desperate for a high, were compelled to blow enormous quantities of coke—10 times as much as had ever been recorded in any such study—in an effort to overcome the dulling powers of the vaccine. Not surprisingly, a few poor souls went broke in the bargain, Kosten reported. (Fortunately, no one OD’d or had a heart attack—a compounded risk given that not only cocaine but the vaccine itself can cause a rapid increase in heart rate as well as other serious cardio effects.)
Because the drug’s benefits can be thwarted by the use of other stimulants like methamphetamine, its most cost-effective use will be for addicts already committed to recovery. “I believe that this approach will work for motivated patients in that it will buy them a period of time where cocaine's effects are blunted, allowing them to focus on treatment. There are clinical data supporting this idea,” says Haney, whose own study of measuring TA-CD antibodies in crack smokers was published in Biological Psychiatry in 2009.
With the National Institute on Drug Abuse’s weighty support, late-stage trials of TA-CD in 300 coke-only addicts are currently enrolling around the country. Results are due in 2014. If these data confirm the 20% efficacy rate, the drug could be available as early as 2016. Iffier than the vax’s success rate is the likelihood of a drug company picking up the tab for its marketing. (Should all these stars align, TA-DC will join the many other, only partially effective behavioral treatments for cocaine addiction. Its trailblazing as the first vaccine against an illegal drug may, in the long run, matter even more.
Walter Armstrong is the Deputy Editor of The Fix and the former Editor-in-Chief of Poz Magazine. He also wrote Spiking Opioid Abuse Linked to Changing Prescription Patterns.