Drug firm makes cocaine 'vaccine'

[Psychadelic_Paisly]

This may get shifted to DITM, but I think it could stimulate some interesting discussion in here anyway....

Drug firm makes cocaine 'vaccine'
From correspondents in London
15jun04
http://www.heraldsun.com.au/common/story_page/0,5478,9849509%5E1702,00.html

A BRITISH drug company says one of its drugs has helped cure cocaine users of their addiction in clinical studies.

Nearly half the addicts who participated in a US clinical trial of the "vaccine" were able to stay off cocaine for six months, David Oxlade, chief executive of Xenova, said.
"The vaccine for cocaine addicts works in very much the same way a regular vaccine works," he said on BBC radio.

According to the company, the anti-cocaine drug blocks the high experienced by users, instead of fighting the chemical addiction itself. Without the high, the cravings for the stimulant apparently diminish as well.

Mr Oxlade said the product worked by attaching cocaine to a larger protein molecule in the body, which then stimulated the immune system to produce anti-bodies that recognised the cocaine and blocked its effect.

"It stops the cocaine from being able to get across from the blood into the brain, which is where you get the high and, of course, where you get the addiction," he said.

The success rate in the clinical trial was "quite remarkable", he said.

The Guardian newspaper reported the study had taken place at Yale Medical School using only 22 regular cocaine users and recovering addicts.

It said Xenova had embarked on a larger study of 130 patients and would report its findings in 2006.

 

[BigTrancer]

Very interesting... some background info from the Xenova webpage:

Press Releases

Xenova Group plc: Positive Results from TA-CD Cocaine Vaccine Trial Presented at CPDD Meeting

Slough, UK, 14 June 2004 - Xenova Group plc (London Stock Exchange: XEN; NASDAQ: XNVA) announced today the presentation of results of two dose escalation Phase II studies of TA-CD, a vaccine being developed for the treatment of cocaine addiction, at the College on Problems of Drug Dependence 66th Annual Scientific Meeting in Puerto Rico, June 12-17. Presented by Dr Bridget Martell, the trials were carried out by Professor Thomas Kosten and his team at Yale University School of Medicine.

The two open-labelled, dose-escalation studies carried out on an out-patient basis, evaluated safety, immunogenicity and clinical efficacy of TA-CD in a total of 22 cocaine users. One of the two studies comprised nine cocaine dependent subjects receiving the TA-CD vaccine and assessed for relapse prevention; these subjects were required to have been free of cocaine use for the two weeks prior to entering the study. The second study included 13 cocaine dependent subjects for abstinence initiation, who were not required to have negative urine cocaine tests prior to enrolment.

Subjects received between three 100 mcg doses and five 400 mcg doses of the TA-CD vaccine (up to 2000 mcg in total). TA-CD was well tolerated in the 20 subjects who completed the two studies.

Results from both studies showed that the maximum mean antibody response occurred between 70 and 90 days post vaccination with specific cocaine antibodies persisting for at least six months. Eight subjects also received a booster 15-18 months post vaccination with TA-CD, all of whom showed increased levels of antibodies two to four weeks later.

Three quarters (75%) of the relapse prevention study group maintained abstinence from cocaine use during the 12-week study duration with 100% relapsing after 12 months when antibody levels had dropped.

In the abstinence initiation study group, 58% achieved and maintained abstinence during the 12-week study and 42% continued to be cocaine free after six months.

The authors additionally reported that the likelihood of using cocaine decreased in those subjects who received a more intense vaccination schedule and as a result were observed to produce higher levels of anti-cocaine antibodies. 88% of subjects in one study and 63% of subjects in the other, who relapsed within six months, reported a reduction in the euphoric effects of cocaine.

Bridget Martell, MD, MA, 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."

David Oxlade, Chief Executive Officer of Xenova said, "These very encouraging results give a strong indication of proof of concept for the TA-CD cocaine vaccine and further validate its potential in assisting cocaine addicts to achieve abstinence."

This study was supported by the US National Institute of Drug Abuse (NIDA). NIDA has also supported earlier clinical work on TA-CD. NIDA has no rights to the commercialisation of TA-CD nor is funding required to be repaid by Xenova.

(SNIP)

Xenova Group plc is a UK-based biopharmaceutical company focused on the development of novel drugs to treat cancer and addiction with a secondary focus in immunotherapy. The Company has a broad pipeline of products in clinical development, including three cancer programmes: its lead product TransMIDTM, for the treatment of high-grade glioma, is in Phase III trials, and its novel DNA targeting agents and XR303 are both in Phase I for cancer indications. Xenova is also developing two therapeutic vaccines for cocaine and nicotine addiction, which are in Phase II and Phase I trials respectively. Quoted on the London Stock Exchange (XEN) and on NASDAQ (XNVA), Xenova employs approximately 112 people throughout its sites in the UK and North America. (Reuters XEN.L; Bloomberg XEN LN)

Cocaine Prevalence

The Office of National Statistics estimate that there are currently 475,000 powder cocaine and 200,000 crack cocaine addicts in Britain. UK Government figures indicate that deaths caused by Class A drugs rose from 96 in 2001 to 139 in 2002 and that deaths from cocaine poisoning have more than doubled with medical evidence that cocaine causes the heart to age prematurely and leads to the rupture of blood vessels. According to Home Office figures, more than 3 million people in the UK spend a total of £6.6 billion on illegal drugs per year.

In the US, it is estimated that there are approximately 1.7 million addicts, some 3 million occasional users and about 900,000 cocaine users seek medical help for their cocaine addiction every year (Lewin Group report from 1997 based on data from SAMHSA Substance Abuse Mental Health Services Administration).

The US Department of Health and Human Services 2002 National Survey on Drug Use found that more than 33 million people age 12 and older had used cocaine at least once in their lifetime. According to What America's Users Spend in Illegal Drugs, users spent $35.3 billion on cocaine in 2000, consuming 259 metric tons of cocaine.

Background on cocaine

Cocaine is extracted from the leaves of the coca plant and originally used in South America in the mid-19th Century by natives to relieve fatigue and then for anaesthetic in surgery. Recreational use of powder cocaine, the most potent stimulant of natural origin, increased substantially throughout the 1970's and crack, the freebase form of cocaine which derives its name from heating the sodium bicarbonate or ammonia used during production, became popular in the mid-1980's due to its immediate high and inexpensive production cost.

BT

 

[Psychadelic_Paisly]

Do you think this is along the lines of the methadone program for heroin addicts?
Is it the same principle?

 

[satricion]

We saw a video on this stuff in abnormal psych the other week.

This is different to methadone...methadone stops you getting high on smack but it's also an opiate agonist (I'm pretty sure) whereas there's no way to get high on this, and this is better than methodone in that methodone is an addictive drug that's actually harder to get off than smack. This is a vaccine against getting high (and hence addiction).

It works by injecting you with a vaccine that means you wind up with an enzyme that binds to the cocaine molecules so that there's no way they can cross the BBB and get into the brain.

I'm all for it as long as it's used as a treatment for addiction, but the video we saw raised issues such as making immunisation against getting high on addictive drugs part of the regular immunisation schedule for kids and so forth. This is an infringement on civil liberties.

 

[MoeBro]

how would this affect legal cocaine derivatives used for local anesthesia? xylocaine etc?

I'm assuming that these derivatives also follow a coke version of the 'morphine rule'?

 

[phase_dancer]

^^ depends on how specific the antibodies are but I'd say to bind with cocaine they'd be pretty specific. It depends mostly on the geometry of the substates and their functional groups, so in that regard it's unlikely to affect lignocaine-xylocaine as this compound is an amide where cocaine is an ester.

Other "caines" are esters, but their geometry is very different and that's what counts. Alternatively, if an antibody was developed for procaine, it may well also bind with others of a similar general structure.



Will there come a day when all users who appear before the courts will be "highly encouraged" to accept these cultured, and probably engineered antibodies to thereby avoid future offences? It could be said such a move would be the chemical castration equivalent for druggies 8)