Nora D. Volkow, M.D., Director, NIDA
Public health interventions and biomedical advances have led to dramatic reductions in the prevalence of tobacco use. Yet, tobacco remains the leading cause of preventable death in the United States, linked to more than 400,000 deaths each year. So, when the American Recovery and Reinvestment Act (ARRA) was enacted less than a year ago, NIDA announced its plans to accelerate research to eradicate tobacco addiction as one of our signature priorities. With the release of a $10 million ARRA grant to Nabi Biopharmaceuticals of Rockville, Maryland, we move ever closer to that goal.
As most people know, addiction to cigarettes is tenacious and relapse is prevalent — with most smokers unable to quit even knowing about and wanting to avoid the myriad health consequences of tobacco addiction. NIDA has therefore channeled significant resources into the development of medications and behavioral interventions to help smokers achieve and sustain abstinence.
To that end, ARRA funding, released in September, will help pay for the first phase III trial ever of a smoking cessation vaccine, NicVAX, designed to help people quit and remain abstinent. Given Fast Track Designation by the U.S. Food and Drug Administration, NicVAX has already successfully completed a proof-of-concept trial; successful completion of the phase III study will bring the vaccine closer to final approval.
Like other vaccines, NicVAX works by stimulating the immune system to produce antibodies, in this case, to the drug nicotine. Normally, nicotine (a small molecule) travels quickly through the lungs into the bloodstream and then the brain. However, when nicotine molecules are bound to antibodies, they become too large to enter the brain, thus subverting the rewarding effects of the drug. Results to date show that smokers who achieved high antibody levels had higher rates of quitting and longer durations of abstinence than those given placebo. The vaccine was also well tolerated, with few side effects.
Remaining abstinent is unquestionably the most challenging part of quitting smoking given that withdrawal symptoms, environmental cues and stress can all trigger relapse. A vaccine that limits nicotine's ability to enter the brain and continues to be effective for 6-12 months following vaccination will give smokers a fighting chance to end the addiction/relapse cycle that plagues the great majority of those trying to quit.
The ARRA award continues a public-private partnership between NIDA and NABI that started in 2001 with a grant to support the basic science that led to NicVAX. The effort continued in 2005 with a grant to help support early clinical trials to test the safety and efficacy of the vaccine. NIDA will keep the public informed about the progress of the phase III trial. In the meantime, we remain committed to the eradication of tobacco addiction.
Nora D. Volkow, M.D.
This article originally appeared on the National Institute on Drug Abuse website.