NicVAX vaccine to treat nicotine addiction enters late phase studies: Nabi Biopharma

NicVAX may also be effective in preventing smoking relapse

NicVAX, a vaccine to treat nicotine addiction and prevent smoking relapse, by Nabi Biopharmaceuticals is currently in late phase clinical studies.

Nabi Biopharmaceuticals has initiated the first of two pivotal phase III clinical trials for NicVAX (Nicotine Conjugate Vaccine), the company said in a press release.

NicVAX study is being funded in part with a $10 million grant from U.S. National Institute on Drug Abuse (NIDA), part of the National Institutes of Health.

NicVAX’ study design, protocol and end points through a Special Protocol Assessment (SPA) are all agreed withe US FDA and Nabi. The SPA forms a basic foundation to support approval of a New Drug Application.

The initial Phase III study for NicVAX is a double-blinded, placebo-controlled study comprised of approximately 1,000 patients.

The primary endpoint of NicVAX study is the abstinence rate at 12 months. Abstinence will be evaluated by several measures, including self-reported cigarette consumption, and exhaled carbon dioxide.

Secondary endpoints of NicVAX study include the abstinence rate at various time intervals, safety and immunogenicity, and the effect of NicVAX on withdrawal symptoms, cigarette consumption, smoking satisfaction and nicotine dependency. Study results are anticipated by the third quarter of 2011.

NicVAX’ study also received scientific advice from the European Medicines Agency (EMEA) that confirms and supports the trial protocol, increasing the possibility of a positive outcome.

“We were very encouraged by the results of the phase IIb proof of concept and believe that since that study, we have improved the dosing schedule and the phase III NicVAX trial design. The initiation of the Phase III study solidifies our leadership position as the most advanced smoking cessation pipeline vaccine,” stated Dr Raafat Fahim, president and chief executive officer of Nabi Biopharmaceuticals.

NicVAX’ mechanism of action depends upon the addictive pathway of neurological response to nicotine.

When nicotine enters the bloodstream, it quickly crosses the blood-brain barrier and binds to nicotinic receptors in the brain, triggering the release of stimulants like dopamine that provide the smoker with a positive sensation that eventually leads to addiction.

NicVAX stimulates the immune system to produce antibodies that bind to nicotine creating an antigen/antibody complex that is too large to cross the blood-brain barrier.

By doing so, NicVAX blocks nicotine from reaching these receptors in the brain and prevents the highly-addictive pleasure sensation experienced by smokers and users of nicotine products.

Pre-clinical and previous clinical data show that NicVAX’s ability to block nicotine from reaching the brain could help people quit smoking.

NicVAX may also be effective in preventing smoking relapse, because the nicotine antibodies circulate for long periods of time, Nabi believes.

Relapse is a significant challenge facing smokers and, with currently-available smoking cessation therapies, relapse rates can be as high as 90% in the first year after a smoker quits.

If NicVAX can address the relapse part of nicotine addiction, it would be able to make a very important difference between NicVAX and existing anti-smoking treatment therapies.

Headquartered in Rockville, Maryland, Nabi Biopharmaceuticals target serious medical conditions in the areas of nicotine addiction and gram-positive bacterial infections.

Apart from NicVAX,  Nabi Biopharmaceuticals is currently developing PentaStaph (Pentavalent S. aureus Vaccine), a vaccine designed to protect against the most dangerous and prevalent strains of S. aureus bacterial infections.