According to the US Centres for Disease Control and Prevention (CDC), tobacco use is the single leading preventable cause of death in the United States and is responsible for more than 440,000 deaths each year.
They estimate that 70 per cent of smokers in the US want to quit, but less than 5 per cent of those who try to quit abstain from smoking for 3 to 12 months.
In addition, tobacco use is thought to cause $75.5 billion (€62.1 billion) in excess medical costs and $81.9 billion in illness- related productivity losses each year in the US.
"Despite the widespread knowledge of nicotine's dangerous health effects, smoking continues to represent a serious public health threat in the US," said Dr Frank Vocci, director, division of pharmacotherapies and medical consequences of drug abuse, at the National Institute on Drug Abuse (NIDA).
"Given nicotine's highly addictive properties, and because other forms of smoking cessation treatments may not be as successful in the long term, vaccines may prove to be a promising alternative for those wishing to stop smoking," he added.
NicVAX is a nicotine derivative bound chemically to a specially selected carrier protein using Nabi Biopharmaceuticals' proprietary vaccine technology. It is designed to cause the immune system to produce antibodies that bind to nicotine and prevent it from entering the brain.
It is believed that these nicotine antibodies will act like a "sponge" soaking up nicotine as it circulates in the bloodstream and preventing it from reaching the brain.
The positive stimulus in the brain that is normally caused by nicotine would then no longer be present, thereby eliminating the addictive properties of nicotine and, consequently, helping people to quit and not relapse.
Studies in animal models have shown that vaccination with NicVAX can prevent nicotine from reaching the brain and block the effects of nicotine, including effects that can lead to addiction or can reinforce and maintain addiction.
Nabi's NicVAX is currently the only vaccine being developed in the US and Europe. Previous clinical trials have demonstrated that at 200 mcg - the highest dose tested - subjects demonstrated acceptable tolerance.
"Nabi Biopharmaceuticals will be in a position in 2005 to produce commercial-scale manufacturing quantities of the vaccine, making NicVAX the most clinically advanced product candidate in development for smoking cessation," said Henrik Rasmussen, senior vice president clinical, medical and regulatory affairs at Nabi Biopharmaceuticals.
Nabi Biopharmaceuticals said that it intended to announce preliminary safety and immunogenicity results from its European Phase II study by the end of 2005.
If all goes well Nabi expect to be in a position to initiate a pivotal efficacy trial, and begin to manufacture NicVAX in its US vaccine manufacturing facility.