Articles

New NicVAX (nicotine vaccine) May Help Smokers If Approved by FDA

By Angie Enloe, R.Ph.

Smoking is a global healthcare problem. The World Health Organization (WHO) estimates that there are 1.3 billion smokers worldwide today and nearly five million tobacco-related deaths each year. If current smoking patterns continue, smoking will cause some 10 million deaths each year by 2020. According to the Centers for Disease Control (CDC), tobacco use is the single leading preventable causes of death in the U.S., responsible for approximately 438,000 deaths each year. More deaths are caused each year by tobacco use than by alcohol use, illegal drug use, suicides, motor vehicle accidents, murders, and HIV combined. The CDC estimates that, among the 45 million adult smokers in the U.S., 70% want to quit, but less than 5% of those who try to quit remain smoke-free after 12 months.

NicVAX is an experimental injectable nicotine vaccine being developed to help billions of patients worldwide who are addicted to smoking tobacco products, or are at risk of becoming addicted. It is also being looked at as an aid in preventing relapses of treated smokers. The investigational vaccine 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. Preclinical studies showed that vaccination with NicVAX can prevent nicotine from reaching the brain and block the effects of nicotine, including effects that can lead to addition or can reinforce and maintain addiction. The effects of NicVAX have been shown to be irreversible for potentially 6-12months following vaccination as antibodies to nicotine continue to be produced by the body’s immune system. This is important due to the extremely high relapse rate that has been observed when a smoker attempts to quit smoking.

In a Phase II study, scientists observed that nicotine antibodies increased in all nicotine vaccine groups. More patients who received the highest dose of vaccine achieved 30 day abstinence in a shorter amount of time than those who received other doses or placebo. Scientists also found that there were no typical withdrawal symptoms, such as cravings, irritability, or compensatory smoking (smoking more of a cigarette or puffing more often to increase nicotine intake). More than 90% of reported side effects were mild to moderate in severity. The most frequently reported events were upper respiratory tract infection, headache, cough, and inflammation of the nasal passages and throat.

Nabi Biopharmaceticals, the company responsible for creating NicVAX, recently reported results from the ongoing Phase IIb study in May 2007. The NicVAX was well tolerated by the patients in the study throughout the first six months of dosing and showed a favorable adverse event profile with no difference between placebo and each dose group, one group at 200mcg and the other at 400mcg per injection. The most common events immediately following the injection included minor aches and tenderness at the injection site, general discomfort, headache, and muscle ache. These reactions resolved quickly and did not increase with the number of injections. Fever and nausea were seen in less than 10% of all patients. This Phase IIb trial is continuing after all patients receive a booster injection at six months. The study will assess a series of endpoints at 12 months, including abstinence rate, total cigarette consumption, antibody concentration, safety and the degree of nicotine dependency.

Even after all of these clinical trials, there are still more to come in order to determine the safety and efficacy of NicVAX. The FDA has given the vaccine Fast Track Designation, which will speed up the process of getting the vaccine on the market and available to patients. Stay tuned in the near future for more to come about this vaccine that may help billions of people successfully quit smoking permanently.