Nabi Biopharmaceuticals announced that enrollment has begun in its Phase I/II clinical trial of NicVAX (Nicotine Conjugate Vaccine), in smokers, ex-smokers and non-smokers. The trial is being conducted at the University of Maastricht, the Netherlands, and represents the company's first clinical trial at a European site. NicVAX is a proprietary and novel investigational vaccine that is being developed to prevent and treat nicotine addiction by eliciting the production of antibodies that bind to nicotine and block it from reaching the brain.

"We are very pleased to begin patient enrollment in our NicVAX trial in smokers, ex-smokers and non-smokers," said David J. Gury, Nabi Biopharmaceuticals chairman and chief executive officer. "The encouraging results that were previously reported for our Phase I trial in non-smokers allow us to take this important next step in assessing the role that NicVAX might play in treating and preventing nicotine addiction."

The trial is a double-blinded, placebo-controlled study that is evaluating the safety and immunogenicity of NicVAX. Thirty subjects will be enrolled, consisting of 21 smokers and 9 ex-smokers or non-smokers who will be assigned to receive either active vaccine or placebo control. All subjects will receive at least three immunizations of either NicVAX or placebo. A fourth immunization may be administered depending on initial results. The primary endpoints of the study will evaluate nicotine specific antibody levels and safety of the vaccine (local and systemic reactions and adverse events) through at least 9 months post-vaccination. Secondary endpoints will include evaluating abstinence from smoking and the time it takes to relapse.

Nabi Biopharmaceuticals previously announced preliminary results of a placebo controlled, double-blinded Phase I clinical trial of NicVAX in non-smokers. In that trial, a single dose of NicVAX produced measurable antibody levels against nicotine in vaccine recipients as early as 7-14 days after vaccination. In addition, these antibody levels were maintained or continued to increase over 4 months. Local and systemic reactions in the 20 study subjects in this trial were generally mild to moderate, temporary and required no therapeutic intervention. No serious adverse events were reported. The initial data from this trial were presented at the annual meeting of the European Society for Research on Nicotine and Tobacco held in Santander, Spain, October 3-5, 2002, and updated information will be presented at the Society for Research on Nicotine and Tobacco meeting in New Orleans, LA on February 20, 2003. In pre-clinical animal studies, NicVAX generated high levels of nicotine-specific antibodies and was able to block the effects of nicotine in animals by reducing nicotine levels in the brain by up to 64%.

Additional clinical trials of NicVAX in smokers and ex-smokers are planned to begin later this year in the United States. Development of NicVAX in the U.S. is funded, in part, by grant DA-13327 from the US National Institute on Drug Abuse, National Institutes of Health.