NABI COMPLETES ENROLLMENT IN NICOTINE VACCINE STUDY

Nabi Biopharmaceuticals has completed enrollment for its Phase IIB study of NicVAX (nicotine conjugate vaccine), the company's investigational vaccine being developed to treat nicotine addiction and prevent smoking relapse. Enrollment for the trial was completed three months earlier than anticipated, paving the way for the release of trial results early in the second quarter of 2007.

The Phase IIB study for NicVAX was designed with extensive input from the FDA, the European Medicines Evaluation Agency, the National Institute on Drug Abuse and leading external consultants. The study is a double-blinded, placebo-controlled, dose-ranging study comprising approximately 300 patients, a large enough sample size to establish both proof-of-concept and optimal dose identification for the Phase III program. The primary endpoint of the study is the abstinence rate at six months. Abstinence will be evaluated by several measures, including reported cigarette consumption, chemical markers of nicotine in the bloodstream and behavioral assessment. Secondary endpoints include the abstinence rate at 12 months, total cigarette consumption, titer levels, safety and nicotine dependency. The efficacy rates in this study will incorporate the benefits of other elements in smoking cessation programs, including counseling and behavioral modification.

The main reason it is so difficult to stop smoking is that smokers crave the rush they get when nicotine reaches and binds to receptors in the brain, according to the company. That releases dopamine, which creates the positive stimulus in the brain and at the same time is very addictive. NicVAX is designed to prevent the rush and the associated addiction by preventing nicotine from entering the brain. The vaccine stimulates the immune system to produce antibodies that bind to nicotine, which prevents nicotine from reaching the receptors in the brain.