Philippe Hoogsteder

Project title
The NicVAX-study, the efficacy and safety of a nicotine vaccine to quit smoking

Prof. dr. O. van Schayck and Dr. D. Kotz

Background: Although nicotine vaccination could be a new approach in smoking cessation, first efficacy results of several nicotine vaccines showed some disappointing results.  Previous studies investigating the efficacy of the nicotine vaccine ‘3’-AmNic-rEPA’ (NicVAX) showed that only a subgroup of top 30% antibody responders achieved significantly higher abstinence rates than placebo. In the current trial we investigated the efficacy of NicVAX co-administered with varenicline and counselling as an aid in smoking cessation and relapse prevention.

Methods: A total of 558 smokers were randomly assigned to 6 injections with NicVAX (N=278) or placebo (N=280). Both treatment groups received a 12-week therapy with open-label varenicline and 23 behavioural counselling sessions over a period of 54 weeks.Outcomes were carbon monoxide validated abstinence from week 9-52 (primary) and week 37-52 (secondary). We also performed a subgroup analysis in the top 30% antibody responders.

Results: There was no difference in abstinence between NicVAX and placebo when co-administered with varenicline and counselling from week 9-52 (27.7% vs. 30.0%, OR=0.89, 95%CI=0.62-1.29) or week 37-52 (33.8% vs. 33.2%,OR=1.03, 95%CI=0.73-1.46). The top 30% antibody responders, compared to the placebo group, showed a tendency towards significantly higher abstinence rates from week 37-52 (42.2% vs. 33.2%, OR=1.47, 95%CI=0.89-2.42).

Conclusion: The combination of NicVAX with varenicline and counselling was not effective in increasing abstinence or preventing relapse. Future research on the development of nicotine vaccines should focus on both increasing the quality of the induced antibodies to bind nicotine and on increasing the amount of circulating antibodies.

Research funding: To conduct this trial we received a TOP-grant from the Netherlands Organisation for Health Research and Development (ZonMW). The study medication was sponsored by Nabi biopharmaceuticals and Pfizer.