Chantix bags Pfizer fourth new drug approval in 2006
Chantix (varenicline), an anti-smoking pill from Pfizer, has become the first new prescription medication to be approved for smoking cessation in nearly a decade, and the fourth new medicine to be approved for Pfizer in 2006, following its priority review and approval by the US Food and Drug Administration (FDA).
Chantix (varenicline), an anti-smoking pill from Pfizer, has become the first new prescription medication to be approved for smoking cessation in nearly a decade, and the fourth new medicine to be approved for Pfizer in 2006, following its priority review and approval by the US Food and Drug Administration (FDA).
Inhaled cigarette smoke sends nicotine to the brain where it binds to nicotinic receptors, activating the "reward pathway" in brain circuitry and stimulating a pleasure centre in the brain. Chantix is specifically designed to partially activate the nicotinic receptors, meaning that it will reduce the severity of a smoker's craving and withdrawal symptoms from nicotine, as well as diminish the stimulation associated with smoking.
In five randomised, placebo-controlled clinical trials, which included a total of 3659 "chronic" cigarette smokers (averaging 21 cigarettes per day over 25 years), a 12-week course of 1mg of Chantix twice-daily quadrupled the likelihood of smoking cessation. In two of the five studies, Chantix-treated patients also achieved higher rates of smoking cessation than patients treated with 150mg of GlaxoSmithKline's Zyban (bupropion) twice-daily.
Patients were followed for an additional 40 weeks without treatment, and after one year approximately one-in-five who had received the 12-week course of Chantix maintained their smoking abstinence. An additional 12-week Chantix course was also shown to result in greater likelihood of "long-term" smoking cessation.
The most common adverse effects were nausea, headache, vomiting, flatulence, constipation, insomnia, abnormal dreams, and dysgeusia (change in taste perception).
According to the Centers for Disease Control and Prevention (CDC), an estimated 44.5 million adults in the US smoke cigarettes, with more than 8.6 million of these suffering from' at least one serious illnes's as a result. According to Hank McKinnell, chairman and ceo of Pfizer, smoking is responsible for approximately one in five deaths in the US and costs the US health care system about $167bn annually.
Pfizer's other new drug approvals this year have been Exubera for diabetes, Eraxis for the treatment of candidemia infections and Sutent for the treatment of advanced kidney cancer and gastrointestinal stromal tumours.