Pfizer smoking cessation drug approved in US

Pfizer is set to launch the first new smoking cessation drug in nearly a decade after it received regulatory approval from the US Food and Drug Administration (FDA).

The prescription-only product, Chantix (varenicline), is set to do battle with GlaxoSmithKline's Zyban (bupropion) in the US market. Chantix received a fast-track review from the FDA and was submitted to European regulators in November last year.

Chantix works differently from other smoking cessation drugs on the market, in that it simulates the effects of nicotine on the brain thus reducing cravings and withdrawal symptoms. It is not a nicotine replacement product like many patches, lozenges, gums, inhalers, and nasal sprays already available for smoking cessation and, unlike Zyban, it is not an antidepressant.

In two Pfizer studies, patients receiving a 12-week course of Chantix nearly quadrupled the likelihood of quitting compared to those on placebo and had nearly twice the likelihood of quitting than those patients on Zyban. Forty-four per cent of Chantix patients managed to give up the habit, compared with 30 per cent who took Zyban.

The recommended therapy lasts 12 weeks, with patients who manage to quit during this time being permitted to continue for another 12 weeks to boost their chances of staying-smoke free, the FDA said.

Pfizer is bullish about the drug's market potential, forecasting annual sales of $1.2bn by 2010. However, analysts have remained cautious on Chantix, suggesting that Pfizer may face a challenge in convincing medical insurance payers that the drug can help to reduce healthcare costs caused by smoking-related illnesses.

ìWe are somewhat wary of payers' reticence to pay for treatments such as Chantix,î Lehman Brothers analyst, Tony Butler, told the Financial Times. ìHowever, payers might view the mid- to long-term savings garnered by reducing the healthcare costs associated with smoking as a beneficial trade-off.î

The American Cancer Society has welcomed the drug, which will be available on the US market in the second half of this year.

ìChantix offers clinicians and smokers a unique therapeutic approach to quitting and an important new tool in the effort to reduce tobacco-related cancers and other diseases,î said the charity's director of cancer science and trends, Tom Glynn.

Pfizer, the world's largest pharma firm, is hoping to offset an estimated loss of $14bn a year due to key patent expiries, by introducing new blockbuster treatments. Other recent approvals are inhaled insulin treatment, Exubera, cancer drug, Sutent, and Eraxis for infections.

The company also recently announced a cost-cutting plan designed to save at least $4bn by 2008.