Pfizer’s smoking cessation drug Champix to face generic competitors in Korea

South Korean drugmakers are rushing to roll out generic copies of Pfizer’s smoking cessation drug Champix, as the treatment’s substance patent here was recently broken by a local patent court. The decision allows copycat drugs to be launched in Korea by as early as November.

Korea’s Intellectual Property Trial and Appeal Board recently ruled in favor of 22 local drugmakers which had claimed that their generic copies of Champix -- slightly modified to use Varenicline salicylate instead of Varenicline tartrate as their main ingredient -- does not infringe Pfizer’s substance patent for Champix. 

As a result, the 22 companies, including Hanmi Pharmaceutical, Chong Kun Dang Pharmaceutical, Daewoong Pharmaceutical, Kolmar Korea and Ildong Pharmaceutical, are legally permitted to launch their modified versions of Champix from November.

To obtain approval for generic drugs, companies have to prove bioequivalence between the generic drug and original drug, without a need to undergo the three-phase clinical trials required of newly developed drugs.

With the aim of delaying the onset of generic competition, Pfizer had extended the patent for the substance used to develop Champix from November 2018 to July 2020 in Korea.

Up until now, Pfizer had dominated Korea’s anti-smoking medication market with Champix on the back of the government’s anti-smoking initiative.

Last year, Champix saw 65 billion won ($60.62 million) in sales, up tenfold from just 6.3 billion won in 2014, according to local pharma sector data provider Iqvia.

Among the Korean drugmakers slated to launch Champix generics, Hanmi Pharmaceutical is perceived as the strongest contender to Pfizer’s original drug, considering the Korean drugmaker already markets a generic version of GSK’s bupropion hydrochloride, a similar smoking cessation drug.

Industry watchers expect Hanmi to leverage its former marketing channels to successfully launch its Champix generic in Korea, edging out rival products including the original drug.

In 2017, around 39.3 percent of Korea’s male population aged 19 years or higher were smokers, according to a survey of 228,381 Koreans by the Korea Centers for Disease Control and Prevention in partnership with 254 community health centers nationwide. 

By Sohn Ji-young (jys@heraldcorp.com)