Pfizer Korea is struggling hard to maintain the No. 1 status of anti-smoking drug Champix (ingredient: varenicline tartrate), which sells more than 60 billion won ($55.8 million) a year.

The drugmaker recently appealed to the Patent Court of Korea, after losing to 20 domestic pharmaceutical firms that won their “passive scope of rights” to the substance patent of Champix in a petition to the court.

Pfizer is also seeking a partner company for joint sales and marketing of Champix.

Pfizer’s strategies aim to thwart local firms’ moves to release rival drugs against the nicotine addiction treatment.

In April, 22 drugmakers, including Hanmi Pharmaceutical and Chong Kun Dang, won the court’s confirmation that they had passive rights to the Champix’ substance patent, which is scheduled to expire on July 19, 2010, during the extension period of the patent.

The court’s ruling allowed the 22 firms to release Champix-targeting generic copies, containing a different base, from as early as November.

Generic medicines would be a threat to Pfizer Korea, which is enjoying 65 billion won annual sales of Champix on the back of the government’s smoking cessation-supporting policies.

Pfizer Korea on filed a suit on May 10 against eight local drug suppliers with the Patent Court to cancel the recent judgment over the patent rights. The eight are Hanmi Pharm, Kolmar Korea, Kyungdong Pharmaceutical, Ahn-Gook Pharmaceutical, Anguk Newpharm, J2H Biotech, Il-yang Pharmaceutical and Whan In Pharm.

If the court rules in favor of Pfizer, the release of generic drugs could be delayed after July 19, 2020.

Pfizer is also eager to find the right partner company to sell Champix jointly.

Pfizer Korea had discussed with a high-ranking domestic drugmaker, but the local firm refused, sources said. Pfizer is searching for a new candidate, they said.

However, major local drug companies do not find it very attractive to sell Champix with Pfizer Korea.

Although Champix is a blockbuster drug selling 65 billion won a year, domestic firms can use a different base and release a generic drug. Plus, there are not many examples of original medicines that kept on selling well even after the expiration of the patent.

For example, hepatitis B treatment Baraclude used to post more than 100 billion won sales a year in the past. However, the drug lost the competition to generic drugs that came out in the market later.

“With sufficient sales power, local drugmakers would have felt that it was meaningless to sell original drugs if the patent lawsuit is completed. As many domestic firms started developing generic drugs, Pfizer might find it hard to search for a partner firm,” said a pharmaceutical source.

sjh@docdocdoc.co.kr

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