As the main patent for Viagra, the world’s bestselling anti-impotence pill, nears its expiration, Korean pharmaceutical companies are gearing up to push generics into the market.

However, their efforts may hit a snag as Pfizer, the maker of the drug, holds a separate patent for it’s main use.

According to the Korea Food and Drug Administration, three out of 29 companies that have applied to sell generic Viagra have passed testing to show that the products are equivalent.

The name of their products will be made public by the end of the month. The others are yet being examined.

Those who have managed to prove equivalent effectiveness to Viagra by using sildenafil, its main active ingredient, will be able to release the product from May 17 when domestic patent for Viagra expires, the industry hopes.

However, the distribution of the drug may be far off, since Pfizer claims it has sole rights until May 2014.

Pfizer, which released Viagra in Korea in 1999, currently holds two patents here in connection to sildenafil: One for the basic compound of sildenafil, which expires after May 17 and the other for its use against erectile dysfunction, valid until May 2014. 

Domestic drug makers, CJ and Hanmi, filed a suit against Pfizer on the extent of patent last May, and related investigation is underway.

“We may have to release the generic on due date even if we may have to compensate Pfizer later,” a CJ spokesman was quoted by Yonhap News.

But Pfizer is stern. “We cannot prevent other drug makers from manufacturing sildenafil, but they won’t be able to use it for erectile dysfunction treatment,” a Pfizer Korea insider told The Korea Herald.

In August last year a U.S. federal court upheld the U.S. patent for Viagra by 2019 on the basis of similar claims.

“We hope likewise sentences will be made at the Korean court,” the Pfizer official said.

If it loses, Pfizer Korea will suffer a huge loss. It currently holds 40 percent of the 100 billion won ($8.6 million) anti-impotence drug market in Korea and has maintained the market leadership since its release. 



By Bae Ji-sook
(baejisook@heraldcorp.com)