Korean pharmaceutical firms are gearing up to enter the 100 billion won anti-impotence drug market as the main patent of the market leader, Pfizer’s Viagra, expired last week, allowing for generic versions of the “blue magic pill.”

However, they will likely face challenges, as Pfizer claims its patent to be effective until 2014, warning of litigation against rivals. A lukewarm market response could be another snag.

According to the Korea Food and Drug Administration, a total of 28 generics produced by 15 domestic pharmaceutical companies have passed bioequivalence tests and are awaiting release.

CJ, one of the country’s largest commodity makers, made the first move and released “Heragra” on May 18, a day after the expiration. CJ says that its product has the same effect as Viagra but at one-third of the price: While Viagra is sold at up to 16,000 won ($13.60) a pill, Heragra costs around 5,000 won.

Hanmi, Ilyang, Daewoong, Seoul, Samjin and others are also reportedly seeking to release versions. Since Pfizer is known to have raked in more than 400 billion won by selling about 36 million pills since the drug’s launch in October 1999, the expiration of the patent is a golden opportunity for them to increase revenue, industry insiders say.

However, their dreams may have to be shelved for a while as Pfizer has declared that its patent for sildenafil, the drug’s main substance, is valid for another two years.

“Pfizer held two different patents in regards to sildenafil. One was for the basic compound of sildenafil, which expired on May 17, and the other is the material’s use in treating erectile dysfunction. This is valid until May 13, 2014,” a Pfizer spokeswoman said.

This means that people are free to use sildenafil but cannot use it for erectile dysfunction treatment, the drugmaker said.

CJ and several others filed a suit against the company with the Korean Intellectual Property Tribunal in May 2011. Both drug makers hoped the verdict would be made earlier this month but the judges are reportedly considering a ruling in June. The U.S. and several other countries have ruled in favor of Pfizer already.

“It is a risky shot for us to release the product before the ruling is made,” Shin Seung-pil, a CJ spokesman, admitted. “But it was also important for us to dominate the market among the generic makers. We are hoping that the court will listen to our lawyers.”

The reason for the premature moves of pharmaceutical firms is the fact that Korea has one of the largest anti-impotence treatment markets in the world, with estimated sales of around 100 billion won a year ― double that when including the black market.

Korea is the only country with where six original erectile dysfunction treatments are sold: Pfizer accounts for 40 percent of the market, followed by Lilly’s Cialis (33 percent), Donga’s Zydena (20 percent), Bayer’s Levitra, Choongwae’s Zepeed and SK Chemical’s Mvix.

“We are hoping that price-sensitive black market users will come out into the light and buy cheaper generics,” a pharmaceutical firm insider said.

Since the pills require a doctor’s prescription, the newcomers said they will run aggressive marketing to attract doctors.

The current market holders, apparently concerned about losing profits, are also busy developing new marketing strategies. The maker of one of the less-competitive drugs is rumored to have even decided to exit the Korean market.

“We released a film-type drug last year, which was a remarkable hit. We are expecting that our customers will not be attracted to cheap drugs because what they care about is the container of the drug being unnoticeable to other people, not the price,” an SK Chemical spokesman said.

Some observers are skeptical.

“The black market users are those who are reluctant to reveal their sexual problems, even to the doctors and pharmacists. They will not go do the doctors for cheaper drugs anyway,” a marketer for an ED drug said.

Some are even more worried that the entrance of generics will mislead the public about erectile dysfunction.

“Many cases of erectile dysfunction are not physical disorders but phenomena that stem from insecurity in one’s mind. Drug makers have successfully positioned it as a ‘treatable disease’ but I am not sure whether it is a good thing for men,” said a doctor who works at a general hospital.

He said Viagra has acted for men as a “happy drug,” which gives mental support to men with sexual difficulties, but he would not prescribe it to every man seeking his help, even for health’s sake.

“Doctors hope that the release of generics won’t stimulate the concerns of men who temporarily face difficulties. All medicines have risks and ED drugs are no exception,” he added.

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