The makers of Viagra, the male impotence drug manufactured in Cork by the Pfizer pharmaceutical company of America, had their exclusive patent removed yesterday by a British High Court judge.
The decision opens the way for other companies to make similar products, thus challenging Pfizer, which employs about 1,000 people in Ireland. The company has a plant at Ringaskiddy.
The High Court in London upheld a challenge by US rival, Lilly Icos, which claimed that Pfizer's monopoly right on the use of Viagra's active ingredient to treat male impotence was invalid and stifled research by other companies.
The judge, Justice Hugh Laddie, ruled that the 1993 patent was "invalid for obviousness," because groundbreaking research used to develop the Viagra ingredient had already been in the public domain.
Researchers behind the original breakthrough had "discovered the essential facts which put the design and production of convenient anti-impotence pills within the reach of the pharmaceutical world," the judge said.
The ruling was a blow for Pfizer but was unlikely to open the door to a wave of similar rulings in other countries, analysts said. Nevertheless, the decision could have important implications. Pfizer said it was "very disappointed", but shrugged off suggestions that it would open the floodgates to cheaper Viagra alternatives.
Only the patent on the use of the ingredient for the treatment of impotence had been revoked, Pfizer said, while the patent on Viagra itself was still in force. It would take several years for rivals to develop new drugs to compete with Viagra.
But Eli Lilly, which jointly owns Lilly Icos with US drugs company Icos, is already developing its own anti-impotence drug.