Pfizer Loses Ruling in Britain on Viagra
Pfizer Inc. on Wednesday lost a patent ruling that could allow competition in Britain for its Viagra impotence drug from a venture backed by Microsoft Corp. Chairman Bill Gates.
An English High Court justice ruled in favor of a patent challenge by Icos Corp. and Eli Lilly & Co., which set up a joint venture for an experimental impotence drug. Gates is Icos’ largest shareholder.
Lilly Icos had brought the case because it is trying to produce a treatment to rival Viagra, one of the world’s fastest-selling drugs.
The ruling only invalidates Pfizer’s patent on the class of drugs in Britain, but a Pfizer spokeswoman said there was a corresponding action in the works on a similar broad patent for the European Union.
The impact of the ruling was limited, New York-based Pfizer said, because the basic patent protecting the active ingredient of Viagra, a chemical called sildenafil, remains unchallenged and will not expire until 2013.
The decision means other companies can sell drugs that treat impotence by blocking PDE-5, or the phosphodiesterase enzyme, but none can sell versions of Viagra until Pfizer’s sildenafil patent expires.
Pfizer’s patent might have blocked British sales of the rival drug from Lilly Icos because both it and Viagra work on the same family of enzymes in the body, said Lehman Bros. researcher Trevor Polischuk.
Shares of New York-based Pfizer rose 56 cents to close at $45.38 on the New York Stock Exchange. Shares of Lilly, based in Indianapolis, rose $3.19 to close at $90.44, also on the NYSE. Shares of Icos, based in Bothell, Wash., fell 56 cents to close at $52 on Nasdaq.
Microsoft’s Gates also serves on Icos’ board.
Pfizer spokesman Andy McCormick said his company is reviewing the decision and considering an appeal. “The patent for Viagra’s active ingredient remains unchallenged,” he said.
Worldwide sales of Viagra rose 36% to $332 million in the third quarter. Viagra is one of the world’s most widely prescribed medications: More than 30 million prescriptions have been written for more than 10 million men and more than 300 million tablets have been dispensed, Pfizer said last month.
