Judge Upholds Burroughs’ Claim to AZT Patent : Drugs: Ruling gives firm exclusive rights to AIDS medication; two others are prohibited from making a cheaper generic.

A federal judge ruled Thursday that scientists at Burroughs Wellcome Co. are the sole inventors of the AIDS drug AZT, meaning that two companies seeking to make and market a cheaper generic version will not be allowed to do so soon.

The decision upholds Burroughs’ exclusive patent on AZT, the most widely prescribed AIDS treatment. But it is expected to be reviewed by an appeals court.

The decision was hailed as a “clear victory” by Burroughs, while a spokesman for Barr Laboratories, one of two companies seeking to make generic AZT, warned: “It’s not over, not by a long stretch.”

The decision was good news for investors in Wellcome, Burroughs Wellcome’s British parent. Its shares rose 37 1/2 cents to close at $9.50 on the New York Stock Exchange. Barr Labs’ stock fell $1.625, to $16.125, on the American Stock Exchange.

AZT typically costs AIDS patients about $2,200 a year. The competing firms have pledged that their product would cost 50% less.

The legal battle centers around the contributions of researchers at the federal government’s National Cancer Institute, who worked with Burroughs scientists in the mid-1980s on studies of the drug.

Barr Laboratories of Pomona, N.Y., and Novopharm Ltd. of Scarborough, Canada, claim that the work of NCI’s Dr. Samuel Broder, now institute director, and Dr. Hiroaki Mitsuya helped determine the value of AZT as an AIDS therapy.

The National Institutes of Health, of which NCI is a part, even granted Barr a license to make the drug--an action that spurred a Burroughs lawsuit, which resulted in Thursday’s decision.

U.S. District Judge Malcolm Howard said, “the court has felt for some time that U.S. law . . . dictates that Burroughs Wellcome scientists were, in fact, the sole inventors of AZT.”

Paul A. Holcombe Jr., Burroughs’ vice president and general counsel, said company officials “believe strongly that this decision is in the best interests of the HIV community and all persons for whom life-saving medications have not yet been found,” because it supports a patent system designed to encourage drug innovation by pharmaceutical companies.

But Barr spokesman Harold Cohen said Barr would continue its fight, adding: “The unfortunate part of all of this is that it will delay generic AZT from getting into the marketplace.”

The Burroughs patent does not expire until 2005.