British Court Says Patent for TPA Is Too Broad : Genentech Dealt Setback Over Blood-Clot Drug

Genentech suffered a legal setback Tuesday in its battle to control the British patent rights to its potentially lucrative drug TPA. The drug has been found to be twice as effective as existing remedies for clearing clogged arteries, which form in 90% of all heart attacks.

The South San Francisco company said in a statement that Britain’s High Court found that a patent for tissue plasminogen activator was too broad and would be revoked unless modified. The company said it would appeal.

The patent, awarded to Genentech in early 1986, was disputed by Wellcome Foundation, an affiliate of Britain’s Wellcome PLC. The two separately devised genetic methods to produce the drug, but Genentech beat Wellcome to the British patent office last year.

The case was the first involving TPA, a drug that analysts have estimated could reap Genentech $1 billion a year in sales, worldwide, if it can hold onto the rights.

Companies have generally been allowed to patent only the lab process for making genetically engineered drugs since the drugs themselves are found in nature.

But Genentech’s patent claims would bar Wellcome from marketing its own of the drug, which it is testing in Britain and Japan.

Last May, the U.S. Food and Drug Administration delayed approval of the drug, asking for more data. That decision sent Genentech’s stock $12 lower to $37.25. On Tuesday, the stock closed down $1.50 at $38.50.

Coincidentally with the ruling, however, Genentech reported that its foreign licensee, Boehringer Ingelheim International GmbH, received approval from France to market the drug under the trade mark Actilyse.

Analysts predicted that the ruling would open up the TPA field to other competitors.

Sarah Gordon, an analyst with Hambrecht & Quist, said the court approved only four of 20 claims in the patent and took particular offense at Genentech’s assertion that its patent covered all first- and second-generation TPA products.

The four approved claims relate to the particular gene-splicing method that Genentech used to produce TPA, Gordon said. Thus, if Wellcome could convince the court that its method of producing TPA was novel, it could make the substance without a license from Genentech.