Genentech Wins Another Battle Over Heart Drug : South San Francisco Firm Awarded Patent for Technology to Make TPA
Genentech won a skirmish in its global battle to protect its genetically engineered heart attack drug from direct competition Tuesday when the U.S. Patent Office awarded the company a patent covering the technology for its production.
This was the second major patent awarded Genentech this year for TPA, which has been touted as the first blockbuster drug from the biotechnology industry. Like the first patent, which was awarded in June and covers the substance itself, the new patent sparked immediate litigation.
As soon as the new patent was issued, Genentech filed a patent infringement suit against competitors Wellcome PLC, Genetics Institute and their affiliates to enjoin them from developing their own versions of TPA, which dissolves blood clots in heart attack patients.
Genentech and Wellcome are also locked in litigation over TPA patents in Great Britain. In July, 1987, the British High Court invalidated Genentech’s broad patent claims involving TPA after a challenge by Wellcome. Genentech appealed the decision, and a ruling is expected soon.
Extent of Patent Key
Wellcome is based in Great Britain, but its U.S. arm, Burroughs-Wellcome, declined comment on the new litigation, as did Genetics Institute of Cambridge, Mass. Genetics Institute has licensed some of its TPA technology to Wellcome and is trying to develop a second-generation version of the drug.
As is the case with the earlier patents, “the extent and breadth of the new patent will be determined by the courts,” predicted Kathleen Behrens, a biotechnology analyst with Robertson, Colman & Stephens, a San Francisco brokerage firm.
The key question, she added, is whether the new patent is broad enough to cover production techniques for the next generation of genetically engineered blood clot dissolvers.
The stakes are high. Approximately 600,000 heart attack patients in the United States are candidates for TPA therapy every year, Behrens said. At $2,200 a dose, the market’s potential value is more than $1 billion, though most analysts say the market will be much smaller because of competition from a less expensive drug called Streptokinase.
Still, “the patent we received today is confirmation of Genentech’s pioneering work in applying recombinant DNA technology to the production of important pharmaceutical products,” said Robert A. Swanson, Genentech’s chief executive.
Genentech’s stock price has been under pressure in recent weeks after British investigators released results of clinical trials showing that the combination of Streptokinase and aspirin reduced the death rate among heart attack patients. Streptokinase is made by Beecham Group PLC and Hoechst AG. Genentech, having traded as high as $53.50 in the past 12 months, closed Tuesday at $20.75, down $1, on the New York Stock Exchange.
The first major study pitting TPA against Streptokinase is being conducted in Italy, and results won’t be available until late 1989.
South San Francisco-based Genentech also came under pressure last March, when federal Medicare administrators refused to increase subsidies for TPA, whose commercial name is Activase.
This week, in a small victory for Genentech, the New Jersey Health Department decided that Medicare patients treated with Activase would be reimbursed by the state’s Medicare pool. “We consider New Jersey to be a significant bellwether for other states,” said a Genentech spokesman.
TPA, or tissue plasminogen activator, is a naturally occurring human protein. Genentech’s technique for producing the substance in bulk involves splicing the genes that dictate the production of TPA into mammalian cells--in this case, cells from from the ovaries of Chinese hamster.
With the genes thus inserted, the cells become tiny factories producing TPA, which is then collected and purified.
