Genentech Wins Suit Over Rights to Cancer Drug

Genentech Inc. prevailed over Chiron Corp. on Friday in a patent dispute concerning rights to one of Genentech’s best-selling medicines, the breast cancer drug Herceptin.

A federal court jury in Sacramento ruled that Chiron’s patent on breast cancer antibodies was invalid, a blow to the Emeryville, Calif.-based firm. Chiron had been seeking as much as $300 million in royalties from Genentech.

The unanimous verdict by the 10-member panel gives Genentech an important victory at a time when its business practices have come under scrutiny. Genentech is appealing a $500-million judgment against it by a Los Angeles County jury that found it cheated City of Hope National Medical Center out of royalties.

The verdict also protects Genentech’s monopoly in antibody drugs that target a breast cancer protein called Her-2, which plays a role in tumor growth.

The dispute between the companies arose from a race during the 1980s to find the molecular cause of breast cancer. Chiron, in its suit, claimed that in 1984, two scientists at Cetus Corp. developed a mouse antibody that targeted the human breast cancer protein. Chiron acquired Cetus in 1991.

Chiron didn’t develop a drug based on the Cetus invention but pursued a patent for it. The patent was issued in 2000.

Genentech argued, and the jury agreed, that Chiron’s patent was not valid. The South San Francisco-based firm said the Chiron patent was not useful or well described, two important tests. It said Chiron invented a mouse antibody that, if used in people, would be destroyed by the immune system before it could attack a cancer cell.

Genentech also argued that Chiron did not mention Her-2 by name in its patent application until 1995, 11 years after it was filed. By that time, Genentech scientists had published a paper describing Her-2.

Genentech also asserted that it makes Herceptin by a different process than the one outlined in the Chiron patent. The Herceptin antibody is part human, part mouse.

Chiron says it continues to believe its patent is valid and will pursue “multiple courses of action” to overturn the verdict, including an appeal, if necessary. On Friday, the company asked U.S. District Judge William B. Shubb to set aside the jury verdict.

Chiron said it will continue to pursue a second patent infringement lawsuit against Genentech over Herceptin. That suit involves a 1998 patent on the same antibody invention. It is scheduled for trial next year.

Meanwhile, Sean Johnston, Genentech vice president for intellectual property, said the company will continue its challenge to Chiron’s patent already underway at the U.S. Patent and Trademark Office. In that dispute, Genentech claims that two scientists at the University of Pennsylvania are the actual inventors of human breast cancer antibodies. Genentech has an exclusive license on the university’s intellectual property.

When it launched in 1998, Herceptin was hailed as an important breakthrough in breast cancer treatment. It has posted total sales of about $1 billion.

Chiron shares rose 96 cents to $36.63 on Nasdaq, and Genentech climbed 30 cents to $31.70 on the New York Stock Exchange.