By Karen Pihl-Carey
Chiron Corp. filed a patent infringement lawsuit against Genentech Inc. regarding the manufacture and sale of Herceptin (trastuzumab), a drug to treat metastatic breast cancer that the FDA approved in September 1998.
Emeryville, Calif.-based Chiron received U.S. Patent No. 6,054,561 in late April. The patent covers monoclonal antibodies that bind selectively to human breast cancer cells, specifically to the c-erbB-2 - or HER-2 - antigen.
Herceptin is a monoclonal antibody treatment for metastatic breast cancer that overexpresses the HER-2 (human epidermal growth factor receptor-2) protein.
Herceptin sales in 1999 were $279.4 million, the highest first-year sales of any anticancer product in the U.S., according to Genentech.
"We very much reject the claim contained in the suit that our product infringes on Chiron's patent," said Sabrina Johnson, director of corporate communications at South San Francisco-based Genentech. "And we intend to defend ourselves vigorously in this matter."
The patent is the latest in a series of patents first issued in 1988 to Cetus Corp., which Chiron later acquired. The patents are based on an application originally filed in 1984. Chiron said its scientists are acknowledged to have pioneered development of the first anti-c-erbB-2 monoclonal antibody, which laid the foundation for future approaches to cancer diagnostics and immunotherapy.
Robert Blackburn, Chiron's vice president and chief patent counsel, said Chiron is willing to license the technology to Genentech and others "on commercially reasonable terms." He also said in a statement that negotiations with Genentech for such a license have failed, leading to the lawsuit, filed in the U.S. District Court for the Eastern District of California.
Chiron has not sought injunctive relief and Herceptin is expected to remain on the market until the two companies resolve the dispute, Blackburn said.
"We're not going to run this litigation in a way that jeopardizes patient access to a drug they need," Blackburn told BioWorld Today.
Johnson said Genentech became aware of Chiron's patent shortly after it was granted. "We are familiar with their patent," she said. "We further suggest that Chiron's patent is invalid, and we intend to defend ourselves vigorously in this matter and prove our case in court. And we have every confidence that the courts will find in our favor."
Johnson said Genentech would not comment on Chiron's statement about negotiations.
Herceptin received FDA approval in September 1998, only five months after Genentech filed a biologics license application. (See BioWorld Today, Sept. 29, 1998, p. 1.)
Blackburn said Chiron's efforts in negotiating a license agreement with Genentech "predate the product's approval."
Genentech is continuing to develop Herceptin, which is in trials as an adjuvant therapy for early-stage breast cancer with HER2 overexpression. The company recently signed an exclusive licensing deal worth up to $40 million to use the maytansinoid Tumor-Activated Prodrug technology of Cambridge, Mass.-based ImmunoGen Inc. with antibodies such as Herceptin. (See BioWorld Today, May 5, 2000, p. 1.)
Chiron's stock (NASDAQ:CHIR) closed Thursday at $41.75, down $1.313, while Genentech's stock (NYSE:DNA) closed at $125.125, down $2.125.