Chiron's European HCV Patent is Upheld in Opposition Hearings in European Patent Office.

EMERYVILLE, Calif.--(BUSINESS WIRE)--April 11, 1996--Chiron Corp. (NASDAQ:CHIR) announced today that the Opposition Division of the European Patent Office (EPO) in Munich, Germany, upheld Chiron's European hepatitis C virus (HCV) patent No. 0 318 216 over oppositions filed by five opponents.

The patent's claims, which were upheld by the EPO in amended form, cover among others: antigenic HCV polypeptides (including structural and non-structural), regardless of method of production (e.g., recombinant, synthetic, etc.); HCV antibodies; the use of such polypeptides and antibodies in immunoassays; HCV polynucleotides; and the use of such polynucleotides in recombinant protein expression, DNA probe tests and PCR (polymerase chain reaction) tests.

Chiron's granted European HCV patent was published on Dec. 15, 1993. During the subsequent nine-month opposition period, oppositions were filed by Murex Diagnostics Ltd., United Biomedical Inc., Behringwerke AG, The Research Foundation for Microbial Diseases of Osaka University, and F. Hoffmann-La Roche and Co. AG.

A separate opposition by Akzo Pharma, B.V., was withdrawn following a settlement agreement between Chiron, Chiron's joint immunodiagnostics partner, Ortho Diagnostic Systems Inc., a Johnson & Johnson company, and Organon Teknika, N.V., a company of the Akzo Nobel Group, regarding patent infringement litigation in Europe and the United Kingdom, where Chiron's U.K. HCV patent has been upheld in a trial.

Chiron's European HCV patent has been enforced successfully against infringers in The Netherlands, Belgium and Germany, including the grant of a preliminary injunction in continental Europe against infringing sales of HCV blood screening assays by Murex Diagnostics Ltd., Organon Teknika, N.V., and United Biomedical Inc. Chiron's European HCV patent is currently the subject of infringement proceedings in Italy as well.

"Strong patent protection helps speed commercial applications of basic biomedical discoveries such as HCV, and thus plays a major role in improving the quality of healthcare worldwide," said William J. Rutter, Ph.D., Chiron's chairman.

"Since Chiron's discovery of HCV in 1987, and subsequent development and widespread introduction of blood screening tests by Chiron and Ortho, HCV infection has been prevented in more than 1 million transfusion and blood products recipients.

"In Japan, quantitative bDNA probe tests from Chiron and our partner Daiichi Pure Chemicals are being used to predict disease outcomes and monitor therapy for thousands of chronic hepatitis patients. We look forward to further contributions emanating from Chiron's HCV invention that will lead ultimately to the control and elimination of this serious infectious disease."

To date, Chiron has licensed aspects of its HCV patent portfolio for use in various fields and in various countries to Ortho Diagnostic Systems, Abbott Laboratories, Daiichi Pure Chemicals, Pasteur Sanofi Diagnostics and Institute Pasteur and Genelabs.

In addition, Chiron's cloning of the HCV genome has led to a significant expansion of research and understanding about this previously unknown agent, a major cause of serious liver disease around the world. Since 1987, more than 3,000 papers in the HCV field have been published by researchers using Chiron's basic invention.

Chiron Corp. is a science-driven healthcare company that combines diagnostic, vaccine and therapeutic strategies for controlling disease. Headquartered in Emeryville, near San Francisco, and with operations on four continents, Chiron had revenues in 1995 of more than $1 billion.

Chiron participates in four global healthcare markets: diagnostics, including immunodiagnostics, critical care diagnostics and new quantitative probe tests; therapeutics, with an emphasis on oncology and infectious disease; pediatric and adult vaccines; and ophthalmic surgical products for the correction of vision.

Chiron also has research programs underway in gene therapy, combinatorial chemistry, cancer, infectious and cardiovascular disease and critical care.

CONTACT: Chiron Corporation, Emeryville

Larry Kurtz, 510/601-2476