Cerus Corporation Expands U.S. Patent Coverage for Pathogen Inactivation in Blood.

Business Editors and Health/Medical Writers

Cerus Corporation (Nasdaq:CERS) today announced that the U.S. Patent and Trademark Office has issued a patent to Cerus that expands its patent coverage for methods to inactivate viruses, bacteria and parasites in blood products using compounds that bind to the nucleic acid (DNA and RNA). U.S. patent number 6410219 covers the use of a wide category of compounds that target DNA or RNA, as well as the therapeutic use of blood or blood components treated with these methods.

"As we approach commercialization with our partner Baxter Healthcare for the INTERCEPT Blood System, we have built a strong proprietary position that establishes high barriers to entry," said Stephen T. Isaacs, president and chief executive officer of Cerus Corporation. "This broad new patent is central to the use of nucleic acid binding compounds to inactivate pathogens in red blood cells."

Cerus' patent portfolio consists of over 60 issued and pending patents covering methods and compositions to inactivate pathogens in blood and blood products using specific compounds that bind with DNA or RNA. The latest patent extends coverage to use of compounds that include chemical structures known as aziridines and aziridiniums.

Cerus and Baxter Healthcare Corporation are collaborating on the development of INTERCEPT Blood System to enhance the safety of blood transfusions. A CE Mark for the INTERCEPT Platelet System disposable set has been received, and the companies have begun the regulatory submission process to obtain approval in the United States. Separately, the companies are preparing the U.S. regulatory submission for the INTERCEPT Plasma System, which will be followed by a CE Mark application for this product. In addition, the companies are conducting Phase III clinical trials for the INTERCEPT Red Blood Cell System.

About Cerus

Cerus Corporation is developing medical systems and therapeutics based on its proprietary Helinx(R) technology for controlling biological replication. Cerus' most advanced programs are focused on systems to enhance the safety of blood products used for transfusion. The INTERCEPT Blood System, based on the company's Helinx technology, is designed to inactivate viruses, bacteria, other pathogens and white blood cells. The Concord, California-based company also is pursuing therapeutic applications of Helinx technology to treat and prevent serious diseases.

Statements in this news release regarding patent protection, regulatory filings, product development and commercial potential are forward-looking statements that involve risks and uncertainties. Actual results could differ materially from the above forward-looking statements as a result of certain factors, including the risks and uncertainty of the timing and results of clinical trials and other development activities, actions by regulatory authorities at any stage of the development process, the uncertainty concerning the enforceability of patents and the effect of patent rights of third parties, additional financing activities, manufacturing, market acceptance of any products, competitive conditions and other factors discussed in the company's most recent filings with the Securities and Exchange Commission.

Note to Editors: Helinx is a U.S. registered trademark of Cerus Corporation INTERCEPT is a trademark of Baxter International Inc.