U.S. Patent Board Awards Enzo Biochem Judgment in Patent Interference after Princeton University Concedes Priority


Enzo Biochem, Inc. (NYSE: ENZ) announced today that the Board of Patents and Interferences has entered judgment in favor of its subsidiary's patent application for nucleic acid signal amplification over two patents owned by Princeton University. Princeton had conceded priority to Enzo.

In the interference declared by the U.S. Patent and Trademark Office in August 2006, Enzo Life Sciences was named the senior party and Princeton, owner of U.S. Patent Nos. 4,882,269 and 5,424,188, was the junior party. The '269 patent was licensed by Princeton to Chiron Corp., who subsequently licensed it to Bayer HealthCare, LLC.

Another interference involving the same technology was declared at the same time by the Patent Office naming Enzo Life Sciences as the senior party against Chiron, the junior party, and Chiron's U.S. Patent No. 5,124,246, which also has been licensed to Bayer. That interference is still pending.

"We believe this development further clarifies the historic account of which party first invented nucleic acid signal amplification technology", said Dr. Elazar Rabbani, Enzo's Chairman & CEO.

This nucleic acid technology is the basis for several significant products in clinical diagnostics and in the life sciences field which are currently marketed or licensed by various commercial companies. According to trade reports, industry-wide annual sales of diagnostic products utilizing this technology are estimated to exceed $100 million in the United States alone. Among these products are the "VERSANT(R) Branched DNA (bDNA) Assays" sold by the Diagnostics Division of Bayer HealthCare, which has recently been acquired by Siemens Medical Solutions.

Enzo's invention uses a bridging probe or strand to find a nucleic acid of interest, such as a gene or pathogen sequence. A signaling probe or strand is hybridized to the bridging probe or strand, and provides for detection including an amplified signal. In this way the invention provides a powerful means for generating and delivering robust signal amplification. Signal amplification can be used instead of target amplification without compromising the sensitivity of the assay.

An interference is a proceeding instituted by the U.S. Patent and Trademark Office when an issued patent and an allowed patent application claim essentially the same invention. The purpose of the proceeding is to determine who is the first inventor and who will be granted patent rights to the invention. Should it issue, Enzo's patent will have a life of 17 years from the issuance date.

About Enzo

Enzo Biochem is engaged in the research, development and manufacture of innovative health care products based on molecular biology and genetic engineering techniques, and in providing diagnostic services to the medical community. The Company's proprietary labeling and detection products for gene sequencing and genetic analysis are sold to the life sciences market throughout the world. The Company's therapeutic division is in various stages of clinical evaluation of its proprietary gene medicine for HIV-1 infection and its proprietary immune regulation medicines for hepatitis B and hepatitis C infection and for Crohn's Disease. Pre-clinical research is being conducted on several candidate compounds aimed at producing new mineral and organic bone, including technology that could provide therapy for osteoporosis and fractures, among other applications. The Company also holds a patent covering a method and materials for correcting point mutations or small insertions or deletions of genetic material that would allow for editing and correcting certain abnormalities in genes. The Company owns or licenses over 200 patents worldwide. For more information visit our website www.enzo.com.

Except for historical information, the matters discussed in this news release may be considered "forward-looking" statements within the meaning of Section 27A of the Securities Act of 1933, as amended and Section 21E of the Securities Exchange Act of 1934, as amended. Such statements include declarations regarding the intent, belief or current expectations of the Company and its management. Investors are cautioned that any such forward-looking statements are not guarantees of future performance and involve a number of risks and uncertainties that could materially affect actual results. The Company disclaims any obligations to update any forward-looking statement as a result of developments occurring after the date of this press release.

VERSANT(R) is a trademark of Bayer HealthCare L.L.C.

Source: Enzo Biochem, Inc.