Enzo Biochem Acquires Assets of OraGen Corporation, a Biotech Firm Involved in Immune Regulation.

Business Editors/Health/Medical Writers

FARMINGDALE, N.Y.--(BUSINESS WIRE)--Feb. 26, 2004

Enzo Biochem, Inc. (NYSE:ENZ), a leading biotechnology company specializing in gene identification and genetic and immunological regulation technologies for diagnostic and therapeutic applications, today announced that it has acquired the assets of OraGen Corporation, a privately owned biotech corporation specializing in immune regulation technologies, headquartered in Morristown, NJ.

Enzo said that the acquisition will broaden its proprietary intellectual and technological capabilities in the area of immunological regulation, particularly as it relates to the treatment of infectious diseases. Enzo stated that the acquisition is in line with the company's strategy to act on opportunities that can be accretive to its efforts in accelerating its developmental program.

"The addition of OraGen's technology in developing immunological therapies for infectious diseases, particularly hepatitis B, provides an added dimension to our Company's considerable intellectual property and product development in this area," said Elazar Rabbani, Ph.D., Chairman and CEO of Enzo. "It will help to accelerate the work we have already accomplished. This move is a clear manifestation of the aggressiveness with which we are pursuing our therapeutic programs."

"Given Enzo's advanced position in the field of immune regulation, combining our technology with Enzo's program makes eminent sense," said John Callahan, President of OraGen. "It's an exciting prospect."

OraGen's work involved developing methods and compositions that would be useful for regulating undesirable immune responses exhibited by individuals with infectious diseases. In the case of hepatitis B virus ("HBV"), most individuals who become infected exhibit few clinical symptoms and eliminate the virus from their system within several weeks following exposure. However, approximately 10% of acutely HBV-infected individuals develop chronic infection, with a worldwide population of approximately 350 million. A large percentage of these patients, develop life threatening cirrhosis and primary hepatocellular carcinoma as a result of the daily assaults on the liver by the immune system in an attempt to clear the virus.

Following a successful open label Phase II clinical study of EHT899, Enzo's medicine for hepatitis B-associated chronic hepatitis, the Company currently is working on arrangements for a multi-site double blind Phase II study of the medicine. A Phase I trial of EHC18, Enzo's proprietary medicine for treating C-associated chronic active hepatitis, met its endpoints and plans for further study are underway. Enzo currently is conducting a double blind Phase II clinical trial involving the application of its proprietary immune regulation therapy for Crohn's disease, following a favorable open label Phase I clinical trial conducted previously.

"OraGen is to be commended for its work in this area, and we are pleased to be able to incorporate its technological efforts with Enzo's proprietary base of immunological regulatory products that we are actively involved in developing and testing," said Dr. Rabbani.

The terms of the acquisition were not disclosed.

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, with approximately 200 patents worldwide, 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. 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. 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.