Enzo Biochem Reports On Successful Treatment of Colitis in Preclinical Studies; Company Plans Clinical Trials.

Business Editors & Health/Medical Writers

FARMINGDALE, N.Y.--(BW HealthWire)--May 23, 2001

Enzo Biochem Inc. (NYSE:ENZ) presented data today from a preclinical animal model study showing how its proprietary immune regulation medicines could be used to manage autoimmune diseases such as inflammatory bowel disease, including colitis and Crohn's Disease. Enzo said that it expects to start clinical trials in the near future, based in part on these new data.

The results of the study were presented by Yaron Ilan, MD, at the annual meeting of the American Gastroenterology Association, in Atlanta, Georgia. Dr. Ilan, in cooperation with Enzo scientists, conducted the research at Hadassah-Hebrew University Medical Center in Jerusalem, Israel.

The research findings demonstrate that when mice with experimentally induced colitis were given specific cell products by oral administration, a marked amelioration of the symptoms was seen. The mice showed significant improvement in tissue inflammation as well as a decrease in the levels of gamma interferon in the serum, both indicative of remission of the condition.

"These data contribute significantly to an understanding of how Enzo's immune regulation medicines function to prevent or reverse autoimmune responses and will give a greater understanding as we move into clinical trials," said Dean L. Engelhardt, Ph.D., Executive Vice President of Enzo.

In the laboratory study, mice were given the specific products by oral administration. The immune cells of these treated mice were isolated and given to recipient mice who were then induced to develop colitis. The data showed that these specific immune cells from the treated donor mice were able to protect the recipient mice from developing colitis, while the same cells from a control group of nontreated mice afforded no protection.

"These data provide us with a further understanding of Enzo's immune regulation medicines by demonstrating that this property of interfering with the autoimmune response resides in certain specific immune cells that can be transferred from one experimental animal to another," continued Dr. Engelhardt. "The significance of this result is that the response to the specific product is a cellular response similar to any other immune response. It is even possible that this result means we can expect that the response has the ability to last for a long period of time - like a vaccination."

Enzo's proprietary broad-spectrum immune regulation technology, based on the oral administration of specific compounds, is being applied to human clinical trials of several serious liver diseases. Enzo's EHT899 medicine for treatment of hepatitis B is currently being tested in a Phase 2 clinical trial. Also underway is a clinical trial of Enzo's EHC18 medicine for treatment of individuals suffering from hepatitis C virus infection (HCV), of which, it is estimated, 85% of people infected develop chronic hepatitis and about 20% develop cirrhosis, an incurable disease. The second arm of this trial is targeted towards individuals with hepatitis C-associated hepatocelluar carcinoma (liver cancer), the most common type of primary liver cancer.

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 science market throughout the world. The Company's therapeutic division is conducting clinical trials for HIV-1-infected patients and for patients infected with hepatitis B and hepatitis C viruses. 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.

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. Prospective 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.