Enzo Biochem Says Outlook Remains Highly Favorable for Company's Growth; Proprietary Technology and New Products Progress Significantly.

Business Editors

FARMINGDALE, N.Y.--(BUSINESS WIRE)--April 13, 2000

Enzo Biochem, Inc. (NYSE:ENZ), commenting on the recent activity of the Company's stock, said today that the Company's management was never more confident regarding the progress being made in all key areas of Enzo's activities -- both therapeutics and genetic analysis products -and that the Company was unusually well situated financially to realize its potential. "Enzo's fundamentals are solid and the Company holds a uniquely strong scientific position. The recent activity of the stock merely mirrors the general weakness that has affected the entire biotech industry and in no way reflects Enzo's intrinsic value," the Company said.

"Enzo's proprietary therapeutic technologies in selective immune down regulation and genetic modulation, combined with a broad-ranging roster of patents and advanced products in the areas of genomics and diagnostic applications, positions Enzo to play a key role in the rapidly advancing field of biotechnology as this millennium gets underway," Enzo commented. "We cannot control the market activity of the stock, but we do know that the science that has been under development at our Company for more than 20 years, resulting in advanced treatments now undergoing human clinical trials with promising results, provides us with a great deal of encouragement regarding Enzo's growth opportunities."

"Everyone agrees that biotechnology in the years ahead will bring profound benefits to mankind, and it is our earnest belief that Enzo will be among the leaders in that effort," the Company said.

Successful preliminary results of Enzo's human clinical trial for its proprietary medicine, EHT899, for treating patients with chronic hepatitis B virus infections conducted at Hadassah University Hospital in Jerusalem were recently reported. A majority of the patients showed a substantial improvement of disease symptoms, including a decrease in the degree of liver inflammation as evidenced by biopsy. The percent of patients responding to this therapy is significantly greater than that achieved by other available treatments. This disease afflicts an estimated 350 million people who are chronically infected and at risk of death from liver disease. The Company has received an award of a matching grant totaling $1.4 million by the Israel-U.S. Binational Industrial Research and Development Foundation. Enzo has begun plans to initiate Phase 2 clinical studies.

Enzo's clinical study at the University of California, San Francisco for HIV-1 infected patients is moving towards its final stages. Enzo has reported that HGTV43, the Company's proprietary medicine, has successfully delivered - and continues to deliver - antisense genes effectively and quickly to blood stem cells outside the human body. Following transduction and infusion into the patients, these genetically engineered cells continue to survive in circulation and continue to produce antisense RNA over many months. An abstract has been accepted for an oral presentation and will be given at the American Society of Gene Therapy in June. The Company has stated that it knows of no other system that has achieved these levels in unablated adult patients (patients in which the blood cells have not been destroyed) and that this proprietary system has application to the entire field of gene medicine. The Company also said it views this achievement as a critical first step forward in development of a gene medicine for the treatment of HIV-1 infection, and that plans for Phase 2 clinical studies are now proceeding.

Enzo's therapeutic pipeline is building with additional Phase 1 trials planned. Preclinical laboratory work in the management of cholesterol, treatment of Crohn's disease, ulcerative colitis, graft vs. host disease, and hepatitis C have been encouraging.

Most recently, the Company disclosed its exciting third therapeutic technology platform that permits the editing of DNA in a cell. This technology, in its early stages of development, has the potential to open new approaches for the treatment of many diseases and conditions.

In addition, Enzo has built a pioneering patent position in broad areas of genetic analysis, including labeling and detection products for gene sequencing and genomics, drug development, and clinical diagnosis of a wide range of diseases. The Company has been awarded over 200 patents worldwide, and almost a like number of patent applications have been filed. "Enzo views these patents and applications as valuable assets of the Company, including the use of this portfolio to advance revenues from manufactured products. Enzo's patent portfolio is one of its most crucial assets, one we have worked on for many years, and one we aggressively enforce," the Company said.

The Company also commented that recent reported sales of stock by a few employees relate, in every case, to long-standing employees selling relatively small amounts of stock. These employees have also exercised options, which in fact has increased their net ownership of Enzo shares.

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.

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 correct actual results.