Hepatitis B Product Development Program Announced and Ribozyme Data Presented

October 3, 2000

Hepatitis B Product Development Program Announced and Ribozyme

Data Presented

Tuesday September 26 7:00am

Source: PR Newswire

BOULDER, Colo. and SHANGHAI, China, Sept. 26 /PRNewswire/ --

Ribozyme Pharmaceuticals, Inc. (RPI) (Nasdaq: RZYM) today presented cell

culture data at the 4th Shanghai International Symposium on Liver Cancer and

Hepatitis (Hepa 2000) regarding several ribozymes designed to inhibit

Hepatitis B replication. The data demonstrated potent anti-viral effects of

the ribozymes in several model systems.

Entitled " Synthesis and Characterization of Nuclease Resistant

Ribozymes Directed Against HBV RNA, " the paper presented today by Dr.

Lawrence M. Blatt, Vice President of Research at RPI, described data on

several ribozymes designed to target highly conserved regions in the

Hepatitis B viral genome. In several cell culture systems the ribozymes

demonstrated inhibitory effects against multiple HBV specific targets.

" These ribozymes are able to inhibit several steps in the HBV

life cycle, which makes this approach unique, " said Ralph E. Christoffersen,

CEO and President of RPI. " We are pleased, therefore, to announce a formal

product development program for HBV, and plan to choose an optimum ribozyme

to enter toxicology studies in the near future. We hope this approach may

meet a significant healthcare need in Asia and around the world. "

Chronic Hepatitis B afflicts over 300 million people worldwide.

In the United States approximately 1.25 million individuals are chronic

carriers of HBV as evidenced by the fact that they have measurable hepatitis

B virus surface antigen HBsAg in their blood. In regions of higher

prevalence, such as in most of Asia, HBV carrier rates range from 7% to 20%.

Chronic carriers are at high risk of progressing to liver cirrhosis,

hepatocellular carcinoma and death.

Ribozymes are the product of Nobel Prize winning science and are

synthetically engineered to act as " molecular scissors " capable of cleaving

target RNA in a highly specific manner.

RPI (www.rpi.com), located in Boulder, Colorado, is the

acknowledged leader in ribozyme therapeutic development. RPI is partnered

with Eli Lilly for development of an anti-Hepatitis C virus ribozyme which

is in clinical trials designed to study safety and to assess the effect of

the compound on HCV viral RNA levels in chronic Hepatitis patients. RPI is

partnered with Chiron Corporation for the development and commercialization

of ANGIOZYME, an anti-angiogenic ribozyme designed to inhibit the growth

of new blood supplies to tumors and prevent tumor growth and metastasis.

ANGIOZYME is in Phase I/II clinical trials in cancer patients at the

Cleveland Clinic. RPI is also partnered with an affiliate of Elan

Corporation plc for development and commercialization of HERZYME, an

anti-HER-2 ribozyme for treatment of breast and other cancers, through RPI's

subsidiary Medizyme Pharmaceuticals Ltd.

This press release contains forward-looking statements that

involve risks and uncertainties, and actual events or results may differ

materially. These risk factors include actions by the U.S. Food and Drug

Administration, technological advances, ability to obtain rights to

technology, ability to obtain and enforce patents, ability to commercialize

and manufacture products and general economic conditions. These and

additional risk factors are identified in RPI Securities and Exchange

Commission filings, including the Forms 10-K and 10-Q and in other SEC

filings.

Source: Ribozyme Pharmaceuticals, Inc.

Contact: Ralph E. Christoffersen, Ph.D., CEO and President

of Ribozyme Pharmaceuticals, Inc., 303-449-6500; or McCue of Freeman

McCue Public Relations, 714-557-3663, for Ribozyme Pharmaceuticals, Inc.

October 3, 2000