Hollis-Eden Pharmaceuticals Announces HE2500 Significantly Reduces Ongoing Paralysis and Accelerates Recovery in Preclinical Model of Multiple Sclerosis.

Business Editors/Health & Medical Writers

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SAN DIEGO--(BW HealthWire)--April 23, 2002

Data with HE2500 Presented at Experimental Biology Meeting

Hollis-Eden Pharmaceuticals, Inc. (NASDAQ:HEPH) today announced data from a preclinical study demonstrating that HE2500, an investigational immune regulating hormone, significantly reduces ongoing paralysis and accelerates recovery from experimental autoimmune encephalomyelitis (EAE), a preclinical model that mimics multiple sclerosis (MS) in humans.

Dr. Halina Offner, Professor of Neurology at Oregon Health & Science University, conducted the study and is presenting the data at the Federation of American Societies for Experimental Biology this week in New Orleans, Louisiana.

[pilcrow (paragraph sign)] The EAE animal model, caused by inflammatory T-cells directed against myelin in the brain and spinal cord, shares many characteristics with MS, and has been widely used to study efficacy in a preclinical model for potential treatments for MS. The experiment was designed to test the effects of HE2500 on the severity of the disease. Treatment of EAE diseased animals with HE2500 injections daily significantly delayed disease onset, reduced the signs of disease, and prevented or attenuated relapses compared to placebo. Also, HE2500 treated animals had a significantly reduced production of inflammatory mediators in the brain. These results suggest that the compound's ability to reduce the severity of the disease was due to its anti-inflammatory action in the brain.

[pilcrow (paragraph sign)] "I am very excited about these initial data, because they demonstrate that this new class of immune regulating hormones is very effective for treating ongoing paralytic disease," says Dr. Offner. "HE2500 acts by limiting the entry of inflammatory cells into the brain and thereby reducing the production of inflammatory mediators in the brain. This compound ultimately could be used to treat both men and women with MS and may also be useful to treat other autoimmune diseases. Dose-finding studies are currently being planned for MS."

Preclinical data to support the use of this class of compounds in collagen induced arthritis (CIA), an animal model for rheumatoid arthritis, will also be presented by Dr. Offner in May at the 6th International Symposium on the Immunotherapy of Rheumatic Diseases in Limassol, Cyprus.

"The results garnered in this experiment continue to scientifically support the important role immune regulating hormones may play in autoimmune diseases," said Richard Hollis, Chairman and CEO, Hollis-Eden Pharmaceuticals. "We are very pleased to be working with Dr. Offner who is a leading researcher in multiple sclerosis and other autoimmune conditions. This result demonstrating the anti-inflammatory properties of HE2500 in this model of MS substantiates the favorable results obtained with HE2500 in an animal model of psoriasis, as well as results demonstrating anti-inflammatory and histological benefits of HE2200 in a model of inflammatory bowel disease. The previously published clinical results with HE2000 in HIV demonstrated multiple inflammatory chemokines being normalized after therapy. We believe the potential ability to restore and regulate a dysregulated immune system in autoimmune diseases with our drug candidates represents an opportunity to serve a number of important markets. There are significant potential commercial benefits for companies that address these markets with drugs that do not cause immunosuppressive side effects, and can be offered with pharmacoeconomic advantages."

Hollis-Eden Pharmaceuticals, Inc. is a development-stage pharmaceutical company based in San Diego, California, engaged in the development of products for the treatment of infectious diseases and immune systems disorders. The Company's vision is to become the world leader in immune regulating hormones and their application to numerous diseases. HE2000 is the Company's lead investigational drug and is currently being studied in clinical trials for HIV/AIDS in South Africa. Hollis-Eden is also conducting a Phase I/II clinical trial with HE2000 in the United States in HIV infected patients failing at least their second antiviral drug regimen. Phase II studies in Thailand are also being conducted with HE2000 in the treatment of malaria, and in Singapore for the treatment of hepatitis B. In addition, Hollis-Eden recently entered into a Cooperative Research and Development Agreement (CRADA) with the United States Department of Defense to develop HE2100 as a radioprotectant (a drug that may potentially be used to protect a person from radiation injury due to a nuclear accident or event). Hollis-Eden recently announced the initiation of a Phase I/II clinical trial with HE2200 for vaccine potentiation in elderly patients receiving a hepatitis B vaccine. The Company also has access to HE2500 through its relationship with Aeson Therapeutics. HE2500 is currently being studied in Phase II clinical trials in cardiovascular disease. For more information on Hollis-Eden, contact the Company's website at www.holliseden.com.

Statements made in this press release may constitute forward-looking statements and are subject to numerous risks and uncertainties, including the failure to successfully complete clinical trials, the Company's future capital needs, the Company's ability to obtain additional funding and required regulatory approvals, the development of competitive products by other companies, and other risks detailed from time to time in the Company's filings with the Securities and Exchange Commission. The actual results may differ materially from those contained in this press release.