Hollis-Eden Pharmaceuticals Announces HE2100 Stimulates Innate Immunity in Preclinical Model of Radiation Injury.

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SAN DIEGO--(BW HealthWire)--April 22, 2002

Data Presented at Radiation Research Society Meeting by

Armed Forces Radiobiology Research Institute 

Hollis-Eden Pharmaceuticals, Inc. (Nasdaq:HEPH) today announced data from a preclinical study conducted in an animal model of radiation injury indicating that its immune regulating hormone, HE2100, is stimulating the innate immune system and key immune cells involved in elimination of infectious pathogens.

Dr. Mark Whitnall from the Radiation Casualty Management Team, Armed Forces Radiobiology Research Institute (AFRRI) is presenting the data at the Radiation Research Society Meeting being held this week in Reno, Nevada. Hollis-Eden Pharmaceuticals and an agency within the Department of Defense recently signed a Collaborative Research and Development Agreement (CRADA) to jointly develop HE2100 for the indication of radiation protection.

AFRRI has conducted numerous preclinical studies with HE2100. Results of several of these studies have been published in the International Journal of Immunopharmacology and in Radiation Research. These studies showed that HE2100, when given to animals shortly before or shortly after exposure to lethal doses of radiation, provided significant survival advantages in HE2100 treated animals versus placebo treated animals.

In the first experiment under the CRADA, the effects of HE2100 were studied on specific immune cells that are known to be involved in innate immune responses associated with protection against infectious agents. In the study, HE2100 when given to animals prior to exposure to lethal doses of radiation stimulated the production of a number of white blood cells involved in innate immune responses (granulocytes, monocytes and natural killer cells). The results also showed that HE2100 enhanced the ability of granulocytes to engulf and eliminate pathogens and the ability of monocytes to destroy pathogens by means of oxidation. The changes in the production and effectiveness of these cells from HE2100 treated animals compared to placebo were statistically significant and may have contributed to the ability of HE2100 treated animals to fend off immune suppression associated with exposure to radiation.

"The positive results of this experiment help us to understand the protective mechanism behind HE2100 and its effects on the immune system," said Dr. Whitnall. "Exposure to radiation results in the loss of key immune fighting cells necessary for defending the body from infection. With the acute loss of these cells due to radiation exposure, a person can die after a few days or weeks due to an infection the body would have normally been able to fight off. Demonstrating in animals that we are able to increase the production and effectiveness of these cells, even when challenged by exposure to lethal doses of radiation, gives us reason to hope HE2100 will be effective in protecting humans against radiation."

"We are pleased with the progress and these early results from our collaboration with Dr. Whitnall and others at AFRRI," said Richard Hollis, Chairman and CEO, Hollis-Eden Pharmaceuticals. "This study is important because it demonstrates that HE2100 has a significant effect on key immune fighting cells associated with protection in a model of acute immune suppression due to radiation exposure. This data is consistent with clinical results from our HIV/AIDS clinical trials where we have demonstrated stimulation of key immune fighting cells in HIV-infected patients after treatment with our lead drug candidate, HE2000. Immune suppression can result from a number of factors including infectious pathogens, radiation and the aging process itself. We are discovering through preclinical and clinical work in multiple disease conditions that these hormones target key transcriptional factors that regulate gene expression for proper production of key cells necessary to fight infections in immune suppressed states. We are focusing on the development of HE2100 for the critical indication of radiation protection, but we are also actively studying the ability of this important class of compounds to affect a number of other diseases and conditions resulting from immune disorders."

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. In addition to HE2100, which the Company is jointly developing with the military for radioprotection, the Company is also developing a series of other compounds in this class. 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 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.