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Hollis-Eden Pharmaceuticals Presents Positive Data with APOPTONE in Preclinical Bone Model of Late-Stage Prostate Cancer

SAN DIEGO--(BUSINESS WIRE)--Apr 14, 2008 - Hollis-Eden Pharmaceuticals, Inc. (NASDAQ:HEPH), the world leader in the development of a new class of small molecule compounds based on endogenous steroid hormones, announced the presentation today of positive data from a preclinical study with APOPTONE(TM) (HE3235), its lead investigational drug candidate for cancer. In this study APOPTONE inhibited the growth of androgen-independent human tumors LuCaP 35V grown subcutaneously as well as growth of C4-2B cells in the bone environment of castrated mice. The results were presented today by Dr. Eva Corey from the University of Washington, who conducted the study, at the 2008 American Association of Cancer Research meeting being held in San Diego, California. The Company also announced it has received regulatory clearance to commence a Phase I/II dose ranging clinical trial with APOPTONE in prostate cancer patients. The patient population for this initial clinical trial will be considered "late stage," which is defined as patients failing at least one round of chemotherapy.

Dr. Eva Corey stated, "Our results show that APOPTONE inhibits growth of androgen-independent subcutaneous prostate tumors and most importantly that these inhibitory effects are also present when androgen-independent C4-2B prostate tumors were growing in the bone environment."

In this model of tumor cell growth in the bone and interactions between tumor and bone cells, C4-2B, hormone-independent human prostate cancer cells were implanted into the tibia of castrated mice and allowed to grow. When serum prostate specific antigen, PSA, was detectable, indicating that the prostate cancer cells were growing in the bone, the animals were randomized to daily intra peritoneal, IP, treatment with either APOPTONE or placebo for a four-week treatment period. At the end of the treatment period there was a statistically significant lowering of PSA levels of greater than 50% (p less than or equal to 0.05) relative to the placebo-treated animals. More importantly, weights of tumored tibiae from animals treated with APOPTONE were significantly lower compared to placebo-treated animals (p less than or equal to 0.05), indicating that tumor growth in the bone was inhibited by APOPTONE treatment.

Additional data presented by Dr. Eva Corey summarized previously reported pre-clinical findings with APOPTONE in models of hormone-dependent and hormone-independent prostate cancer. Dr. Corey's results show that APOPTONE inhibits growth of the human prostate tumor cell line LNCaP in the presence and absence of hormones known to stimulate prostate cancer cell growth. Using a technique called flow cytometry, her results indicate that treatment with APOPTONE causes growth arrest of the cells in the early cell cycle phase or G1 phase and also stimulates apoptosis or programmed cell death. Previous work in Dr. Corey's lab demonstrated that APOPTONE could inhibit the growth of an androgen-independent human tumor, LuCaP 35V, in castrated male SCID mice.

"This newly released preclinical data is exciting and timely as we are about to commence our Phase I/II clinical trial with APOPTONE in late-stage prostate cancer patients," said Richard Hollis, Chairman and CEO of Hollis-Eden Pharmaceuticals. "Thus far APOPTONE has demonstrated activity in a variety of animal models representing castrate-resistant and hormone-independent prostate cancer. As we look to commence our initial clinical trial in prostate cancer patients, our primary focus will be to establish the safety of the drug candidate, however we will be assessing the activity of the compound as well. The patient population receiving APOPTONE will be classified as patients with advanced prostate cancer who have failed hormone therapy and at least one chemotherapy regimen and with limited treatment options available. Based on what we believe is a unique mechanism of action and the compound's preclinical activity to date, we look forward to assessing the clinical utility of APOPTONE for this major unmet medical need."

Hollis-Eden believes the mechanism of APOPTONE in inhibiting prostate tumor growth in these preclinical studies appears to be due to the tumor cells undergoing apoptosis. Analysis of gene expression in APOPTONE-treated LNCaP cells suggests that APOPTONE appears to act as an apoptotic agent, down-regulating genes that protect tumor cells from apoptosis such as Bcl-2 while increasing the expression of pro-apoptotic genes such as caspases. Alteration in phenotype of LNCaP cells after exposure also indicate that APOPTONE may increase the susceptibility of tumor cells to chemotherapeutic agents by down-regulating the gene for the multi-drug resistant protein ABCG2, originally known as the Breast Cancer Resistance Protein (BCRP1).

In the United States alone approximately 234,000 men are diagnosed annually with prostate cancer and approximately 30,000 men die from the disease each year. Current treatments for prostate cancer focus on blocking testosterone and other hormones associated with disease progression range in annual sales from $500 million to $1.2 billion. Chemotherapeutic agents used in later stage disease after hormone therapy fails, exceed $2 billion in annual sales.

Hollis-Eden Pharmaceuticals

Hollis-Eden Pharmaceuticals, Inc. is a world leader in the development of a proprietary class of adrenal steroid hormones as novel pharmaceuticals for human health. Through its Hormonal Signaling Technology Platform, Hollis-Eden is developing a new series of small molecule compounds that are metabolites or synthetic analogs of endogenous hormones derived by the adrenal glands from the body's most abundant circulating adrenal steroid. These steroid hormones, designed to restore the biological activity of cellular signaling pathways disrupted by disease and aging, have been demonstrated in humans to possess several properties with potential therapeutic benefit -- they regulate innate and adaptive immunity, reduce nonproductive inflammation and stimulate cell proliferation. The Company's clinical drug development candidates include TRIOLEX(TM) (HE3286), currently in clinical trials for the treatment of metabolic disorders as well as ulcerative colitis and being prepared for a clinical trial in rheumatoid arthritis, and APOPTONE(TM) (HE3235), a next-generation compound selected for cancer. In addition to these clinical development candidates, Hollis-Eden has an active research program that is generating additional new clinical drug candidates that are being further evaluated in preclinical models of a number of different diseases. For more information on Hollis-Eden, visit the Company's website at

This press release contains forward-looking statements within the meaning of the federal securities laws concerning, among other things, the potential and prospects of the Company's drug discovery program and its drug candidates. Any statement included in this press release that are not a description of historical facts are forward-looking statements that involve risks, uncertainties, assumptions and other factors which, if they do not materialize or prove correct, could cause the Company's actual results to differ materially from historical results or those expressed or implied by such forward-looking statements. Such statements are subject to certain risks and uncertainties inherent in the Company's business, including, but not limited to: the ability to complete preclinical and clinical trials successfully and within specified timelines, if at all; the ability to obtain regulatory approval for TRIOLEX (HE3286), APOPTONE (HE3235) or any other investigational drug candidate; the Company's future capital needs; the Company's ability to obtain additional funding; the ability of the Company to protect its intellectual property rights and to not infringe the intellectual property rights of others; 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. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. Except as required by law, the Company undertakes no obligation to update or revise the information contained in this press release as a result of new information, future events or circumstances arising after the date of this press release.


Hollis-Eden Pharmaceuticals, Inc.
Scott Rieger, Director, Corporate Communications

Posted: April 2008