Researchers Discover That Phenoxodiol Kills Rapidly Proliferating T-Cells

NEW CANAAN, CT and SYDNEY, AUSTRALIA--(Marketwire - July 7, 2009) - Researchers at the Malaghan Institute of Medical Research in Wellington, New Zealand have found that abnormally proliferating human T-cells, rapidly dividing cancer cells such as primary myeloid and lymphoid leukemic blast cells undergo programmed cell death when exposed briefly to the investigational anti-tumor drug phenoxodiol.

These results make phenoxodiol a promising candidate for the treatment of pathologically activated lymphocytes such as those in acute lymphoid leukemia, or diseases driven by T-cell proliferation such as autoimmune diseases and graft-versus-host disease, according to an article published in the Haematologica Journal on June 16, 2009, http://www.haematologica.org/cgi/reprint/94/7/928.

The researchers demonstrated that phenoxodiol inhibited plasma membrane electron transport and cell proliferation and promoted apoptosis of rapidly proliferating human T-cells, induced to undergo rapid proliferation by exposure to cells from an incompatible donor, but at the same time it did not affect normal resting T-cells.

"These findings indicate that phenoxodiol may have utility against autoimmune diseases, such as rheumatoid arthritis and psoriasis, as well as having potential in management of graft rejection in transplantation patients," said Prof. Alan Husband, Group Director of Research, Marshall Edwards, Inc. "We're appreciative of Dr. Patries Herst and colleagues for undertaking this important research."

About phenoxodiol

Phenoxodiol is being developed by the U.S. oncology company Marshall Edwards, Inc. (NASDAQ: MSHL) as a chemosensitizing agent in combination with platinum drugs for late stage, chemoresistant ovarian cancer and as a monotherapy for prostate and cervical cancers. It has a unique mechanism of action, binding to cancer cells via a surface oxidase, disrupting membrane electron transport and causing major downstream disturbances in expression of proteins necessary for cancer cell survival and responsible for the development of drug resistance.

In cancer cells, phenoxodiol appears to inhibit selectively the pro-survival regulator known as S-1-P (sphingosine-1-phosphate) that is overexpressed in cancer cells. In response to phenoxodiol, the S-1-P content in cancer cells is decreased, rendering those cells more sensitive to chemotherapy. Indeed, in laboratory studies, it has been demonstrated that cancer cells pre-treated with phenoxodiol were killed with lower doses of chemotherapy drugs.

Importantly, phenoxodiol has been shown not to affect adversely normal cells in animal and laboratory testing. Phenoxodiol is being investigated as a therapy for late-stage, chemoresistant ovarian, prostate and cervical cancers. Phenoxodiol has received Fast Track status from the FDA to facilitate its development as a therapy for recurrent ovarian and prostate cancers. Phenoxodiol is an investigational drug and, as such, is not commercially available. Under U.S. law, a new drug cannot be marketed until it has been investigated in clinical trials and approved by FDA as being safe and effective for the intended use.

Phenoxodiol is the first of a family of compounds in the Marshall Edwards, Inc. drug pipeline of flavonoid derivatives.

About Marshall Edwards, Inc.

Marshall Edwards, Inc. is a specialist oncology company focused on the clinical development of novel anti-cancer therapeutics. These derive from a flavonoid technology platform, which has generated a number of novel compounds characterized by broad ranging activity against a range of cancer cell types with few side effects. The combination of anti-tumor cell activity and low toxicity is believed to be a result of the ability of these compounds to target an enzyme present in the cell membrane of cancer cells, thereby inhibiting the production of pro-survival proteins within the cell. Marshall Edwards has licensed rights from Novogen Limited (ASX: NRT) (NASDAQ: NVGN) to bring three oncology drugs -- phenoxodiol, triphendiol and NV-143 -- to market globally.

Marshall Edwards is majority owned by Novogen (ASX: NRT) (NASDAQ: NVGN), an Australian biotechnology company that is specializing in the development of therapeutics based on a flavonoid technology platform. Novogen is developing a range of therapeutics across the fields of oncology, cardiovascular disease and inflammatory diseases. More information on phenoxodiol and on the Novogen group of companies can be found at www.marshalledwardsinc.com and www.novogen.com.

Under U.S. law, a new drug cannot be marketed until it has been investigated in clinical trials and approved by the FDA as being safe and effective for the intended use. Statements included in this press release that are not historical in nature are "forward-looking statements" within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. You should be aware that our actual results could differ materially from those contained in the forward-looking statements, which are based on management's current expectations and are subject to a number of risks and uncertainties, including, but not limited to, our failure to successfully commercialize our product candidates; costs and delays in the development and/or FDA approval, or the failure to obtain such approval, of our product candidates; uncertainties in clinical trial results; our inability to maintain or enter into, and the risks resulting from our dependence upon, collaboration or contractual arrangements necessary for the development, manufacture, commercialization, marketing, sales and distribution of any products; competitive factors; our inability to protect our patents or proprietary rights and obtain necessary rights to third party patents and intellectual property to operate our business; our inability to operate our business without infringing the patents and proprietary rights of others; general economic conditions; the failure of any products to gain market acceptance; our inability to obtain any additional required financing; technological changes; government regulation; changes in industry practice; and one-time events. We do not intend to update any of these factors or to publicly announce the results of any revisions to these forward-looking statements.

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