April 22, 2008 07:30 ET

Lorus initiates development program exploring novel route of administration for LOR-2040

TORONTO, ONTARIO--(Marketwire - April 22, 2008) - Lorus Therapeutics Inc. ('Lorus') (TSX:LOR)(AMEX:LRP), a biopharmaceutical company specializing in the research and development of pharmaceutical products and technologies for the management of cancer, today announced the start of a development program aimed at expanding the therapeutic application of its lead clinical-stage drug LOR-2040 for the treatment of superficial bladder cancer.

The new development program will examine direct (intravesical) administration of LOR-2040 into the bladder as a treatment for superficial or non-invasive bladder cancer. Formal toxicology evaluation, which is currently in progress, will be used to determine the appropriate human dose and dose schedule for LOR-2040 with this route of administration.

Results of these studies will be used in support of an Investigational New Drug (IND) application for the use of LOR-2040 in the treatment of bladder cancer. Lorus intends to submit the IND during Q3, 2008, following successful completion of the toxicology program.

LOR-2040, formerly known as GTI-2040, has shown potent antiproliferative activity and target downregulation in bladder cancer in preclinical studies. LOR-2040 is currently being investigated in several phase I and phase II clinical trials in a broad range of cancer indications, both alone and in combination with a number of standard cancer therapies. In clinical trials, LOR-2040 has demonstrated a high safety profile when administered intravenously, which is the current route of administration for this drug.

In the U.S. more than 60,000 new cases of bladder cancer are diagnosed each year, which accounts for approximately 13,000 deaths annually. At initial diagnosis, up to 90% of subjects with bladder cancers have superficial disease that is confined to the inner layers of tissue in the urinary bladder. Systemic chemotherapy is considered less effective than the intravesical (instilled in the bladder) agents in treating locally confined, superficial bladder tumors. In fact intravesical administration exposes the bladder tumor to higher levels of drugs that may prevent tumor cells from becoming invasive and spreading (metastasizing) to other organs. This treatment method is a standard regimen used for many approved chemotherapy drugs to treat superficial bladder cancer.

"I am pleased that we have initiated the studies that explore a novel way of administering LOR-2040 directly to bladder tumors and that we are on schedule to advance LOR-2040 in this indication", said Dr. Aiping Young, President and CEO of Lorus. "Bladder cancer is seventh most common cancer worldwide and is a significant target indication for new therapeutics. Coupled with the high risk of recurrence, even in patients with early stage disease, adding a non-systemic treatment to the currently available treatment options has significant potential."

About LOR-2040

LOR-2040 (formerly GTI-2040) is an RNA-targeted drug candidate specific for the R2 subunit of ribonucleotide reductase, which is required for DNA synthesis and cell proliferation. LOR-2040 has demonstrated strong antitumor and antimetastatic activity in a variety of tumor types in both in vivo and in vitro models. LOR-2040 is under study in a multiple Phase I/II clinical program, including an advanced Phase II clinical trial with LOR-2040 and high dose Ara-C (HiDAC) in refractory and relapsed Acute Myeloid Leukemia (AML). The R2 target has been described as a malignant determinant that is elevated in a wide range of tumors, which can cooperate with a variety of cellular cancer causing genes known as oncogenes to enhance tumor growth and metastatic potential.

About Lorus

Lorus is a biopharmaceutical company focused on the research and development of novel therapeutics for the treatment of cancer that are at various stages of development spanning discovery to clinical trials. Lorus' goal is to capitalize on its research, preclinical, clinical and regulatory expertise by developing new drugs that can be used, either alone, or in combination with other agents, to successfully manage cancer. Through its own discovery efforts and an acquisition and in-licensing program, Lorus is building a portfolio of promising anticancer drugs. Lorus Therapeutics Inc. is listed on the Toronto Stock Exchange under the symbol LOR, and on the American Stock Exchange under the symbol LRP.

Forward-looking Statements

This press release contains forward-looking statements within the meaning of Canadian and U.S. securities laws. Such statements include, but are not limited to, statements relating to: financings and corporate reorganizations, the establishment of corporate alliances, the Company's plans, objectives, expectations and intentions and other statements including words such as "continue", "expect", "intend", "will", "should", "would", "may", and other similar expressions. Such statements reflect our current views with respect to future events and are subject to risks and uncertainties and are necessarily based upon a number of estimates and assumptions that, while considered reasonable by us are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Many factors could cause our actual results, performance, achievements or the transactions described in this press release to be materially different from any future results, performance, achievements or transactions described in this press release, if at all, that may be expressed or implied by such forward-looking statements, including, among others: the progress of negotiations; our ability to obtain regulatory, security holder and other approvals; our ability to obtain the capital required for research and operations; the inherent risks in early stage drug development including demonstrating efficacy; development time/cost and the regulatory approval process; the progress of our clinical trials; our ability to find and enter into agreements with potential partners; our ability to attract and retain key personnel; changing market conditions; and other risks detailed from time-to-time in our ongoing quarterly filings, annual information forms, annual reports and annual filings with Canadian securities regulators and the United States Securities and Exchange Commission.

Should one or more of these risks or uncertainties materialize, or should the assumptions set out in the section entitled "Risk Factors" in our filings with Canadian securities regulators and the United States Securities and Exchange Commission underlying those forward-looking statements prove incorrect, actual results may vary materially from those described herein. These forward-looking statements are made as of the date of this press release and we do not intend, and do not assume any obligation, to update these forward-looking statements, except as required by law. We cannot assure you that such statements will prove to be accurate as actual results and future events could differ materially from those anticipated in such statements. Investors are cautioned that forward-looking statements are not guarantees of future performance and accordingly investors are cautioned not to put undue reliance on forward-looking statements due to the inherent uncertainty therein.

Lorus Therapeutics' recent press releases are available through its website at www.lorusthera.com. For Lorus' regulatory filings on SEDAR, please go to www.Sedar.com. For SEDAR filings prior to July 10, 2007 you will find these under the company profile for Global Summit Real Estate Inc. (Old Lorus).

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