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

Lorus Therapeutics Inc. 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.