Lorus Therapeutics Inc. (Lorus), a biopharmaceutical company, announced that its wholly owned subsidiary, GeneSense Technologies Inc., has been allowed a patent from the United States Patent and Trademark Office for antisense oligonucleotides directed towards the novel cancer target neuropilin.
The patent, titled "Neuropilin antisense oligonucleotide sequences and methods of using same to modulate cell growth," protects a series of antisense molecules that specifically bind to and decrease neuropilin target RNA in cells. The patent also protects the use of these antisense agents in the treatment of various forms of human cancer, including lung, colon, prostate, and breast cancers.
Neuropilin is a coreceptor for a form of vascular endothelial growth factor (VEGF), which is a soluble protein that stimulates tumour growth and angiogenesis (growth of blood vessels, which support tumour growth). Neuropilin is expressed on tumour blood vessel cells as well as by multiple cancer types, including breast cancer, prostate cancer, lung cancer, and melanoma. This expression increases the binding of VEGF to tumour cells and has been shown to promote cancer cell growth and tumour progression.
Included in the patent is Lorus' lead neuropilin antisense drug GTI-3611. In preclinical studies, GTI-3611 significantly inhibited growth of several cancer types, and markedly reduced the number of lung tumours in a mouse model of metastatic human melanoma. Consistent with an antisense mechanism of action, high levels of neuropilin coding RNA found in cancer cells were substantially decreased following treatment with GTI-3611, as well as with other neuropilin antisense oligonucleotides listed in the patent.
"In addition to the ongoing clinical trials with the anticancer drugs GTI-2040 and GTI-2501, Lorus has preclinical programs in antisense and the related area of siRNA technology that have yielded novel drug candidates," said Dr. Jim A. Wright, President and CEO of Lorus. "This new patent in the US, one of the largest markets in the world for anticancer drugs, fits into our strategy of protecting our novel technologies and adds to our strong global intellectual property portfolio."
The company also provided an update on a financing agreement. As previously announced on July 14, 2006, Lorus entered into a subscription agreement with HighTech Beteiligungen GmbH & Co. KG to issue 28.8 million common shares at $0.36 per share for gross proceeds of $10.4 million. The closing is subject to certain conditions, including approval from the Toronto Stock Exchange (the TSX), the American Stock Exchange (the AMEX), and the filing and clearance of a prospectus in Ontario. Lorus has received conditional approval for the transaction from both the TSX and the AMEX and filed a preliminary short form prospectus on August 11, 2006. The transaction is now expected to close on or before August 28, 2006.