BioWorld International Correspondent

OTTAWA, Ontario - A toxin produced by E. coli, and commonly linked to food poisoning, could spawn a new generation of anticancer therapies.

That's the goal of a new Toronto-based venture, Molecular Templates Inc. (MTI), which has been launched with an initial investment of C$1.5 million (US$1 million). Milestone Medica Corporation and Sunnybrook Working Ventures Medical Breakthrough Fund, both of Toronto, and a private investor have teamed with the laboratory of Jean Gariepy, professor at the University of Toronto and senior scientist at the Ontario Cancer Institute, to form MTI.

Taking the lead in the initial financing round is Milestone Medica Corp., whose CEO, David Shindler, told BioWorld International that it invested in the technology because there is an urgent need for new, very selective anticancer drugs that can search and destroy cancer cells wherever they may be in the body.

"The list of organizations involved in MTI demonstrates the substantial collaborative research effort that has already been applied to this exciting area," he said. "We are investing in important molecular engineering technology that can potentially develop a wide range of molecules aimed at a variety of cancers."

MTI will use its proprietary production and screening technologies to generate molecular libraries based on the bacterial Shiga-like toxin 1 (SLT-1) that has been found to bind specifically to the MUC-1 receptor expressed on numerous epithelial cancers including breast, ovarian and colorectal cancer. It potentially provides an alternative to MUC-1-directed monoclonal antibodies.

Gariepy said a powerful strategy for developing more promising antitumor agents relies on the development of combinatorial libraries in which molecular templates are either selectively or randomly modified to create vast arrays of related compounds. Search procedures using simple assays can then be employed to identify lead compounds.

Gariepy's laboratory has been exploring the utility of SLT-1 as a purging agent able to delete tumor cells present in stem cell grafts of patients undergoing autologous stem cell transplants. The researchers found that while the toxin kills a variety of cancer cells, it does not affect healthy blood stem cells.

MTI's proprietary applied proteomics technology is designed to enable the development of protein-based agents that will ignore normal, healthy body cells and selectively attack cancer tissue, either in localized tumors or, more importantly, in metastatic cancer cells.

"Until now, the usefulness of natural bacterial toxins in cancer therapy has been limited to specially defined circumstances. We are essentially harnessing an already well-engineered cell killer to make new cancer weapons," said Gariepy, who has been appointed MTI's chief scientific officer.

The financing will be used for demonstrating the flexibility of the company's new techniques. MTI intends to advance the preclinical and clinical development of novel treatments for breast, prostate and other cancers with the goal of moving into clinical trials in 24 to 36 months.

The technology platform that MTI will be using to generate lead compounds has been licensed from Toronto's University Health Network, of which Princess Margaret Hospital and its research arm, the Ontario Cancer Institute, are members.