DRAXIS Granted U.S. Patent For Bifunctional Compounds Novel Technology for the Development of New Diagnostic and Therapeutic Agents

DRAXIMAGE, the radiopharmaceutical subsidiary of DRAXIS Health has been granted a U.S. patent for an important new family of chelating compounds that have significant potential for the development of imaging and radiotherapeutic agents to diagnose and treat diseases, including cancerous tumours or metastases.

The invention, described under US Patent 6,623,721, describes the synthesis and application of a new family of molecules known as high affinity bifunctional chelators containing hydroxamic acid residues. Chelators are organic molecules with the property to bind metals with high affinity. These unique and proprietary chelators can be used to develop and commercialize radiopharmaceuticals based on metallic radioisotopes such as Gallium-67, Gallium-68, Indium-111 and others.

These patented chelating agents are bifunctional since their molecular structure also contains a reactive group that permits their attachment to biologically active substances such as peptides, proteins or antibodies. This feature means that combining the new chelating agent with a biologically active molecule results in a compound that can be subsequently radiolabelled with an appropriate radioisotope to form a new diagnostic or therapeutic agent.

"This invention is part of the ongoing commitment by DRAXIMAGE to advance molecular imaging by discovering and developing new, more effective and site-specific radiopharmaceuticals for diagnostic imaging and for the treatment of cancer," said Dr. Richard Flanagan, President of DRAXIMAGE

The new family of DRAXIMAGE chelating compounds will permit the discovery and development of diagnostic imaging agents to visualize important biological receptors or receptor-positive tumours when combined with gamma-emitting radioisotopes. The compounds are also potentially useful as therapeutic radiopharmaceuticals for the in-vivo treatment of tumours and metastases when combined with more powerful beta-emitting or alpha-emitting radioisotopes.

DRAXIMAGE discovers, develops, manufactures and markets diagnostic imaging and therapeutic radiopharmaceuticals for the global marketplace. Products currently marketed by DRAXIMAGE include a line of lyophilized technetium-99m kits used in nuclear imaging procedures, a line of imaging and therapeutic products labeled with a variety of isotopes including radioiodine, and BrachySeed, a next-generation brachytherapy implant for treating prostate cancer. DRAXIMAGE has several products in late-stage development, including three technetium-99m-based diagnostic imaging products: Fibrimage for imaging deep vein thrombosis currently in Phase III, Amiscan for the early diagnosis of acute myocardial infarct currently in Phase II, and INFECTON for imaging infection, currently in Phase II.

DRAXIS Health is a specialty pharmaceutical company involved in the development, production, marketing and distribution of therapeutic and diagnostic radiopharmaceuticals through DRAXIMAGE and in the provision of pharmaceutical contract manufacturing services, specializing in liquid and freeze-dried injectables and other sterile products through DRAXIS Pharma DRAXIS Health employs over 400 staff and reported sales in 2002 in excess of US$38 million.