Non-Toxic Treatment for Cancer: Circadian's Latest Weapon Against Metastasis

Circadian Technologies Limited recently announced interesting research results relating to their anti-tumour investigations and cancer treatments including angiogenic inhibitors. They have developed an anti-tumour antibody that inhibits tumour growth and metastasis, and increases the effectiveness of chemotherapy agents.

This antibody inhibits the metastasis of cancer by blocking a protein receptor, VEGFR3, found in the walls of lymph and blood vessels. During cancer growth VEGFR3 activates a factor required for the formation of new blood vessels that provide the oxygen and nutrients necessary for tumours to grow and metastasize. The antibody prevents the action of VEGFR3 which means that new blood vessels can not grow towards or within the tumours thereby starving them and inhibiting their metastatic spread.

Rapid tumour growth and metastasis of cancer cells to other parts of the body are what make cancer difficult to treat and cure such as in breast, colorectal, lung and other cancers. Sometimes traditional chemotherapy stops working because the tumour cells become resistant and no longer respond to treatment. The cancer continues to metastasize uncontrolled leading to the death of the individual.

Anti-tumour antibodies that prevent the growth of blood vessels in cancer (also called angiogenic inhibitors) may act as a safety mechanism where chemotherapy fails, or as an additional line of defence in combination with chemotherapeutic treatment. To date, these angiogenic inhibitors have proven to be non-toxic to normal body tissues and produce minimal side effects. Known side effects include slow wound healing, and damage to the intestinal wall; both of which are perhaps preferable to terminal cancer. Furthermore tumour cells do not seem to become resistant to this treatment.

Professor Kari Alitalo from the University of Helsinki is the research scientist who discovered the importance of VEGFR3 in the metastasis of tumour cells through lymph vessels. Professor Alitalo has been awarded the InBev-Baillet Latour Health Prize in Belgium for his contribution to cancer treatment.

Australian biotechnology company, Circadian Technologies Limited, owns the company Vegenics which was awarded world wide patent rights to develop Professor Alitalo's discovery for direct clinical applications. The research conducted by Dr Marguerita O'Mahony and colleagues used human colorectal and pancreatic tumours implanted into mice. It is therefore hopeful that the antibody will function efficiently and safely in humans during clinical trials.

We won't have to wait years before this treatment will become available for clinical use either. Federal Drug Authorities have already approved another angiogenic inhibitor, marketed under the brand name Avastin, for the treatment of cancers which have begun to metastasize. Avastin works by a similar mechanism to the anti-VEGFR3 antibody. It was first approved in the US in 2004 for colorectal cancer, then again in 2006 for lung cancer and in 2008 for breast cancer. The most recent approval has been granted for a type of brain cancer, glioblastoma, known for its resistance to treatment.

Furthermore, cancer treatment isn't the only application for these therapies. We are only just beginning to see the importance and value of angiogenic inhibitors in medicine. Other diseases that depend on blood vessel growth may also become more treatable in the future, including eye disease such as retinopathy from complications due to diabetes, and macular degeneration.

More information on Circadian Technologies may be obtained from their website at www.circadian.com.au.