Hope For A More Effective And Less Toxic Cancer Drug

Dr David Huang, Dr Andrew Roberts, Prof Jerry Adams and their teams from WEHI's cancer research divisions have been assessing the potential of a new compound, ABT-737, that was developed by US-based healthcare company, Abbott.

Under normal circumstances, human cells have a limited lifespan. They die when they are damaged, worn out or no longer needed by the body. When they die, these cells are replaced by new ones. The body depends on a normal and healthy process called programmed cell death - or apoptosis - to ensure that unwanted cells die on cue. If this process fails, then the damaged cells live on and multiply indefinitely and uncontrollably. This uncontrolled multiplication of rogue cells can lead to cancer.

Conventional chemotherapeutic drugs target and attempt to kill rapidly dividing cancer cells. This is sometimes successful in halting the disease, but these drugs inevitably damage many normal tissues. Hence, even when the chemotherapy works, the side effects for the patient can be very serious.

ABT-737 is a drug with a different strategy for attacking cancer. Rather than attempting to poison the rogue cells, the new drug attempts to reactivate the healthy and normal cell death program that failed to kill the unwanted cells on cue.

WEHI's leading researcher with the assessment project, Dr David Huang, explains, "Normally, the cell death machinery is switched on when damaged cells need to be removed. The failure of the machinery to be turned on when it should can lead to cancer. ABT-737 is a 'switch flicker' that kicks the cell death machinery into action. Much more remains to be done to assess the drug's safety and effectiveness in patients, but early results from the laboratory are promising. Our hope is that the new drug will prove to be more effective while having fewer side effects."

The findings of the scientific assessment team are published in the 13 November 2006 issue of the prestigious international journal Cancer Cell.