Early stage drug shows promise against cancer cells from young patients

Oct 2 2007

A new drug has shown promising pre-clinical activity against cells from several types of children's cancers, scientists reveal at the National Cancer Research Institute Conference in Birmingham today (Tuesday).

Scientists from Cancer Research UK's Paterson Institute at the University of Manchester have shown in laboratory tests that the drug RH1 can kill tumour cells from neuroblastoma, osteosarcoma and Ewing's sarcoma, three types of childhood and adolescent cancer that are often resistant to current types of chemotherapy.

Despite increases in survival rates for childhood cancers, new drugs are needed to combat drug resistance seen in current treatments. On the strength of these pre-clinical results, the researchers are planning a phase I trial for the drug involving children with cancer.

All cells have natural suicide mechanisms that become active when cells are damaged or grow uncontrollably. In cancer cells, this suicide mechanism switches off or becomes faulty and treatment is needed to encourage the process.

The researchers - based at the Paterson Institute for Cancer Research Manchester and the Royal Manchester Children's Hospital - found in their pre-clinical study that even very low doses of RH1 could increase cancer cell death by around 50 per cent when compared with untreated cells.

RH1's activity is greatly enhanced by an enzyme, DT-diaphorase (DTD), which is found in higher quantities in many adult tumours, including lung, liver and breast cancers, and the drug has recently completed phase I studies in adults.

Dr Guy Makin, the study's lead researcher from the Paterson Institute said: "We are very excited that we have been able to work with a new drug that has only just completed an adult phase I study. RH1 is a very potent agent and our pre-clinical results suggest that it could be effective against childhood tumours that express DTD. We hope that this will be just the first of many new agents that we can show are useful for treating childhood cancer."

The planned trial would be the first for a drug tested for children through Cancer Research UK's drug development office.

Dr Bruce Morland, chairman of the Children's Cancer and Leukaemia Group (CCLG), who were instrumental in the selection of RH1 for evaluation, said: "Survival rates for children with cancer are already high at 75 per cent. But in many cases, patients become resistant to their drugs and need new options.

"This is an exciting moment in the history of the CCLG. Our increasingly close relationship with the Cancer Research UK drug development office means new potentially promising anticancer drugs can be tested in children at a much earlier point in their development. In this way we hope that new, effective drugs are introduced in the fight against children's cancer at the earliest opportunity, saving even more lives in the process."

RH1 was synthesised from MeDZQ, an anti-tumour chemical that selectively kills cancer cells. The RH1 compound was manufactured by scientists to be a water-soluble version of MeDZQ, making it more effective as a drug for potential clinical use.

Dr Sally Burtles, Cancer Research UK's director of drug development, said: "Helping more children survive cancer by finding new treatments is a top priority for the charity. Currently, not many drugs are developed specifically for children so it's great news that the drug is showing such encouraging effects in preclinical studies. We hope this type of drug development will continue and help improve the treatment of childhood cancer patients."

http://info.cancerresearchuk.org