Norwood Releases Data on Immune-boosting Therapy

Researchers working with Melbourne medical technology company Norwood Abbey (ASX: NAL) will present results from their trials on the company's promising immune-boosting therapy in leukaemia and lymphoma patients at next month's meeting of the American Society of Haematology (ASH) in Washington, DC.

Norwood's manager of investor relations, Tony Romanin, says the results have already been published as abstracts in the leading industry journal Blood, but unpublished data will be presented the ASH meeting.

Romanin says while the detailed results must await next month's ASH meeting, the trials have confirmed that Norwood's therapy, gives "a real boost to the immune system" in profoundly immunosuppressed leukaemia and lymphoma patients who have undergone bone-marrow transplants. The Melbourne clinical trials involved 40 volunteer patients.

"Their ability to fight off infection is significantly enhanced," he said.

Romanin says patients who undergo a bone marrow transplant after having their own bone marrow - the source of their cancer - ablated by chemotherapy, are at high risk of potentially lethal microbial infections, particularly while recovering in hospital, where antibiotic-resistant bacteria are abundant.

"The standard treatment for someone with acute myeloid leukaemia involves a bone-marrow transplant," he said. "Finding a compatible donor is just the first hurdle."

"Between 30 and 50 per cent of patients who undergo transplants die before they can recover protective immunity."

Norwood Abbey's experimental therapy is based on the discovery by Dr Richard Boyd, of Monash University, that drugs which block the release of gonadotropin-releasing hormone (GnRH) from the brain, allowing the thymus to regrow by preventing the gonads releasing sex hormones.

The thymus is the source of the T cells that prevent infection and cancer by identifying and eliminating virus-infected and mutant cells. In teenage, surging sex hormones cause the thymus to atrophy, and the production of naive T-cells capable of responding to novel antigens declines.

Researchers from Monash University, the Peter MacCallum Cancer Institute, and the Alfred Hospital, have been treating leukaemia and lymphoma patients with a GnRH-blocking drug, Lupron Depot, made by US-based TAP Pharmaceutical Products.

The drug causes the thymus to regenerate, and begin producing new, naive T-cells, restoring the patient's cellular immunity system.

Norwood has already announced that its trials in bone-marrow transplant (BMT) patients will be expanded to several leading cancer treatment centres overseas - Memorial Sloan Kettering Hospital in New York, M.D. Anderson Hospital in Houston, the University of Minnesota, and the Royal Free Hospital in London.

While the trials involve bone-marrow transplant patients with lymphomas and leukaemias, Norwood Abbey is also planning trials in immunosuppressed patients who have been treated to remove solid tumours.

"We want to make it clear that we're not trying to cure cancer, we're trying to significantly enhance existing treatments for cancer," he said.

Romanin says restoring thymus function also restores immunosurveillance - the mechanism that detects cancerous cells that have escaped surgery, chemotherapy or radiotherapy, and which have the potential to form new, secondary tumours.

Norwood Abbey is also planning to trial Lupron Depot in HIV-AIDS patients, with the aim of restoring their CD-4 helper-inducer T cells. These cells, the linchpin of the anti-viral response, are selectively targeted by the AIDS virus, eroding the immune system's capacity to fight off infection.