Norwood commences phase II cancer vaccine trial

Melbourne meditech Norwood Immunology (AIM:NIM) has recruited the first of 100 post-surgical melanoma patients into a phase II clinical trial of its thymus-rejuvenating technology, using the gonadotrophin releasing hormone (GNRH) analogue Lupron Depot.

The first volunteer patient has been injected with the GNRH agonist Lupron Depot; 50 patients will receive the treatment, and 50 a placebo.

Norwood's COO, Dr Suzanne Lipe, said the drug, provided by Takeda-Abbott US joint-venture company TAP Pharmaceuticals, is predicted to boost the immune response to a model melanoma vaccine developed by the National Institutes of Health in the US.

By stimulating the pituitary gland to over-produce GNRH, the drug activates a pituitary-gonad feeback loop, blocking production of the sex hormones. The hormonal tides of puberty cause the thymus gland, high in the chest, to atrophy progressively and reducing its production of naive T-cells.

The declining supply of naive T-cells blunts the cytotoxic response, which is vital to immunosurveillance: the routine detection and elimination of of virus-infected and cancerous cells expressing unfamiliar antigens.

The success of cancer vaccines depends in part on their ability to stimulate a potent cytotoxic T-cell response. In the 1990s, Monash University immunologist Professor Richard Boyd discovered that overdosing with GNRH mimics caused the thymus to regrow and resume production of naive T-cells capable of targeting cells displaying novel antigens.

The trial will determine whether the therapy reslts in an enhanced immune response to the NIH melanoma vaccine, which Norwood Immunology is funding the trial, and TAP is supplying the drug.

The NIH melanoma vaccine contains two synthetic peptides, MAGE3 and GP100 - it is publicly available for biotechnology companies to Lipe said that, should the therapy be shown to be safe and effective, TAP will market it in the US, while Japan's Takeda and Europe's Abbott will share the rest of the global market, and receive milestone payments, and and royalties on the sale of Lupron Depot.

Lipe said that NIM's therapy is potentially a generic treatment to prevent metastatic cancers after surgical resection of primary cancers.