Grant to boost Prana's Alzheimer's project

Melbourne drug-development company Prana Biotechnology (ASX:PBT) will turn up the wick on development of its second-generation drug candidate for Alzheimer's disease PBT-2, after receiving a $1.35 million federal government R&D Start grant.

The competitive, peer-reviewed Start grant is Prana's second. The company used its first grant to develop a suite of more than 200 metal-chelating compounds, of which PBT-2 proved the most active in in vitro tests of its ability to dissolve the toxic amyloid protein deposits in brain tissue that cause Alzheimer's disease.

Prana plans to begin Phase I human clinical trials late this year.

Prana's first-generation compound, the obsolete traveller's diarrhoea antibiotic clioquinol, confirmed that its metal-chelating activity could improve cognitive function a mouse model of Alzheimer's disease, and in a small group of human volunteers.

The metal-chelator therapeutic approach is based on a hypothesis developed in the 1990s by Prana co-founder Dr Ashley Bush that the growth of amyloid plaques in the brain is mediated by heavy metal ions -- chiefly copper and zinc -- that catalyse the production of hydroxyl radicals that are directly toxic to neurons in the brain.

In vitro tests showed the drug's chelating activity dissolve stubborn amyloid plaques by removing the ions that bind amyloid molecules together.