Prana pleased with Alzheimer's trial results

Prana Biotech (ASX:PBT, NASDAQ:PRAN) announced today that its candidate PBT2 therapy for Alzheimer's disease has come through a phase I single-dose escalation trial in the Netherlands, with a superior pharmacokinetic profile to its predecessor, clioquinol.

Conducted at a facility in Utrecht, the double-blind, placebo-controlled trial involved 55 healthy male volunteers aged 18 to 50. The study group tolerated the drug well, with little difference in adverse events relative to the placebo group.

Prana said concurrent preclinical studies showed PBT2 crossed the blood-brain barrier with 20 times greater efficiency than clioquinol -- a crucial finding for a drug designed to ameliorate oxidative damage within the brain tissues of Alzheimer's patients.

The pharmacokinetic analysis also showed that the concentration of PBT2 in the brain rises predictably and in a linear manner with escalating dosage - excellent properties for a central nervous system drug, according to Prana.

Described the results as "compelling", Prana's COO, Ross Murdoch, said they confirmed evidence from laboratory trials showing that PBT2 had great potential for treating Alzheimer's disease, which currently affects 4.5 million people in the US, and 14 million worldwide.

PBT2 is a synthetic, metal chelating drug designed by Prana chemists to capture and sequester copper and zinc ions that catalyse the formation of amyloid plaques -- tiny deposits of a neurotoxic amyloid-beta protein in the brains of all aging mammals. The copper ions, in particular, spawn reactive hydroxyl radicals that damage nerve cells, which then undergo apoptosis -- programmed cell death. Both PBT2 and clioquinol target these abnormal metal-protein interactions.

Prana CEO Geoffrey Kempler said the early results were "extremely exciting" and gave hope to the battle against Alzheimer's disease.

Based on positive results already demonstrated in a previous trial of clioquinol in elderly patients with Alzheimer's disease, which provided proof of concept for the company's metal-protein chelating compounds (MPACs), Kempler said Prana holds "very high expectations" for PBT2 in phase II trials.

Like clioquinol, on which it is based, PBT2 is an 8-hydroxyquinoline molecule. Prana chemists redesigned the molecule for greater safety, efficacy and brain penetration.

Prana has completed three of four stages of a multi-dose escalation safety clinical trial of PBT2 in healthy, elderly male and female volunteers, and hopes to complete the trial before year's end. It is also running chronic toxicology and good manufacturing practice (GMP) development required for phase II and III clinical studies.

Murdoch said the multi-dose escalation trial has several clinical markers designed into it, which may provide some indications of efficacy in aged patients when the trial is completed.