Prana starts second generation trials

Melbourne's Prana Biotechnology (ASX:PBT) has begun a Phase I clinical trial of its synthetic, second-generation molecule PBT2 in healthy volunteers.

The company announced it had dosed its first subject at a facility associated with the University of Utrecht, in the Netherlands. The trial will assess PBT2 for safety and tolerability - Prana chemists hope the new metal-protein attenuating compound (MPAC) will be safer and more efficacious than PBT1

In in vitro trials, and in a mouse model of a severe, early-onset form of Alzheimer's disease, PBT2 proved significantly more effective in reducing amyloid plaques - the dense aggregations of protein fragments that occlude the brains of Alzheimer's patients.

The company said PBT2 also appeared to be superior to PBT1 in reducing the toxicity of amyloid plaques by inhibiting hydrogen peroxide production. It also appears to have better pharmaceutical characteristics, including improved solubility.

Prana co-founder Dr Ashley Bush has produced evidence that reactive copper and zinc ions play a central role in the aggregation of amyloid, and catalyse production of hydrogen peroxide. Hydrogen peroxide molecules decompose rapidly, producing water and toxic hydroxyl (OH-) radicals that damage and eventually kill neurons.

Late last year Prana announced that UK health authorities had approved a phase II/III trial of PBT1 in Alzheimer's patients. The first patients will be enrolled before the middle of the year.