Strong Ph II data on Prana's PBT2

Delegates at the 2008 International Conference on Alzheimer's Disease, in Chicago, USA, heard strong mid-stage data on PBT2, developed by Australia's Prana Biotechnology. 250mg of the metal-protein attenuating compound demonstrated a statistically-significant reduction of cerebrospinal fluid Ab-42 after 12 weeks of treatment compared with placebo (p=0.006), a dose-dependent effect (p=0.023).

In the 78-patient trial, PBT2 250mg demonstrated statistically-significant improvements in both the Trail Making Test Part B and the Category Fluency Test (components of the Neuropsychological Test Battery related to executive function) compared with placebo (p=0.009 and p=0.041, respectively). However, unlike another recent amyloid-targeting drug, Wyeth/Elan's bapinezumab (Marketletter August 4), PBT2 had no effect on the AD Assessment Scale-Cognitive Subscale.

According to Prana, PBT2 reduces the toxic form of beta amyloid by preventing the interaction of beta amyloid with copper and zinc. MPACs have been shown to restore normal function to beta amyloid-impaired synapses and improve cognitive performance in mouse models of AD. "These results indicate that PBT2 is having an impact on the underlying biology of Alzheimer's, which is very exciting," said Jeffrey Cummings of the David Geffen School of Medicine at UCLA, Los Angeles. "This is a critical proof-of-concept, and the safety and efficacy demonstrated by PBT2 in this study warrant evaluation in larger-scale clinical trials in Alzheimer's," he added.