Anavex Life Sciences Corp (AVXL)

[blu_1]

Both P300 latency and amplitude reliably measure cognitive decline in elderly w/Alzheimers Disease. Latency is considered the more reliable of the two. The reason is b/c amplitude is effected by the attention level of the testee. It is also effected by the testing methodologies and variables used. Apparently, those variables aren't standardized and thus vary quite a bit from study to study. That is thought to result in more inconsistencies in P300 amp levels from study to study. The P300 latency is a bit more consistent from study to study despite different testing methodologies used. Some methodologies are thought to better measure the amp decline in AD patients than other methodologies. These are reasons why the traditional consensus has favored latency, but that is not to say a definite correlation between amp and cognitive decline in AD patients has not been observed in studies. A correlation most definitely has been observed.

Refer to this chart. [urlhttp://www.scielo.br/img/revistas/bjorl/v78n4/en_a23cha02m.jpg][/url][tag]insert-text-here[/tag] It lists P300 mean scores from 8 different studies comparing AD patients w/control groups. 8 of 8 studies showed longer P300 latencies for those w/AD. Only 5 out of the 8 studies recorded P300 amplitudes. 4 out of the 5 showed lower amps for those w/AD. However, one of those studies (the 4th one down in the chart w/Yamaguchi as author) lists a mean amp of 45.8 for the AD group! I don't think that's even possible! Makes no sense. Something went awry w/the testing in that study. The methodology used in that study probably wasn't a satisfactory one to measure amps in people w/AD. If you throw out that study, the other 4 all show lower mean amps for the AD groups vs control groups.

Anavex is conducting its current Ph 2A trial at multiple locations in and around Melbourne, a huge city. It can do this, and record P300's and ERP's at all those sites, b/c Anavex is using Neurontrix's Cognision system. This technology is new, FDA approved, portable, anyone can easily administer it, and it measures and interprets ERP's. The system does also report a value for the P300 wave and that is the Peak Alpha (highest amplitude recorded within the frequency of 8-12Hz). I don't think most standard recordings of P300 amp are that discriminating. Neuronetrix must feel that is the best way to measure P300 amps. I don't think Cognision reports P300 latencies. Neuronetrix places more emphasis on the ERP measurements and Cognision's interpretations of them. It doesn't discount the P300, it just emphasizes ERP's as the better way to track physiological changes taking place in the brain due to disease progression, or the positive effects of a therapy. Neuronetrix states that changes in ERP's, and to a lesser extent the P300, detect slight physiological changes taking place in the brain, either good or bad, at earlier stages than psyche tests, such as the MMSE, ADAS Cog, Cogstate, etc. Neuronetrix says the ERP's its system reports correlate w/P300 latencies very closely. However, Neuronetrix prefers ERP's to P300 latencies.

Anavex's Ph 2A presentations report updated P300 amplitudes and ERP's. Neuronetrix has been impressed w/the performance of 2-73 in the Ph 2A trial. Might have been after CTAD 2015 that they said that, I can't remember when exactly.