Replies to post #99928 on Anavex Life Sciences Corp (AVXL)

[FooBarAndGrill]

re. P300
This talk of P300 caused me to wonder the correlation of latency vs. amplitude. I found this interesting graph which illustrates the correlation. Seems we are at the top of our game at age 22.

[MycroftHolmes]

Re: P300

Just to underscore why in the proper context the P300 data seems encouraging and this concern seems off base.

Donepezil has been shown to have correlations between P300 Amplitude, ADAS-Cog and MMSE






Therefore one would hope to see an improvement in A2-73. That is exactly what the data shows.





Other data shows that Anavex improvements also demonstrate correlations between P300 Amplitude, ADAS-Cog and MMSE.


That is why I am failing to understand the frenzied concern over latency.

FYI: this is spring 2016 data I've shown. I believe there is later data but this seems sufficient to prove the point.

Cheers

Mycroft

[OFP]

I do not believe this statement to be accurate.

There are studies tracking the P300 Amplitude of Donepezil against healthy controls. Donepezil has been shown to increase amplitude in AD patients. A2-73 data shows both an earlier and larger increase than the Donepezil studies which is why they are touting it in their slides.

AVXL made reference to the article below in making the claim you are referring to.

Donepezil Versus Vitamin E in Alzheimer's Disease Part 2: Mild Versus Moderate–Severe Alzheimer's Disease Onofrj, Marco; Thomas, Astrid; Luciano, Anna Lisa; More Clinical Neuropharmacology . 25(4):207-215, July/August 2002.
Refer to page 212 for this:

Neuropsychologic test scores at baseline were statistically related to P3 latencies but not to P3 amplitudes.

This is what I recalled from the past readings. However, given your assertion I pulled the study again to confirm. This revealed that there was a significant improvement vs. baseline for DZP in patients with MMSE </=18 in that study. Thank you (again) for pointing out an error and my "NEVER" statement was wrong.

That being said, the primary points remain:
1. Latency is a far more robust measure shown consistently, earlier, and with higher significance across all groups
2. The MMSE >18 group did not show the effect on amplitude whereas latency showed the effect at p<0.001.
3. The effect on the P300 was progressive over 6 months whereas at 6 months 2-73's amplitude increase had disappeared
4. 2-73 in no way "outperformed" DZP...this was an early and spurious assertion by AVXL using non-significant data