Something you're not accounting for is the Anavex trial is for Mild to Moderate AD patients. They decline much faster than just Mild AD patients. Make sure you're comparing the Anavex trial with other trials that include Mild to Moderate patients. And also make sure the mean ages of the two groups you're comparing are the same as that also has big effect on rate of decline.
MMSE is subject to variability. Anavex also used Cogstate, ERP's and P3a amplitude using the trademark Cognision system, Ham D, and ADCS ADL assessments. Changes in scores for all assessments were consistent with each other over time and were also dose/blood concentration dependent.
To assess cognition in the Ph 2/3, Anavex will be using ADAS Cog
My second source was not MMSE specific. I’d love to hear your breakdown of it’ validity in comparison to Anavex’s trial.
“The maximum MMSE score is 30 points. A score of 20 to 24 suggests mild dementia, 13 to 20 suggests moderate dementia, and less than 12 indicates severe dementia. On average, the MMSE score of a person with Alzheimer's declines about two to four points each year.”