If you read the notes at the bottom of the slide it says the aducanumab threshold for being a responder for the odds ratio is worsening less than or equal of 0.5 points.
Anavex used a threshold of improving 0.5 or more as a threshold. Pretty different starting points.
The slide does give an "estimated" percentage of responders in the placebo group not the percentage of responders in the treatment group.