2. Determine the effects of treatment on disease progression and accumulation of disability.
I suspect you are asking what treatments..need to do better
In this study people with progressive MS were behaving as predicted in terms of their progression rates, is this to be expected because they are not recieving any effective treatments.
However the question is if PPMSers are in trials then will this rate be the same. In the CUPID trial of tetrahydrocannabinol people in the trial progressed at at much slower rate than predicted.