For me - the approval of grants is a very good news as - it allows to start a trial in a orphan disease - the trial is comparatively short and it could indicate efficacy - ALZ trial improvements are much subjective but Rett improvements are more visible and objective
Efficacy signs in Rett will add to credibility of A2-73 as a drug that is crossing Brain Blood Barrier safely and having meaningful positive impact. It could become for targeting any CNS
That itself will bring more confidence in A2-73 and guide positive sentiment - they can then look at epilepsy etc besides ALZ.
This itself will bring more BP attention much before approval.