Yes, some of the best evidence from sleep quality and insomnia is from the PDD studies and trials where RSBDQ (REM Sleep Behavior Disorder Screening Questionnaire) was a secondary outcome measure.
All we really know so far is that Anavex stated sleep did not get worse by taking A2-73, no hard data published so far AFAIK. As in the open label P2 AD trial is not in my book hard data.