Spinal Muscular Atrophy Clinical Trials: Lessons Learned

There are few completed randomized clinical trials for spinal muscular atrophy (SMA). There is no known effective treatment and most trials have been open label. However, much has been learned from those negative trials that helped improve trial design so that future studies will be powered and valid. Lessons learned include the fact that easy fatigability influences a subject's performance on outcome measures and that this fatigue can be induced by prolonged travel to the study site and prolonged procedures during the study visit. There is new and concerning use of social media by subjects and their families that could affect enrollment and outcomes; this demands new guidelines for trial participants and for investigators. Finally, it is very clear that all study groups must have received standard of care at the time of enrollment and throughout the study in order to avoid confounders of outcome measures.