Nusinersen improves walking distance and reduces fatigue in later-onset spinal muscular atrophy.

"both study designs and results of an integrated analysis have been described in previous work 20 the list of cs2 and cs12 study group investigators and site personnel is provided in data s1 online."

"CONFLICTS OF INTEREST J.M. has been an advisory board member for Astellas, Biogen, Cytokinetics, Roche, and Scholar Rock; a consultant to Biogen and Ionis Pharmaceuticals, Inc; and has received research support from the Muscular Dystrophy Association and the Eunice Kennedy Shriver National Institute of Child Health and Human Development/National Institutes of Health. S.D.Y. has been an advisory board member for Biogen, Roche, and Scholar Rock; received personal compensation for activities with Biogen, Cure SMA, and Scholar Rock as a consultant; and received research support from the SMA Foundation. E.S.M. has been an advisory board member for Biogen, Roche, and Scholar Rock; and been a consultant for AveXis, Cytokinetics, Ionis Pharmaceuticals, Inc, and Roche. A.P. has received research support from the SMA Foundation; serves as a consultant for Biogen; and has been an advisory board member for AveXis, Biogen, Roche, and Scholar Rock. A.M.G. received travel/lodging and compensation from Biogen to serve on an advisory board; licensing fees from Children's Hospital of Philadelphia for development of the CHOP INTEND motor scale; institutional support from AveXis, Biogen, and Roche for trial training; and personal compensation from ATOM International and Mallinckrodt for trial training. R.S.F. received grants and advisor fees from Biogen and Ionis Pharmaceuticals, Inc during ENDEAR and CHERISH and from Biogen during NURTURE and SHINE, and grants from Cytokinetics; outside the submitted work, he has received advisor fees and grants from AveXis and Roche, and has served as an advisor to Novartis; he has served in an advisory capacity for the nonprofit organizations Cure SMA, SMA Europe, the SMA Foundation, and SMA Reach (UK); he has been on the data safety monitoring board for the AveXis AVXS‐101 phase I gene transfer study and the Roche Moonfish phase IIb study; received personal compensation for serving as coeditor of Swaiman's Pediatric Neurology text (2018); received licensing fees from Children's Hospital of Philadelphia for development of the CHOP INTEND motor scale; and was recipient of grants from AveXis, Cytokinetics, Ionis Pharmaceuticals, Inc/Biogen, and Roche. B.T.D. has been an advisory board member for AveXis, Biogen, Cytokinetics, Dynacure, PTC, Roche, and Sarepta; received research support from Cure SMA, the National Institutes of Health/National Institute of Neurological Disorders and Stroke, the Slaney Family Fund for SMA, the SMA Foundation, and the Working on Walking Fund; and received grants from Biogen and Ionis Pharmaceuticals, Inc during the ENDEAR, CHERISH, CS2, CS12, and CS11 studies, and also from Cytokinetics, Fibrogen, PTC, Roche, Santhera, Sarepta, and Summit, and reports no personal financial interests in these companies. F.M. is principal investigator for ongoing AveXis, Ionis Pharmaceuticals, Inc/Biogen, and Roche clinical trials; has received funding from Biogen, SMA Europe, and the SMA Trust; and has been an advisory board member for AveXis, Biogen, Novartis, Pfizer, PTC, Roche, Sarepta, Summit, and Wave, and has no financial interests in these companies. E.M. has been a an advisory board member for SMA studies for AveXis, Biogen, Ionis Pharmaceuticals, Inc, Novartis, and Roche; is principal investigator for ongoing AveXis, Ionis Pharmaceuticals, Inc/Biogen, and Roche clinical trials; and received funding from Famiglie SMA Italy, Italian Telethon, and SMA Europe. D.C.D. has been an advisor/consultant for AveXis, Biogen, Cytokinetics, Ionis Pharmaceuticals, Inc, Metafora, Roche, Sanofi, Sarepta, and the SMA Foundation, with no financial interests in these companies; received grants from the Department of Defense, Glut1 Deficiency Foundation, Hope for Children Research Foundation, the National Institutes of Health, and the SMA Foundation; and received clinical trial funding from Biogen, Mallinckrodt, PTC, Sarepta, Scholar Rock, and Ultragenyx. K.M.B. is an employee of Otonomy, Inc; and is an unpaid advisor to the nonprofit organizations Myotonic Dystrophy Foundation and SMA Foundation. E.S. and C.F.B. are employees of and hold stock/stock options in Ionis Pharmaceuticals, Inc. R.F. and W.F. are employees of and hold stock/stock options in Biogen."

"Funding information Biogen"