Remote ambulation monitoring enhances composite disability measurement in MS to deliver reduced trial sample size

In multiple sclerosis trials, event-based endpoints like the composite confirmed disability progression (cCDP) are often limited by infrequent in-clinic testing. We present a framework that converts high-frequency, remote smartphone-based gait assessments into progression events, and establishes a new composite endpoint that blends digital and clinical progression events. Evaluated in the Phase 3b CONSONANCE study (N = 667), this digitally enhanced endpoint reduced required trial sample size by 24.9% at Week 48 compared to the original cCDP. Furthermore, it achieved equivalent statistical power 24 weeks earlier (Week 72 vs Week 96), demonstrating potential to shorten trial observation periods by 25%. In conclusion, this framework provides a practical pathway to optimize clinical trial efficiency in MS and other neurological conditions, potentially reshaping the path to therapeutic innovation.