Feasibility of Simon Two‐Stage Futility Trials in People with Early, Symptomatically Treated Parkinson's Disease

Phase 2 futility trials using the Simon two-stage methodology are feasible in early PD, including in treated and untreated patients. OFF-state scores are preferable to ON-state scores as the primary outcome measure. Futility trials offer a smaller-scale, faster, and cost-effective approach to assessing new candidate treatments in PD. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.