3844 Towards digital mobility outcome measures in Parkinson’s disease: mobilise-d to EJS ACT-PD

Abstract Background A key challenge for disease-modifying trials in Parkinson’s disease (PD) is the lack of sensitive, patient-relevant outcome measures. Digital mobility outcomes (DMOs), captured using body-worn devices, offer a novel, objective means to assess real-world gait and mobility. The Mobilise-D study validated DMOs in PD, demonstrating that the analytics software could accurately and reliably monitor mobility in the real world. However, to progress towards regulatory qualification, demonstration of responsiveness to therapy is required. The Edmond J Safra Accelerating Clinical Trials in Parkinson’s Disease (EJS ACT-PD) multi-arm multi-stage (MAMS) trial provides a unique opportunity to advance this work. Methods The EJS ACT-PD trial will commence in autumn 2025; overall the trial will recruit 1600 participants across 43 sites and will embed DMOs as an exploratory endpoint. Participants will apply a body-worn sensor every six months, and DMOs such as gait speed, stride length, and number of walking bouts will be extracted using the validated Mobilise-D pipeline. The largely remote setup, including sensor application, is designed to enhance accessibility. Results To evaluate the potential of DMOs as digital trial endpoints, analyses will include DMO correlation with and predictive of the main trial outcomes, in addition to longitudinal change of DMOs. The study will also assess adherence, data completeness, and acceptability, informing the feasibility of remotely deploying DMOs in large MAMS trials. Demographic comparisons between those who consent to the digital measures study and the main trial cohort will identify any participation biases. Conclusion Embedding DMOs within the EJS ACT-PD trial allows comprehensive evaluation in a large PD population. The findings will support the development and validation of DMOs as digital biomarkers, helping accelerate early Go/No-Go decisions and paving the way for regulatory qualification. This has the potential to speed up the evaluation of therapies and ultimately improve outcomes for people with PD.