A landmark clinical trial aiming to slow or halt the progression of Parkinson’s disease has just been launched in the United Kingdom. Led collaboratively by University College London (UCL) and Newcastle University, this is being billed as the largest-ever effort to evaluate disease-modifying therapies in Parkinson’s. The trial is ambitious both in scale and in design, with the potential to shorten drug development timelines by years.
Trial Overview and Rationale
The clinical study, named Edmond J. Safra Accelerating Clinical Trials in Parkinson’s Disease (EJS ACT-PD), is backed by an investment of £26 million. It employs a flexible, multi-arm, multi-stage (MAMS) protocol, allowing multiple candidate treatments to be tested in parallel against a single placebo arm.
Because MAMS trials allow interim analyses and adaptive decision-making, ineffective arms can be dropped early and new ones introduced without halting the entire study. This design is estimated to reduce the time to evaluate a new therapy by up to three years (around 25 %) compared to conventional sequential trials.
The trial is recruiting up to 1,600 participants across over 40 hospital sites in England, Wales, Scotland, and Northern Ireland. Recruitment began at UCLH (London) and Newcastle, with further sites phasing in through the following months.
Disease Context and Urgency
Parkinson’s disease is a progressively degenerative neurological disorder characterized by motor symptoms (tremor, rigidity, slowness) and non-motor manifestations (sleep disturbance, depression, autonomic dysfunction). While treatments exist that address symptoms, none currently alter or halt the underlying disease process. Over time, symptomatic therapies lose potency, and patients face increasing disability.
In the UK alone, an estimated 166,000 people currently live with Parkinson’s. The disease represents one of the fastest-growing burdens among neurological disorders—a trend seen globally as populations age.
Thus, there is a compelling unmet need for therapies that can slow or stop disease progression, not merely palliate symptoms.
Drug Candidates and Selection Process
At launch, the EJS ACT-PD trial will test two repurposed drugs already approved for other conditions:
Telmisartan (a blood pressure medication)
Terazosin (used for benign prostatic hyperplasia)
A third candidate, ursodeoxycholic acid (UDCA)—commonly used in liver disease—may be added in 2026.
The selection of these agents followed a structured process: an expert Treatment Selection Working Group screened 293 interventions, of which 52 passed “Go/No-Go” criteria and 14 were shortlisted for further review. Final prioritization used scientific metrics, mechanistic plausibility, logistics, and patient/public input.
This rigorous approach reflects the trial’s ambition not only to test therapies but also to refine methods of therapeutic prioritization for neurodegenerative disease.
Adaptive Trial Design and Participant Experience
The MAMS design permits ongoing analysis of accumulating data. Treatments failing to show early promise are dropped, while new ones may be added—without pausing the entire trial. This adaptability accelerates discovery and conserves resources.
Participants will be followed every six months for up to three years, with options for in-person or remote visits to reduce travel burden. Medications will be shipped to participants’ homes, easing logistical barriers especially in rural or mobility-limited settings. Eligibility criteria include a Parkinson’s diagnosis (onset ≥30 years), use of dopaminergic therapy, and no prior deep brain stimulation or infusion treatments.
Importantly, patients, caregivers, and community representatives have been integrated into trial design. Their feedback shaped decisions such as hybrid visit scheduling and patient-reported outcome measures to ensure the trial is sensitive to the lived experience of Parkinson’s.
Scientific Innovations and Embedded Sub-Studies
EJS ACT-PD is also a platform for ancillary studies. One such sub-study, funded by the Michael J. Fox Foundation, explores wearable sensor technologies to continuously monitor symptoms. Another seeks molecular biomarkers (e.g., in blood or CSF) that may correlate with disease trajectory or treatment response.
Additionally, a consensus framework for outcome measures has been developed to guide which scales, biomarkers, or composite measures are most appropriate for future disease-modifying trials.
PubMed
Professor Sonia Gandhi, co-leader of the trial’s innovation program, emphasized that the approach will help us understand which patients respond to which drug, how it works, and why, thereby informing future personalized strategies.
Challenges and Prospects
Despite its promise, the EJS ACT-PD trial faces significant challenges: logistical complexity across multiple sites, harmonizing data collection, retaining participants over multiple years, and ensuring statistical integrity in adaptive analyses. Nevertheless, its architecture is founded on rigorous methodology and stakeholder engagement.
If successful, this trial could serve as a blueprint for future neurodegenerative disease trials—not only in Parkinson’s but also in Alzheimer’s, amyotrophic lateral sclerosis, and others—by demonstrating the value of platform-based, adaptive testing.
Conclusion
The EJS ACT-PD trial represents an unprecedented and ambitious effort to transform how we test therapies in Parkinson’s disease. By combining innovative trial design, patient-centric features, and embedded scientific studies, it seeks not just to identify a disease-modifying drug—but to fundamentally reshape the research infrastructure. With recruitment already underway across the UK, the coming years will reveal whether this bold experiment can deliver faster, more efficient paths to new treatments for people living with Parkinson’s.
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