Parkinson’s Research Review 2025
In this presentation, Professor Simon Lewis provides an expert overview of the most significant global developments in Parkinson’s disease (PD) research emerging in 2025, highlighting advances that are reshaping the landscape of diagnosis, disease modification, and future therapeutic strategies. A major focus is the accelerating progress in cell-based therapies, including the landmark clinical trials evaluating human embryonic stem-cell–derived dopaminergic neurons (e.g., Sawamoto et al., Nature 2025) and the first-in-human, phase I/II trials of induced pluripotent stem cell (iPSC)-derived dopaminergic progenitors, such as the Kyoto University study demonstrating graft survival, dopamine production, and encouraging early motor benefits without tumour formation (Kikuchi et al., Nature 2025). These studies represent a critical step toward scalable, ethically robust regenerative treatments for PD.
Professor Lewis also examines the transformative impact of α-synuclein seed amplification assays (SAA), which show sensitivity for detecting misfolded α-synuclein in prodromal populations—including individuals with REM sleep behaviour disorder (RBD) and hyposmia—and provide some of the strongest predictors of phenoconversion to PD or DLB (Coughlin et al., Neurology 2025). These assays are rapidly becoming central to early-stage trial design and precision neuroprotective strategies. Key therapeutic developments from 2025 are also reviewed, including the decision to proceed with a phase III prasinezumab trial, following exploratory signals of slowed progression in early PD seen in the PASADENA and PADOVA trials. In contrast, Professor Lewis considers the implications of the PD-3 exenatide trial, which reported no significant disease-modifying benefit despite strong mechanistic rationale and earlier phase II signals (Vijiaratnam et al., Lancet 2025), prompting renewed scrutiny of GLP-1 agonists in PD.
Overall, the presentation synthesises these developments into a coherent view of where PD research is heading, emphasising the rapid convergence of biomarkers, targeted therapeutics, and regenerative neuroscience.