Prasinezumab, a monoclonal antibody targeting alpha-synuclein aggregation, shows promise in slowing motor deterioration in rapidly progressing Parkinson's disease (PD), according to an exploratory analysis from the phase 2 PASADENA clinical trial. While there are currently no disease-modifying treatments for PD, prasinezumab offers a potential breakthrough by specifically binding to aggregated alpha-synuclein, a key driver of PD pathology.