Prothena partner Roche PADOVA study misses primary endpoint

Prothena (PRTA) announced results from the Phase IIb PADOVA study conducted by partner Roche (RHHBY) investigating prasinezumab in 586 people with early-stage Parkinson’s disease, treated for a minimum of 18 months while on stable symptomatic treatment. Prasinezumab showed potential clinical effect in the primary endpoint of time to confirmed motor progression with a hazard ratio of 0.84 and p-value of 0.0657. The effect of prasinezumab was more pronounced in a pre-specified analysis in the population treated with levodopa, hazard ratio 0.79 and nominal p-value 0.0431. Pre-specified supplementary covariate-adjusted analyses of these endpoints demonstrated nominally significant effects on the primary endpoint and in the levodopa subgroup. Consistent positive trends across multiple secondary and exploratory endpoints were also observed. Prasinezumab continues to be well tolerated and no new safety signals were observed in the study. The Phase IIb PADOVA results along with prior clinical study results will inform future clinical development, including study design, statistical analysis, and appropriate evaluation of patient sub-groups, of prasinezumab as a potential first-in-class disease-modifying treatment for patients with Parkinson’s disease.