Prothena and Roche Move Parkinson's Drug to Phase III in Bid for First Disease-Modifying Treatment

Prothena Corporation plc (NASDAQ:PRTA) today announced partner Roche will advance prasinezumab, an investigational anti-alpha-synuclein antibody, into Phase III development in early-stage Parkinson's disease. This decision is informed by data from the Phase IIb PADOVA study and ongoing open-label extensions (OLE) from both PADOVA and the Phase II PASADENA study.

"As pioneers in developing the first anti-alpha-synuclein targeting antibody, we are excited to see Roche advancing prasinezumab into Phase III development, with the potential to deliver the first disease-modifying treatment option to the millions of individuals living with Parkinson's disease and their families," stated Gene Kinney, Ph.D., President and Chief Executive Officer, Prothena.

Multiple endpoints from the PADOVA and OLE studies suggest a potential clinical benefit of prasinezumab when added to effective symptomatic treatment in early-stage Parkinson's disease. Prasinezumab showed potential clinical efficacy in the primary endpoint of time to confirmed motor progression, although missed statistical significance. Positive trends towards reduced motor progression at 104 weeks (two years) were observed; these effects appear to be sustained over longer treatment periods based on additional OLE data. The PADOVA study also provided the first biomarker evidence of prasinezumab impacting the underlying disease biology.

The PASADENA and PADOVA OLE studies, which are evaluating the long-term safety and efficacy of prasinezumab in over 750 people with early-stage Parkinson's disease, are ongoing.