Genentech, a member of the Roche Group , announced its decision to advance prasinezumab, an investigational anti-alpha-synuclein antibody, to Phase III clinical development for the treatment of early-stage Parkinson’s disease. This move is based on encouraging data from the Phase IIb PADOVA trial and ongoing open-label extension (OLE) studies from both PADOVA and the earlier Phase II PASADENA trial.
According to Dr. Levi Garraway, Chief Medical Officer and Head of Global Product Development at Genentech, the totality of evidence from the clinical program supports further development of prasinezumab. “We are encouraged by the efficacy signals observed across the two Phase II trials and their open-label extensions, along with the favorable safety and tolerability profile,” he stated. “There remains a significant unmet need for disease-modifying therapies in Parkinson’s disease, and the data suggest prasinezumab may hold potential to be the first of its kind.”
The PADOVA trial, which evaluated prasinezumab in people with early-stage Parkinson’s disease already receiving standard symptomatic therapy, assessed multiple clinical endpoints. While the primary endpoint—time to confirmed motor progression—did not achieve statistical significance, the study revealed consistent positive trends. Notably, prasinezumab appeared to slow motor symptom progression over a 104-week period, and these effects were sustained during longer treatment in the OLE studies. Importantly, PADOVA also yielded the first biomarker data indicating that prasinezumab may be modifying underlying disease biology—an important step in establishing a disease-modifying mechanism.
The PASADENA and PADOVA open-label extensions, which together include more than 750 participants, are ongoing and continue to evaluate the long-term safety and efficacy of prasinezumab. Data from these studies will further inform the design and objectives of the upcoming Phase III program.
With this decision, Genentech aims to advance prasinezumab into late-stage trials as part of its ongoing commitment to bringing innovative therapies to individuals living with Parkinson’s disease—a progressive neurological disorder that currently lacks approved treatments that alter disease progression.