Roche’s Parkinson’s Drug Faces Another Trial Setback

Roche's experimental Parkinson’s disease drug, prasinezumab, has faced a setback after failing a key clinical trial. Despite the disappointment, the company remains cautiously optimistic. Roche’s Chief Medical Officer, Levi Garraway, stated that some positive results from the latest trial warrant further investigation. Roche plans to present the findings at a future medical meeting and will work with health authorities to decide on next steps. Prasinezumab originated from Prothena, with Roche gaining access to the drug over a decade ago through a $45 million upfront deal and a total potential investment of $600 million. Roche also agreed to fund most of the development and commercialization costs in exchange for 70% of any profits. Clinical trials for prasinezumab have so far failed to show clear benefits. The PASADENA trial, involving 300 participants with early Parkinson’s, revealed no significant improvement in slowing disease progression. The more recent PADOVA trial, with 586 participants, showed a modest 16% improvement in motor function decline compared to placebo but failed to achieve statistical significance. However, among patients taking levodopa — the standard treatment for Parkinson’s symptoms — the drug demonstrated more pronounced benefits, along with consistent positive trends across other study objectives. Roche plans to continue follow-up studies where all participants receive prasinezumab. Analysts suggest that future trials focusing on patients already using levodopa may improve outcomes, but this approach could limit the drug’s market potential. Prasinezumab is an antibody drug targeting alpha-synuclein, a protein linked to Parkinson’s disease when it misfolds. Many pharmaceutical companies, including AstraZeneca, Sanofi, and AbbVie, have pursued similar approaches, but breakthroughs remain elusive.