Prasinezumab (, ; developmental code names NEOD002, PRX-002, RG-7935, RO-7046015) is an anti-ñ-synuclein drug acting as a monoclonal antibody against ñ-synuclein which is under development for the treatment of Parkinson's disease. No significant effect on disease progression was seen in a 52-week phase 2 clinical trial. There have been concerns about research misconduct and data fabrication relevant to prasinezumab.
As of May 2024, prasinezumab is in phase 3 clinical trials for Parkinson's disease. It is under development by Prothena Biosciences and Roche.
Prasinezumab is a humanized IgG1 monoclonal antibody that selectively binds to aggregated forms of alpha-synuclein while sparing the physiological monomeric form. The antibody recognizes the C-terminus of ñ-synuclein and preferentially targets pathological aggregates that form insoluble fibrils and Lewy bodiesâÂÂhallmark features of Parkinson's disease pathology.
Prasinezumab was originally developed under the designation PRX002 through a collaboration between Hoffmann-La Roche and Prothena. The drug entered clinical development as a potential disease-modifying therapy for Parkinson's disease, representing one of the first attempts to target aggregated ñ-synuclein therapeutically.
The Phase II PASADENA trial was a randomized, double-blind, placebo-controlled study that evaluated prasinezumab in participants with early-stage Parkinson's disease. Participants were randomly assigned to receive either placebo or prasinezumab at doses of 1500 mg or 4500 mg intravenously every 4 weeks for 52 weeks.
While the trial did not meet its primary endpoint (change in Movement Disorder Society Unified Parkinson's Disease Rating Scale [MDS-UPDRS] sum of Parts I + II + III from baseline to week 52), exploratory analyses revealed promising signals:
The Phase IIb PADOVA trial further evaluated prasinezumab's efficacy and safety profile. While the primary endpoint of time to confirmed motor progression did not achieve statistical significance (HR=0.84, p=0.0657), the results suggested potential clinical benefit, particularly in pre-specified subgroups.
Based on encouraging results from Phase II studies, Genentech announced in June 2025 its decision to advance prasinezumab into Phase III clinical development for early-stage Parkinson's disease. This represents a significant milestone in the development of ñ-synuclein-targeting therapies.
As of 2025, prasinezumab development includes: