Roche’s Prasinezumab Fails Primary Endpoint in Phase 2b Parkinson’s Trial, Shows Promising Trends

Clinical Trial Outcome:
Roche's prasinezumab, a monoclonal antibody targeting alpha-synuclein, failed to meet its primary endpoint in a phase 2b trial for treating early-stage Parkinson's disease35.

Primary Endpoint:
The trial aimed to assess the change in time to confirmed motor progression, which prasinezumab did not achieve with statistical significance (p=0.066)3.

Positive Trends:
Despite missing the primary endpoint, prasinezumab showed numerical delays in motor progression and positive trends on multiple secondary and exploratory endpoints, including a 16% extension in time to motor progression versus placebo23.

Sub-Analysis:
In a sub-analysis of participants taking levodopa, prasinezumab demonstrated a 21% increase in time to motor progression3.

Safety Profile:
Prasinezumab was well-tolerated with no new safety concerns reported3.

Future Plans:
Roche plans to further evaluate the data and collaborate with health authorities to determine next steps, with ongoing open-label extension studies continuing3.

Challenges in Treating Parkinson’s:
The failure underscores the challenges in developing treatments for Parkinson’s disease, with less than 50% of potential therapies advancing from phase 2 to phase 3 and less than 15% achieving approval since 19993.

Sources:

2. https://www.finanznachrichten.de/nachrichten-2024-12/64121747-prothena-corporation-plc-roche-s-phase-iib-study-of-prasinezumab-missed-primary-endpoint-but-suggests-possible-clinical-benefit-in-early-stage-parki-004.htm

3. https://www.biopharma-reporter.com/Article/2024/12/19/roche-and-prothenas-parkinsons-antibody-treatment-fails-at-phase-2/

5. https://endpts.com/roches-parkinsons-drug-flunks-second-mid-stage-trial/