Parkinson’s Disease: New Drug Prasinezumab Shows Promise to Slow Progression – Clinical Trial at Erlangen University Hospital

Berlin – For individuals living with Parkinson’s disease, a new sense of hope is emerging: the possibility of a treatment that doesn’t just manage symptoms, but potentially slows the disease’s progression. Although existing therapies primarily address motor symptoms like rigidity and tremors, a novel investigational drug called prasinezumab aims to target the underlying causes of Parkinson’s. Researchers at the Molecular Neurology Department of the University Hospital Erlangen are now seeking participants for a Phase 3 clinical trial, dubbed “PARAISO,” to evaluate the efficacy of this monoclonal antibody in the early stages of the disease.

Parkinson’s disease is a progressive neurodegenerative disorder affecting dopamine-producing neurons in the brain. This loss of dopamine leads to the characteristic motor symptoms, but likewise non-motor symptoms like sleep disturbances, cognitive changes, and depression. Currently, there is no cure for Parkinson’s, and treatment focuses on managing symptoms, primarily through medication like levodopa. However, levodopa’s effectiveness can diminish over time, and it can be associated with side effects. This is why the development of disease-modifying therapies, like prasinezumab, is so crucial.

The PARAISO study, making the University Hospital Erlangen the first German center participating in the Phase 3 trial sponsored by Roche Pharma AG, will enroll approximately 900 patients globally. Eligible participants will be between 50 and 85 years aged, have received a Parkinson’s diagnosis within the past three months to three years, and currently be taking levodopa to manage their symptoms. Participants will receive either prasinezumab or a placebo via monthly intravenous infusions for a minimum of two years, with regular follow-up appointments to monitor their response to the treatment.

Understanding Prasinezumab: Targeting Alpha-Synuclein

Prasinezumab is a humanized IgG1 monoclonal antibody designed to selectively bind to aggregated forms of alpha-synuclein, a protein that accumulates in the brains of people with Parkinson’s disease. These aggregates form insoluble fibrils and Lewy bodies, hallmark pathological features of the condition. According to information from Wikipedia, prasinezumab recognizes the C-terminus of α-synuclein and preferentially targets these pathological aggregates while sparing the physiological monomeric form of the protein. Prasinezumab is being developed by Prothena Biosciences and Roche.

The rationale behind targeting alpha-synuclein is that its accumulation is believed to play a central role in the development and progression of Parkinson’s disease. By binding to and potentially clearing these aggregates, prasinezumab aims to sluggish down the neurodegenerative process. However, it’s important to note that a 52-week Phase 2 clinical trial did not show a significant effect on disease progression, as reported by Wikipedia. This highlights the complexities of developing effective therapies for Parkinson’s and the need for larger, longer-term studies like PARAISO.

Phase 3 Trials and the Road to Approval

Phase 3 clinical trials represent a critical step in the drug development process. They are designed to confirm the efficacy and safety of a drug in a larger patient population. The PARAISO study, as a Phase 3 trial, will gather comprehensive data on prasinezumab’s performance before a potential application for regulatory approval can be submitted. Phase 3 trials follow Phase 1 and Phase 2 studies, which focus on safety, tolerability, and preliminary efficacy in smaller groups of participants.

The University Hospital Erlangen’s involvement as a leading German center in the PARAISO study underscores the growing importance of immunotherapy in the treatment of neurodegenerative diseases. “Prasinezumab could represent a turning point in the treatment of Parkinson’s disease,” stated Professor Dr. Jürgen Winkler, Head of Molecular Neurology at the University Hospital Erlangen, in a press release. “The PARAISO study further emphasizes the importance of Erlangen as a location for immunotherapy of neurodegenerative diseases.”

Recent Findings and Ongoing Concerns

While the Phase 2 trial did not demonstrate a significant overall effect, a post-hoc subgroup analysis, published in February 2025, suggested potential therapeutic benefits of prasinezumab in certain patient populations. This analysis, available through the National Center for Biotechnology Information, indicated a possible slowing of motor progression in a specific subset of patients. However, these findings require further investigation and confirmation in the larger Phase 3 trial.

It’s also important to acknowledge that concerns have been raised regarding research misconduct and data fabrication related to prasinezumab. According to Wikipedia, these concerns have prompted scrutiny of the research process and the integrity of the data. These allegations underscore the importance of rigorous scientific standards and transparency in clinical research.

Participating in the PARAISO Study

The University Hospital Erlangen is actively recruiting participants for the PARAISO study. Individuals meeting the eligibility criteria – aged 50-85, diagnosed with Parkinson’s disease within the last three years, and currently taking levodopa – are encouraged to inquire about participation. The study involves a thorough initial assessment, followed by monthly infusions of either prasinezumab or a placebo for at least two years, along with regular follow-up appointments at the Movement Disorders Outpatient Clinic at the University Hospital Erlangen.

Interested individuals can find more information at www.uker.de/mn-paraiso or by contacting the study team by phone at 09131 85-39324 or by email at bewegungsstoerungen(at)uk-erlangen.de. PD Dr. Martin Regensburger can also be reached for further information at 09131 85-39324 or martin.regensburger(at)uk-erlangen.de.

Key Takeaways

• Prasinezumab is an investigational monoclonal antibody targeting aggregated alpha-synuclein, a protein implicated in Parkinson’s disease.
• The Phase 3 PARAISO study, conducted at the University Hospital Erlangen and other sites globally, aims to assess the drug’s efficacy in slowing disease progression.
• While previous trials have yielded mixed results, recent subgroup analyses suggest potential benefits in specific patient populations.
• Concerns regarding research misconduct have been raised, highlighting the need for rigorous scientific standards.
• The University Hospital Erlangen is currently recruiting participants for the PARAISO study.

The PARAISO study represents a significant step forward in the search for disease-modifying therapies for Parkinson’s disease. The results of this trial, expected in the coming years, will be crucial in determining whether prasinezumab can offer a new hope for individuals living with this debilitating condition. The next major milestone will be the completion of patient enrollment and the subsequent analysis of the trial data. We will continue to follow this story and provide updates as they grow available.

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