A Study to Evaluate the Efficacy and Safety of Intravenous (IV) Prasinezumab in Participants With Early-Stage Parkinson's Disease

Not Applicable

Not yet recruiting

• Conditions: Parkinson's Disease
• Interventions: Drug: Prasinezumab; Drug: Placebo

• Registration Number: NCT07174310
• Lead Sponsor: Hoffmann-La Roche

Brief Summary

The purpose of this study is to evaluate the efficacy, safety, and pharmacokinetics (PK) of prasinezumab compared with placebo in participants with early-stage Parkinson's disease (PD) on stable symptomatic monotherapy with levodopa.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-09
• Study First Submitted: 2025-09-12
• Study First Submitted QC: 2025-09-12
• Last Update Submitted: 2025-09-12
• Study First Posted: 2025-09-15
• Last Update Posted: 2025-09-15
• Study Start: 2025-12-31
• Primary Completion: 2029-07-27
• Study Completion: 2031-07-25

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 900

Inclusion Criteria

• Body weight within 40-110 kilograms (kg) (88-242 pounds [lbs]) and a body mass index within the range 18-34 kg/m2
• Diagnosis of idiopathic PD based on Movement Disorder Society (MDS) criteria
• Has received monotherapy treatment
• An MDS-UPDRS Part IV score of 0 at screening and prior to randomization
• Hoehn and Yahr (H&Y) Stage 1 or 2 off medication at screening and prior to randomization
• Agreement to adhere to the contraception requirements

Exclusion Criteria

• Pregnant or breastfeeding, or intention of becoming pregnant during the study or within the time frame in which contraception is required
• Medical history indicating a parkinsonian syndrome other than idiopathic PD
• Diagnosis of a significant neurologic disease other than PD
• Chronic uncontrolled hypertension

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Prasinezumab	Prasinezumab	Participants will receive Prasinezumab as an IV infusion in the double blind treatment period. Upon completion, eligible participants will enter into the Open Label Extension (OLE) phase.
Placebo	Placebo	Participants will receive placebo as an IV Infusion.

Primary Outcome Measures

Name	Time	Method
Time to Confirmed Motor Progression Event on Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III Score	Up to at least Week 104

Secondary Outcome Measures

Name	Time	Method
Time to Meaningful Worsening in Clinician Global Impression of Change (CGI-C), Overall Disease Subscale	Up to at least Week 104
Time to increase in Levodopa Equivalent Daily Dose (LEDD)	Up to at least Week 104
Change From Baseline in Motor Function as Measured by the MDS-UPDRS Part III off Medication Score	Baseline, Week 104
Time to Worsening of Participants Motor Function as Reported by the Participant in the Presence of a Confirmed Motor Progression Event	Up to at least Week 104
Percentage of Participants With Treatment Emergent Adverse Events (TEAEs)	From Baseline up to 70 days after the final study dose (up to at least Week 104)
Percentage of Participants With Adverse Events of Special Interest (AESI)	From Baseline up to 70 days after the final study dose (up to at least Week 104)
Percentage of Participants With Infusion Related Reactions (IRRs)	From Baseline up to 70 days after the final study dose (up to at least Week 104)
Percentage of Participants With Suicidal Ideation, as Measured by the Columbia-Suicide Severity Rating Scale (C-SSRS)	From Baseline up to 70 days after the final study dose (up to at least Week 104)
Serum Concentration of Prasinezumab	Predose and postdose at Baseline, Week 1, 4, 12, 24, 36, 52, 76, and after week 76 every 12 weeks thereafter until end of study (up to at least Week 104)
Percentage of Participants With Anti-drug Antibodies (ADAs) Against Prasinezumab at Baseline	At Baseline
Percentage of Participants With ADAs Against Prasinezumab During the Study	From Baseline up to 70 days after the final study dose (up to at least Week 104)