A Study to Evaluate the Efficacy and Safety of Intravenous (IV) Prasinezumab in Participants With Early-Stage Parkinson's Disease
PARAISO
A Phase III, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Intravenous Prasinezumab in Participants With Early-Stage Parkinson's Disease
2 other identifiers
interventional
900
16 countries
137
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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_3
Started Nov 2025
Longer than P75 for phase_3
137 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
September 12, 2025
CompletedFirst Posted
Study publicly available on registry
September 15, 2025
CompletedStudy Start
First participant enrolled
November 24, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 30, 2029
ExpectedStudy Completion
Last participant's last visit for all outcomes
June 30, 2031
May 6, 2026
May 1, 2026
3.6 years
September 12, 2025
May 4, 2026
Conditions
Outcome Measures
Primary Outcomes (1)
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 Outcomes (11)
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
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
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)
- +6 more secondary outcomes
Study Arms (2)
Prasinezumab
EXPERIMENTALParticipants 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
EXPERIMENTALParticipants will receive placebo as an IV Infusion.
Interventions
Participants will receive Prasinezumab as an IV Infusion as per the schedule mentioned in the protocol.
Participants will receive Placebo as an IV Infusion per the schedule mentioned in the protocol
Eligibility Criteria
You may qualify if:
- 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
You may not qualify if:
- 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
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Hoffmann-La Rochelead
- Prothena Biosciences Limitedcollaborator
Study Sites (142)
University of Alabama at Birmingham
Birmingham, Alabama, 35233, United States
Barrow Neurological Institute
Phoenix, Arizona, 85013, United States
Neurology Center of North Orange County
Fullerton, California, 92835, United States
Keck School of Medicine of USC
Los Angeles, California, 900033, United States
Parkinson?s Research Centers of America ? Palo Alto
Palo Alto, California, 94301, United States
Profound Research LLC at The Neurology Center of Southern California
Pasadena, California, 91105, United States
UCSF Weill Institute for Neurosciences
San Francisco, California, 94158, United States
Rocky Mountain Movement Disorders
Englewood, Colorado, 80113, United States
Institute for Neurodegenerative Disorders
New Haven, Connecticut, 06510, United States
Georgetown University
Washington D.C., District of Columbia, 20007, United States
JEM Research LLC
Atlantis, Florida, 33462, United States
Parkinson's Disease and Movement Disorders Center of Boca Raton
Boca Raton, Florida, 33486, United States
K2 - Villages
Lady Lake, Florida, 32159, United States
K2 Medical Research-Maitland
Maitland, Florida, 32751, United States
Charter Research - Winter Park/Orlando
Orlando, Florida, 32803, United States
Hawaii Pacific Neuroscience
Honolulu, Hawaii, 96817, United States
Northwestern University Feinberg School Of Medicine
Chicago, Illinois, 60611, United States
University of Kansas Medical Center
Kansas City, Kansas, 66160, United States
Massachusetts General Hospital
Boston, Massachusetts, 02114, United States
Quest Research Institute
Farmington Hills, Michigan, 48334, United States
Washington Uni School of Medicine
St Louis, Missouri, 63110, United States
Cleveland Clinic Lou Ruvo
Las Vegas, Nevada, 89106, United States
Renown Health
Reno, Nevada, 89502, United States
University of New Mexico
Albuquerque, New Mexico, 87106, United States
Dent Neurological Institute
Amherst, New York, 14226, United States
Parkinson's Research Centers of America - Long Island
Commack, New York, 11725, United States
Weill Cornell Medical College
New York, New York, 10021, United States
NeuroCare Center
Canton, Ohio, 44718, United States
Cleveland Clinic
Cleveland, Ohio, 44195, United States
The Movement Disorder Clinic of Oklahoma
Tulsa, Oklahoma, 74136, United States
Allegheny General Hospital
Pittsburgh, Pennsylvania, 15212, United States
Veracity Neuroscience
Memphis, Tennessee, 38157, United States
Texas Neurology PA
Dallas, Texas, 75206, United States
Central Texas Neurology Consultants
Round Rock, Texas, 78681, United States
University of Virginia Health System
Charlottesville, Virginia, 22903, United States
VCU Health North Hospital
Richmond, Virginia, 23298, United States
West Virginia University
Morgantown, West Virginia, 26506, United States
Southern Neurology
Kogarah, New South Wales, 2217, Australia
Westmead Hospital
Westmead, New South Wales, 2145, Australia
Monash Health
Clayton, Victoria, 3168, Australia
The Alfred Hospital
Prahan, Victoria, 3181, Australia
Perron Institute for Neurological and Translational Science
Nedlands, Western Australia, 6009, Australia
Medizinische Universität Graz
Graz, 8036, Austria
Uniklinik fuer Neurologie, Medizinische Universitaet Innsbruck
Innsbruck, 6020, Austria
Kepler Universitätsklinikum GmbH - Neuromed Campus
Linz, 4020, Austria
Medizinische Universität Wien
Vienna, 1090, Austria
Klinik Ottakring
Vienna, 1160, Austria
L2 Ip Instituto de Pesquisas Clinicas Ltda ME
Brasília, Federal District, 70200-730, Brazil
Instituto de Neurologia de Curitiba
Curitiba, Paraná, 81210-310, Brazil
Núcleo de Pesquisa do Rio Grande do Sul
Porto Alegre, Rio Grande do Sul, 90430-001, Brazil
Faculdade de Medicina de Sao Jose do Rio Preto - FAMERP*X*
São José do Rio Preto, São Paulo, 15090-000, Brazil
Centro de Pesquisas Clinicas
São Paulo, São Paulo, 01228-200, Brazil
Toronto Western Hospital
Toronto, Ontario, M5T 2S8, Canada
CHUM
Montreal, Quebec, H2X 0A9, Canada
Montreal Neurological Institute and Hospital
Montreal, Quebec, H3A 2B4, Canada
Beijing Friendship Hospital Affiliated of Capital University of Medical Science
Beijing, 100050, China
Beijing Tian Tan Hospital,Capital Medical University
Beijing, 100071, China
Beijing Hospital of Ministry of Health
Beijing, 100730, China
The First Hospital of Jilin University
Changchun, 130021, China
West China Hospital of Sichuan University
Chengdu, 610041, China
The First Affiliated Hospital, Chongqing Medical University
Chongqing, 400016, China
Fujian Medical University Union Hospital
Fuzhou, 350001, China
The First Affiliated Hospital of Sun Yat-sen University
Guangzhou, 510080, China
Guangdong Provincial People's Hospital
Guangzhou, 510115, China
The First Affiliated Hospital of Guangzhou Medical University
Guangzhou, 510120, China
The Second Affiliated Hospital of Zhejiang University School of Medicine
Hangzhou, 310009, China
Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University
Hangzhou, China
Nanjing Brain Hospital
Nanjing, 210029, China
Ruijin Hospital Shanghai Jiaotong University School of Medicine
Shanghai, 200025, China
Huashan Hospital, Fudan University
Shanghai, 200040, China
The Second Affiliated Hospital of Suzhou University
Suzhou, 215025, China
Tianjin Medical University General Hospital
Tianjin, 300052, China
First Affiliated Hospital of Medical College of Xi'an Jiaotong University
Xi'an, 710061, China
The Affiliated Hospital of Xuzhou Medical University
Xuzhou, China
Aarhus Universitetshospital Skejby
Aarhus N, 8200, Denmark
Bispebjerg Hospital;Neurologisk Afdeling
København NV, 2400, Denmark
Hospices Civils de Lyon - Hôpital Pierre Wertheimer
Bron, Rhône, 69003, France
APHP - Hopital Henri Mondor
Créteil, 94010, France
CHU de Montpellier - Hôpital Gui de Chauliac
Montpellier, 34295, France
Kliniken Beelitz GmbH
Beelitz, 14547, Germany
Charite Universitaetsmedizin Berlin - Campus Benjamin Franklin
Berlin, 12203, Germany
Heinrich-Heine Universitätsklinik Düsseldorf
Düsseldorf, 40225, Germany
Universitätsklinikum Erlangen, Abteilung Molekulare Neurologie
Erlangen, 91054, Germany
Paracelsus Elena Klinik Kassel
Kassel, 34128, Germany
Klinikum rechts der Isar der TU München
Munich, 81675, Germany
Universitatsklinikum Munster
Münster, 48149, Germany
Universitaettsklinikum Tübingen
Tübingen, 72076, Germany
Universitätsklinikum Würzburg, Neurologische Klinik und Poliklinik
Würzburg, 97080, Germany
Università degli studi della Campania Luigi Vanvitelli
Naples, Campania, 80138, Italy
Az. Osp. OO.RR. S. Giovanni di Dio e Ruggi D' Aragona
Salerno, Campania, 84131, Italy
Ospedale Bellaria
Bologna, Emilia-Romagna, 40139, Italy
IRCCS San Raffaele;Clinical Trial Center
Rome, Lazio, 00166, Italy
Irccs A.O.U.San Martino Ist
Genoa, Liguria, 16132, Italy
Azienda Ospedaliera Spedali Civili
Brescia, Lombardy, 25100, Italy
Centro Parkinson e Parkinsonismi
Milan, Lombardy, 20126, Italy
IRCCS Ospedale San Raffaele
Milan, Lombardy, 20132, Italy
IRCCS Istituto Neurologico Carlo Besta
Milan, Lombardy, 20133, Italy
A.O. Universitaria Pisana
Pisa, Tuscany, 56126, Italy
Instituto Nacional de Neurologia y Neurocirugia
Mexico City, Mexico CITY (federal District), 14390, Mexico
Hospital General de Mexico
Mexico City, Mexico CITY (federal District), 6726, Mexico
Podlaskie Centrum Psychogeriatrii
Bia?ystok, 15-756, Poland
NZOZ Vitamed
Bydgoszcz, 85-079, Poland
Szpital Sw. Wojciecha
Gda?sk, 80-462, Poland
NEURO-CARE Sp. z o.o. Sp. Komandytowa
Katowice, 40-749, Poland
Krakowska Akademia Neurologii Sp z o.o. Centrum Neurologii K
Krakow, 31-505, Poland
Indywidualna Praktyka Lekarska Prof. Dr Hab. N. Med. Konrad Rejdak.
Lublin, 20-410, Poland
Instytut Zdrowia Dr Boczarska-Jedynak Sp. z o.o. Sp. k.
Oświęcim, 32-600, Poland
Nmedis sp. z o.o.
Rzeszów, 35-232, Poland
NeuroProtect
Warsaw, 01-684, Poland
Mazowiecki Szpital Bródnowski w Warszawie Sp. z o.o.
Warsaw, 03-242, Poland
Hospital de Braga
Braga, 4710-243, Portugal
Hospital da Luz Coimbra
Coimbra, 3020-479, Portugal
Hospital Dr. Nélio Mendonça;Serviço de Neurologia
Funchal, 9004-514, Portugal
Hospital Pedro Hispano
Matosinhos Municipality, 4464-513, Portugal
CNS - Campus Neurológico
Torres Vedras, 2560-280, Portugal
Severance Hospital, Yonsei University Health System
Seoul, 03722, South Korea
Asan Medical Center
Seoul, 05505, South Korea
Boramae Medical Center
Seoul, 07061, South Korea
Seoul National University Hospital
Seoul, 110-744, South Korea
Hospital General Universitario de Elche
Elche, Alicante, 03203, Spain
Hospital General De Catalunya
Sant Cugat del Vallès, Barcelona, 08195, Spain
Policlinica Guipuzcoa
Donostia / San Sebastian, Guipuzcoa, 20009, Spain
Hospital Universitario Fundación Alcorcón
Alcorcón, Madrid, 28922, Spain
Hospital Quiron de Madrid
Pozuelo de Alarcón, Madrid, 28223, Spain
Hospital Universitari Vall d Hebron
Barcelona, 08035, Spain
Hospital Clinic Barcelona
Barcelona, 08036, Spain
Hospital Ruber Juan Bravo
Madrid, 28006, Spain
Hospital Universitario de La Princesa
Madrid, 28006, Spain
Hospital Univ 12 de Octubre
Madrid, 28041, Spain
Hospital Regional Universitario de Malaga ? Hospital General
Málaga, 29009, Spain
Changhua Christian Hospital
Changhua County, 500, Taiwan
China Medical University Hospital
North Dist., 40447, Taiwan
National Cheng Kung University Hospital
Tainan, 704, Taiwan
National Taiwan University Hospital
Taipei, 100, Taiwan
Taipei Veterans General Hospital
Taipei, 11217, Taiwan
Ninewells Hospital, Dundee- Scotland
Dundee, DD2 1SY, United Kingdom
Royal Devon and Exeter Hospital (Wonford)
Exeter, EX2 5DW, United Kingdom
Royal London Hospital
London, E1 1FR, United Kingdom
Charing Cross Hospital
London, W6 8RF, United Kingdom
Campus for Ageing and Vitality
Newcastle, NE4 5PL, United Kingdom
Oxford University Hospitals NHS Foundation Trust
Oxford, OX3 7LE, United Kingdom
Plymouth Hospitals NHS Trust - Derriford Hospital
Plymouth,Devon, PL6 8DH, United Kingdom
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- STUDY DIRECTOR
Clinical Trials
Hoffmann-La Roche
Central Study Contacts
Reference Study ID Number: BN44715 https://forpatients.roche.com/
CONTACT
Study Design
- Study Type
- interventional
- Phase
- phase 3
- Allocation
- RANDOMIZED
- Masking
- TRIPLE
- Who Masked
- PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
September 12, 2025
First Posted
September 15, 2025
Study Start
November 24, 2025
Primary Completion (Estimated)
June 30, 2029
Study Completion (Estimated)
June 30, 2031
Last Updated
May 6, 2026
Record last verified: 2026-05
Data Sharing
- IPD Sharing
- Will share
For eligible studies, qualified researchers may request access to individual patient level clinical data. See Roche's commitment to transparency of clinical study information here: https://go.roche.com/data\_sharing