A Study to Learn About the Safety of BIIB122 Tablets and Whether They Can Slow the Worsening of Early-Stage Parkinson's Disease in Adults Between the Ages of 30 and 80 (LUMA)

A Phase 2b, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Determine the Efficacy and Safety of BIIB122 in Participants With Parkinson's Disease

In this study, researchers will learn more about BIIB122 in participants with early-stage Parkinson's disease (PD). The study will include adults aged 30 to 80 who were diagnosed with PD within 2 years of starting the study.

The main objective of the study is to learn about the effect BIIB122 has on slowing down the worsening of PD symptoms. The main question researchers want to answer is:

- How long does it take for PD symptoms to worsen during BIIB122 treatment?

Researchers will answer this and other questions by measuring the symptoms of PD over time using a variety of scoring tools. These include the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and the modified Schwab and England Activities of Daily Living Scale (mSE-ADL).

The MDS-UPDRS is used to measure symptoms of PD. It has 4 parts: Part I, II, III, and IV. Each part measures different aspects of motor and non-motor symptoms. The mSE-ADL measures a participant's ability to perform daily activities or personal chores.

Researchers will also learn more about the safety of BIIB122. They will check participants for adverse events. Adverse events are unwanted health problems that may or may not be caused by the study drug.

The study will be done as follows:

• Participants will be randomly assigned to take either BIIBB122 or placebo. A placebo looks like the study drug but contains no real medicine.
• Neither the researchers nor the participants will know if the participants are receiving BIIB122 or placebo.
• Participants will take BIIB122 or placebo tablets by mouth once a day.
• The treatment period for each participant will last between 48 and 144 weeks.
• There will be a safety follow-up period for 2 weeks after the last dose of BIIB122.
• In total, participants will have up to 29 study visits.
• Participants will stay in the study for at least 1 year, up to about 3 years.

Study Overview

• Status: Completed
• Conditions: Parkinson Disease
• Intervention / Treatment: Drug: BIIB122; Drug: BIIB122-Matching Placebo

Detailed Description

BIIB122 is an investigational central nervous system-penetrant small molecule inhibitor of leucine-rich repeat kinase 2 (LRRK2). Participants who completed the early termination (ET) visit of the study 283PD302 (NCT05418673) would be eligible for screening of this study and if enrolled, these participants are not eligible for the sub studies of 283PD201.

• Study Type: Interventional
• Enrollment (Actual): 650
• Phase: Phase 2

Contacts and Locations

Study Locations

• Austria
  • Innsbruck, Austria, 6020
    • Medizinische Universität Innsbruck
  • Vienna, Austria, 1160
    • Klinik Ottakring
  • Tyrol
    • Innsbruck, Tyrol, Austria, 6020
      • Medizinische Universitat
• Canada
  • Alberta
    • Calgary, Alberta, Canada, T2N4Z6
      • University of Calgary
    • Calgary, Alberta, Canada, T2N 1N4
      • University of Calgary
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3S 1M7
      • True North Clinical Research
  • Ontario
    • Toronto, Ontario, Canada, M5T 2S8
      • Toronto Western Hospital
    • Toronto, Ontario, Canada, M5T 2S8
      • Toronto Western Hospital Movement Disorder Clinic
  • Quebec
    • Montreal, Quebec, Canada, H3A 2B4
      • Montreal Neurological Institute
    • Montreal, Quebec, Canada, H2X 0A9
      • CHUM
    • Montreal, Quebec, Canada, H2L 4M1
      • CHUM Centre de Recherche
    • Montreal, Quebec, Canada, H3A 2B4
      • Montreal Neurological Institute - Hospital, Clinical Research Unit
• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100730
      • Beijing Hospital
    • Beijing, Beijing Municipality, China, 100053
      • Xuanwu Hospital Capital Medical University
  • Jiangsu
    • Jiangsu, Jiangsu, China, 215004
      • Second Affiliated Hospital of Soochow University
    • Suzhou, Jiangsu, China, 215004
      • The Second Affiliated Hospital of Soochow University
  • Sichuan
    • Chengdu, Sichuan, China, 610041
      • West China Hospital, Sichuan University
• France
  • Paris, France, 75013
    • Groupe Hospitalier Pitie-Salpetriere
  • Paris, France, 94010
    • Hôpital Henri Mondor
  • Bouches-du-Rhône
    • Marseille, Bouches-du-Rhône, France, 13385
      • Hôpital de la Timone
    • Marseille, Bouches-du-Rhône, France, 13005
      • Hôpital de la Timone
  • Haute Garonne
    • Toulouse, Haute Garonne, France, 31059
      • Hopital Purpan
  • Herault
    • Montpellier, Herault, France, 34295
      • Hopital Gui de Chauliac
  • Ille Et Vilaine
    • Rennes, Ille Et Vilaine, France, 35033
      • CHU Rennes - Hopital Pontchaillou
  • Loire Atlantique
    • Saint-Herblain, Loire Atlantique, France, 44800
      • CHU Nantes - Hopital Nord Laënnec
  • Loire-Atlantique
    • Loire-Atlantique, Loire-Atlantique, France, 44093
      • CHU Nantes - Hopital Nord Laën
  • Puy De Dome
    • Clermont-Ferrand, Puy De Dome, France, 63003
      • CHU Clermont Ferrand - Hopital Gabriel Montpied
  • Rhone
    • Bron, Rhone, France, 69500
      • Centre Hospitalier Universitaire de Lyon-Hospices Civils de Lyon-Hopital Pierre Wertheimer
  • Val De Marne
    • Créteil, Val De Marne, France, 94010
      • Hôpital Henri Mondor
• Germany
  • Baden-Wurttemberg
    • Tübingen, Baden-Wurttemberg, Germany, 72076
      • Universitaetsklinikum Tuebingen
    • Ulm, Baden-Wurttemberg, Germany, 89081
      • Universitaetsklinikum Ulm
  • Bavaria
    • Munich, Bavaria, Germany, 81377
      • Klinikum der Universität München
    • Munich, Bavaria, Germany, 81675
      • Klinikum rechts der Isar der TU Muenchen
    • Würzburg, Bavaria, Germany, 97080
      • Universitaetsklinikum Wuerzburg
  • Hesse
    • Kassel, Hesse, Germany, 34128
      • Paracelsus-Elena-Klinik Kassel
    • Marburg, Hesse, Germany, 35043
      • Philipps University of Marburg
    • Marburg, Hesse, Germany, 35043
      • Universitaetsklinikum Giessen und Marburg GmbH Standort Marburg
  • Lower Saxony
    • Hanover, Lower Saxony, Germany, 30625
      • Medizinische Hochschule Hannover
  • North Rhine-Westphalia
    • Bochum, North Rhine-Westphalia, Germany, 44791
      • Katholisches Klinikum Bochum gGmbH
    • Düsseldorf, North Rhine-Westphalia, Germany, 40225
      • Universitaetsklinikum Duesseldorf AoeR
  • Saxony
    • Dresden, Saxony, Germany, 01307
      • Universitaetsklinikum Carl Gustav Carus TU Dresden
  • Schleswig-Holstein
    • Lübeck, Schleswig-Holstein, Germany, 23538
      • Universitaetsklinikum Schleswig-Holstein - Campus Luebeck
• Israel
  • Petah Tikva, Israel, 49100
    • Rabin Medical Center
  • Petah Tikva, Israel, 4941492
    • Rabin Medical Center
  • Ramat Gan, Israel, 5265601
    • Chaim Sheba Medical Center
  • Ramat Gan, Israel, 5262000
    • Center Chaim Sheba Medical Center
  • Tel Aviv, Israel, 6423906
    • Tel Aviv Sourasky Medical Center
• Italy
  • Bologna, Italy, 40139
    • IRCCS-Institute of Neurological Sciences of Bologna
  • Brescia, Italy, 25123
    • Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia (Presidio Spedali Civili)
  • Brescia, Italy, 25123
    • Azienda Ospedaliera Spedali
  • Catania, Italy, 95123
    • Azienda Ospedaliero Universitaria Policlinico 'Gaspare Rodolico - San Marco' (Presidio G. Rodolico)
  • Catania, Italy, 95123
    • Azienda Ospedaliero Universitaria Policlinico "Gaspare Rodolico - San Marco' (Presidio G. Rodolico)
  • Chieti, Italy, 66100
    • Ospedale Clinicizzato SS. Annu
  • Chieti, Italy, 66100
    • Ospedale Clinicizzato SS. Annunziata
  • Milan, Italy, 20132
    • Ospedale San Raffaele
  • Milan, Italy, 20122
    • Fondazione
  • Naples, Italy, 80138
    • AOU Luigi Vanvitelli
  • Naples, Italy, 80138
    • Azienda Ospedaliera Universitaria- Università degli Studi della Campania "Luigi Vanvitelli"
  • Padova, Italy, 35128
    • Azienda Ospedale-Università di Padova
  • Pisa, Italy, 56126
    • Azienda Ospedaliero Universitaria Pisana
  • Pisa, Italy, 56126
    • AO Universitaria Pisana
  • Roma, Italy, 00163
    • IRCCS San Raffaele Pisana
  • Centonze
    • Diego, Centonze, Italy, 86077
      • I.R.C.C.S. Neuromed
• Japan
  • Asahikawa-shi, Japan, 070-8644
    • NHO Asahikawa Medical Center
  • Himeji-shi, Japan, 672-8043
    • Himeji Central
  • Sendai, Japan, 982-8555
    • Sendai Nishitaga National Hospital
  • Tokyo, Japan, 113-8431
    • Juntendo University
  • Hokkaido
    • Asahikawa-shi, Hokkaido, Japan, 070-8644
      • NHO Asahikawa Medical Center
  • Hyōgo
    • Himeji-shi, Hyōgo, Japan, 672-8043
      • Himeji Central Hospital Clinic
  • Miyagi
    • Sendai, Miyagi, Japan, 982-8555
      • NHO Sendai-Nishitaga Hospital
  • Okinawa
    • Haeburu, Okinawa, Japan, 901-1105
      • Okinawa Prefectural Nanbu
    • Shimajiri-gun, Okinawa, Japan, 901-1193
      • Okinawa Prefectural Nanbu Medical Center & Children's Medical Center
  • Osaka
    • Osaka, Osaka, Japan, 530-8480
      • Tazuke-kofukai Medical Research Institute Kitano Hospital
  • Tokyo-To
    • Bunkyō City, Tokyo-To, Japan, 113-8431
      • Juntendo University Hospital
• Netherlands
  • Amsterdam, Netherlands, 1081 GN
    • Brain Research Center Amsterdam
  • Nijmegen, Netherlands, 6525 GA
    • Radboudumc
  • Zwolle, Netherlands, 8025 AZ
    • Brain Research Center Zwolle B.V.
• Poland
  • Bydgoszcz, Poland, 85-163
    • Centrum Medyczne Neuromed
  • Katowice, Poland, 40-650
    • Nzoz Novo-Med
  • Oświęcim, Poland, 32-600
    • Instytut Zdrowia dr Boczarska-Jedynak sp.z.o.o, Sp.K
  • Warsaw, Poland, 01-684
    • Centrum Medyczne NeuroProtect
  • Warsaw, Poland, 02-699
    • INSULA Centrum Badan Klinicznych
  • Warsaw, Poland, 03-505
    • MD Clinic Praga
  • Katowice
    • Oświęcim, Katowice, Poland, 32-600
      • Instytut Zdrowia dr Boczarska-Jedynak sp.z.o.o, Sp.K
  • Masovian Voivodeship
    • Warsaw, Masovian Voivodeship, Poland, 01-684
      • NeuroProtect Sp. z o.o.
• Spain
  • A Coruña, Spain, 15006
    • Complejo Hospitalario Universitario A Coruña
  • Barakaldo, Spain, 48903
    • Hospital de Cruces
  • Barcelona, Spain, 08036
    • Hospital Clinic De Barcelona
  • Barcelona, Spain, 08035
    • Hospital Universitari Vall d'Hebron
  • Barcelona, Spain, 08041
    • Hospital De La Santa Creu I Sant Pau
  • Barcelona, Spain, 8036
    • Hospital Clinic De Barcelona
  • Barcelona, Spain, 08035
    • Hospital Universitari Vall d'Hebron - VHIR
  • Donostia / San Sebastian, Spain, 20014
    • Policlinica Gipuzkoa
  • Madrid, Spain, 28006
    • Hospital Universitario de La Princesa
  • Seville, Spain, 41013
    • Hospital Universitario Virgen del Rocio
  • Barcelona
    • Sant Cugat del Vallès, Barcelona, Spain, 08190
      • Hospital General de Catalunya
    • Sant Cugat del Vallès, Barcelona, Spain, '08190
      • Hospital General de Catalunya
  • Cantabria
    • Santander, Cantabria, Spain, 38003
      • Hospital Universitario Marqués de Valdecilla
  • Guipuzcoa
    • Donostia / San Sebastian, Guipuzcoa, Spain, 20014
      • Policlinica Gipuzkoa
  • La Coruña
    • A Coruña, La Coruña, Spain, 15006
      • Complejo Hospitalario Universitario A Coruña
  • Navarre
    • Pamplona, Navarre, Spain, 31008
      • Clinica Universidad de Navarra
  • Santanda
    • Santanda, Santanda, Spain, 38003
      • Hospital Universitario Marques
• United Kingdom
  • Bristol, United Kingdom, BS32 4SY
    • Re Cognition Health Bristol
  • Dundee, United Kingdom, DD1 9SY
    • Ninewells Hospital
  • Devon
    • Plymouth, Devon, United Kingdom, PL6 8DH
      • University Hospitals Plymouth
  • Greater London
    • London, Greater London, United Kingdom, WC1N 3BG
      • The National Hospital for Neurology & Neurosurgery
    • London, Greater London, United Kingdom, W6 8RF
      • Charing Cross Hospital
    • London, Greater London, United Kingdom, W1G 9RU
      • Re:Cognition Health Ltd (London)
    • London, Greater London, United Kingdom, W1G 8TA
      • Re:Cognition Health Ltd (London)
  • Greater Manchester
    • Salford, Greater Manchester, United Kingdom, M6 8HD
      • Salford Royal NHS Foundation Trust
    • Salford, Greater Manchester, United Kingdom, M6 8HD
      • Salford Care Organisation
  • Strathclyde
    • Motherwell, Strathclyde, United Kingdom, ML1 4UF
      • NeuroClin Limited
  • Tayside Region
    • Dundee, Tayside Region, United Kingdom, DD1 9SY
      • Ninewells Hospital
  • Tyne & Wear
    • Newcastle upon Tyne, Tyne & Wear, United Kingdom, NE4 5PL
      • Newcastle University- Clinical Ageing Research Unit
  • Tyne and Wear
    • Newcastle upon Tyne, Tyne and Wear, United Kingdom, NE4 5PL
      • Newcastle University
  • West Midlands
    • Birmingham, West Midlands, United Kingdom, B16 8LT
      • Re:Cognition Health - Birmingham
• United States
  • Arizona
    • Phoenix, Arizona, United States, 85054
      • Mayo Clinic Arizona
    • Sun City, Arizona, United States, 85351
      • Banner Sun Health Research Institute
  • California
    • Los Angeles, California, United States, 90033
      • University of Southern California
    • Los Angeles, California, United States, 90048
      • Cedars Sinai Medical Center
    • Los Angeles, California, United States, 90048
      • Cedars Sinai
    • Pasadena, California, United States, 91105
      • SC3 Research Group Inc.
    • Pasadena, California, United States, 91106
      • Quantum Clinical Research, Inc.
    • San Francisco, California, United States, 94143
      • University of California San Francisco (UCSF)
    • San Francisco, California, United States, 94143
      • University of California, San Francisco - Liver Clinic
  • Colorado
    • Aurora, Colorado, United States, 80045
      • University of Colorado
    • Englewood, Colorado, United States, 80113
      • CenExel Rocky Mountain Clinical Research
  • Connecticut
    • New Haven, Connecticut, United States, 06510
      • Invicro
  • Florida
    • Boca Raton, Florida, United States, 33486
      • Parkinson's Disease and Movement Disorders Center of Boca Raton
    • Boca Raton, Florida, United States, 33486
      • Parkinson's Disease and Movement Disorders Center
    • Miami, Florida, United States, 33136
      • University of Miami
    • Orlando, Florida, United States, 32803
      • Adventist Health System/Sunbelt, Inc.
    • Tampa, Florida, United States, 33613
      • USF Health Byrd Alzheimer's Institute
    • Tampa, Florida, United States, 33613
      • USF Health Byrd Institute
  • Hawaii
    • Honolulu, Hawaii, United States, 96817
      • Hawaii Pacific Neuroscience
    • Honolulu, Hawaii, United States, 96817
      • Hawaii Pacific Neuroscience, LLC
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern University
    • Chicago, Illinois, United States, 60612
      • Rush University Medical Center
    • Chicago, Illinois, United States, 60611
      • Northwestern University PD and Movement Disorders Center
  • Kansas
    • Kansas City, Kansas, United States, 66160
      • University of Kansas Medical Center Research Institute, Inc.
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Beth Israel Deaconess Medical Center
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
    • Boston, Massachusetts, United States, 02118
      • Boston University Medical Center
    • Boston, Massachusetts, United States, 02421
      • Massachusetts General Hospital
  • Michigan
    • Farmington Hills, Michigan, United States, 48334
      • Quest Research Institute
  • New York
    • New York, New York, United States, 10021
      • Weill Medical College of Cornell University
    • New York, New York, United States, 10003
      • Mount Sinai Beth Israel
  • North Carolina
    • Durham, North Carolina, United States, 27705
      • Duke Movement Disorders Clinic
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • The Cleveland Clinic Foundation
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19107
      • Pennsylvania Hospital
    • Philadelphia, Pennsylvania, United States, 19107
      • UPHS
    • Pittsburgh, Pennsylvania, United States, 15213
      • University of Pittsburgh
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina (MUSC)
  • Tennessee
    • Cordova, Tennessee, United States, 38018
      • Neurology Clinic, PC
    • Germantown, Tennessee, United States, 38138
      • Neurology Clinic, PC
  • Texas
    • Houston, Texas, United States, 77030
      • The Methodist Hospital Research Institute
    • Houston, Texas, United States, 77030
      • Houston Methodist Hospital/Houston Neurological Institute
    • Round Rock, Texas, United States, 78681
      • Central Texas Neurology Consultants
  • Virginia
    • Henrico, Virginia, United States, 23233
      • Virginia Commonwealth University Department of Neurology
    • Richmond, Virginia, United States, 23298
      • Virginia Commonwealth University Department of Neurology
  • Washington
    • Kirkland, Washington, United States, 98034
      • Evergreen Hospital Medical Center
    • Kirkland, Washington, United States, 98034
      • EvergreenHealth
    • Spokane, Washington, United States, 99202
      • Inland Northwest Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria:

• Clinical diagnosis of PD meeting the Movement Disorder Society Clinical Diagnostic Criteria within 2 years of the Screening Visit, inclusive, and at least 30 years of age at the time of diagnosis
• Modified Hoehn and Yahr scale stages 1 to 2 (in OFF state), inclusive, at screening
• MDS-UPDRS Parts II and III (in OFF state) combined score less than or equal to (≤)50 at screening

Key Exclusion Criteria:

• Clinically significant neurological disorder other than PD, including but not limited to stroke, dementia, or seizure, within 5 years of screening visit, in the opinion of the Investigator
• Clinical evidence of atypical parkinsonism (e.g., multiple-system atrophy or progressive supranuclear palsy) or evidence of drug-induced parkinsonism.
• Montreal Cognitive Assessment (MoCA) score <24 at the screening visit.

NOTE: Other protocol-defined Inclusion/Exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BIIB122 225 mg; Participants will receive BIIB122, 225 mg tablets, by mouth, once daily (QD) for up to a minimum of 48 weeks and a maximum of 144 weeks. Participants who received BIIB122 and completed the ET visit of study 283PD302 (NCT05418673) will continue to receive BIIB122, 225 mg tablets, by mouth, QD for up to a minimum of 48 weeks and a maximum of 144 weeks.	Drug: BIIB122; Administered as specified in the treatment arm; Other Names: DNL151
Placebo Comparator: BIIB122 Matching Placebo; Participants will receive BIIB122 matching placebo tablets, by mouth, QD for up to a minimum of 48 weeks and a maximum of 144 weeks. Participants who received placebo and completed the ET visit of study 283PD302 (NCT05418673) will continue to receive BIIB122 matching placebo tablets, by mouth, QD for up to a minimum of 48 weeks and a maximum of 144 weeks.	Drug: BIIB122-Matching Placebo; Administered as specified in the treatment arm

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Confirmed Worsening in Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts II and III Combined Score Over the Treatment Period	Time to confirmed worsening is defined as a worsening event sustained over 2 consecutive assessments. MDS-UPDRS is a multimodal scale assessing impairment and disability consisting of 4 parts. Part II assesses motor experiences of daily living (Range 0-52). It contains 13 questions which are to be completed by the participant. Part III assesses the motor signs of PD and is administered by the rater (Range 0-132). Part III contains 33 scores based on 18 items. For each question a numeric score is assigned between 0-4, where 0 = Normal, 1 = Slight, 2 = Mild, 3 = Moderate, 4 = Severe. MDS-UPDRS Part II and III combined score equals the sum of Parts II and III (Range 0-184). A higher score indicates more severe symptoms of PD.	Up to Week 144

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Confirmed Worsening in MDS-UPDRS Part II Score Over the Treatment Period	Time to confirmed worsening is defined as a worsening event sustained over 2 consecutive assessments. MDS-UPDRS is a multimodal scale assessing impairment and disability consisting of 4 parts. Part II assesses motor experiences of daily living (Range 0-52). It contains 13 questions which are to be completed by the participant. For each question a numeric score is assigned between 0-4, where 0 = Normal, 1 = Slight, 2 = Mild, 3 = Moderate, 4 = Severe. A higher score indicates more severe symptoms of PD.	Up to a minimum of 48 weeks and a maximum of 144 weeks
Change From Baseline in MDS-UPDRS Parts II and III Combined Score	MDS-UPDRS is a multimodal scale assessing impairment and disability consisting of 4 parts. Part II assesses motor experiences of daily living (Range 0-52). It contains 13 questions which are to be completed by the participant. For each question a numeric score is assigned between 0-4, where 0 = Normal, 1 = Slight, 2 = Mild, 3 = Moderate, 4 = Severe. A higher score indicates more severe symptoms of PD. Part III assesses the motor signs of PD and is administered by the rater (Range 0-132). Part III contains 33 scores based on 18 items. For each question a numeric score is assigned between 0-4, where 0 = Normal, 1 = Slight, 2 = Mild, 3 = Moderate, 4 = Severe. MDS-UPDRS Parts II and III combined score equals the sum of Part II and III (Range 0-184). A higher score indicates more severe symptoms of PD.	From Baseline up to Week 48
Change From Baseline in MDS-UPDRS Parts I, II, and III Combined Score	MDS-UPDRS is a multimodal scale assessing impairment and disability consisting of 4 parts. Part I assesses non-motor experiences of daily living and has 2 components (Range 0-52). Part IA contains 6 questions and is assessed by the examiner (Range 0-24). Part IB contains 7 questions on non-motor experiences of daily living which are to be completed by the participant (Range 0-28). Part II assesses motor experiences of daily living (Range 0-52). It contains 13 questions which are to be completed by the participant. Part III assesses the motor signs of PD and is administered by the rater (Range 0-132). Part III contains 33 scores based on 18 items. For each question a numeric score is assigned between 0-4, where 0 = Normal, 1 = Slight, 2 = Mild, 3 = Moderate, 4 = Severe. MDS-UPDRS total score equals the sum of Parts I, II, and III (Range 0-236). A higher score indicates more severe symptoms of PD.	From Baseline up to Week 48
Time to Confirmed Worsening in Modified Schwab and England Activities of Daily Living Scale (mSE-ADL) Over the Treatment Period	Time to confirmed worsening is defined as a worsening event sustained over 2 consecutive assessments. The mSE-ADL scale reflects the speed, ease, and independence with which an individual performs daily activities or personal chores with 100% indicating total independence, falling to 0%, which indicates a state of complete dependence. The individual is asked to rate his or her function using an 11-point scale (10% increments), from 100% (completely independent; able to do all chores without slowness, difficulty, or impairment; essentially normal; unaware of any difficulty) to 0% (vegetative functions such as swallowing, bladder and bowels are not functioning; bedridden). The lower the score, the worse the functional status.	Up to a minimum of 48 weeks and a maximum of 144 weeks
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)	An AE is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. An SAE is any untoward medical occurrence that at any dose results in death; in the view of the investigator, places the participant at immediate risk of death (a life-threatening event); requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; results in a congenital anomaly/birth defect or is a medically important event.	Up to Week 144

Collaborators and Investigators

• Sponsor: Biogen
• Collaborators: Denali Therapeutics Inc.
• Investigators: Study Director: Medical Director, Biogen

Publications and helpful links

General Publications

• Joshi D, Kulkarni M, Parekh P, Shah S, Greig NH, Acharya S. Targeting protein kinases in Parkinson's disease: the emerging role of phytoconstituents. Nutr Neurosci. 2025 Dec;28(12):1532-1563. doi: 10.1080/1028415X.2025.2531356. Epub 2025 Jul 18.

Helpful Links

• Click here to learn more about this trial, visit our study website.

Study record dates

Study Major Dates

• Study Start (Actual): April 19, 2022
• Primary Completion (Actual): March 9, 2026
• Study Completion (Actual): March 9, 2026

Study Registration Dates

• First Submitted: April 4, 2022
• First Submitted That Met QC Criteria: April 26, 2022
• First Posted (Actual): April 27, 2022

Study Record Updates

• Last Update Posted (Actual): May 29, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Early-stage Parkinson Disease
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease; DNL151
• Other Study ID Numbers: 283PD201; 2023-505645-12 (Other Identifier: EU CT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: In accordance with Biogen's Clinical Trial Transparency and Data Sharing Policy on https://www.biogentrialtransparency.com/

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No