A Study to Assess Efficacy and Safety of Efgartigimod PH20 SC in Adults With Ocular Myasthenia Gravis (ADAPT oculus)

December 10, 2025 updated by: argenx

A Randomized, Double-Blinded, Placebo-Controlled, Phase 3, Parallel-Group Design Study Evaluating the Efficacy and Safety of Efgartigimod PH20 SC Administered by Prefilled Syringe in Adult Participants With Ocular Myasthenia Gravis

The purpose of this study is to evaluate the efficacy and safety of efgartigimod PH20 SC given by a pre-filled syringe in adult patients with ocular myasthenia gravis. The study consists of a part A (approximately 7 weeks) and a part B (up to 2 years). In part A, half of the participants will receive efgartigimod PH20 SC and the other half will receive placebo. In part B, all participants will receive efgartigimod PH20 SC. The participants will be in the study for about up to 2 years and 12 weeks.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

141

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Australia
      • Box Hill, Australia, 3128
        • Box Hill Hospital
      • Melbourne, Australia, 3004
        • The Alfred Hospital
      • Southport, Australia, 4215
        • Gold Coast University Hospital
  • Austria
      • Vienna, Austria, 1090
        • Universitätsklinikum AKH Wien
  • Belgium
      • Leuven, Belgium, 3000
        • UZ Leuven
      • Liège, Belgium, 4000
        • Hôpital de la Citadelle
  • Canada
      • Halifax, Canada, B3R 1V9
        • Maritime Neurology
      • London, Canada, N6A 5A5
        • London Health Sciences Centre
      • Montreal, Canada, H2X 0A9
        • Centre Hospitalier de l'Université de Montréal
      • Ottawa, Canada, K1Y 4E9
        • Ottawa Hospital Research Institute
      • Québec, Canada, G1J 1Z4
        • Hopital de l'Enfant Jesus
      • Toronto, Canada, M5G 2C4
        • Toronto General Hospital
  • China
      • Changsha, China, 410008
        • Xiangya Hospital Central South University
      • Chengdu, China, 610072
        • Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital
      • Chongqing, China, 400016
        • The First Affiliated Hospital of Chongqing Medical University
      • Fuzhou, China, 350001
        • Fujian Medical University Union Hospital
      • Guangzhou, China, 510405
        • The First Affiliated Hospital of Guangzhou University Chinese Medicine
      • Guangzhou, China, 510120
        • Guangdong Province Traditional Chinese Medical Hospital
      • Jinan, China, 250012
        • Qilu Hospital of Shandong University
      • Nanchang, China, 330000
        • The First Affiliated Hospital of Nanchang University - Xianghu Campus
      • Shanghai, China, 200040
        • Huashan Hospital Fudan University
      • Shijiazhuang, China, 050011
        • Shijiazhuang People's Hospital - Fangbeilu Campus
      • Wuhan, China, 430030
        • Tongji Hospital Tongji Medical College Huazhong University of Science and Technology
      • Wuhan, China, 430060
        • Renmin Hospital of Wuhan University - Main Campus
  • Cyprus
      • Égkomi, Cyprus, 2371
        • Cyprus Institute of Neurology and Genetics
  • Czechia
      • Brno, Czechia, 625 00
        • Fakultni nemocnice Brno
      • Pardubice, Czechia, 532 03
        • Nemocnice Pardubickeho kraje, a.s., Pardubicka nemocnice
  • Denmark
      • Aarhus N, Denmark, 8200
        • Aarhus Universitetshospital
      • Copenhagen, Denmark, 2100
        • Rigshospitalet
  • Finland
      • Turku, Finland, 20521
        • Turun yliopistollinen keskussairaala
  • France
      • Paris, France, 75019
        • Hôpital Fondation Adolphe de Rothschild
  • Georgia
      • Tbilisi, Georgia, 114
        • New Hospitals
      • Tbilisi, Georgia, 112
        • Petre Sarajishvili Institute of Neurology
      • Tbilisi, Georgia, 114
        • Pineo Medical Ecosystem
      • Tbilisi, Georgia, 186
        • LLC Caucasus Medical Centre
  • Germany
      • Berlin, Germany, 13353
        • Charité - Universitätsmedizin Berlin
      • Göttingen, Germany, 37075
        • Universität Georg August
  • Greece
      • Athens, Greece, 115 28
        • Eginitio Hospital
      • Pátrai, Greece, 265 04
        • University General Hospital of Patras
  • Italy
      • Bergamo, Italy, 24127
        • ASST Papa Giovanni XXIII - Ospedale Papa Giovanni XXIII
      • Bologna, Italy, 40139
        • IRCCS Istituto dell Scienze Neurologiche di Bologna
      • Milan, Italy, 20133
        • Fondazione IRCCS Istituto Neurologico Carlo Besta
      • Milan, Italy, 20132
        • Ospedale San Raffaele S.r.l.
      • Napoli, Italy, 80131
        • AORN Antonio Cardarelli
      • Roma, Italy, 00189
        • Azienda Ospedaliero-Universitaria Sant'Andrea
  • Japan
      • Chūōku, Japan, 260-8677
        • Chiba University Hospital
      • Fukuoka, Japan, 812-8582
        • Kyushu University Hospital
      • Hanamaki-shi, Japan, 025-0075
        • General Hanamaki Hospital
      • Hiroshima, Japan, 734-8551
        • Hiroshima University Hospital
      • Kawagoe, Japan, 350-0844
        • Saitama Medical Center
      • Kyoto, Japan, 616-8255
        • National Hospital Organization Utano National Hospital
      • Narita, Japan, 286-8520
        • IUHW Narita Hospital
      • Sapporo, Japan, 063-0005
        • National Hospital Organization Hokkaido Medical Center
      • Sayama, Japan, 589-8511
        • Kindai University Hospital
      • Shinjuku-Ku, Japan, 160-0023
        • Tokyo Medical University Hospital
      • Suita-Shi, Japan, 565-0871
        • Osaka University Hospital
  • Netherlands
      • Leiden, Netherlands, 2333 ZA
        • Leids Universitair Medisch Centrum
  • Poland
      • Bydgoszcz, Poland, 85-065
        • MICS Centrum Medyczne Bydgoszcz
      • Katowice, Poland, 40-689
        • Centrum Medyczne Neurologia Slaska
      • Krakow, Poland, 31-505
        • Krakowska Akademia Neurologii
      • Krakow, Poland, 31-503
        • Sp Zoz Szpital Uniwersytecki
      • Lublin, Poland, 20-064
        • CLINIREM Sp z o.o.
  • Portugal
      • Lisbon, Portugal, 1649-035
        • ULS de Santa Maria, EPE - Hospital de Santa Maria
      • Porto, Portugal, 4099-001
        • ULS de Santo António, EPE - Hospital de Santo António
  • Serbia
      • Belgrade, Serbia, 11000
        • University Clinical Center of Serbia
      • Niš, Serbia, 18 000
        • University Clinical Center Niš
  • South Korea
      • Daegu, South Korea, 41404
        • Kyungpook National University Chilgok Hospital
      • Seoul, South Korea, 2841
        • Korea University Anam Hospital
      • Seoul, South Korea, 3722
        • Severance Hospital Yonsei University Health System
  • Spain
      • Barcelona, Spain, 08035
        • Hospital Universitario Vall d'Hebron
      • Barcelona, Spain, 8003
        • Hospital del Mar
      • Madrid, Spain, 28040
        • Hospital Clinico San Carlos
      • Madrid, Spain, 28304
        • Hospital Universitario Ramon y Cajal
      • San Sebastián, Spain, 20014
        • Hospital Universitario DE Donostia
      • Valencia, Spain, 46010
        • Hospital Clinico Universitario de Valencia
  • Sweden
      • Gothenburg, Sweden, 413 45
        • Sahlgrenska Universitetssjukhuset
  • United Arab Emirates
      • Dubai, United Arab Emirates, 51122
        • Mediclinic Parkview
  • United Kingdom
      • Brighton, United Kingdom, BN2 5BE
        • Royal Sussex County Hospital
      • Glasgow, United Kingdom, G51 4TY
        • Panthera Biopartners - Glasgow
      • Leeds, United Kingdom, LS1 3EX
        • Leeds General Infirmary
      • London, United Kingdom, W1G 9ST
        • Dementech Neurosciences Clinical Academic Centre
      • Southampton, United Kingdom, SO16 6YD
        • Southampton General Hospital
  • United States
    • Arizona
      • Scottsdale, Arizona, United States, 85251
        • HonorHealth Neurology - Bob Bove Neuroscience Institute
    • California
      • Loma Linda, California, United States, 92354
        • Loma Linda University Health
      • Los Angeles, California, United States, 90033
        • USC Roski Eye Institute - Los Angeles
      • San Francisco, California, United States, 94143
        • University of California San Francisco
    • Florida
      • Boca Raton, Florida, United States, 33428-4221
        • Neurology Offices of South Florida
      • Boca Raton, Florida, United States, 33487-2768
        • SFM Clinical Research, LLC
      • Maitland, Florida, United States, 32751
        • Neurology Associates PA
      • Tampa, Florida, United States, 33620
        • University of South Florida
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Northwestern Memorial Hospital
    • Maryland
      • Columbia, Maryland, United States, 21044
        • University of California Irvine
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
    • Michigan
      • Detroit, Michigan, United States, 48202
        • Henry Ford Health System
    • New Jersey
      • New Brunswick, New Jersey, United States, 08901
        • Robert Wood Johnson Medical School
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27514
        • University of North Carolina at Chapel Hill
      • Durham, North Carolina, United States, 27710
        • Duke Neurological Disorders Clinic
    • Ohio
      • Cleveland, Ohio, United States, 44195
        • Cleveland Clinic
      • Columbus, Ohio, United States, 43221
        • Martha Morehouse Medical Plaza
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • Penn Medicine University City
    • Texas
      • Austin, Texas, United States, 78759-8402
        • National Neuromuscular Research Institute
      • Houston, Texas, United States, 77030
        • Houston Methodist Neurological Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Is at least 18 years of age and the local legal age of consent for clinical studies
  • Has been diagnosed with myasthenia gravis and supported by seropositivity for AChR-Ab; or abnormal neuromuscular transmission demonstrated by abnormal neurophysiology testing and history on positive edrophonium chloride testing or demonstrated improvement on MG therapy"
  • Is MGFA Class I (any ocular muscle weakness)
  • Has a screening and baseline MGII (PRO) ocular score of at least 6 with at least 2 ocular items with a score of at least 2

Exclusion Criteria:

  • Other diseases that lead to eyelid drooping, peripheral muscle weakness, or diplopia
  • Known autoimmune disease or any medical condition other than indication under study that would interfere with an accurate assessment of clinical symptoms of ocular myasthenia gravis or puts the participant at undue risk

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Efgartigimod PH20 SC in part A+B
Participants receiving efgartigimod PH20 SC during part A and part B
Combination product: Efgartigimod PH20 SC
Subcutaneous efgartigimod PH20 SC given by prefilled syringe
Experimental: Placebo PH20 SC in Part A + Efgartigimod PH20 SC in Part B
Participants receiving placebo PH20 SC in Part A and Efgartigimod PH20 SC in Part B
Combination product: Efgartigimod PH20 SC
Subcutaneous efgartigimod PH20 SC given by prefilled syringe
Other: Placebo PH20 SC
Subcutaneous placebo PH20 SC given by prefilled syringe

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
MGII (PRO) ocular score change from baseline to day 29 in part A
Time Frame: Up to 29 days
The Myasthenia Gravis Impairment Index (MGII) is a scoring tool measuring disease severity. It consists of 22 patient-reported outcomes (PRO) and 6 physical examinations (PE). The Ocular PRO score varies between 0 and 18. The higher the score, the more severe the disease.
Up to 29 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of (serious) adverse events
Time Frame: Up to 111 weeks
Up to 111 weeks
Percent change from baseline in total IgG levels over time in part A+B
Time Frame: Up to 111 weeks
Up to 111 weeks
Percent change from baseline in AChR-Ab levels in AChR-Ab seropositive participants over time in part A+B
Time Frame: Up to 111 weeks
Up to 111 weeks
Incidence of Anti-Drug Antibodies and Neutralizing Antibodies against efgartigimod in part A+B
Time Frame: Up to 111 weeks
Up to 111 weeks
Incidence of antibodies and Neutralizing Antibodies against rHuPH20 in part A+B
Time Frame: Up to 111 weeks
Up to 111 weeks
MGII (PRO+PE) ocular score change from baseline to day 29 in part A
Time Frame: Up to 29 days
The Myasthenia Gravis Impairment Index (MGII) is a scoring tool measuring disease severity. It consists of 22 patient-reported outcomes (PRO) and 6 physical examinations (PE). The Ocular PRO score varies between 0 and 18. The ocular PE score varies between 0 and 5. The higher the score, the more severe the disease.
Up to 29 days
MG-ADL ocular domain score change from baseline to day 29 in part A
Time Frame: Up to 29 days
The Myasthenia Gravis Activities of Daily Living (MG-ADL) scale assesses MG symptoms and their effects on daily activities. The ocular score varies between 0 and 16 (with 16 the most severe).
Up to 29 days
MGII total score change from baseline to day 29 in part A
Time Frame: Up to 29 days
The Myasthenia Gravis Impairment Index (MGII) is a scoring tool measuring disease severity. It consists of 22 patient-reported outcomes (PRO) and 6 physical examinations (PE). The score varies between 0 and 84. The higher the score, the more severe the disease.
Up to 29 days
MGII (PE) ocular score change from baseline to day 29 in part A
Time Frame: Up to 29 days
The Myasthenia Gravis Impairment Index (MGII) is a scoring tool measuring disease severity. It consists of 6 physical examinations (PE). The score varies between 0 and 5. The higher the score, the more severe the disease.
Up to 29 days
MG-ADL total score change from baseline to day 29 in part A
Time Frame: Up to 29 days
The Myasthenia Gravis Activities of Daily Living (MG-ADL) scale assesses MG symptoms and their effects on daily activities. The score varies between 0 and 24 (with 24 the most severe).
Up to 29 days
MGII ocular scores changes (PRO) from baseline in part A+B
Time Frame: Up to 111 weeks
The Myasthenia Gravis Impairment Index (MGII) is a scoring tool measuring disease severity. It consists of 22 patient-reported outcomes (PRO) and 6 physical examinations (PE). The Ocular PRO score varies between 0 and 18. The ocular PE score varies between 0 and 5. The higher the score, the more severe the disease.
Up to 111 weeks
MG-QoL15r total score changes from baseline in part A+B
Time Frame: Up to 111 weeks
The Myasthenia Gravis Quality of Life 15-item scale revised (MG-QoL15r) questionnaire is a patient-reported instrument that measures the impact of MG symptoms on Quality of Life. The score varies between 0 and 30 (with 30 the lowest quality of life).
Up to 111 weeks
NEI VFQ-25 score changes from baseline in part A+B
Time Frame: Up to 111 weeks
The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) is a 25-item vision-targeted questionnaire. The score varies between 0 and 100 (with 0 being the worst score)
Up to 111 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

argenx

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 18, 2024

Primary Completion (Estimated)

January 1, 2026

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

August 14, 2024

First Submitted That Met QC Criteria

August 14, 2024

First Posted (Actual)

August 16, 2024

Study Record Updates

Last Update Posted (Actual)

December 15, 2025

Last Update Submitted That Met QC Criteria

December 10, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ARGX-113-2315
  • 2024-514133-38-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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