A Study to Investigate the Efficacy and Safety of Efgartigimod PH20 SC in Adult Participants With Active Idiopathic Inflammatory Myopathy. (ALKIVIA)

A Phase 2/3, Randomized, Double-Blinded, Placebo-Controlled, Parallel-Group, 2-Arm, Multicenter, Operationally Seamless Study to Evaluate the Efficacy, Safety, Tolerability, Pharmacodynamics, Pharmacokinetics, and Immunogenicity of Efgartigimod PH20 SC in Participants Aged 18 Years and Older With Active Idiopathic Inflammatory Myopathy

This study's purpose is to measure the treatment response from efgartigimod PH20 SC compared with placebo in participants with Idiopathic Inflammatory Myopathy (IIM). Participants with the IIM subtypes of dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM), or certain other subtypes of polymyositis (PM; including antisynthetase syndrome [ASyS]) will be included in the study. Treatment response will be measured by Total improvement score (TIS). Additional information can be found on https://myositis-study.com/.

Study Overview

• Status: Active, not recruiting
• Conditions: Myositis; Dermatomyositis; Polymyositis; Antisynthetase Syndrome; Immune-Mediated Necrotizing Myopathy; Active Idiopathic Inflammatory Myopathy
• Intervention / Treatment: Biological: EFG PH20 SC; Other: PBO

• Study Type: Interventional
• Enrollment (Actual): 265
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• Argentina
  • Córdoba, Argentina, 5000
    • Consultora Integral de Salud
  • La Plata, Argentina, B1902COS
    • Framingham Centro Medico
  • Ramos Mejía, Argentina, B1704ETD
    • DIM Clinica Privada
  • San Miguel, Argentina, B1663GKT
    • Centro Dermatologico Schejtman
  • San Miguel De Tucumán, Argentina, T4000AXL
    • Centro de Investigaciones Medicas Tucuman
• Australia
  • Auchenflower, Australia, 4066
    • The Wesley Medical Research
  • Murdoch, Australia, 6150
    • Fiona Stanley Hospital
• Austria
  • Innsbruck, Austria, 6020
    • Medical University Innsbruck
  • Wien, Austria, 1090
    • Allgemeines Krankenhaus der Stadt Wien (AKH Wien)
• Belgium
  • Charleroi, Belgium, 6042
    • Centre Hospitalier Universitaire de Charleroi
  • Gent, Belgium, 9000
    • AZ Sint Lucas Gent-Campus Sint Lucas
  • Leuven, Belgium, 3000
    • Universitair Ziekenhuis Leuven Gasthuisberg Campus
  • Liège, Belgium, 4000
    • Centre Hospitalier Universitaire Sart Tilman
• Bulgaria
  • Plovdiv, Bulgaria, 4002
    • Multiprofile hospital for active treatment Kaspela EOOD
  • Plovdiv, Bulgaria, 4002
    • Medical Centre Artmed
• Canada
  • Montréal, Canada, H4A 3T2
    • Genge Partners
  • Ottawa, Canada, K1Y 4E9
    • Ottawa Hospital Research Institute-Civic Campus
• China
  • Beijing, China, 100730
    • Peking Union Medical College Hospital
  • Beijing, China, 100191
    • Peking University Third Hospital
  • Beijing, China, 100034
    • Peking University First Hospital
  • Changchun, China, 130021
    • The First Hospital of Jilin University
  • Changsha, China, 410008
    • Xiangya Hospital Central South University
  • Changsha, China, 410011
    • The second Xiangya hospital of central south university
  • Chengdu, China, 610072
    • Sichuan Provincial Peoples Hospital
  • Guangzhou, China, 510515
    • Nanfang Hospital, Southern Medical University
  • Guangzhou, China, 510000
    • Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University
  • Hangzhou, China, 310003
    • The First Affiliated Hospital - School of Medicine - ZheJiang University
  • Hefei, China, 230001
    • Anhui Provincial Hospital
  • Nanchang, China, 330000
    • The Second Affiliated Hospital of Nanchang University
  • Nanjing, China, 210008
    • Nanjing Drum Tower Hospital
  • Shanghai, China, 200025
    • Ruijin Hospital, Shanghai Jiaotong University School of Medicine
  • Shanghai, China, 200127
    • Shanghai Renji Hospital
  • Shanghai, China, 200000
    • Huashan Hospital affiliated to Fudan University
  • Shanxi, China, 30001
    • First Affiliated Hospital of Shanxi Medical College
  • Shenyang, China, 110001
    • China Medical University (CMU) - First Affiliated Hospital
  • Wuhan, China, 430030
    • Huazhong University of Science and Technology - Tongji Medical College - Tongji Hospital
  • Zhengzhou, China, 450052
    • First Affiliated Hospital (Henan Medical University - First Affiliated Hospital)-Zhengzhou University
• Cyprus
  • Nicosia, Cyprus, 2371
    • Cyprus Institute of Neurology and Genetics
• Czechia
  • Praha, Czechia, 128 00
    • Revmatologicky ustav
• Denmark
  • Copenhagen, Denmark, 2100
    • Copenhagen University Hospital-Rigshospitalet University Hospital
• France
  • Lyon, France, 69003
    • Hôpital Edouard Herriot
  • Paris, France, 75013
    • Reference Center Neuro-Muscular Diseases - CHU Paris Group Hospitalier La Pitie Salpetriere-Charles Foix
  • Rouen, France, 76031
    • Centre Hospitalier Universitaire (CHU) Hopitaux de Rouen
  • Strasbourg, France, 67098
    • Hopitaux Universitaire de Strasbourg-Centre de References des Maladies Autoimmunes
• Georgia
  • Tbilisi, Georgia, 0160
    • Aversi Clinic
  • Tbilisi, Georgia, 0180
    • The First Medical Center
  • Tbilisi, Georgia, 0114
    • Ltd New Hospitals
  • Tbilisi, Georgia, 0186
    • LTD Tbilisi Heart Center
  • Tbilisi, Georgia, 0102
    • American Hospital Network
  • Tbilisi, Georgia, 0179
    • LLC MediClub Georgia
• Germany
  • Berlin, Germany, 10117
    • Charité - Universitaetsmedizin Berlin
  • Düsseldorf, Germany, 40225
    • Universitaetsklinikum Duesseldorf
  • Göttingen, Germany, 37075
    • Universitätsmedizin Göttingen - Georg-August-Universität
  • Hamburg, Germany, 20246
    • Universitaetsklinikum Hamburg-Eppendorf
  • Herne, Germany, 44649
    • Rheumazentrum Ruhrgebiet
  • Mannheim, Germany, 68167
    • Universitätsmedizin Mannheim
  • Muenchen, Germany, 80336
    • Ludwig-Maximilians-Universitat Munchen Friedrich-Baur-Institut Neurologische Klinik und Poliklinik
  • Sendenhorst, Germany, 48324
    • St. Josef-Stift Sendenhorst
  • Tuebingen, Germany, 72076
    • Universitaetsklinikum Tuebingen (UKT)
  • Ulm, Germany, 89081
    • Universitatsklinikum Ulm - Standort Oberer Eselsberg
• Greece
  • Athens, Greece, 115 27
    • National and Kapodistrian University of Athens - School of Health Sciences - Faculty of Medicine
  • Athens, Greece, 115 28
    • National and Kapodistrian University of Athens - Eginition Hospital
  • Athens, Greece, 151 25
    • Athens Medical Center
  • Athens, Greece, 12462
    • Attikon General University Hospital
  • Ioánnina, Greece, 45110
    • University of Ioannina Medical School
• Hungary
  • Budapest, Hungary, 1083
    • Semmelweis Egyetem, Institute of Genomic Medicine and Rare Disorders
  • Debrecen, Hungary, 4032
    • Debreceni Egyetem - University of Debrecen
• Ireland
  • Dublin, Ireland, D04 T6F4
    • St. Vincents University Hospital
  • Dublin, Ireland, D15 X40D
    • Connolly Hospital Blanchardstown
  • Manorhamilton, Ireland, F91 X012
    • North West Rheumatology Unit - Our Lady's Hospital
• Israel
  • Haifa, Israel, 3109601
    • Rambam Health Care Campus
  • Haifa, Israel, 31048
    • Bnai Zion Medical Center
  • Kfar-Saba, Israel, 44281
    • Meir Medical Center
  • Petach Tikva, Israel, 49100
    • Rabin Medical Center - Beilinson Campus (Beilinson and Hasharon Hospital)
  • Ramat Gan, Israel, 52621
    • Sheba Medical Center - Rheumatology
• Italy
  • Bari, Italy, 70124
    • Azienda Ospedaliera Universitaria Policlinico Consorziale Di Bari - Rheumatology
  • Firenze, Italy, 50139
    • Azienda Ospedaliero Universitaria Careggi
  • Milan, Italy, 20132
    • Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) - Ospedale San Raffaele Hospital
  • Pavia, Italy, 27100
    • San Matteo Hospital
  • Pisa, Italy, 56126
    • A.O. Universitaria Pisana
  • Reggio Emilia, Italy, 42123
    • IRCCS Arcispedale Santa Maria Nuova
  • Roma, Italy, 00168
    • Fondazione Policlinico Universitario Agostino Gemelli IRCCS - Università Cattolica del Sacro Cuore
  • Roma, Italy, 00189
    • Azienda Ospedaliero Universitaria Sant'Andrea
  • Rozzano, Italy, 20089
    • IRCCS Istituto Clinico Humanitas - Rheumatology
  • Torino, Italy, 10126
    • Azienda Ospedaliero Universitaria Citta della Salute e della Scienza di Torino - Presidio Molinette
  • Udine, Italy, 33100
    • ASU FC - Presidio Ospedaliero Universitario Santa Maria della Misericordia
  • Verona, Italy, 37134
    • Azienda Ospedaliera Universitaria Integrata di Verona - Ospedale Borgo Roma
• Japan
  • Bunkyo-ku, Japan, 113-8519
    • Tokyo Medical and Dental University Hospital, Faculty of Medicine
  • Bunkyo-ku, Japan, 113-8603
    • Nippon Medical School - Nippon Medical School Hospital
  • Kawasaki, Japan, 216-8511
    • St. Marianna University School of Medicine Hospital
  • Kurume, Japan, 830-0011
    • Kurume University Hospital
  • Matsudo-shi, Japan, 270-2251
    • Chiba-Nishi General Hospital
  • Nagoya, Japan, 457-8510
    • Japan Community Healthcare Organization Chukyo Hospital
  • Sagamihara-shi, Japan, 252-0375
    • Kitasato University Hospital (KUH)
  • Sapporo-shi, Japan, 060-8604
    • Sapporo City Hospital
  • Sapporo-shi, Japan, 060-8648
    • Hokkaido University Hospital - Rheumatology
  • Sasebo-shi, Japan, 857-1165
    • Sasebo Chuo Hospital
  • Sendai-shi, Japan, 980-8574
    • Tohoku University Hospital
  • Tokushima, Japan, 770-8503
    • Tokushima University Hospital
  • Tokyo, Japan, 160-8582
    • Keio University Hospital
  • Tokyo, Japan, 113-8655
    • The University of Tokyo Hospital
  • Tokyo, Japan, 113-8431
    • Juntendo University Hospital - Rheumatology
  • Tsukuba-shi, Japan, 305-8576
    • University of Tsukuba Hospital - Rheumatology
  • Ube-shi, Japan, 755-8505
    • Yamaguchi University Hospital
  • Wakayama-shi, Japan, 641-8509
    • Wakayama Medical University Hospital - Dermatology
• Korea, Republic of
  • Daejeon, Korea, Republic of, 35015
    • Chungnam National University Hospital (CNUH)
  • Incheon, Korea, Republic of, 21565
    • Gachon University Gil Medical Center
  • Seoul, Korea, Republic of, 03080
    • Seoul National University Hospital
  • Seoul, Korea, Republic of, 04763
    • Hanyang University Seoul Hospital
  • Seoul, Korea, Republic of, 02447
    • Kyung Hee University Medical Center
  • Suwon, Korea, Republic of, 16499
    • Ajou University Hospital
• Lithuania
  • Kaunas, Lithuania, 50161
    • Hospital of Lithuanian University of Health Sciences Kauno klinikos
  • Vilnius, Lithuania, 08661
    • Vilnius University Hospital Santaros Klinikos
• Mexico
  • Mexico City, Mexico, 06700
    • CITER - Centro de Investigacion y Tratamiento de las Enfermedades Reumaticas S.A. de C.V.
  • Mérida, Mexico, 97000
    • Centro Peninsular De Investigacion Clinica
• Netherlands
  • Amsterdam, Netherlands, 1105 AZ
    • Amsterdam University Medical Center (Amsterdam UMC), Academic Medical Center (AMC)
  • Utrecht, Netherlands, 3584 CX
    • Universitair Medisch Centrum Utrecht (Umc Utrecht)
• Peru
  • Arequipa, Peru, 4018
    • Hogar Clínica San Juan de Dios
  • Lima, Peru, 31
    • Hospital Nacional Cayetano Heredia
  • Lima, Peru, 15023
    • Investigaciones Clinicas S.A.C.
  • Lima, Peru, 27
    • Instituto Peruano Del Hueso Y La Articulacion Sac-Privado-Lima, Centro De Investigacion Iphar
• Poland
  • Bydgoszcz, Poland, 85-168
    • Szpital Uniwersytecki nr 2 im. dr Jana Biziela w Bydgoszczy
  • Szczecin, Poland, 71-252
    • Centrum Wsparcia Badan Klinicznych Pomorski Uniwersytet Medyczny w Szczecinie
  • Łódź, Poland, 90-549
    • USK-WAM Centralny Szpital Weteranow - Szpital Kniniczny ul. Zeromskiego 113
• Portugal
  • Lisboa, Portugal, 1649-035
    • Centro Hospitalar Lisboa Norte, E.P.E- Hospital Santa Maria
  • Porto, Portugal, 4099-001
    • Centro Hospitalar Universitário de Santo António
• Serbia
  • Belgrad, Serbia, 11000
    • Institute of Rheumatology
  • Belgrade, Serbia, 11000
    • Clinical Center of Serbia
• Slovakia
  • Piešťany, Slovakia, 92112
    • Narodny Ustav Reumatickych Chorob
• Spain
  • Alicante, Spain, 03010
    • Hospital General Universitario de Alicante
  • Barcelona, Spain, 08041
    • Hospital de la Santa Creu i Sant Pau
  • Barcelona, Spain, 08036
    • Hospital Clinic de Barcelona - Sede Villarroel - Rheumatology
  • Madrid, Spain, 28034
    • Hospital Universitario Ramon y Cajal
  • Madrid, Spain, 28046
    • Universidad Autonoma de Madrid (UAM) - Hospital Universitario La Paz
  • Madrid, Spain, 451086
    • Hospital Universitario 12 de Octubre
  • Sevilla, Spain, 9-41014
    • Hospital De Valme
  • Valencia, Spain, 46026
    • Hospital Universitario y Politecnico La Fe
  • Vigo, Spain, 36200
    • Hospital Do Meixoeiro
• Sweden
  • Stockholm, Sweden, 17164
    • Karolinska Universitestssjukhus Solna
• Switzerland
  • Lugano, Switzerland, 6900
    • Neurocenter of Southern Switzerland
• Taiwan
  • Taichung, Taiwan, 40402
    • China Medical University and Hospital
  • Taichung City, Taiwan, 40705
    • Taichung Veterans General Hospital
  • Taichung city, Taiwan, 402
    • Chung Shan Medical University Hospital
• Thailand
  • Bangkok, Thailand, 10400
    • Phramongkutklao Hospital
  • Bangkok, Thailand, 10400
    • Ramathibodi Hospital
  • Bangkok, Thailand, 10700
    • Siriraj Hospital, Mahidol University of Internal medicine
  • Bangkok, Thailand, 10300
    • Chulalongkorn University - Faculty of Medicine - King Chulalongkorn Memorial Hospital (KCMH)
  • Chiang Mai, Thailand, 50200
    • Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University
  • Khon Kaen, Thailand, 40000
    • Khon Kaen University
  • Pathum Thani, Thailand, 12120
    • Thammasat University Hospital
• Turkey
  • Ankara, Turkey, 06800
    • Ankara City Hospital
  • Ankara, Turkey, 06230
    • Ankara University Medical Faculty
  • Konya, Turkey, 42090
    • Necmettin Erbakan University Meram Medical Faculty
• United Kingdom
  • Bath, United Kingdom, BA1 3NG
    • Royal National Hospital for Rheumatic Diseases - Royal United Hospitals Bath NHS Foundation Trust
  • Doncaster, United Kingdom, DN2 5LT
    • Doncaster Royal Infirmary - Doncaster And Bassetlaw Hospitals Nhs Foundation Trust
  • Leeds, United Kingdom, LS7 4SA
    • Leeds Institute of Rheumatic & Musculoskeletal Medicine - University of Leeds
  • Liverpool, United Kingdom, L9 7AL
    • Aintree University Hospital - Liverpool University Hospitals NHS Foundation Trust
  • London, United Kingdom, SE5 9RS
    • Kings College Hospital NHS Foundation Trust
  • London, United Kingdom, WC1N 3BG
    • The National Hospital for Neurology and Neurosurgery
  • London, United Kingdom, NW3 2QG
    • The Royal Free Hospital - Royal Free London NHS Foundation Trust
  • Middlesbrough, United Kingdom, TS4 3BW
    • James Cook University Hospital - South Tees Hospitals NHS Foundation Trust
  • Salford, United Kingdom, M6 8HD
    • Salford Royal Hospital, Northern Care Alliance NHS Foundation Trust
• United States
  • Arizona
    • Phoenix, Arizona, United States, 85028
      • Neuromuscular Research Center
    • Scottsdale, Arizona, United States, 85251
      • HonorHealth Neurology - Bob Bove Neuroscience Institute - Neurology
  • California
    • Beverly Hills, California, United States, 90039
      • Attune Health Research, Inc
    • Los Angeles, California, United States, 90033
      • University of Southern California Norris Comprehensive Cancer Center
    • Oceanside, California, United States, 92056
      • Profound Research LLC - Oceanside
    • Orange, California, United States, 92868
      • University of California, Irvine
    • Rancho Mirage, California, United States, 92270
      • Eisenhower Medical Center
    • Redwood City, California, United States, 94063-3132
      • Stanford Medicine Outpatient Center - Stanford Dermatology Clinic-Stanford University School of Medicine
    • San Francisco, California, United States, 94109
      • California Pacific Medical Center - Sutter Health
    • San Francisco, California, United States, 94143-2202
      • Amyotrophic Lateral Sclerosis (ALS) Treatment Center,University of California San Francisco (UCSF)
  • Colorado
    • Denver, Colorado, United States, 80230
      • Denver Arthritis Clinic
  • Connecticut
    • New Haven, Connecticut, United States, 06520
      • Yale Cancer Center-Yale University School Of Medicine
  • District of Columbia
    • Washington, District of Columbia, United States, 20007
      • Georgetown University Hospital
  • Florida
    • Gainesville, Florida, United States, 32610-3008
      • UF Health Rheumatology
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic
    • Tampa, Florida, United States, 33616
      • University of South Florida (USF) - Morsani Center (USF Health Carol and Frank Morsani Center for Advanced Healthcare)
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Emory University Hospital, The Emory Clinic
    • Augusta, Georgia, United States, 30312
      • Augusta University
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern Memorial Hospital
  • Kansas
    • Kansas City, Kansas, United States, 66160
      • University of Kansas Medical Center
  • Maryland
    • Baltimore, Maryland, United States, 21224
      • Johns Hopkins Medicine - Johns Hopkins Myositis Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02115-6110
      • Harvard Medical School - Brigham and Women's Hospital (BWH) - The Schuster Family Transplantation Research Center (TRC)
  • Michigan
    • East Lansing, Michigan, United States, 48824
      • Michigan State University - Neurology
  • Minnesota
    • Saint Paul, Minnesota, United States, 55121
      • St. Paul Rheumatology, PA
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University School of Medicine
  • New York
    • Great Neck, New York, United States, 11021
      • Northwell Health
    • New York, New York, United States, 10021
      • Hospital for Special Surgery
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27514-4220
      • University of North Carolina (UNC) School of Medicine
    • Wilmington, North Carolina, United States, 28401
      • Carolina Arthritis Associates
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • Cleveland Clinic - Main Campus
    • Columbus, Ohio, United States, 43201
      • The Ohio State University
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73120
      • Mercy Hospital - Mercy Clinic Neurology Oklahoma City - Neurology
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health and Science University
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15261
      • University of Pittsburg Medical Center
  • Tennessee
    • Nashville, Tennessee, United States, 37232-0028
      • Vanderbilt University Medical Center (VUMC) - Vanderbilt Rheumatology Clinic
  • Texas
    • Austin, Texas, United States, 78759
      • Austin Neuromuscular Center
    • Houston, Texas, United States, 77030
      • Nerve And Muscle Center Of Texas
    • Houston, Texas, United States, 77030
      • McGovern Medical School -The University of Texas Health Science Center at Houston
  • Vermont
    • Burlington, Vermont, United States, 05401
      • University of Vermont Medical Center - Main Campus
  • Washington
    • Seattle, Washington, United States, 98195
      • University of Washington Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Ability to consent in the jurisdiction in which the study is taking place and capable of giving signed informed consent.
• A definite or probable clinical diagnosis of idiopathic inflammatory myopathy (IIM)
• One of the following medical histories: Diagnosis of dermatomyositis (DM) or juvenile dermatomyositis (JDM), Diagnosis of polymyositis (PM) (including antisynthetase syndrome (ASyS)), Diagnosis of immune-mediated necrotizing myopathy (IMNM)
• Diagnosed with active disease as defined by the presence of at least 1 of the following criteria: Abnormal levels of at least 1 of the following enzymes: creatine kinase (CK), aldolase, lactate dehydrogenase, aspartate aminotransaminase (AST), alanine aminotransferase (ALT), based on central laboratory results; Electromyography demonstrating active disease within the past 3 months; Active dermatomyositis (DM) skin rash; Muscle biopsy indicative of active idiopathic inflammatory myopathy (IIM) in the past 3 months; Magnetic resonance imaging within the past 3 months indicative of active inflammation
• Muscle weakness
• Receiving a permitted background treatment for idiopathic inflammatory myopathy.
• Contraceptive use consistent with local regulations, where available, for individuals participating in clinical studies. Women of childbearing potential must have a negative serum pregnancy test during screening and a negative urine pregnancy test at baseline before receiving investigational medicinal product (IMP).

The full list of inclusion criteria can be found in the protocol.

Exclusion Criteria:

• A clinically significant active infection at screening
• A COVID-19 polymerase chain reaction (PCR)-positive test before enrollment
• Any other known autoimmune disease that, in the investigator's opinion, would interfere with an accurate assessment of clinical symptoms of idiopathic inflammatory myopathy (IIM) or put the patient at undue risk
• A history of malignancy unless considered cured by adequate treatment, with no evidence of recurrence for ≥ 3 years before the first administration of the investigational medicinal product (IMP). Adequately treated participants with the following cancers can be included at any time: Basal cell or squamous cell skin cancer ; Carcinoma in situ of the cervix; Carcinoma in situ of the breast; Incidental histological finding of prostate cancer
• Severe muscle damage
• Glucocorticoid-induced myopathy that the investigator considers the primary cause of muscle weakness or permanent weakness linked to a non-idiopathic inflammatory myopathy (IIM) cause
• Juvenile myositis (JDM) diagnosed > 5 years from screening or juvenile myositis with extensive calcinosis or severe calcinosis.
• Uncontrolled interstitial lung disease or any other uncontrolled idiopathic inflammatory myopathy (IIM) manifestation that, in the opinion of the investigator, would be likely to require treatment with prohibited medication during the study
• Other inflammatory and noninflammatory myopathies: inclusion body myositis, overlap myositis), metabolic myopathies, muscle dystrophies or a family history of muscle dystrophy, drug-induced or endocrine induced myositis, and juvenile myositis (other than juvenile dermatomyositis (JDM))
• Clinically significant disease, recent major surgery or intends to have surgery during the study, or has any other condition in the opinion of the investigator that could confound the results of the trial or put the patient at undue risk
• Known hypersensitivity reaction to investigational medicinal product (IMP) or 1 of its excipients
• Received a live or live-attenuated vaccine less than 4 weeks before screening.
• Positive serum test at screening for active viral infection with any of the following conditions: Hepatitis B virus (HBV); Hepatitis C virus (HCV); HIV
• Participant has previously participated in an efgartigimod clinical trial and received at least 1 dose of investigational medicinal product (IMP).
• Participant is concurrently participating in any other clinical study, including a noninterventional study.
• Participant has a current or history (ie, within 12 months of screening) of alcohol, drug, or medication abuse.
• Participant is pregnant or lactating or intends to become pregnant during the study.
• Participant has severe renal impairment .
• Participant is institutionalized by a court or other governmental order or is in a dependent relationship with the sponsor or investigator.

The full list of exclusion criteria can be found in the protocol.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: EFG PH20 SC; participants receiving efgartigimod PH20 SC on top of background treatment	Biological: EFG PH20 SC; Subcutaneous injection of efgartigimod coformulated with rHuPH20, a permeation enhancer
Placebo Comparator: PBO PH20 SC; participants receiving placebo PH20 SC on top of background treatment	Other: PBO; Subcutaneous injection of placebo coformulated with rHuPH20, a permeation enhancer

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Total improvement score (TIS); measured on a [0,100] scale. Higher scores represent improvement; zero indicates no improvement or worsening (from baseline).	phase 2: 24 weeks; phase 3: 52 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Time to reach TIS ≥ 20 (first "minimal clinical improvement")	phase 2: up to 24 weeks; phase 3: up to 52 weeks
Percentage of participants with TIS ≥ 20	phase 2: 24 weeks; phase 3: 52 weeks
Time to reach TIS ≥ 40 (first "moderate clinical improvement")	phase 2: up to 24 weeks; phase 3: up to 52 weeks
Percentage of participants with TIS ≥ 40	phase 2: 24 weeks; phase 3: 52 weeks
Change in manual muscle testing-8 (MMT8) score	phase 2: 24 weeks; phase 3: 52 weeks
Change in Patient Global Assessment of Disease Activity (PGA)	phase 2: 24 weeks; phase 3: 52 weeks
Change in Physician Global Assessment of Disease Activity (MDGA)	phase 2: 24 weeks; phase 3: 52 weeks
Proportion of participants achieving target dose of ≤ 5 mg (prednisone equivalent)	Phase 3: 52 weeks

Collaborators and Investigators

• Sponsor: argenx

Publications and helpful links

Helpful Links

• Study website

Study record dates

Study Major Dates

• Study Start (Actual): October 12, 2022
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): February 1, 2027

Study Registration Dates

• First Submitted: August 30, 2022
• First Submitted That Met QC Criteria: August 30, 2022
• First Posted (Actual): August 31, 2022

Study Record Updates

• Last Update Posted (Actual): July 23, 2025
• Last Update Submitted That Met QC Criteria: July 22, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Nervous System Diseases; Neuromuscular Diseases; Connective Tissue Diseases; Skin Diseases; Muscular Diseases; Dermatomyositis; Polymyositis; Myositis
• Other Study ID Numbers: ARGX-113-2007; 2024-512785-33-00 (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