A Study to Assess the Long-term Safety and Efficacy of a Subcutaneous Formulation of Efgartigimod in Adults With Active Idiopathic Inflammatory Myopathy (ALKIVIA+)

A Phase 3, Single-Arm, Multicenter, Open-label Extension of Study ARGX-113-2007 to Investigate the Long-term Safety, Tolerability, and Efficacy of Efgartigimod PH20 SC in Participants Aged 18 Years and Older With Active Idiopathic Inflammatory Myopathy

The main purpose of this study is to measure the long-term safety and tolerability of efgartigimod PH20 SC in adult participants with Idiopathic Inflammatory Myopathy (IIM) who previously participated in ARGX-113-2007.

The study consists of a treatment period where participants will receive efgartigimod PH20 SC for up to 51 months. The treatment period will be followed by a treatment-free safety follow-up period of 56 days.

Study Overview

• Status: Enrolling by invitation
• Conditions: Myositis; Dermatomyositis; Polymyositis; Antisynthetase Syndrome; Immune-Mediated Necrotizing Myopathy; Active Idiopathic Inflammatory Myopathy
• Intervention / Treatment: Biological: Efgartigimod PH20 SC

• Study Type: Interventional
• Enrollment (Estimated): 240
• Phase: Phase 3

Contacts and Locations

Study Locations

• Argentina
  • La Plata, Argentina, B1902COS
    • Framingham Centro Medico
  • San Miguel, Argentina, B1663GKT
    • Centro Dermatologico Schejtman
  • San Miguel de Tucumán, Argentina, 4000
    • Centro Medico Privado de Reumatologia
• Austria
  • Innsbruck, Austria, 6020
    • Tirol Kliniken - A.o. Landeskrankenhaus Innsbruck - Neurology
• Belgium
  • Ghent, Belgium, 9000
    • AZ Sint-Lucas - Campus Sint-Lucas - Neurology
  • Leuven, Belgium, 3000
    • Universitair Ziekenhuis Leuven Gasthuisberg Campus
• Bulgaria
  • Plovdiv, Bulgaria, 4002
    • Multiprofile hospital for active treatment Kaspela EOOD
  • Plovdiv, Bulgaria, 4002
    • Medical Centre Artmed
• China
  • Beijing, China, 100730
    • Peking Union Medical College Hospital
  • Beijing, China, 100191
    • Peking University Third Hospital
  • Chengdu, China, 610072
    • Sichuan Provincial Academy of Medical Sciences and Sichuan Provincial People's Hospital
  • Shanghai, China, 200040
    • Huashan Hospital Affiliated to Fudan University
  • Shanghai, China, 200001
    • Shanghai Jiao Tong University School of Medicine - Renji Hospital - Shanghai Institute of Digestive Disease (SIDD)
  • Shenyang, China, 110001
    • China Medical University (CMU) - First Affiliated Hospital
  • Zhengzhou, China, 450052
    • First Affiliated Hospital (Henan Medical University - First Affiliated Hospital)-Zhengzhou University
  • Jingsu
    • Nanjing, Jingsu, China, 210000
      • Nanjing University Medical School - Taikang Xianlin Drum Tower Hospital (Nanjing Drum Tower Hospital)
• Cyprus
  • Nicosia, Cyprus, 2371
    • Cyprus Institute of Neurology and Genetics
• Czechia
  • Prague, Czechia, 12850
    • Revmatologicky Ustav
• Denmark
  • Copenhagen, Denmark, 2100
    • Copenhagen University Hospital-Rigshospitalet University Hospital
• France
  • Paris, France, 75013
    • Reference Center Neuro-Muscular Diseases - CHU Paris Group Hospitalier La Pitie Salpetriere-Charles Foix
• Georgia
  • Tbilisi, Georgia, 0160
    • Aversi Clinic
  • Tbilisi, Georgia, 0180
    • The First Medical Center
  • Tbilisi, Georgia, 0160
    • LLC MediClub Georgia
  • Tbilisi, Georgia, 0162
    • New Hospitals
• Germany
  • Berlin, Germany, 10117
    • Charite Universitaetsmedizin Berlin - Campus Charite Mitte (CCM) - Rheumatology
  • Hamburg, Germany, 20246
    • Universitaetsklinikum Hamburg-Eppendorf
  • Herne, Germany, 44649
    • Rheumazentrum Ruhrgebiet
  • Mannheim, Germany, 68167
    • Universitatsmedizin Mannheim GmbH
  • Tübingen, Germany, 72076
    • Universitaetsklinikum Tuebingen (UKT)
  • Ulm, Germany, 89081
    • Klinikum der Universitaet Ulm
• 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, 12462
    • ATTIKON University General Hospital - Neurology
• Ireland
  • Dublin, Ireland, D04 T6F4
    • University College Dublin (UCD) - St. Vincent's University Hospital (SVUH)
• Italy
  • Bari, Italy, 70124
    • Azienda Ospedaliero Universitaria Consorziale Policlinico
  • Milan, Italy, 20132
    • Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) - Ospedale San Raffaele Hospital
  • Pisa, Italy, 56126
    • Azienda Ospedaliero Universitaria Pisana - Ospedale Santa Chiara - Rheumatology
  • Roma, Italy, 00189
    • Ospedale Sant'Andrea Hospital
  • Roma, Italy, 168
    • Fondazione Policlinico Universitario Agostino Gemelli - Neurology
  • Udine, Italy, 33100
    • Azienda sanitaria universitaria Friuli Centrale - ASUFC
• Japan
  • Bunkyō City, Japan, 113-8431
    • Juntendo University Hospital
  • Bunkyō City, Japan, 113-8655
    • The University of Tokyo Hospital
  • Nagoya, Japan, 457-8510
    • Japan Community Healthcare Organization Chukyo Hospital
  • Tokyo, Japan, 113-8519
    • Institute of Science Tokyo Hospital
  • Wakayama, Japan, 641-8510
    • Wakayama Medical University Hospital
• Lithuania
  • Vilnius, Lithuania, 08410
    • Santaros University Clinic
• Mexico
  • Mexico City, Mexico, 06700
    • Hospital Angeles Clinica Londres
• Netherlands
  • Amsterdam, Netherlands, 1105 AZ
    • Amsterdam UMC Research BV
• Peru
  • Arequipa, Peru, 4000
    • Clinica San Juan de Dios - sede Arequipa - Rheumatology
  • Lima, Peru, 33
    • Investigaciones Clinicas S.A.C.
  • Lima, Peru, 27
    • Instituto Peruano Del Hueso Y La Articulacion Sac-Privado-Lima,Centro De Investigacion Iphar
• Poland
  • Lodz, Poland, 90-549
    • USK-WAM Centralny Szpital Weteranow - Szpital Kniniczny ul. Zeromskiego 113 - Rheumatology
  • Szczecin, Poland, 71-252
    • Centrum Wsparcia Badan Klinicznych Pomorskiego Uniwersytetu Medycznego w Szczecinie (CWBK PUM) - Rheumatology
• Portugal
  • Porto, Portugal, 4099-001
    • Centro Hospitalar do Porto - Hospital Santo Antonio
• Serbia
  • Belgrade, Serbia, 11000
    • Clinical Center of Serbia
  • Belgrade, Serbia, 11000
    • Institute of Rheumatology
• South Korea
  • Seoul, South Korea, 03080
    • Seoul National University Hospital
• Spain
  • Barcelona, Spain, 08041
    • Hospital De La Santa Creu I Sant Pau
  • Madrid, Spain, 28041
    • Hospital Universitario 12 de Octubre
  • Valencia, Spain, 46026
    • Hospital Universitari i Politecnic La Fe de Valencia - Neurology
• Sweden
  • Solna, Sweden, 17176
    • Karolinska Universitestssjukhus Solna
• Taiwan
  • Taichung, Taiwan, 402
    • Chung Shan Medical University Hospital
• Thailand
  • Bangkok, Thailand, 10400
    • Phramongkutklao Hospital
  • Bangkok, Thailand, 10400
    • Ramathibodi Hospital
  • Bangkok, Thailand, 10330
    • King Chulalongkorn Memorial Hospital - Neurology
  • Bangkok, Thailand, 10700
    • Siriraj Hospital, Mahidol University of Internal medicine
  • Khon Kaen, Thailand, 40002
    • Faculty Of Medicine, Khon Kaen University
• United Kingdom
  • Liverpool, United Kingdom, L9 7AL
    • Aintree University Hospital - Liverpool University Hospitals NHS Foundation Trust
  • London, United Kingdom, NW3 2QG
    • The Royal Free Hospital
  • Salford, United Kingdom, M6 8HD
    • Northern Care Allicance NHS Foundation Trust - Salford Royal - Rheumatology
• United States
  • Arizona
    • Phoenix, Arizona, United States, 85028
      • Neuromuscular Clinical and Research Center - Neurology
  • California
    • Beverly Hills, California, United States, 90039
      • Attune Health Research, Inc
    • Orange, California, United States, 92868
      • UCI Health - ALS and Neuromuscular Center - Neurology
    • San Francisco, California, United States, 94143
      • UCSF Health - ALS and Neurodegenerative Disease Center - Dermatology
  • Connecticut
    • New Haven, Connecticut, United States, 06520
      • Yale Cancer Center-Yale University School Of Medicine
  • Florida
    • Gainesville, Florida, United States, 32610
      • UF Health - Rheumatology Medical Specialties Medical Plaza
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic - Florida - Neurology
    • 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 Healthcare - Emory Clinic - Rheumatology
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern Medicine - Northwestern Memorial Hospital
  • Maryland
    • Baltimore, Maryland, United States, 21224-2734
      • John Hopkins Medicine - Johns Hopkins Myositis Center
  • New York
    • Great Neck, New York, United States, 11021
      • Northwell Health Physician Partners Rheumatology
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27514
      • University of North Carolina (UNC) School of Medicine
  • Ohio
    • Columbus, Ohio, United States, 43201
      • The Ohio State University
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health and Science University
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15261
      • University of Pittsburgh Medical Center
  • Texas
    • Austin, Texas, United States, 78759
      • Austin Neuromuscular Center (National Neuromuscular Research Institute, PLLC)
    • Houston, Texas, United States, 77030
      • Nerve And Muscle Center Of Texas

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Has completed trial ARGX-113-2007
• Being capable of providing signed informed consent and complying with protocol requirements
• Agrees to use contraceptive measures consistent with local regulations and women of childbearing potential must have a negative urine pregnancy test at baseline before receiving the study drug

Exclusion Criteria:

• Intention to have major surgery during the study period or any other medical condition that has arisen since enrollment in study ARGX-113-2007, that in the investigator's opinion, would confound the results of the study or put the participant at undue risk
• Known hypersensitivity reaction to the study drug or 1 of its excipients
• Development of any malignancy, either new or recurrent, other than basal cell carcinoma of the skin, regardless of relatedness

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Efgartigimod PH20 SC; Participants receiving efgartigimod PH20 subcutaneously	Biological: Efgartigimod PH20 SC; Subcutaneous injection of Efgartigimod PH20 given by vials or prefilled syringe (PFS)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of AEs, SAEs and AESIs over time	AE : adverse event ; SAE : serious adverse event ; AESI : adverse event of special interest.	Up to 53 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
C-GTI comprising the AIS over time	The Composite Glucocorticoid Toxicity Index (C-GTI) serves as a primary instrument to capture toxicities likely caused by glucocorticoid exposure and enables monitoring of long-term tolerability of glucocorticoids during prolonged use. The Aggregate Improvement Score (AIS) is an analytical scores generated from the weighted C-GTI. The AIS can be used to assess whether a new therapy is effective in reducing glucocorticoid toxicity over time; higher AIS scores are associated with less toxicity.	Up to 51 months
C-GTI comprising the CWS over time	The Composite Glucocorticoid Toxicity Index (C-GTI) serves as a primary instrument to capture toxicities likely caused by glucocorticoid exposure and enables monitoring of long-term tolerability of glucocorticoids during prolonged use. The Cumulative Worsening Score (CWS) is an analytical score generated from the weighted C-GTI. The CWS is designed to assess cumulative glucocorticoid toxicity; higher scores indicate increased steroid toxicity.	Up to 51 months
C-GTI comprising the GTI-MD over time	The Composite Glucocorticoid Toxicity Index (C-GTI) serves as a primary instrument to capture toxicities likely caused by glucocorticoid exposure and enables monitoring of long-term tolerability of glucocorticoids during prolonged use. The Glucocorticoid Toxicity Index-Metabolic Domains (GTI-MD) is an abbreviated GTI version limited to the 4 metabolic domains. A GTI-MD score of 0 indicates a low likelihood of toxicity in the assessed metabolic domains.	Up to 51 months
Prednisone dose reduction (average monthly dose) over time		Up to 51 months
TIS over time	The total improvement score (TIS) assesses minimal, moderate, and major clinical response, and it is assessed using the ACR/EULAR criteria. The total score varies between 0 and 100, with higher scores indicating greater improvement.	Up to 51 months
Proportion of TIS responders (minimal, moderate, major) over time	The total improvement score (TIS) assesses minimal, moderate, and major clinical response, and it is assessed using the ACR/EULAR criteria. The total score varies between 0 and 100, with higher scores indicating greater improvement	Up to 51 months
Individual CSMs of the TIS over time	The total improvement score (TIS) assesses minimal, moderate, and major clinical response, and it is assessed using the ACR/EULAR criteria. The ACR/EULAR criteria calculate TIS using the 6 core set measure (CSMs): MDGA, PGA, MMT8, HAQ-DI, muscle enzymes, and extramuscular global assessment (assessed by the MDAAT).	Up to 51 months
Percentage of participants with clinically inactive disease	Clinically inactive disease is defined as no evidence of disease activity, based on an Physician Global Assessment of Disease Activity (MDGA) and Extramuscular Global Assessment of the Myositis Disease Activity Assessment Tool (MDAAT) of 0 and normal creatine kinase (CK) values for at least 12 weeks (at week 28 and every 24 weeks thereafter).	Up to 51 months
Percentage of participants with remission during the study	Remission is defined as a clinically inactive disease for at least 24 weeks	Up to 51 months
PGI-S over time	The Patient Global Impression of Severity (PGI-S) asks participants to rate the severity of their disease symptoms over the past 7 days on a 4-point Likert scale, where scores range from "no symptoms" to "severe."	Up to 51 months
CGI-S over time	The Clinical Global Impression of Severity (CGI-S) asks the physician to rate the severity of the participant's disease on a 4-point Likert scale, where scores range from "no activity" to "severe".	Up to 51 months
Physical Functioning subscale and Physical Component Summary scores of the SF-36v2 over time	The 36-Item Short Form Survey version 2 (SF-36v2) is a 36-item scale constructed to survey health-related quality of life in 8 domains.	Up to 51 months
EQ-5D-5L utilities over time	The EQ-5D-5L questionnaire is a standardized test recognized by many health authorities as a generic measure of health status for clinical and economic appraisal. The descriptive system comprises 5 dimensions, each having 5 levels ranging from "No problem" to "Extreme problem".	Up to 51 months
EQ-5D-5L VAS over time	The EQ-5D-5L questionnaire is a standardized test recognized by many health authorities as a generic measure of health status for clinical and economic appraisal. A visual analog scale (VAS) is included in the EQ-5D-5L, where participants will mark their health status from 0 (the worst health you can imagine) to 100 (the best health you can imagine).	Up to 51 months
Percent change from baseline in total IgG levels in serum over time		Up to 53 months
Incidence of ADA against efgartigimod (serum levels) over time	ADA : anti-drug antibodies.	Up to 53 months
Proportion of participants achieving sustained low disease activity while on IMP, over time	Sustained low disease activity is defined as a CGI-S score of "mild" or "no activity" and a PGI-S score of "mild" or "no symptoms" for at least 12 weeks.	Up to 51 months
Proportion of participants with low disease activity over time, while on IMP	Low disease activity is defined as a CGI-S score of "mild" or "no activity" and a PGI-S score of "mild" or "no symptoms"	Up to 51 months
Proportion of participants with low disease activity who continue dosing every 2 weeks at week 52 and every 24 weeks thereafter	Low disease activity is defined as a CGI-S score of "mild" or "no activity" and a PGI-S score of "mild" or "no symptoms"	Up to 51 months
Proportion of participants who have marked worsening during the period of dosing every 2 weeks	Marked worsening is defined as a CGI-S score of "moderate" or "severe" and a PGI-S score of "moderate" or "severe"	Up to 51 months
Duration of dosing every 2 weeks		Up to 51 months

Collaborators and Investigators

• Sponsor: argenx

Publications and helpful links

Helpful Links

• Study website

Study record dates

Study Major Dates

• Study Start (Actual): September 12, 2023
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: July 28, 2023
• First Submitted That Met QC Criteria: July 28, 2023
• First Posted (Actual): August 7, 2023

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Diseases; Connective Tissue Diseases; Skin Diseases; Skin and Connective Tissue Diseases; Dermatomyositis; Polymyositis; Myositis; Antisynthetase syndrome
• Other Study ID Numbers: ARGX-113-2011; 2022-502851-79-00 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

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