for people ages 18 years and up (full criteria)
at Orange, California and other locations
study started
completion around



The purpose of this study is to measure the long-term safety and tolerability of efgartigimod PH20 SC in adult participants with IIM who previously participated in ARGX-113-2007. Secondary objectives include efficacy measures of efgartigimod PH20 SC in participants with IIM.

Official Title

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


Myositis, Active Idiopathic Inflammatory Myopathy, Dermatomyositis, Polymyositis, Immune-Mediated Necrotizing Myopathy, Antisynthetase Syndrome, Muscular Diseases, EFG PH20 SC


You can join if…

Open to people ages 18 years and up

  • 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 investigational medicinal product

You CAN'T join if...

  • 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 investigational medicinal product or 1 of its excipients Development of any malignancy, either new or recurrent, other than basal cell carcinoma of the skin, regardless of relatedness
  • Permanent discontinuation of IMP in ARGX-113-2007, or met the permanent discontinuation criteria at the rollover visit
  • Diagnosis with a deselected subtype of myositis based on the analysis of the phase 2 stage data in ARGX-113-2007, unless the investigator determines that the participant is benefiting from IMP as defined by a score of "much better" or "moderately better" on the 'Clinical Global Impression of Change' and 'Patient Global
  • Impression of Change' assessments for at least 12 weeks, and that enrolling in the study is in the participant's best interest


  • UCI Health - ALS and Neuromuscular Center - Neurology accepting new patients
    Orange California 92868 United States
  • Attune Health Research, Inc accepting new patients
    Beverly Hills California 90039 United States


accepting new patients
Start Date
Completion Date
Study website
Phase 3 research study
Study Type
Expecting 240 study participants
Last Updated