Overview
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.
Eligibility
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 investigational medicinal product
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 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