Clinical Trials

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.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 10/17/23. Questions regarding updates should be directed to the study team contact.