A Study to Assess the Long-term Safety and Efficacy of a Subcutaneous Formulation of Efgartigimod in Adults with Active Idiopathic Inflammatory Myopathy

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 - alkivia+

Status

Recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2031240524

Enrollment

Registered

2024-12-05

Start date

2025-06-06

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Idiopathic inflammatory myopathy

Interventions

Biological: efgartigimod PH20 SC Subcutaneous injection of efgartigimod coformulated with rHuPH20

Eligibility

Sex/Gender

All

Inclusion criteria

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

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. However, the investigator determines that administering the investigational medicinal product to participant would be beneficial for the participant(criteria: if the participant is evaluated as "much better" or "moderately better" for at least 12 weeks on the CGI-C and PGI-C assessments

Design outcomes

Primary

Measure	Time frame
- Incidence and severity of TEAEs, AESIs, and SAEs - Changes and abnormalities in vital signs, ECG, and laboratory parameters	—

Countries

Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Cyprus, Czechia, Denmark, France, Georgia, Germany, Greece, Hungary, Ireland, Israel, Italy, Japan, Korea Republic of, Lithuania, Mexico, Netherland, Peru, Poland, Portugal, Servia, Spain, Sulovakia, Sweden, Switzerland, United States

Contacts

Public ContactClinical trial contact

ICON Clinical Research GK

Japan-Chiken@iconplc.com+81-6-4560-2001

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026