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

argenx141 sites in 21 countries240 target enrollmentSeptember 12, 2023

ConditionsMyositis Active Idiopathic Inflammatory Myopathy Dermatomyositis Polymyositis Immune-Mediated Necrotizing Myopathy Antisynthetase Syndrome

InterventionsEfgartigimod PH20 SC

Overview

Phase: Phase 3
Intervention: Efgartigimod PH20 SC
Conditions: Myositis
Sponsor: argenx
Enrollment: 240
Locations: 141
Primary Endpoint: Incidence of AEs, SAEs and AESIs over time
Status: Enrolling By Invitation
Last Updated: last month

Overview Investigators Eligibility Criteria Arms & Interventions Outcomes Sites Similar Trials

Overview

Brief Summary

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.

Registry

clinicaltrials.gov

Start Date

September 12, 2023

End Date

September 1, 2028

Last Updated

last month

Study Type

Interventional

Study Design

Single Group

Sex

All

Investigators

Sponsor

argenx

Responsible Party

Sponsor

Eligibility 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 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

Arms & Interventions

Efgartigimod PH20 SC

Participants receiving efgartigimod PH20 subcutaneously

Intervention: Efgartigimod PH20 SC

Outcomes

Primary Outcomes

Incidence of AEs, SAEs and AESIs over time

Time Frame: Up to 53 months

AE : adverse event ; SAE : serious adverse event ; AESI : adverse event of special interest.

Secondary Outcomes

C-GTI comprising the AIS over time(Up to 51 months)
C-GTI comprising the CWS over time(Up to 51 months)
C-GTI comprising the GTI-MD over time(Up to 51 months)
Prednisone dose reduction (average monthly dose) over time(Up to 51 months)
TIS over time(Up to 51 months)
Proportion of TIS responders (minimal, moderate, major) over time(Up to 51 months)
Individual CSMs of the TIS over time(Up to 51 months)
Percentage of participants with clinically inactive disease(Up to 51 months)
Percentage of participants with remission during the study(Up to 51 months)
PGI-S over time(Up to 51 months)
CGI-S over time(Up to 51 months)
Physical Functioning subscale and Physical Component Summary scores of the SF-36v2 over time(Up to 51 months)
EQ-5D-5L utilities over time(Up to 51 months)
EQ-5D-5L VAS over time(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(Up to 53 months)
Proportion of participants achieving sustained low disease activity while on IMP, over time(Up to 51 months)
Proportion of participants with low disease activity over time, while on IMP(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(Up to 51 months)
Proportion of participants who have marked worsening during the period of dosing every 2 weeks(Up to 51 months)
Duration of dosing every 2 weeks(Up to 51 months)