Evaluating Long-term Safety of Efgartigimod Administered Intravenously and Efgartigimod PH20 Administered Subcutaneously in Children With Generalized Myasthenia Gravis

NCT05374590 | Enrolling By Invitation Phase 2 DMC FDA Drug

• 2 other identifiers: ARGX-113-20082023-507379-23-00
• Study Type: interventional
• Target: 12
• Locations: 10 countries
• Sites: 16

Brief Summary

The purpose of this trial is to evaluate the long-term safety of efgartigimod IV and efgartigimod PH20 SC administered to participants with gMG in the antecedent studies, ARGX-113-2006 and ARGX-113-2207, respectively. Participants will receive efgartigimod IV or efgartigimod PH20 SC, using the dose administered in the antecedent studies. Participants who have not reached the age of 18 can remain in the study until efgartigimod becomes commercially available in the respective country or available through another continued access program for gMG. Participants who have reached the age of 18 can remain in the study for a maximum of 2 years, until efgartigimod becomes commercially available in the respective country or available through another continued access program for gMG, whichever comes first.

Conditions

Generalized Myasthenia Gravis; gMG

Outcome Measures

Primary Outcomes (1)

• Incidence of AEs, SAEs and AESIs

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

  Up to 4 years

Secondary Outcomes (2)

• Incidence of ADAs against efgartigimod

  Up to 4 years

• Incidence of antibodies against rHuPH20

  Up to 4 years

Study Arms (1)

Efgartigimod or Efgartigimod PH20 SC

EXPERIMENTAL

Patients receiving Efgartigimod IV treatment or Efgartigimod PH 20 SC treatment

Biological: Efgartigimod IV or Efgartigimod PH20 SC

Interventions

Efgartigimod IV or Efgartigimod PH20 SC BIOLOGICAL

Intravenous infusion of Efgartigimod or Subcutaneous injection of Efgartigimod PH20 SC

Efgartigimod or Efgartigimod PH20 SC

Eligibility Criteria

• Age: 2 Years - 18 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• The participant completed ARGX-113-2006, defined as:
• The participant reached End of Trial in trial ARGX-113-2006 or End of Study in ARGX-113-2207 and agreed to participate in the ARGX-113-2008 trial.
• The participant qualifies for retreatment in trial ARGX-113-2006, but cannot complete a Treatment Period (TP) and the required Intertreatment Period (IP) visits within the ARGX-113-2006 trial's timeframe.
• Either the participant or the participant's legally authorized representative can understand the requirements of the trial and provide written informed consent/assent, and willingness and ability to comply with the trial protocol procedures.
• Contraceptive use for sexually active participants should be consistent with local regulations for those participating in clinical studies.

You may not qualify if:

• Female adolescents of childbearing potential (FAOCBP): Pregnancy or lactation, or the participant intends to become pregnant during their participation in the study.
• Discontinued early from ARGX-113-2006 or ARGX-113-2207 treatment.
• Clinically significant uncontrolled chronic bacterial, viral, or fungal infection at study entry not sufficiently resolved in the investigator's opinion or known autoimmune disease or any medical condition that would interfere with an accurate assessment of clinical symptoms of gMG or put the participant at undue risk.

Sponsors & Collaborators

• argenx: lead

Study Sites (16)

Ann and Robert H Lurie Children's Hospital of Chicago - Main Hospital

Chicago, Illinois, 60611, United States

Location

Atrium Health Neurology Specialty Care

Charlotte, North Carolina, 28207, United States

Location

University of Virginia (UVA) Health - Developmental Pediatrics Clinic

Charlottesville, Virginia, 22903, United States

Location

Universitair Ziekenhuis Antwerpen

Edegem, 2650, Belgium

Location

UZ Gent

Ghent, 9000, Belgium

Location

Childrens Hospital of Eastern Ontario

Ottawa, K1H 8L1, Canada

Location

AP-HM- Hôpital de La Timone

Marseille, 13005, France

Location

Universitätsklinikum Essen

Essen, 45147, Germany

Location

Hadassah Medical Center- Ein Kerem

Jerusalem, 9112001, Israel

Location

Leids Universitair Medisch Centrum

Leiden, 2333 ZA, Netherlands

Location

Uniwersyteckie Centrum Kliniczne w Gdansku

Gdansk, 80-211, Poland

Location

Wielospecjalistyczna Poradnia Lekarska Synapsis

Katowice, 40-123, Poland

Location

Centralny Szpital Kliniczny - Uniwersyteckie Centrum Kliniczne WUM

Warsaw, 02-097, Poland

Location

Hospital Universitari i Politecnic La Fe de Valencia

Valencia, 46026, Spain

Location

Great Ormand Street Hospital for Children NHS Foundation Trust - Great Ormond Street Hospital - Pediatric Neurology

London, WC1N 3JH, United Kingdom

Location

Oxford University Hospitals NHS Foundation Trust - John Radcliffe Hospital Children's Hospital

Oxford, OX3 9DU, United Kingdom

Location

MeSH Terms

Conditions

Myasthenia Gravis

Condition Hierarchy (Ancestors)

Paraneoplastic Syndromes, Nervous System; Nervous System Neoplasms; Neoplasms by Site; Neoplasms; Paraneoplastic Syndromes; Autoimmune Diseases of the Nervous System; Nervous System Diseases; Neurodegenerative Diseases; Neuromuscular Junction Diseases; Neuromuscular Diseases; Autoimmune Diseases; Immune System Diseases

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 1, 2022
• First Posted: May 16, 2022
• Study Start: August 18, 2022
• Primary Completion (Estimated): September 1, 2029
• Study Completion (Estimated): September 1, 2029
• Last Updated: April 23, 2026

Record last verified: 2026-01

Locations

DE (1); IL (1); CA (1); PL (3); GB (2); NL (1); BE (2); US (3); ES (1); FR (1)