ADAPT Forward 1 - ISA1 - a Study to Evaluate Empasiprubart IV as add-on Therapy to Efgartigimod IV in Participants With AChR-Ab Seropositive Generalized Myasthenia Gravis With a Partial Clinical Response to Efgartigimod

June 2, 2026 updated by: argenx

An ISA to Master Protocol ARGX-999-2-MG-2000 for an Exploratory, Phase 2a, Proof-of-Concept Study to Evaluate the Safety, Tolerability, and Efficacy of Empasiprubart IV as Add-On Therapy to Efgartigimod IV in Participants With AChR-Ab Seropositive Generalized Myasthenia Gravis With a Partial Clinical Response to Efgartigimod

This study is part of the ADAPT Forward platform study (NCT07294170). ADAPT Forward is a platform study with the aim to look at how safe different drugs are and how well they work for people with myasthenia gravis. The goal is to find the best therapeutic approach to reduce patients' side effects and improve their quality of life.

The aim of this ISA1 is to evaluate the safety and therapeutic relevance of empasiprubart as add-on therapy to efgartigimod in participants with AChR-Ab seropositive generalized myasthenia gravis.

The ADAPT Forward master protocol is registered on https://clinicaltrials.gov/study/NCT07294170

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Once the master protocol and ISA1 screening periods are completed, eligible participants can enroll in the run-in period (part A) where they will receive efgartigimod IV. Eligible participants can then continue to the add-on period (part B) where they will receive both efgartigimod IV and empasiprubart IV.

Participants who are not eligible for part B will continue directly to the safety follow-up period (part C) where they will receive efgartigimod IV only.

The study duration for each participant is approximately up to 54 weeks.

Study Type

Interventional

Enrollment (Estimated)

70

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Belgium
      • Leuven, Belgium, 3000
  • Italy
    • Lombardy
      • Bergamo, Lombardy, Italy, 24127
        • Recruiting
        • ASST Papa Giovanni XXIII - Ospedale Papa Giovanni XXIII
        • Contact:
  • Poland
    • Kuyavian-Pomeranian Voivodeship
      • Bydgoszcz, Kuyavian-Pomeranian Voivodeship, Poland
    • Silesian Voivodeship
      • Katowice, Silesian Voivodeship, Poland, 40-689
  • Spain
    • Malaga
      • Málaga, Malaga, Spain, 29010
        • Recruiting
        • Hospital Regional Universitario de Malaga - Hospital General
        • Contact:
  • United States
    • California
      • Carlsbad, California, United States, 92011
        • Recruiting
        • Profound Research LLC - Carlsbad
        • Contact:
    • Florida
      • Miami, Florida, United States, 33176
        • Recruiting
        • Visionary Investigators Network
        • Contact:
      • Tampa, Florida, United States, 33620
        • Recruiting
        • University of South Florida
        • Contact:
          • Tuan Vu, MD
          • Phone Number: 813-974-9413
          • Email: tvu6@usf.edu
    • New York
      • Amherst, New York, United States, 14226
        • Recruiting
        • Dent Neurologic Institute - Amherst
        • Contact:
    • Ohio
      • Columbus, Ohio, United States, 43221-3502
        • Recruiting
        • Ohio State Martha Morehouse Outpatient Care
        • Contact:
    • Tennessee
      • Chattanooga, Tennessee, United States, 37403
    • Texas
      • Austin, Texas, United States, 78756
        • Recruiting
        • National Neuromuscular Research Institute
        • Contact:
      • San Antonio, Texas, United States, 78229
        • Recruiting
        • University of Texas- San Antonio - Health Science Center - PPDS
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Is seropositive for anti-acetylcholine receptor antibodies (AChR-Ab)
  • Has confirmed diagnosis of gMG and is Myasthenia Gravis Foundation of America (MGFA) Class II, III, IVa, or IVb
  • Has documented immunization against encapsulated bacterial pathogens (Neisseria meningitidis and Streptococcus pneumoniae) within 5 years of ISA screening or is willing to receive immunization at least 14 days before the first study drug administration

Exclusion Criteria:

  • Clinical diagnosis of systemic lupus erythematosus (SLE)
  • Any known complement deficiency
  • Current administration of a complement inhibitor or received zilucoplan or eculizumab <2 months or ravulizumab <6 months before the first study drug administration
  • Patients proven to be refractory to efgartigimod (ie, not achieving a clinically meaningful improvement in total Myasthenia Gravis Activities of Daily Living (MG-ADL) score defined as an improvement of ≥2 points)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Efgartigimod IV + Empasiprubart IV
Participants receive efgartigimod IV in part A, B and C and empasiprubart IV in part B
Biological: Efgartigimod IV
Intravenous infusion of efgartigimod
Biological: Empasiprubart IV
Intravenous infusion of empasiprubart
Experimental: Efgartigimod IV (part A + C)
Participants not eligible for part B, receiving efgartigimod IV in part A and C
Biological: Efgartigimod IV
Intravenous infusion of efgartigimod

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Incidence of adverse events and serious adverse events in parts A and B
Time Frame: Up to 21 weeks
Up to 21 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
MG-ADL total score change from baseline at week 18 in part B (cycle 2 day 29) compared with MG ADL total score change from baseline at week 4 in part A
Time Frame: Up to 18 weeks
The Myasthenia Gravis Activities of Daily Living (MG- ADL) scale is an 8-item instrument used to assess MG symptoms and their effects on daily activities. The total score ranges from 0 (normal symptoms) to 24 (most severe symptoms)
Up to 18 weeks
Proportion of participants reaching MSE at any point in part B cycles 1 and 2, and part B cycles 1 or 2
Time Frame: Up to 21 weeks
MSE: Minimal symptom expression
Up to 21 weeks
MG-ADL total score changes from baseline over time in part B compared with part A
Time Frame: Up to 21 weeks
The Myasthenia Gravis Activities of Daily Living (MG- ADL) scale is an 8-item instrument used to assess MG symptoms and their effects on daily activities. The total score ranges from 0 (normal symptoms) to 24 (most severe symptoms)
Up to 21 weeks
QMG total score change from baseline at week 18 in part B (cycle 2 day 29) compared with QMG total score change from baseline at week 4 in part A
Time Frame: Up to 18 weeks
The Quantitative myasthenia gravis (QMG) includes 13 items that measure endurance or fatigability and accounts for fluctuations in disease state. The total score ranges from 0 (no disease severity) to 39 (highest disease severity)
Up to 18 weeks
QMG total score changes from baseline over time in part B compared with part A
Time Frame: Up to 21 weeks
The Quantitative myasthenia gravis (QMG) includes 13 items that measure endurance or fatigability and accounts for fluctuations in disease state. The total score ranges from 0 (no disease severity) to 39 (highest disease severity)
Up to 21 weeks
Proportion of participants who have a 50% MG ADL total score improvement in part B cycles 1 and 2
Time Frame: Up to 21 weeks
The Myasthenia Gravis Activities of Daily Living (MG ADL) scale is an 8-item instrument used to assess MG symptoms and their effects on daily activities. The total score ranges from 0 (normal symptoms) to 24 (most severe symptoms)
Up to 21 weeks
Proportion of participants who have positive PASS in part B cycles 1 and 2, and part B cycles 1 or 2
Time Frame: Up to 21 weeks
PASS: Patient acceptable symptom state
Up to 21 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

argenx

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 19, 2025

Primary Completion (Estimated)

March 7, 2028

Study Completion (Estimated)

March 7, 2028

Study Registration Dates

First Submitted

December 8, 2025

First Submitted That Met QC Criteria

December 8, 2025

First Posted (Actual)

December 16, 2025

Study Record Updates

Last Update Posted (Actual)

June 3, 2026

Last Update Submitted That Met QC Criteria

June 2, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ARGX-999-2-MG-20001
  • 2025-522492-28-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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