An Open-label Study to Investigate the Clinical Efficacy of Different Dosing Regimens of Efgartigimod IV in Patients With Generalized Myasthenia Gravis

argenx69 enrolled

Overview

The purpose of this open-label study is to investigate the efficacy, safety, and tolerability of a continuous regimen of efgartigimod compared with a cyclic regimen in participants with Generalized Myasthenia Gravis (gMG). Participants will receive efgartigimod throughout the study. The participants will be randomized to the continuous regimen arm or to the cyclic regimen arm. The study consists of a part A (regimen comparison period) where participants will continue the treatment based on the treatment regimen arm they were assigned at randomization. Following part A, participants will enter part B (extension period) where all participants will receive efgartigimod in the continuous regimen. The study duration for participants is up to 138 weeks.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Generalized Myasthenia Gravis MG - Myasthenia Gravis gMG

Interventions

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * At least 18 years of age, at the time of signing the informed consent. * Diagnosed with Generalized Myasthenia Gravis (gMG) with confirmed documentation and supported by a physical exam and confirmed seropositivity for anti-acetylcholine receptor antibodies (AChR-Abs). * Meets the clinical criteria as defined by the Myasthenia Gravis Foundation of America (MGFA) class II, III, or IV Exclusion Criteria: * Any other condition that, in the opinion of the investigator, would interfere with an accurate assessment of the clinical symptoms of gMG and/or put the participant at undue risk * A thymectomy within 3 months of screening * Use of the following prior or concomitant therapies: 1. intravenous immunoglobulin (IVIg) or subcutaneous immunoglobulin (SCIg) within 14 days of day 1 2. Rituximab within 6 months of day 1 3. Eculizumab within 1 month of day 1 4. Other monoclonal antibodies (eg, adalimumab, tocilizumab, ixekizumab)

Locations (39)

Investigator Site 10 - US0010007

Carlsbad, California, United States

Investigator Site 7 - US0010001

Orange, California, United States

Investigator Site 9 - 0010006

Boca Raton, Florida, United States

Investigator Site 15 - US0010014

Coral Springs, Florida, United States

Investigator Site 16 - US0010009

Augusta, Georgia, United States

Outcomes

Primary Outcomes

Mean of the Average MG-ADL Total Score Change From Baseline During the Visit of Week 1 Through Week 21 by Regimen Arm

The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.

Time frame: Up to 21 weeks

Secondary Outcomes

Incidence of AEs, SAEs and AESIs

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

Time frame: Up to 135 weeks

Change From Baseline in the MG-ADL Total Score Over Time

Time frame: Up to 126 weeks

Normalized Area Under the Effect Curve (AUEC) of MG-ADL Total Score Improvement From Baseline

Time frame: Up to 21 weeks

Characterization of MG-ADL Total Score Change From Baseline

Time frame: Up to 21 weeks

Percentage of Participants Who Have a ≥ 2, 3, 4, or 5 Points Improvement in MG-ADL Total Score From Baseline

Time frame: Up to 21 weeks

Percentage of Time Participants Have a Change in MG-ADL Total Score of at Least 2 Points From Baseline During Week 4 Through Week 21

Time frame: From week 4 to week 21

Percentage of Participants Who Achieve MSE, Defined as a MG-ADL Total Score of 0 or 1

MSE = minimal symptom expression; The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.

Time frame: Up to 21 weeks