Evaluating the Pharmacodynamic Noninferiority of Efgartigimod PH20 SC Administered Subcutaneously as Compared to Efgartigimod Administered Intravenously in Patients With Generalized Myasthenia Gravis (ADAPTsc)
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ClinicalTrials.gov Identifier: NCT04735432 |
Recruitment Status :
Completed
First Posted : February 3, 2021
Last Update Posted : February 1, 2022
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Generalized Myasthenia Gravis | Biological: efgartigimod PH20 SC Biological: efgartigimod IV | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 111 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | A Phase 3, Randomized, Open-Label, Parallel-Group Study to Compare the Pharmacodynamics, Pharmacokinetics, Efficacy, Safety, Tolerability, and Immunogenicity of Multiple Subcutaneous Injections of Efgartigimod PH20 SC With Multiple Intravenous Infusions of Efgartigimod in Patients With Generalized Myasthenia Gravis |
Actual Study Start Date : | February 5, 2021 |
Actual Primary Completion Date : | November 2, 2021 |
Actual Study Completion Date : | December 13, 2021 |

Arm | Intervention/treatment |
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Experimental: efgartigimod PH20 SC
Patients receiving efgartigimod PH20 subcutaneous (SC) treatment
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Biological: efgartigimod PH20 SC
Subcutaneous injection with efgartigimod PH20 SC |
Experimental: efgartigimod
Patients receiving efgartigimod intravenous (IV) treatment
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Biological: efgartigimod IV
Intravenous infusion of efgartigimod |
- Percent change from baseline in total Immunoglobulin (IgG) levels at day 29 [ Time Frame: at day 29 ]
- Absolute values in total immunoglobulin (IgG) levels over time [ Time Frame: up to 12 weeks ]
- Change from baseline in total immunoglobulin (IgG) levels over time [ Time Frame: up to 12 weeks ]
- Percent change from baseline in total immunoglobulin (IgG) levels over time [ Time Frame: up to 12 weeks ]
- Absolute values in acetylcholine receptor binding autoantibodies (AChR-Ab) levels over time in AChR-Ab positive patients [ Time Frame: up to 12 weeks ]
- Change from baseline in acetylcholine receptor binding autoantibodies (AChR-Ab) levels over time in AChR-Ab positive patients [ Time Frame: up to 12 weeks ]
- Percent change from baseline in acetylcholine receptor binding autoantibodies (AChR-Ab) levels over time in AChR-Ab positive patients [ Time Frame: up to 12 weeks ]
- Absolute values in immunoglobulin IgG subtype levels (IgG1, IgG2, IgG3, and IgG4) over time [ Time Frame: up to 12 weeks ]
- Change from baseline in immunoglobulin IgG subtype levels (IgG1, IgG2, IgG3, and IgG4) over time [ Time Frame: up to 12 weeks ]
- Percent change from baseline in immunoglobulin IgG subtype levels (IgG1, IgG2, IgG3, and IgG4) over time [ Time Frame: up to 12 weeks ]
- Area under the effect curve (AUEC) of the percentage change from baseline total immunoglobulin G [ Time Frame: up to 12 weeks ]
- Similar Area under the effect curve (AUEC) for each IgG subtype per dosing interval (days 1-8, days 8-15, days 15-22, and days 22-29), days 1-29, and over the entire study (days 1-71) [ Time Frame: up to 12 weeks ]
- Pharmacokinetics (PK) parameters: maximum concentration (Cmax) (after all doses for the IV treatment arm) [ Time Frame: up to 12 weeks ]
- Pharmacokinetics (PK) parameters: concentration observed predose (Ctrough) [ Time Frame: up to 12 weeks ]
- Incidence of anti-drug antibodies (ADAs) against efgartigimod [ Time Frame: up to 12 weeks ]
- Prevalence of anti-drug antibodies (ADAs) against efgartigimod [ Time Frame: up to 12 weeks ]
- Incidence of anti-drug antibodies (ADAs) against rHuPH20 in the SC treatment arm [ Time Frame: up to 12 weeks ]
- Prevalence of anti-drug antibodies (ADAs) against rHuPH20 in the SC treatment [ Time Frame: up to 12 weeks ]
- Incidence of adverse events (AEs) and serious adverse events (SAEs) [ Time Frame: up to 12 weeks ]
- Severity of adverse events (AEs) [ Time Frame: up to 12 weeks ]
- Number of Myasthenia Gravis Activities of Daily Living (MG-ADL) responders [ Time Frame: up to 12 weeks ]
- Percentage of Myasthenia Gravis Activities of Daily Living (MG-ADL) responders [ Time Frame: up to 12 weeks ]
- Number of Quantitative Myasthenia Gravis (QMG) responders [ Time Frame: up to 12 weeks ]
- Percentage of Quantitative Myasthenia Gravis (QMG) responders [ Time Frame: up to 12 weeks ]
- Change from baseline in Myasthenia Gravis Activities of Daily Living (MG-ADL) total score over time. A higher total score indicates more impairment. [ Time Frame: up to 12 weeks ]
- Change from baseline in Quantitative Myasthenia Gravis (QMG) score over time. A higher total score indicates more severe impairment [ Time Frame: up to 12 weeks ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
Bullet list of each inclusion criterium:
- Must be capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.
- At least 18 years of age at the time of signing the informed consent form.
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Diagnosed with generalized Myasthenia Gravis (gMG) with confirmed documentation and supported by at least 1 of the following:
- History of abnormal neuromuscular transmission demonstrated by single fiber electromyography or repetitive nerve stimulation
- History of positive edrophonium chloride test
- Demonstrated improvement in Myasthenia Gravis (MG) signs upon treatment with oral acetylcholinesterase (AChE) inhibitors as assessed by the treating physician
- Meeting the clinical criteria as defined by the Myasthenia Gravis Foundation of America (MGFA) class II, III, IVa, or IVb
Exclusion Criteria:
Bullet list of each exclusion criterium:
- Are pregnant or lactating, or intend to become pregnant during the study or within 90 days after the last dose of Investigational Medicinal Product.
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Has any of the following medical conditions:
- Clinically significant uncontrolled active or chronic bacterial, viral, or fungal infection at screening
- Any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of clinical symptoms of myasthenia gravis or put the participant at undue risk.
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History of malignancy unless deemed cured by adequate treatment with no evidence of reoccurrence for ≥3 years before the first administration of the IMP. Participants with the following cancers can be included at any time:
- adequately treated basal cell or squamous cell skin cancer
- carcinoma in situ of the cervix
- carcinoma in situ of the breast
- incidental histological findings of prostate cancer (TNM Classification of Malignant Tumors stage T1a or T1b).
- Clinical evidence of other significant serious diseases, or the participant has had a recent major surgery, or who have any other condition that, in the opinion of the investigator, could confound the results of the study or put the participant at undue risk.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04735432

Responsible Party: | argenx |
ClinicalTrials.gov Identifier: | NCT04735432 |
Other Study ID Numbers: |
ARGX-113-2001 |
First Posted: | February 3, 2021 Key Record Dates |
Last Update Posted: | February 1, 2022 |
Last Verified: | January 2022 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Product Manufactured in and Exported from the U.S.: | No |
Myasthenia Gravis Muscle Weakness Muscular Diseases Musculoskeletal Diseases Neuromuscular Manifestations Neurologic Manifestations Nervous System Diseases Pathologic Processes Paraneoplastic Syndromes, Nervous System Nervous System Neoplasms |
Neoplasms by Site Neoplasms Paraneoplastic Syndromes Autoimmune Diseases of the Nervous System Neurodegenerative Diseases Neuromuscular Junction Diseases Neuromuscular Diseases Autoimmune Diseases Immune System Diseases |