Evaluating the Long-Term Safety and Tolerability of Efgartigimod PH20 SC Administered Subcutaneously in Patients with Generalized Myasthenia Gravis

• Register: ClinicalTrials.gov
• Last refreshed on: 3 February 2025
• Main ID: NCT04818671
• Date of registration: 11/03/2021
• Prospective Registration: Yes
• Primary sponsor: argenx
• Public title: Evaluating the Long-Term Safety and Tolerability of Efgartigimod PH20 SC Administered Subcutaneously in Patients with Generalized Myasthenia Gravis ADAPTSC+
• Scientific title: A Long-Term, Single-Arm, Open-label, Multicenter Phase 3 Study to Evaluate the Safety and Tolerability of Multiple Subcutaneous Injections of Efgartigimod PH20 SC in Patients with Generalized Myasthenia Gravis
• Date of first enrolment: April 26, 2021
• Target sample size: 184
• Recruitment status: Completed
• URL: https://clinicaltrials.gov/ct2/show/NCT04818671
• Study type: Interventional
• Study design: Allocation: N/A. Intervention model: Single Group Assignment. Primary purpose: Treatment. Masking: None (Open Label).
• Phase: Phase 3

Countries of recruitment

Belgium, Czechia, Georgia, Germany, Hungary, Italy, Japan, Netherlands, Poland, Russian Federation, Spain, United States

Key inclusion & exclusion criteria

Inclusion Criteria:

1. 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.

2. Previously participated in antecedent studies ARGX-113-2001 or ARGX-113-1705 and are
eligible for roll over.

3. Contraceptive use by men and women should be consistent with local regulations
regarding the methods of contraception for those participating in clinical studies
and:

- Women of Child bearing potential (WOCBP) must have a negative urine pregnancy
test at baseline before investigational medicinal product (IMP) can be
administered.

Exclusion Criteria:

1. The participant was discontinued early from studies ARGX-113-2001 or ARGX-113-1705,
unless the reason for discontinuation from study ARGX-113-1705 was to roll over into
study ARGX-113-2002.

a. Participants who, in the investigator's judgment, are not benefiting from
efgartigimod IV in study ARGX-113-1705 Part B are not eligible for roll over into
ARGX-113-2002.

2. Are pregnant or lactating, or intend to become pregnant during the study or within
90 days after the last dose of investigational medicinal product (IMP)

3. Has any of the following medical conditions:

1. Clinically significant uncontrolled chronic bacterial, viral, or fungal
infection at roll-over

2. Any other known autoimmune disease that, in the opinion of the investigator,
would interfere with accurate assessment of clinical symptoms of myasthenia
gravis or put the participant at undue risk

3. History of malignancy unless deemed cured by adequate treatment with no
evidence of reoccurrence for =3 years before the first administration of
investigational medicinal product (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)

4. 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

4. Received a live-attenuated vaccine within 28 days prior to study entry or plan to
receive a live-attenuated vaccine during the study

5. A known hypersensitivity reaction to efgartigimod, rHuPH20, or any of its excipients


Age minimum: 18 Years
Age maximum: N/A
Gender: All

Health Condition(s) or Problem(s) studied

Generalized Myasthenia Gravis

Intervention(s)

Biological: efgartigimod PH20 SC

Primary Outcome(s)

Incidence and severity of Adverse Events (AEs) [Time Frame: Up to 3.5 years]

Incidence of Adverse Events of Special Interest (AESI) [Time Frame: Up to 3.5 years]

Incidence of Serious Adverse Events (SAEs) [Time Frame: Up to 3.5 years]

Secondary Outcome(s)

Changes in EuroQoL 5 Dimensions 5-Level (EQ-5D-5L) visual analog scale (VAS) score from baseline [Time Frame: Up to 3.5 years]

Cycle baseline over time by cycle (for MG-ADL) [Time Frame: Up to 3.5 years]

EQ-5D-5L responses over time by cycle [Time Frame: Up to 3.5 years]

Incidence of NAbs against rHuPH20 over time [Time Frame: Up to 3.5 years]

Percentage of participants who performed self-administration at home over time by cycle [Time Frame: Up to 3.5 years]

Changes in total Myasthenia Gravis Quality of Life Questionnaire (15-item scale revised) (MG-QoL15r) from baseline [Time Frame: Up to 3.5 years]

Cycle baseline by cycle (for MG-QoL15r) [Time Frame: Up to 3.5 years]

Myasthenia Gravis Activities of Daily Living (MG-ADL) total score changes from baseline [Time Frame: Up to 3.5 years]

Number of participants who performed self-administration at home over time by cycle [Time Frame: Up to 3.5 years]

Percentage of self- or caregiver-supported study drug administration among all study treatment visits at home [Time Frame: Up to 3.5 years]

Cycle baseline by cycle (for EQ-5D-5L) [Time Frame: Up to 3.5 years]

Prevalence of NAbs against rHuPH20 over time [Time Frame: Up to 3.5 years]

Number of caregivers who administered the injection to the participant at home over time by cycle [Time Frame: Up to 3.5 years]

Number of training visits needed for the participant or caregiver to be competent to start administering efgartigimod PH20 SC [Time Frame: Up to 3.5 years]

Prevalence of neutralizing antibodies (NAbs) against efgartigimod over time [Time Frame: Up to 3.5 years]

Percentage change of anti-acetylcholine receptor antibodies (AChR-Ab) from baseline [Time Frame: Up to 3.5 years]

Prevalence of ADAs to rHuPH20 over time [Time Frame: Up to 3.5 years]

Prevalence of anti-drug antibodies (ADAs) to efgartigimod over time [Time Frame: Up to 3.5 years]

Incidence of ADAs to rHuPH20 over time [Time Frame: Up to 3.5 years]

Incidence of anti-drug antibodies (ADAs) to efgartigimod over time [Time Frame: Up to 3.5 years]

Percentage of caregivers who administered the injection to the participant at home over time by cycle [Time Frame: Up to 3.5 years]

Cycle baseline over time by cycle in AChR-Ab seropositive participants (for acetylcholine receptor binding autoantibodies (AChR-Ab)) [Time Frame: Up to 3.5 years]

Incidence of neutralizing antibodies (NAbs) against efgartigimod over time [Time Frame: Up to 3.5 years]

Number of self- or caregiver-supported study drug administration among all study treatment visits at home [Time Frame: Up to 3.5 years]

Cycle baseline over time by cycle (for total immunoglobulin G (IgG) [Time Frame: Up to 3.5 years]

Efgartigimod serum concentrations [Time Frame: Up to 3.5 years]

Percentage change in levels of total immunoglobulin G (IgG) from baseline [Time Frame: Up to 3.5 years]

Secondary ID(s)

ARGX-113-2002

Source(s) of Monetary Support

Please refer to primary and secondary sponsors