Trial Outcomes & Findings for Evaluating the Long-Term Safety and Tolerability of Efgartigimod PH20 SC Administered Subcutaneously in Patients With Generalized Myasthenia Gravis (NCT NCT04818671)

Last Updated: 2026-01-22

Results Overview

Adverse events, Serious Adverse event and Adverse events of special interest. Adverse events in the 'Infections and infestations' SOC were defined as AESIs because efgartigimod causes a transient reduction in total IgG levels.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

184 participants

Primary outcome timeframe

Up to 3.5 years

Results posted on

2026-01-22

Participant Flow

This study was conducted at 47 sites that enrolled participants in 12 countries. A total of 184 participants rolled over from ARGX-113-2001 and ARGX-113-1705, of whom 180 participants were exposed to efgartigimod PH20 SC treatment.

All participants were adults with gMG who participated in ARGX-113-2001 or ARGX-113-1705. No randomization or blinding was performed because this was an open-label study.

Participant milestones

Participant milestones
Measure	Efgartigimod PH20 SC Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Overall Study STARTED	180
Overall Study COMPLETED	138
Overall Study NOT COMPLETED	42

Reasons for withdrawal

Reasons for withdrawal
Measure	Efgartigimod PH20 SC Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Overall Study Withdrawal by Subject	16
Overall Study Adverse Event	5
Overall Study Lack of Efficacy	5
Overall Study Death	4
Overall Study Physician Decision	4
Overall Study Requires Prohibited Medication	4
Overall Study Lost to Follow-up	2
Overall Study Approved Drug Available for Indication	1
Overall Study Sponsor Request	1

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Efgartigimod PH20 SC n=180 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Age, Categorical <=18 years	0 Participants n=270 Participants
Age, Categorical Between 18 and 65 years	139 Participants n=270 Participants
Age, Categorical >=65 years	41 Participants n=270 Participants
Age, Continuous	50.8 years STANDARD_DEVIATION 15.50 • n=270 Participants
Sex: Female, Male Female	119 Participants n=270 Participants
Sex: Female, Male Male	61 Participants n=270 Participants
Race/Ethnicity, Customized Asian	16 Participants n=270 Participants
Race/Ethnicity, Customized Black or African American	2 Participants n=270 Participants
Race/Ethnicity, Customized White	161 Participants n=270 Participants
Race/Ethnicity, Customized Multiple	1 Participants n=270 Participants
Race/Ethnicity, Customized Hispanic or Latino	8 Participants n=270 Participants
Race/Ethnicity, Customized Not Hispanic or Latino	172 Participants n=270 Participants

PRIMARY outcome

Timeframe: Up to 3.5 years

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=180 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Number of AEs, SAEs and AESIs Number of AEs	3325 events
Number of AEs, SAEs and AESIs Number of SAEs	107 events
Number of AEs, SAEs and AESIs Number of AESIs	420 events

SECONDARY outcome

Timeframe: Up to week 4 of the first cycle

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. Only participants with an assessment at baseline and the respective weeks of first cycle are reported in each row.

The Myasthenia Gravis Activities of Daily Living (MG-ADL) is an 8-item patient-reported scale that assesses MG symptoms and their effects on daily activities. It evaluates a participant's capacity to perform different activities in their daily life. The total score ranges from 0 to 24 with higher scores indicating more impairment.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=180 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
MG-ADL Total Score Changes From Baseline Cycle 1, Week 1	-2.2 score on a scale Standard Error 0.20
MG-ADL Total Score Changes From Baseline Cycle 1, Week 2	-3.4 score on a scale Standard Error 0.21
MG-ADL Total Score Changes From Baseline Cycle 1, Week 3	-3.9 score on a scale Standard Error 0.22
MG-ADL Total Score Changes From Baseline Cycle 1, Week 4	-4.0 score on a scale Standard Error 0.23

SECONDARY outcome

Timeframe: Up to week 4 of the first cycle

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. Only participants with an assessment at baseline and week 4 of the first cycle are reported.

IgG: immunoglobulin G

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=164 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Percent Change in Total IgG Levels From Baseline	-62.6 Percent change Standard Error 0.93

SECONDARY outcome

Timeframe: Up to week 4 of the first cycle

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. Only participants with an assessment at baseline and week 4 of the first cycle are reported.

AchR-Ab: anti-acetylcholine receptor antibodies.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=124 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Percent Change in AChR-Ab From Baseline in AChR-Ab Seropositive Participants	-57.6 Percent change Standard Error 2.29

SECONDARY outcome

Timeframe: Up to week 4 of the first cycle

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. Only participants with an assessment at baseline and week 4 of the first cycle are reported.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=141 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Efgartigimod Serum Concentrations	21693 ng/mL Standard Deviation 8242

SECONDARY outcome

Timeframe: Up to 3.5 years

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. The number analyzed is the total number of ADA evaluable participants.

ADA: Anti-drug antibodies.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=178 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Incidence of ADAs Against Efgartigimod Over Time	35 Participants

SECONDARY outcome

Timeframe: Up to 3.5 years

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. The number analyzed is the total number of NAb-evaluable participants.

NAbs: neutralizing antibodies

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=178 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Incidence of NAbs Against Efgartigimod Over Time	11 Participants

SECONDARY outcome

Timeframe: Up to 3.5 years

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. The number analyzed is the total number of rHuPH20 Ab evaluable participants.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=170 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Incidence of Antibodies Against rHuPH20 Over Time	49 Participants

SECONDARY outcome

Timeframe: Up to 3.5 years

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. The number analyzed is the total number of rHuPH20 NAb-evaluable participants.

NAbs: neutralizing antibodies

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=167 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Incidence of NAbs Against rHuPH20 Over Time	1 Participants

SECONDARY outcome

Timeframe: Up to week 4 of the first cycle

Myasthenia Gravis Quality of Life 15 item scale revised (MG-QoL 15r) scores range from 0 to 30 with a higher score representing more severe symptoms.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=180 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Changes in Total MG-QoL15r From Baseline Cycle 1, Week 1	-2.5 score on a scale Standard Error 0.29
Changes in Total MG-QoL15r From Baseline Cycle 1, Week 2	-3.7 score on a scale Standard Error 0.34
Changes in Total MG-QoL15r From Baseline Cycle 1, Week 3	-4.5 score on a scale Standard Error 0.38
Changes in Total MG-QoL15r From Baseline Cycle 1, Week 4	-4.7 score on a scale Standard Error 0.39

SECONDARY outcome

Timeframe: Up to week 4 of the first cycle

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. Only participants with an assessment at baseline and week 4 of the first cycle are reported.

EuroQoL 5 Dimensions 5-Level (EQ-5D-5L) visual analog scale (VAS) scores range from 0 to 100 with a higher score representing better health.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=169 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Changes in EQ-5D-5L VAS Score From Baseline	13.9 score on a scale Standard Error 1.32

SECONDARY outcome

Timeframe: Up to 3.5 years

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study. The number analyzed is the total number of participants adequately trained and capable of doing self- or caregiver-supported administrations.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=166 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 22 visits	0.6 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 37 visits	0.6 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 42 visits	0.6 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 5 visits	1.8 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 6 visits	5.4 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 9 visits	1.2 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 11 visits	0.6 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 12 visits	0.6 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 0 visits	4.8 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 1 visit	45.8 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 2 visits	13.9 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 3 visits	11.4 Percent of participants
Percent of Participants or Caregivers by Number of Training Visits Needed to be Competent to Start Self- or Caregiver-Supported Administration 4 visits	12.7 Percent of participants

SECONDARY outcome

Timeframe: Up to 3.5 years

Population: Safety analysis set: all participants who were exposed to efgartigimod PH20 SC in this study.

Outcome measures

Outcome measures
Measure	Efgartigimod PH20 SC n=180 Participants Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Percent of Self- or Caregiver-supported Study Drug Administration Among All Study Treatment Visits at Home	49.2 Percent

Adverse Events

Efgartigimod PH20 SC

Serious events: 55 serious events

Other events: 167 other events

Deaths: 5 deaths

Serious adverse events

Serious adverse events
Measure	Efgartigimod PH20 SC n=180 participants at risk Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Blood and lymphatic system disorders Anaemia	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Cardiac disorders Acute myocardial infarction	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Cardiac disorders Angina unstable	1.1% 2/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Cardiac disorders Cardiac arrest	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Cardiac disorders Cardiac failure congestive	1.1% 2/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Eye disorders Diplopia	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Eye disorders Retinal detachment	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Eye disorders Vitreous haemorrhage	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Gastric ulcer haemorrhage	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Gastrointestinal haemorrhage	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Inguinal hernia	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Intestinal perforation	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Terminal ileitis	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Anal abscess	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Bacteraemia	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Cellulitis	1.1% 2/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Cellulitis gangrenous	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations COVID-19	2.2% 4/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations COVID-19 pneumonia	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Diarrhoea infectious	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Diverticulitis	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Herpes zoster	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Orchitis	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Pneumonia	3.9% 7/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Rotavirus infection	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Sepsis	1.1% 2/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Urinary tract infection	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Viral infection	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Fall	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Post procedural complication	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Rib fracture	1.1% 2/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Shunt occlusion	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Shunt stenosis	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Spinal fracture	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Tendon injury	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Back pain	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Enthesopathy	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Muscular weakness	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Osteoarthritis	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Spinal osteoarthritis	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Spondyloarthropathy	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Bladder transitional cell carcinoma	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Metastases to liver	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Ovarian adenoma	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Rectal cancer stage IV	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Renal cancer metastatic	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Renal cell carcinoma	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Thymoma	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Uterine leiomyoma	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Nervous system disorders Coma	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Nervous system disorders Myasthenia gravis	6.1% 11/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Nervous system disorders Myasthenia gravis crisis	2.2% 4/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Nervous system disorders Syncope	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Renal and urinary disorders Renal failure	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Acute respiratory failure	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Chronic obstructive pulmonary disease	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Chronic respiratory failure	1.1% 2/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Hydrothorax	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Interstitial lung disease	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Pulmonary mass	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Respiratory failure	2.2% 4/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Surgical and medical procedures Umbilical hernia repair	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Surgical and medical procedures Uterine polypectomy	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Vascular disorders Brachiocephalic vein stenosis	0.56% 1/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Vascular disorders Hypertension	1.1% 2/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.

Other adverse events

Other adverse events
Measure	Efgartigimod PH20 SC n=180 participants at risk Patients receiving efgartigimod PH20 subcutaneous (SC) treatment; efgartigimod PH20 SC: efgartigimod for SC administration coformulated with recombinant human hyaluronidase PH20
Infections and infestations Upper respiratory tract infection	17.8% 32/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Urinary tract infection	8.9% 16/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Blood and lymphatic system disorders Anaemia	10.0% 18/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Blood and lymphatic system disorders Iron deficiency anaemia	7.2% 13/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Eye disorders Cataract	5.0% 9/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Abdominal pain upper	6.1% 11/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Diarrhoea	17.8% 32/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Gastrointestinal disorders Nausea	8.9% 16/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Fatigue	5.6% 10/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Influenza like illness	7.8% 14/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site bruising	13.3% 24/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site erythema	30.6% 55/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site haematoma	5.6% 10/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site pain	12.2% 22/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site pruritus	11.7% 21/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site rash	8.3% 15/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site reaction	5.6% 10/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Injection site swelling	6.1% 11/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
General disorders Pyrexia	5.0% 9/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Bronchitis	5.0% 9/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations COVID-19	28.9% 52/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Influenza	5.0% 9/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Infections and infestations Nasopharyngitis	20.0% 36/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Injury, poisoning and procedural complications Contusion	5.0% 9/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Investigations Activated partial thromboplastin time prolonged	6.7% 12/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Arthralgia	9.4% 17/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Back pain	12.2% 22/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Muscle spasms	6.1% 11/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Musculoskeletal and connective tissue disorders Pain in extremity	6.1% 11/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Nervous system disorders Dizziness	7.2% 13/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Nervous system disorders Headache	26.7% 48/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Nervous system disorders Myasthenia gravis	10.0% 18/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Respiratory, thoracic and mediastinal disorders Cough	6.7% 12/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.
Vascular disorders Hypertension	7.8% 14/180 • 3.5 years Any clinically significant changes occurring during the study were reported as adverse events.

Additional Information

Regulatory Manager

argenx BV

Phone: +32 93103400

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place