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CompletedNCT05225675ARDAUpdated May 8, 2026Results posted

A Clinical Trial to Investigate the Safety and Tolerability, Efficacy, Pharmacokinetics, Pharmacodynamics and Immunogenicity of 2 Dose Regimens of ARGX-117 in Adults With Multifocal Motor Neuropathy

A Phase 2 interventional study of ARGX-117 and Placebo in Multifocal Motor Neuropathy, sponsored by argenx. Completed at 40 sites in 11 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-08.

Sponsored by argenx · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
54
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

This is a phase 2, randomized, double-blinded, placebo-controlled, parallel-group, multicenter trial to evaluate the safety and efficacy of 2 dose regimens of ARGX-117 versus placebo, in participants with MMN previously stabilized with IVIg (intravenous immunoglobulin).

02

Conditions studied

  • Multifocal Motor Neuropathy
03

In context

Lead sponsor

argenx is the lead sponsor of 87 studies on the registry; 33 are open to participants now.

Of its 22 completed or terminated interventional studies of FDA-regulated products, 16 (73%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  1. Capable of giving signed informed consent form (ICF)
  2. Male/female at least 18 years of age at the time the informed consent form (ICF) is signed
  3. Probable or definite MMN according to the European Federation of Neurological Societies (EFNS)/Peripheral Nerve Society (PNS) (EFNS/PNS) 2010 guidelines at screening confirmed by the MMN Confirmation Committee (MCC)
  4. Receiving a stable IVIg regimen for at least 3 months before screening or recently initiated IVIg treatment
  5. IVIg treatment dependency confirmation by the MMN Confirmation Committee (MCC)
  6. Immunization with the first meningococcal vaccine and pneumococcal vaccine, and the single Haemophilus influenza type B vaccine must be performed at least 14 days before IMP administration at V1 according to local country-specific immunization schedules. A documented history of vaccination against Neisseria meningitides, Haemophilus influenza type B, and streptococcus pneumonia will be permitted
  7. Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies

Exclusion criteria

Exclusion Criteria:

  1. Any coexisting condition which may interfere with the outcome assessments
  2. Clinical signs or symptoms suggestive for neuropathies other than MMN such as motor neuron disease or other inflammatory neuropathies
  3. Severe psychiatric disorder, history of suicide attempt, or current suicidal ideation that in the opinion of the investigator could create undue risk to the participant or could affect adherence with the trial protocol.
  4. Clinically significant uncontrolled active or chronic bacterial, viral, or fungal infection during the screening and/or IVIg monitoring period (IVMP).
  5. Any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of clinical symptoms of MMN or put the participant at undue risk (eg, SLE).

  6. History of malignancy unless resolved by adequate treatment with no evidence of recurrence for ≥3 years before the first administration of the IMP. Participants with the following carcinomas will be eligible:

    1. Adequately treated basal cell or squamous cell skin cancer
    2. Carcinoma in situ of the cervix
    3. Carcinoma in situ of the breast
    4. Incidental histological finding of prostate cancer
  7. Clinical evidence of other significant serious diseases, have had a recent major surgery (including a splenectomy at any time), or who have any other condition in the opinion of the investigator, that could confound the results of the trial or put the participant at undue risk

  8. Prior/concomitant therapy

    1. Cyclophosphamide and/or rituximab and/or eculizumab and/or mycophenolate mofetil within 3 months prior to screening
    2. Use of an investigational product within 3 months or 5 half-lives (whichever is longer) before the first dose of the IMP.

  9. Positive serum test at screening for an active viral infection with any of the following conditions:

    1. Hepatitis B virus (HBV) that is indicative of an acute or chronic infection
    2. Hepatitis C virus (HCV) based on HCV antibody assay
    3. HIV based on test results that are associated with an AIDS-defining condition
  10. Current or history of (ie, within 12 months of screening) alcohol, drug, or medication abuse
  11. Known hypersensitivity reaction to 1 of the components of the IMP or any of its excipients
  12. Female participants with a positive serum or urine pregnancy test, lactating females, and those who intend to become pregnant during the trial or within 15 months after last dose of the IMP
  13. ALT or AST ≥2 × upper limit of normal and total bilirubin ≥1.5 × upper limit of normal of the central laboratory reference range
  14. An estimated glomerular filtration rate of ≤60 mL/min/1.73m2
05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
54 participants (actual)

Study arms

  • Experimental
    ARGX-117

    Intravenous administration of ARGX-117

    Biological: ARGX-117

  • Placebo comparator
    Placebo

    Intravenous administration of placebo

    Other: Placebo

Interventions

  • BiologicalARGX-117

    Intravenous administration of ARGX-117

  • OtherPlacebo

    Intravenous administration of placebo

06

What researchers measure

Primary outcomes

  1. Number of Participants With AEs and SAEs

    AE : Adverse Events, SAE: Serious Adverse Events

    Time frame: Up to 80 weeks

Secondary outcomes

  1. Time to the First Retreatment With IVIg

    The time to first retreatment with intravenous immunoglobulin (IVIg) is defined as the time from the last IVIg administration before randomization until the first IVIg retreatment during the 16-week treatment period

    Time frame: Up to 16 weeks

  2. Time-to-relapse

    Time-to-relapse is defined as the time from randomization until a participant met the threshold for clinically meaningful deterioration

    Time frame: Up to 16 weeks

  3. iAUC of the Change From Baseline in mMRC-10 Sum Score

    The Modified Medical Research Council (mMRC)-10 sum score assesses muscle strength of 10 muscles groups, both sides (left and right). A score between 0 (paralysis) and 5 (normal strength) is assigned for each muscle group. A higher value indicates better muscle strength. The total score, ranging from 0 to 100, is based on the sum of both the left and right side of the body. The Incremental Area Under Curve (iAUC) is the area under the curve of the change from baseline in the Modified Medical Research Council (mMRC)-10 score. A positive AUC indicates a favorable outcome while a negative AUC indicates an unfavorable outcome.

    Time frame: Up to 16 weeks

  4. Change From Baseline in the Average Score of the 2 Most Important Muscle Groups as Assessed by the mMRC-14 Sum Score

    The Modified Medical Research Council (mMRC)-14 assesses muscle strength of 14 muscles groups, both sides (left and right). A score between 0 and 5 (normal strength) is assigned. This endpoint is the change from baseline in the average score of the 2 most important muscle groups affected by the disease. It ranges between 0 and 5. A change of more than 0 represents an improvement in strength, and a change less than 0 represents worsening.

    Time frame: At week 16

  5. Change From Baseline in the mMRC-14 Sum Score

    The Modified Medical Research Council (mMRC)-14 scores range from 0 to 140 with a higher score representing better muscle strength. A change of more than 0 represents an improvement in strength, and a change less than 0 represents worsening.

    Time frame: At week 16

  6. Proportion of Participants Showing a Deterioration of at Least 2 Points as Assessed by the mMRC-10 Sum Score

    The Modified Medical Research Council (mMRC)-10 scores evaluates motor strength/weakness from 10 predetermined muscle groups. A higher proportion of participants showing a deterioration represents a worsening of the outcome.

    Time frame: Up to 16 weeks

  7. iAUC of the Change From Baseline in GS Daily Average

    Measurement of grip strength (GS) has been done using the Martin vigorimeter in kPa. The incremental Area Under Curve (iAUC) is the area under the curve of the change from baseline of GS daily average. The 3 daily measurements of GS from the left hand and the 3 daily measurements of GS from the right hand have been recorded and the daily average for the left hand and right hand has been calculated, respectively.

    Time frame: Up to 16 weeks

  8. Percent Change From Baseline in GS 3-day Moving Average

    Measurement of grip strength (GS) has been done using the Martin vigorimeter in kPa. The 3 daily measurements of GS from the left hand and the 3 daily measurements of GS from the right hand have been recorded and the daily average for the left hand and right hand has been calculated, respectively. A 3-day moving average has been generated based on the average over the last 3 days of the obtained daily averages for each hand.

    Time frame: At week 16

  9. Change From Baseline in the MMN-RODS Centile Score

    The Rasch-built Overall Disability Scale for MMN (MMN-RODS) is a disease-specific PRO instrument constructed to capture activity limitations in patients with MMN. Raw sum scores of the 25-item MMN-RODS (range, 0-50) were converted to a centile metric score ranging from 0 to 100. Lower scores indicated a greater degree of disability.

    Time frame: At week 16

  10. Percent Change From Baseline in the Average Time for Upper Extremity (Arm and Hand) Function

    The 9-Hole Peg Test (9-HPT) results are based on the time to complete the assessment with a shorter time representing better muscle strength. A change of less than 0 represents an improvement in strength, and a change more than 0 represents worsening.

    Time frame: At week 16

  11. Proportion of Participants by Level of Severity on Each Dimension of the EQ-5D-5L Scale

    The EuroQol 5-Dimension 5-Level (EQ-5D-5L) scale includes five dimensions: mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. Each dimension is ranked with a level 1-5 with level 1 being no problems and level 5 representing extreme problems.

    Time frame: At week 16

  12. Change From Baseline in Quality of Life Using EQ-5D-5L Visual Analog Scale

    The EQ-5D-5L visual analog scale is from 0-100 with 0 representing the worst health. A change of more than 0 represents an improvement in health, and a change of less than 0 represents worsening.

    Time frame: At week 16

  13. Change From Baseline in the CAP-PRI

    The Chronic Acquired Polyneuropathy Patient-reported Index (CAP-PRI) assesses disease-specific quality of life. This instrument includes the assessment of 15 items yielding a total score ranging from 0 to 30. A change of less than 0 represents an improvement in health, and a change more than 0 represents worsening.

    Time frame: At week 16

  14. Proportion of Participants by Level of Improvement Using the PGI-C Scale

    Patient Global Impression of Change (PGI-C) scale ranks a patients condition from 1-7 with 1 representing the most improvement and 7 representing the most decline in their condition.

    Time frame: Up to 16 weeks

  15. Change From Baseline in the 9-item FSS Average Total Score

    9-item Fatigue Severity Scale (FSS) average score is the sum of the 9 items divided by the number of items. It ranges from 0 to 7 a higher score representing more severe fatigue. A change of less than 0 indicates an improvement.

    Time frame: Up to 16 weeks

  16. Percent of Total Hours for Work-related and Household Chore Activities Lost, as Part of the HRPQ

    The Health-Related Productivity Questionnaire (HRPQ) provides data related to missed hours at work or educational activities and reduced effectiveness during any attempted work.

    Time frame: Up to 16 weeks

  17. Change From Baseline in Effectiveness, Side Effects, Convenience, and Overall Satisfaction Scores as Assessed by the TSQM-14

    Each Treatment Satisfaction Questionnaire for Medication-14 items (TSQM-14) domain score ranges from 0-100 with higher scores representing greater satisfaction with the treatment. A change greater than 0 indicates an improvement in satisfaction.

    Time frame: Up to 16 weeks

  18. Maximum Empasiprubart Serum Concentrations (Cmax)

    Time frame: Up to 16 weeks

  19. Percent Change From Baseline in Free C2, Total C2, and Functional Complement Activity (CH50)

    Time frame: At week 16

  20. Incidence of Antidrug Antibodies (ADA) Against Empasiprubart

    Time frame: Up to 16 weeks

07

Results

Posted May 8, 2026

Participant flow

Participant flow — Overall Study
MilestoneARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Started189189
Completed178189
Not completed1100
Withdrew: Adverse event1000
Withdrew: Withdrawal by subject0100

Outcome measures

PrimaryNumber of Participants With AEs and SAEs

AE : Adverse Events, SAE: Serious Adverse Events

Time frame:
Up to 80 weeks
Reported as:
Count of participants · Participants
Number of Participants With AEs and SAEs
ParticipantsARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Number of Participants with a AE145146
Number of Participants with a Treatment-related AE7022
Number of Participants with a SAE2000
Number of Participants with a Treatment-related SAE1000
SecondaryTime to the First Retreatment With IVIg

The time to first retreatment with intravenous immunoglobulin (IVIg) is defined as the time from the last IVIg administration before randomization until the first IVIg retreatment during the 16-week treatment period

Time frame:
Up to 16 weeks
Reported as:
Median · days
Time to the First Retreatment With IVIg
daysARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Time to the First Retreatment With IVIgNA37 (16.0 to —)NANA
Statistical analysis
  • ARGX-117 Cohort 1 vs Placebo Cohort 1 · Regression, Cox · Hazard ratio (hr): 0.09 · 95% CI 0.02 to 0.44
  • ARGX-117 Cohort 2 vs Placebo Cohort 2 · Regression, Cox · Hazard ratio (hr): 0.17 · 95% CI 0.02 to 1.60
SecondaryTime-to-relapse

Time-to-relapse is defined as the time from randomization until a participant met the threshold for clinically meaningful deterioration

Time frame:
Up to 16 weeks
Reported as:
Median · days
Time-to-relapse
daysARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Time-to-relapseNA (17.0 to —)26 (7.0 to —)NA (70.0 to —)28.0 (7.0 to 99.0)
SecondaryiAUC of the Change From Baseline in mMRC-10 Sum Score

The Modified Medical Research Council (mMRC)-10 sum score assesses muscle strength of 10 muscles groups, both sides (left and right). A score between 0 (paralysis) and 5 (normal strength) is assigned for each muscle group. A higher value indicates better muscle strength. The total score, ranging from 0 to 100, is based on the sum of both the left and right side of the body. The Incremental Area Under Curve (iAUC) is the area under the curve of the change from baseline in the Modified Medical Research Council (mMRC)-10 score. A positive AUC indicates a favorable outcome while a negative AUC indicates an unfavorable outcome.

Time frame:
Up to 16 weeks
Reported as:
Median · mMRC score*weeks
iAUC of the Change From Baseline in mMRC-10 Sum Score
mMRC score*weeksARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
iAUC of the Change From Baseline in mMRC-10 Sum Score110.25 (-32.25 to 228.75)-182.50 (-362.50 to 130.50)283.75 (-17.50 to 432.00)-93.50 (-158.50 to -13.00)
SecondaryChange From Baseline in the Average Score of the 2 Most Important Muscle Groups as Assessed by the mMRC-14 Sum Score

The Modified Medical Research Council (mMRC)-14 assesses muscle strength of 14 muscles groups, both sides (left and right). A score between 0 and 5 (normal strength) is assigned. This endpoint is the change from baseline in the average score of the 2 most important muscle groups affected by the disease. It ranges between 0 and 5. A change of more than 0 represents an improvement in strength, and a change less than 0 represents worsening.

Time frame:
At week 16
Reported as:
Median · score on a scale
Change From Baseline in the Average Score of the 2 Most Important Muscle Groups as Assessed by the mMRC-14 Sum Score
score on a scaleARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Change From Baseline in the Average Score of the 2 Most Important Muscle Groups as Assessed by the mMRC-14 Sum Score0.50 (0.50 to 0.50)0.00 (0.00 to 0.50)0.50 (0.00 to 1.00)0.00 (0.00 to 0.50)
SecondaryChange From Baseline in the mMRC-14 Sum Score

The Modified Medical Research Council (mMRC)-14 scores range from 0 to 140 with a higher score representing better muscle strength. A change of more than 0 represents an improvement in strength, and a change less than 0 represents worsening.

Time frame:
At week 16
Reported as:
Median · score on a scale
Change From Baseline in the mMRC-14 Sum Score
score on a scaleARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Change From Baseline in the mMRC-14 Sum Score4.0 (2.0 to 8.0)0.0 (-8.0 to 0.0)7.0 (1.0 to 11.0)1.0 (-2.0 to 8.0)
SecondaryProportion of Participants Showing a Deterioration of at Least 2 Points as Assessed by the mMRC-10 Sum Score

The Modified Medical Research Council (mMRC)-10 scores evaluates motor strength/weakness from 10 predetermined muscle groups. A higher proportion of participants showing a deterioration represents a worsening of the outcome.

Time frame:
Up to 16 weeks
Reported as:
Count of participants · Participants
Proportion of Participants Showing a Deterioration of at Least 2 Points as Assessed by the mMRC-10 Sum Score
ParticipantsARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Proportion of Participants Showing a Deterioration of at Least 2 Points as Assessed by the mMRC-10 Sum Score1422
SecondaryiAUC of the Change From Baseline in GS Daily Average

Measurement of grip strength (GS) has been done using the Martin vigorimeter in kPa. The incremental Area Under Curve (iAUC) is the area under the curve of the change from baseline of GS daily average. The 3 daily measurements of GS from the left hand and the 3 daily measurements of GS from the right hand have been recorded and the daily average for the left hand and right hand has been calculated, respectively.

Time frame:
Up to 16 weeks
Reported as:
Median · kPa*weeks
iAUC of the Change From Baseline in GS Daily Average
kPa*weeksARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Most Affected Hand508.25 (237.17 to 1788.08)-63.75 (-591.42 to 671.08)1269.67 (289.00 to 3139.17)1.67 (-267.67 to 124.00)
Least Affected Hand356.08 (-57.17 to 1372.42)-363.17 (-975.67 to 655.50)554.00 (111.00 to 2847.00)-100.33 (-291.00 to 478.50)
SecondaryPercent Change From Baseline in GS 3-day Moving Average

Measurement of grip strength (GS) has been done using the Martin vigorimeter in kPa. The 3 daily measurements of GS from the left hand and the 3 daily measurements of GS from the right hand have been recorded and the daily average for the left hand and right hand has been calculated, respectively. A 3-day moving average has been generated based on the average over the last 3 days of the obtained daily averages for each hand.

Time frame:
At week 16
Reported as:
Median · Percent change
Percent Change From Baseline in GS 3-day Moving Average
Percent changeARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Most Affected Hand31.88 (0.00 to 53.91)1.63 (-1.96 to 10.42)61.48 (8.12 to 101.10)3.68 (-3.64 to 16.67)
Least Affected Hand13.13 (0.25 to 37.68)5.69 (-0.52 to 7.07)17.97 (6.43 to 69.38)4.90 (1.61 to 7.69)
SecondaryChange From Baseline in the MMN-RODS Centile Score

The Rasch-built Overall Disability Scale for MMN (MMN-RODS) is a disease-specific PRO instrument constructed to capture activity limitations in patients with MMN. Raw sum scores of the 25-item MMN-RODS (range, 0-50) were converted to a centile metric score ranging from 0 to 100. Lower scores indicated a greater degree of disability.

Time frame:
At week 16
Reported as:
Median · score on a scale
Change From Baseline in the MMN-RODS Centile Score
score on a scaleARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Change From Baseline in the MMN-RODS Centile Score6.0 (0.0 to 14.0)0.0 (-2.0 to 0.0)7.5 (0.0 to 17.0)0.0 (-5.0 to 1.0)
SecondaryPercent Change From Baseline in the Average Time for Upper Extremity (Arm and Hand) Function

The 9-Hole Peg Test (9-HPT) results are based on the time to complete the assessment with a shorter time representing better muscle strength. A change of less than 0 represents an improvement in strength, and a change more than 0 represents worsening.

Time frame:
At week 16
Reported as:
Median · Percent change
Percent Change From Baseline in the Average Time for Upper Extremity (Arm and Hand) Function
Percent changeARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Dominant Hand-10.760 (-41.463 to -1.250)-5.691 (-16.049 to 9.254)-8.571 (-20.907 to 0.000)-12.150 (-16.212 to 2.500)
Non-Dominant Hand-5.236 (-23.529 to 6.343)-3.394 (-20.690 to 5.000)-14.286 (-25.714 to -8.725)-1.402 (-7.368 to 4.762)
SecondaryProportion of Participants by Level of Severity on Each Dimension of the EQ-5D-5L Scale

The EuroQol 5-Dimension 5-Level (EQ-5D-5L) scale includes five dimensions: mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. Each dimension is ranked with a level 1-5 with level 1 being no problems and level 5 representing extreme problems.

Time frame:
At week 16
Reported as:
Count of participants · Participants
Proportion of Participants by Level of Severity on Each Dimension of the EQ-5D-5L Scale
ParticipantsARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Mobility — 1 - No Problem93112
Mobility — 2 - Slight Problem2326
Mobility — 3 - Moderate Problem6231
Mobility — 4 - Severe Problem1110
Mobility — 5 - Unable to0010
Self-Care — 1 - No Problem5383
Self-Care — 2 - Slight Problem8485
Self-Care — 3 - Moderate Problem4211
Self-Care — 4 - Severe Problem1000
Self-Care — 5 - Unable to0010
Usual Activities — 1 - No Problem5282
Usual Activities — 2 - Slight Problem6454
Usual Activities — 3 - Moderate Problem6243
Usual Activities — 4 - Severe Problem1100
Usual Activities — 5 - Unable to0010
Pain/Discomfort — 1 - No Problem96102
Pain/Discomfort — 2 - Slight Problem5155
Pain/Discomfort — 3 - Moderate Problem3222
Pain/Discomfort — 4 - Severe Problem1010
Pain/Discomfort — 5 - Unable to0000
Anxiety/Depression — 1 - No Problem132155
Anxiety/Depression — 2 - Slight Problem4612
Anxiety/Depression — 3 - Moderate Problem1122
Anxiety/Depression — 4 - Severe Problem0000
Anxiety/Depression — 5 - Unable to0000
SecondaryChange From Baseline in Quality of Life Using EQ-5D-5L Visual Analog Scale

The EQ-5D-5L visual analog scale is from 0-100 with 0 representing the worst health. A change of more than 0 represents an improvement in health, and a change of less than 0 represents worsening.

Time frame:
At week 16
Reported as:
Median · score on a scale
Change From Baseline in Quality of Life Using EQ-5D-5L Visual Analog Scale
score on a scaleARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Change From Baseline in Quality of Life Using EQ-5D-5L Visual Analog Scale5.0 (0.0 to 13.0)7.0 (-8.0 to 10.0)6.0 (2.0 to 8.0)-6.0 (-10.0 to 9.0)
SecondaryChange From Baseline in the CAP-PRI

The Chronic Acquired Polyneuropathy Patient-reported Index (CAP-PRI) assesses disease-specific quality of life. This instrument includes the assessment of 15 items yielding a total score ranging from 0 to 30. A change of less than 0 represents an improvement in health, and a change more than 0 represents worsening.

Time frame:
At week 16
Reported as:
Median · score on a scale
Change From Baseline in the CAP-PRI
score on a scaleARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Change From Baseline in the CAP-PRI-2.5 (-6.0 to -1.0)0.0 (-1.0 to 2.0)-2.0 (-5.0 to -1.0)1.0 (-1.0 to 2.0)
SecondaryProportion of Participants by Level of Improvement Using the PGI-C Scale

Patient Global Impression of Change (PGI-C) scale ranks a patients condition from 1-7 with 1 representing the most improvement and 7 representing the most decline in their condition.

Time frame:
Up to 16 weeks
Reported as:
Count of participants · Participants
Proportion of Participants by Level of Improvement Using the PGI-C Scale
ParticipantsARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
1 - Very much improved7040
2 - Much improved3182
3 - Minimally improved7032
4 - No change0322
5 - Minimally worse1202
6 - Much worse0111
7 - Very much worse0200
SecondaryChange From Baseline in the 9-item FSS Average Total Score

9-item Fatigue Severity Scale (FSS) average score is the sum of the 9 items divided by the number of items. It ranges from 0 to 7 a higher score representing more severe fatigue. A change of less than 0 indicates an improvement.

Time frame:
Up to 16 weeks
Reported as:
Median · score on a scale
Change From Baseline in the 9-item FSS Average Total Score
score on a scaleARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Change From Baseline in the 9-item FSS Average Total Score-0.444 (-1.556 to 0.000)0.222 (0.111 to 1.222)-0.111 (-0.556 to 0.111)0.222 (-0.222 to 1.000)
SecondaryPercent of Total Hours for Work-related and Household Chore Activities Lost, as Part of the HRPQ

The Health-Related Productivity Questionnaire (HRPQ) provides data related to missed hours at work or educational activities and reduced effectiveness during any attempted work.

Time frame:
Up to 16 weeks
Reported as:
Median · Percent
Percent of Total Hours for Work-related and Household Chore Activities Lost, as Part of the HRPQ
PercentARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Work Activities lost10.00 (0.00 to 15.00)36.00 (0.00 to 46.00)0.00 (0.00 to 12.13)24.17 (17.50 to 37.78)
Household Chore Activities lost33.33 (10.00 to 60.00)20.00 (12.50 to 64.50)15.00 (0.00 to 35.00)43.75 (27.62 to 60.00)
SecondaryChange From Baseline in Effectiveness, Side Effects, Convenience, and Overall Satisfaction Scores as Assessed by the TSQM-14

Each Treatment Satisfaction Questionnaire for Medication-14 items (TSQM-14) domain score ranges from 0-100 with higher scores representing greater satisfaction with the treatment. A change greater than 0 indicates an improvement in satisfaction.

Time frame:
Up to 16 weeks
Reported as:
Median · score on a scale
Change From Baseline in Effectiveness, Side Effects, Convenience, and Overall Satisfaction Scores as Assessed by the TSQM-14
score on a scaleARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Effectiveness0.000 (-16.667 to 27.778)-22.222 (-33.333 to -16.667)25.000 (0.000 to 38.889)-11.111 (-16.667 to 5.556)
Side effects0.000 (0.000 to 18.750)0.000 (0.000 to 18.750)0.000 (0.000 to 0.000)0.000 (0.000 to 12.500)
Convenience5.556 (0.000 to 22.222)5.556 (0.000 to 5.556)5.556 (0.000 to 11.111)-5.556 (-11.111 to 5.556)
Overall Satisfaction3.6 (-7.1 to 28.6)-14.3 (-28.6 to -14.3)3.6 (0.0 to 28.6)-14.3 (-21.4 to -7.1)
SecondaryMaximum Empasiprubart Serum Concentrations (Cmax)
Time frame:
Up to 16 weeks
Reported as:
Mean · ug/mL
Maximum Empasiprubart Serum Concentrations (Cmax)
ug/mLARGX-117 Cohort 1ARGX-117 Cohort 2
Day 1777.1 ± 202.6400.1 ± 73.4
Day 8590.8 ± 164.0273.8 ± 88.1
Day 15672.3 ± 118.4340.5 ± 59.0
Day 22802.3 ± 202.4356.2 ± 42.3
Day 29725.2 ± 176.5394.1 ± 60.6
Day 43797.3 ± 153.2—
Day 57819.9 ± 187.6391.6 ± 128.1
Day 71871.9 ± 183.4—
Day 85876.3 ± 222.5349.4 ± 71.1
Day 99891.8 ± 125.2—
SecondaryPercent Change From Baseline in Free C2, Total C2, and Functional Complement Activity (CH50)
Time frame:
At week 16
Reported as:
Median · Percent change
Percent Change From Baseline in Free C2, Total C2, and Functional Complement Activity (CH50)
Percent changeARGX-117 Cohort 1ARGX-117 Cohort 2Total Placebo (Cohort 1 and 2 Combined)
Free C2-98.915 (-99.031 to -98.635)-98.079 (-98.532 to -97.324)-0.669 (-13.876 to 7.625)
Total C2331.82 (314.29 to 475.34)296.34 (219.80 to 332.00)3.85 (-4.00 to 10.88)
CH50-89.01 (-95.68 to -83.92)-64.33 (-69.00 to -45.27)-1.50 (-13.04 to 9.71)
SecondaryIncidence of Antidrug Antibodies (ADA) Against Empasiprubart
Time frame:
Up to 16 weeks
Reported as:
Count of participants · Participants
Incidence of Antidrug Antibodies (ADA) Against Empasiprubart
ParticipantsARGX-117 Cohort 1ARGX-117 Cohort 2Total Placebo (Cohort 1 and 2 Combined)
Incidence of Antidrug Antibodies (ADA) Against Empasiprubart010

Adverse events

Collected over Up to 80 weeks. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
ARGX-117 Cohort 10/18 (0%)2/18 (11.1%)14/18 (77.8%)
Placebo Cohort 10/9 (0%)0/9 (0%)5/9 (55.6%)
ARGX-117 Cohort 20/18 (0%)0/18 (0%)14/18 (77.8%)
Placebo Cohort 20/9 (0%)0/9 (0%)6/9 (66.7%)
Most frequent serious events
Most frequent serious events
EventARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
Acute coronary syndromeCardiac disorders1/180/90/180/9
PneumoniaInfections and infestations1/180/90/180/9
Most frequent other events
Showing 10 of 71
Most frequent other events
EventARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2
NasopharyngitisInfections and infestations0/180/94/183/9
HeadacheNervous system disorders5/181/95/182/9
FatigueGeneral disorders0/180/92/182/9
CoughRespiratory, thoracic and mediastinal disorders0/180/93/180/9
Urinary tract infectionInfections and infestations2/180/91/180/9
Upper respiratory tract infectionInfections and infestations0/181/91/180/9
Gastrointestinal infectionInfections and infestations0/181/90/180/9
ParonychiaInfections and infestations0/181/90/180/9
Sinusitis bacterialInfections and infestations0/180/90/181/9
Oedema peripheralGeneral disorders0/181/91/180/9

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)ARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2Total
<=18 years00000
Between 18 and 65 years16716746
>=65 years22228
Age, Continuous
Age, Continuous(years)ARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2Total
Median54.5 (47.0 to 61.0)44.0 (42.0 to 54.0)55.5 (50.0 to 59.0)58.0 (55.0 to 61.0)55.0 (47.0 to 61.0)
Sex: Female, Male
Sex: Female, Male(Participants)ARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2Total
Female746421
Male11512533
Race/Ethnicity, Customized
Race/Ethnicity, Customized(Participants)ARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2Total
White17717849
Not Reported01113
Other11002
Race/Ethnicity, Customized
Race/Ethnicity, Customized(Participants)ARGX-117 Cohort 1Placebo Cohort 1ARGX-117 Cohort 2Placebo Cohort 2Total
Hispanic or Latino00101
Not Hispanic or Latino17816748
Not Reported10124
Unknown01001
08

Study locations

40 sites
  • HonorHealth Research Institute-Neuroscience Research
    Scottsdate, Arizona 85251, United States
  • California Pacific Medical Center-Forbes Norris MDA/ALS Research Center
    San Francisco, California 94109, United States
  • George Washington Medical Faculty Associates
    Washington D.C., District of Columbia 20037, United States
  • HonorHealth Research Institute-Neuroscience Research
    Maitland, Florida 32751, United States
  • University of South Florida Carol and Frank Morsani Center for Advanced Healthcare
    Tampa, Florida 33612, United States
  • NorthShore University HealthSystem
    Glenview, Illinois 60026, United States
  • University of Kansas Medical Center
    Kansas City, Kansas 66160, United States
  • University of Minnesota Delware Clinic Research Unit
    Minneapolis, Minnesota 55414, United States
  • University of North Carolina at Chapel Hill
    Chapel Hill, North Carolina 27514, United States
  • Cleveland Clinic
    Cleveland, Ohio 44195, United States
  • Perelman Center for Advanced Medicine-University of Penssylvania
    Philadelphia, Pennsylvania 19104, United States
  • Austin Neuromuscular Center
    Austin, Texas 78756, United States
  • West Virginia University Medicine
    Morgantown, West Virginia 26506, United States
  • Medizinische Universitat Wien Universitatsklienik fur Neurologie
    Vienna, 1090, Austria
  • AZ Sint-Lucas
    Ghent, 9000, Belgium
  • Genge Partners Montreal
    Québec, H4A 3TA, Canada
  • Toronto General Hospital
    Toronto, M5G 2C4, Canada
  • CHU de Bordeaux-Hopital Pellegrin
    Bordeaux, 33076, France
  • CHRU de Lille-Hopital Roger Salengro
    Lille, 59037, France
  • CHU de Nice-Hopital Pasteur 2
    Nice, 06001, France
  • Hopital Pitie Salpetriere
    Paris, 75651, France
  • Katholisches Klinikum Bochum
    Bochum, 44791, Germany
  • Universitatsklinikum Essen
    Essen, 45147, Germany
  • Universitatsmedzin Gottingen, Klinik fur Neurologie
    Göttingen, 37075, Germany
  • Medizinische Hochschule Hannover Klinik Fur Neurologie
    Hanover, 30625, Germany
  • Universitatsklinikum Munster
    Münster, 48419, Germany
  • IRCCS Ospedale San Raffaele
    Milan, 20132, Italy
  • Azienda Ospedaliero Univeritaria Pisana-UOS Neurologia
    Pisa, 56126, Italy
  • Azienda Ospedaliera Sant'Andrea-UOS Malattie Neuromuscolari
    Rome, 00189, Italy
  • Instituto Clinico Humanitas (IRCCS)
    Rozzano, 20089, Italy
  • Amsterdam UMC location AMC, Dep of Neurology
    Amsterdam, 1105 AZ, Netherlands
  • University Medical Centre Utrecht
    Utrecht, 3584 CX, Netherlands
  • Michalscy I Partnerzy Lekarze Spolka Partnerska
    Krakow, 31-426, Poland
  • Uniwersyteckie centrum kliniczne Warszawskiego
    Warsaw, 02-097, Poland
  • Hospital Universitario Vall d'Herbon
    Barcelona, 08035, Spain
  • Hospital de la Santa Creu I Santa Pau -Sevicio Neurologia
    Barcelona, 08041, Spain
  • Hospital Universitari I Politecnic La Fe de Valencia-Servicio Neurologia
    Valencia, 46026, Spain
  • Queen Elisabeth University Hospital
    Glasgow, G51 4TF, United Kingdom
  • University College London Hospital
    London, ZC1N 3BG, United Kingdom
  • Oxford University Hospitals NHS Trust-Jonh Radcliffe Hospital
    Oxford, OX3 9DU, United Kingdom
09

References and documents

Study documents

  • Study protocol · Mar 2, 2023
  • Statistical analysis plan · Jul 12, 2024

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 8, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT05225675
Lead sponsor
argenx
Responsible party
Sponsor
First posted
Feb 4, 2022
Start date
Mar 31, 2022
Primary completion
Jun 4, 2024
Completion
Jun 4, 2024
Results posted
May 8, 2026
Last update
May 8, 2026

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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