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    Clinical Trial Results:
    A Phase 2, Randomized, Double-Blinded, Placebo-Controlled, Parallel-Group, Multicenter Trial to Evaluate the Safety and Tolerability, Efficacy, Pharmacokinetics, Pharmacodynamics, and Immunogenicity of 2 Dose Regimens of ARGX-117 in Adults With Multifocal Motor Neuropathy

    Summary
    EudraCT number
    		 2021-003302-50
    Trial protocol
    		 FR   ES   DE   BE   IT   PL   AT   NL  
    Global end of trial date
    04 Jun 2024

    Results information
    Results version number
    		 v1(current)
    This version publication date
    20 Jun 2025
    First version publication date
    20 Jun 2025
    Other versions

    Trial information

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    Trial identification
    Sponsor protocol code
    ARGX-117-2002
    Additional study identifiers
    ISRCTN number
    		 -
    US NCT number
    		 NCT05225675
    WHO universal trial number (UTN)
    		 -
    Sponsors
    Sponsor organisation name
    argenx BV
    Sponsor organisation address
    Industriepark Zwijnaarde 7, Zwijnaarde (Ghent), Belgium, 9052
    Public contact
    Regulatory, argenx, regulatory@argenx.com
    Scientific contact
    Regulatory, argenx, regulatory@argenx.com
    Paediatric regulatory details
    Is trial part of an agreed paediatric investigation plan (PIP)
    No
    Does article 45 of REGULATION (EC) No 1901/2006 apply to this trial?
    No
    Does article 46 of REGULATION (EC) No 1901/2006 apply to this trial?
    No
    Results analysis stage
    Analysis stage
    Final
    Date of interim/final analysis
    10 Apr 2025
    Is this the analysis of the primary completion data?
    Yes
    Primary completion date
    04 Jun 2024
    Global end of trial reached?
    Yes
    Global end of trial date
    04 Jun 2024
    Was the trial ended prematurely?
    No
    General information about the trial
    Main objective of the trial
    To evaluate the safety and tolerability of empasiprubart (ARGX-117) compared to placebo in adult participants previously stabilized with IVIg
    Protection of trial subjects
    This study was conducted in accordance with the protocol and consensus ethical principles derived from international guidelines, including the Declaration of Helsinki, applicable ICH GCP guidelines, and applicable laws and regulations. The participant’s informed consent was documented by the dated signature of the participant and the dated signature of the investigator or investigator’s delegate before enrollment.
    Background therapy
    		 -
    Evidence for comparator
    		 This study is placebo-controlled and Placebo IV is used for comparator.
    Actual start date of recruitment
    31 Mar 2022
    Long term follow-up planned
    Yes
    Long term follow-up rationale
    		 Safety
    Long term follow-up duration
    		 15 Months
    Independent data monitoring committee (IDMC) involvement?
    Yes
    Population of trial subjects
    Number of subjects enrolled per country
    Country: Number of subjects enrolled
    Netherlands: 6
    Country: Number of subjects enrolled
    Poland: 3
    Country: Number of subjects enrolled
    Spain: 8
    Country: Number of subjects enrolled
    Austria: 1
    Country: Number of subjects enrolled
    Belgium: 2
    Country: Number of subjects enrolled
    France: 6
    Country: Number of subjects enrolled
    Germany: 4
    Country: Number of subjects enrolled
    Italy: 6
    Country: Number of subjects enrolled
    United Kingdom: 3
    Country: Number of subjects enrolled
    Canada: 2
    Country: Number of subjects enrolled
    United States: 13
    Worldwide total number of subjects
    54
    EEA total number of subjects
    36
    Number of subjects enrolled per age group
    In utero
    0
    Preterm newborn - gestational age < 37 wk
    0
    Newborns (0-27 days)
    0
    Infants and toddlers (28 days-23 months)
    0
    Children (2-11 years)
    0
    Adolescents (12-17 years)
    0
    Adults (18-64 years)
    46
    From 65 to 84 years
    8
    85 years and over
    0

    Subject disposition

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    Recruitment
    Recruitment details
    		 78 participants were screened: 27 directly entered IVIg monitoring period (IVMP), and 30 entered IVMP after completing IVIg dependency period (IVDP). Of the 57 participants who entered IVMP, 54 completed IVMP and were enrolled in 2 cohorts. In each cohort, 27 participants were randomized (2:1) to receive: EMP IV (N=18) or PBO (N=9).

    Pre-assignment
    Screening details
    		 Screening period: Up to 28 days

    Period 1
    Period 1 title
    DBTP - double-blinded treatment period (overall period)
    Is this the baseline period?
    		 Yes
    Allocation method
    Randomised - controlled
    Blinding used
    		 Double blind
    Roles blinded
    		 Subject, Investigator, Monitor, Data analyst, Carer, Assessor

    Arms
    Are arms mutually exclusive
    Yes

    Arm title
    		 ARGX-117 Cohort 1
    Arm description
    		 Participants received dosing regimen 1 of ARGX-117 via intravenous (IV) infusion
    Arm type
    		 Experimental

    Investigational medicinal product name
    Empasiprubart
    Investigational medicinal product code
    Other name
    ARGX-117
    Pharmaceutical forms
    Solution for infusion
    Routes of administration
    Intravenous use
    Dosage and administration details
    Participants received dosing regimen 1 of ARGX-117 via intravenous (IV) infusion.

    Arm title
    		 Placebo Cohort 1
    Arm description
    		 Participants received placebo via intravenous (IV) infusion
    Arm type
    		 Placebo

    Investigational medicinal product name
    Placebo IV
    Investigational medicinal product code
    Other name
    Pharmaceutical forms
    Solution for infusion
    Routes of administration
    Intravenous use
    Dosage and administration details
    Participants received Placebo via intravenous (IV) infusion.

    Arm title
    		 ARGX-117 Cohort 2
    Arm description
    		 Participants received dosing regimen 2 of ARGX-117 via intravenous (IV) infusion
    Arm type
    		 Experimental

    Investigational medicinal product name
    Empasiprubart
    Investigational medicinal product code
    Other name
    ARGX-117
    Pharmaceutical forms
    Solution for infusion
    Routes of administration
    Intravenous use
    Dosage and administration details
    Participants received dosing regimen 2 of ARGX-117 via intravenous (IV) infusion.

    Arm title
    		 Placebo Cohort 2
    Arm description
    		 Participants received placebo via intravenous (IV) infusion
    Arm type
    		 Placebo

    Investigational medicinal product name
    Placebo IV
    Investigational medicinal product code
    Other name
    Pharmaceutical forms
    Solution for infusion
    Routes of administration
    Intravenous use
    Dosage and administration details
    Participants received Placebo via intravenous (IV) infusion.

    Number of subjects in period 1
    		ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Started
    18
    9
    18
    9
    Completed
    17
    8
    18
    9
    Not completed
    1
    1
    0
    0
         Adverse event, non-fatal
    1
    -
    -
    -
         Withdrawal by participant
    -
    1
    -
    -

    Baseline characteristics

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    Baseline characteristics reporting groups
    Reporting group title
    ARGX-117 Cohort 1
    Reporting group description
    		 Participants received dosing regimen 1 of ARGX-117 via intravenous (IV) infusion

    Reporting group title
    Placebo Cohort 1
    Reporting group description
    		 Participants received placebo via intravenous (IV) infusion

    Reporting group title
    ARGX-117 Cohort 2
    Reporting group description
    		 Participants received dosing regimen 2 of ARGX-117 via intravenous (IV) infusion

    Reporting group title
    Placebo Cohort 2
    Reporting group description
    		 Participants received placebo via intravenous (IV) infusion

    Reporting group values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2 Total
    Number of subjects
    		 18 9 18 9 54
    Age categorical
    Units: Subjects
        Adults (18-64 years)
    		 16 7 16 7 46
        From 65-84 years
    		 2 2 2 2 8
    Age continuous
    Units: years
        median (inter-quartile range (Q1-Q3))
    		 54.5 (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) -
    Gender categorical
    Units: Subjects
        Female
    		 7 4 6 4 21
        Male
    		 11 5 12 5 33

    End points

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    End points reporting groups
    Reporting group title
    ARGX-117 Cohort 1
    Reporting group description
    		 Participants received dosing regimen 1 of ARGX-117 via intravenous (IV) infusion

    Reporting group title
    Placebo Cohort 1
    Reporting group description
    		 Participants received placebo via intravenous (IV) infusion

    Reporting group title
    ARGX-117 Cohort 2
    Reporting group description
    		 Participants received dosing regimen 2 of ARGX-117 via intravenous (IV) infusion

    Reporting group title
    Placebo Cohort 2
    Reporting group description
    		 Participants received placebo via intravenous (IV) infusion

    Subject analysis set title
    ENR - enrolled analysis set
    Subject analysis set type
    		 Full analysis
    Subject analysis set description
    All participants who signed an informed consent to participate in the study

    Subject analysis set title
    SAF - safety analysis set
    Subject analysis set type
    		 Safety analysis
    Subject analysis set description
    All enrolled participants who were randomized and who received at least 1 dose or part of a dose of IMP (empasiprubart or placebo). Participants were analyzed according to the treatment they received.

    Subject analysis set title
    PK set - pharmacokinetic(s)
    Subject analysis set type
    		 Sub-group analysis
    Subject analysis set description
    All participants in the SAF for whom at least 1 postdose serum PK concentration was available, excluding participants who received placebo.

    Subject analysis set title
    PD set - pharmacodynamic(s) set
    Subject analysis set type
    		 Sub-group analysis
    Subject analysis set description
    All participants in the SAF for whom at least 1 postbaseline value for PD parameters (including free C2, total C2, and CH50) was available

    Subject analysis set title
    Total Placebo (Cohort 1 and 2 Combined)
    Subject analysis set type
    		 Sub-group analysis
    Subject analysis set description
    Total Placebo (Cohort 1 and 2 Combined)

    Primary: Number of participants with AEs and SAEs

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    End point title
    		 Number of participants with AEs and SAEs [1]
    End point description
    AE: adverse events, SAE: serious adverse events
    End point type
    Primary
    End point timeframe
    Up to 80 weeks
    Notes
    [1] - No statistical analyses have been specified for this primary end point. It is expected there is at least one statistical analysis for each primary end point.
    Justification: Only descriptive analyses were performed for the primary safety endpoint
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: Number of participants with AEs and SAEs
        Number of participants with a AE
    14
    5
    14
    6
        Number of participants with a Treatment-related AE
    7
    0
    2
    2
        Number of participants with a SAE
    2
    0
    0
    0
        Number of participants with a Treatment-related SA
    1
    0
    0
    0
    No statistical analyses for this end point

    Secondary: Time to First Retreatment with IVIg

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    End point title
    		 Time to First Retreatment with IVIg
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18 [2]
    9 [3]
    18 [4]
    9 [5]
    Units: days
    median (confidence interval 95%)
        Time to first retreatment with IVIg
    0.00 (0.00 to 0.00)
    37.0 (16.0 to 9999)
    0.00 (0.00 to 0.00)
    0.00 (0.00 to 0.00)
    Notes
    [2] - Not evaluable because fewer than 50% of participants were re-treated with IVIg during the DBTP
    [3] - Too few participants were retreated with IVIg to estimate the 95% CI. “9999” = data not estimable
    [4] - Not evaluable because fewer than 50% of participants were re-treated with IVIg during the DBTP
    [5] - Not evaluable because fewer than 50% of participants were re-treated with IVIg during the DBTP
    Statistical analysis title
    		 Cox regression model
    Comparison groups
    ARGX-117 Cohort 1 v Placebo Cohort 1
    Number of subjects included in analysis
    27
    Analysis specification
    Pre-specified
    Analysis type
    		 other [6]
    Method
    		 Regression, Cox
    Parameter type
    		 Hazard ratio (HR)
    Point estimate
    0.09
    Confidence interval
         level
    		 95%
         sides
    2-sided
         lower limit
    		 0.02
         upper limit
    		 0.44
    Notes
    [6] - Descriptive analysis
    Statistical analysis title
    		 Cox regression model
    Comparison groups
    ARGX-117 Cohort 2 v Placebo Cohort 2
    Number of subjects included in analysis
    27
    Analysis specification
    Pre-specified
    Analysis type
    		 other [7]
    Method
    		 Regression, Cox
    Parameter type
    		 Hazard ratio (HR)
    Point estimate
    0.17
    Confidence interval
         level
    		 95%
         sides
    2-sided
         lower limit
    		 0.02
         upper limit
    		 1.6
    Notes
    [7] - Descriptive analysis

    Secondary: Time-to-Relapse

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    End point title
    		 Time-to-Relapse
    End point description
    Time-to-Relapse is defined as the time from randomization until a participant met the threshold for clinically meaningful deterioration.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18 [8]
    9 [9]
    18 [10]
    9
    Units: days
    median (confidence interval 95%)
        Time-to-Relapse
    9999 (17.0 to 9999)
    26.0 (7.0 to 9999)
    9999 (70.0 to 9999)
    28.0 (7.0 to 99.0)
    Notes
    [8] - “9999” is a dummy value as the data is not estimable
    [9] - “9999” is a dummy value as the data is not estimable
    [10] - “9999” is a dummy value as the data is not estimable
    No statistical analyses for this end point

    Secondary: iAUC of the Change From Baseline in mMRC-10 Sum Score

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    End point title
    		 iAUC of the Change From Baseline in mMRC-10 Sum Score
    End point description
    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 favourable outcome while a negative AUC indicates a nonfavourable outcome.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
        median (inter-quartile range (Q1-Q3))
    110.25 (-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)
    No statistical analyses for this end point

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

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    End point title
    		 Change From Baseline in the Average Score of the 2 Most Important Muscle Groups as Assessed by the mMRC-14 Sum Score
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At week 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
        median (inter-quartile range (Q1-Q3))
    0.50 (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)
    No statistical analyses for this end point

    Secondary: Change From Baseline in the mMRC-14 Sum Score

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    End point title
    		 Change From Baseline in the mMRC-14 Sum Score
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At week 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
    median (inter-quartile range (Q1-Q3))
        Change From Baseline in the mMRC-14 Sum Score
    4.0 (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)
    No statistical analyses for this end point

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

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    End point title
    		 Proportion of Participants Showing a Deterioration of at Least 2 Points as Assessed by the mMRC-10 Sum Score
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: Percentage of participants
        number (not applicable)
    5.6
    44.4
    11.1
    22.2
    No statistical analyses for this end point

    Secondary: iAUC of the Change From Baseline in GS daily average

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    End point title
    		 iAUC of the Change From Baseline in GS daily average
    End point description
    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. Safety analysis set – Only participants with data for these timepoints are included
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: kPa
    median (inter-quartile range (Q1-Q3))
        Most affected Hand
    508.25 (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 Hand
    356.08 (-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)
    No statistical analyses for this end point

    Secondary: Percent Change From Baseline in GS 3-day moving average

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    End point title
    		 Percent Change From Baseline in GS 3-day moving average
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At week 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: percent change
    median (inter-quartile range (Q1-Q3))
        Most Affected Hand
    31.88 (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 Hand
    13.13 (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)
    No statistical analyses for this end point

    Secondary: Change From Baseline in the MMN-RODS centile score

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    End point title
    		 Change From Baseline in the MMN-RODS centile score
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At week 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
        median (inter-quartile range (Q1-Q3))
    6.0 (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)
    No statistical analyses for this end point

    Secondary: Percent change From Baseline in the Average Time for Upper Extremity (Arm and Hand) Function

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    End point title
    		 Percent change From Baseline in the Average Time for Upper Extremity (Arm and Hand) Function
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At week 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    17
    9
    Units: seconds
    median (inter-quartile range (Q1-Q3))
        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)
    No statistical analyses for this end point

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

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    End point title
    		 Proportion of Participants by Level of Severity on Each Dimension of the EQ-5D-5L Scale
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At weeks 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: participants
        Mobility - 1 No Problem
    9
    3
    11
    2
        Mobility - 2 Slight Problem
    2
    3
    2
    6
        Mobility - 3 Moderate Problem
    6
    2
    3
    1
        Mobility - 4 Severe Problem
    1
    1
    1
    0
        Mobility - 5 Unable to
    0
    0
    1
    0
        Self-Care - 1 No Problem
    5
    3
    8
    3
        Self-Care - 2 Slight Problem
    8
    4
    8
    5
        Self-Care - 3 Moderate Problem
    4
    2
    1
    1
        Self-Care - 4 Severe Problem
    1
    0
    0
    0
        Self-Care - 5 Unable to
    0
    0
    1
    0
        Usual Activities - 1 No Problem
    5
    2
    8
    2
        Usual Activities - 2 Slight Problem
    6
    4
    5
    4
        Usual Activities - 3 Moderate Problem
    6
    2
    4
    3
        Usual Activities - 4 Severe Problem
    1
    1
    0
    0
        Usual Activities - 5 Unable to
    0
    0
    1
    0
        Pain/Discomfort - 1 No Problem
    9
    6
    10
    2
        Pain/Discomfort - 2 Slight Problem
    5
    1
    5
    5
        Pain/Discomfort - 3 Moderate Problem
    3
    2
    2
    2
        Pain/Discomfort - 4 Severe Problem
    1
    0
    1
    0
        Pain/Discomfort - 5 Unable to
    0
    0
    0
    0
        Anxiety/Depression - 1 No Problem
    13
    2
    15
    5
        Anxiety/Depression - 2 Slight Problem
    4
    6
    1
    2
        Anxiety/Depression - 3 Moderate Problem
    1
    1
    2
    2
        Anxiety/Depression - 4 Severe Problem
    0
    0
    0
    0
        Anxiety/Depression - 5 Unable to
    0
    0
    0
    0
    No statistical analyses for this end point

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

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    End point title
    		 Change From Baseline in Quality of Life Using EQ-5D-5L Visual Analog Scale
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At week 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
        median (inter-quartile range (Q1-Q3))
    5.0 (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)
    No statistical analyses for this end point

    Secondary: Change From Baseline in the CAP-PRI

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    End point title
    		 Change From Baseline in the CAP-PRI
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    At week 16
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
    median (inter-quartile range (Q1-Q3))
        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)
    No statistical analyses for this end point

    Secondary: Proportion of Participants by Level of Improvement Using the PGI-C Scale

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    End point title
    		 Proportion of Participants by Level of Improvement Using the PGI-C Scale
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: participants
        1 - Very much improved
    7
    0
    4
    0
        2 - Much improved
    3
    1
    8
    2
        3 - Minimally improved
    7
    0
    3
    2
        4 - No change
    0
    3
    2
    2
        5 - Minimally worse
    1
    2
    0
    2
        6 - Much worse
    0
    1
    1
    1
        7 - Very much worse
    0
    2
    0
    0
    No statistical analyses for this end point

    Secondary: Change From Baseline in the 9-item FSS average Total Score

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    End point title
    		 Change From Baseline in the 9-item FSS average Total Score
    End point description
    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 with a higher score representing more severe fatigue. A change of less than 0 indicates an improvement.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
        median (inter-quartile range (Q1-Q3))
    -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)
    No statistical analyses for this end point

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

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    End point title
    		 Percent of Total Hours for Work-related and Household Chore Activities Lost, as Part of the HRPQ
    End point description
    The Health-Related Productivity Questionnaire (HRPQ) provides data related to missed hours at work or educational activities and reduced effectiveness during any attempted work. Safety analysis set - only participants with HRPQ data are shown. This is limited to employed/partially employed participants.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: percent
    median (inter-quartile range (Q1-Q3))
        Work Activities lost
    10.00 (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 lost
    33.33 (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)
    No statistical analyses for this end point

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

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    End point title
    		 Change From Baseline in Effectiveness, Side Effects, Convenience, and Overall Satisfaction Scores as Assessed by the TSQM-14
    End point description
    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.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    End point values
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Number of subjects analysed
    18
    9
    18
    9
    Units: score on a scale
    median (inter-quartile range (Q1-Q3))
        Effectiveness
    0.000 (-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 effects
    0.000 (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)
        Convenience
    5.556 (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 Satisfaction
    3.6 (-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)
    No statistical analyses for this end point

    Secondary: Maximum Empasiprubart Serum Concentrations (Cmax)

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    End point title
    		 Maximum Empasiprubart Serum Concentrations (Cmax) [11]
    End point description
    PK set - All participants for whom at least 1 postdose serum PK concentration was available, excluding participants who received placebo.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    Notes
    [11] - The end point is not reporting statistics for all the arms in the baseline period. It is expected all the baseline period arms will be reported on when providing values for an end point on the baseline period.
    Justification: The participants who received placebo (placebo cohorts 1 and 2) have been excluded from the PK analysis
    End point values
    		 ARGX-117 Cohort 1 ARGX-117 Cohort 2
    Number of subjects analysed
    18
    18
    Units: μg/mL
    arithmetic mean (standard deviation)
        Day 1
    777.1 ( 202.6 )
    400.1 ( 73.4 )
        Day 8
    590.8 ( 164.0 )
    273.8 ( 88.1 )
        Day 15
    672.3 ( 118.4 )
    340.5 ( 59.0 )
        Day 22
    802.3 ( 202.4 )
    356.2 ( 42.3 )
        Day 29
    725.2 ( 176.5 )
    394.1 ( 60.6 )
        Day 43
    797.3 ( 153.2 )
    0.0 ( 0.0 )
        Day 57
    819.9 ( 187.6 )
    391.6 ( 128.1 )
        Day 71
    871.9 ( 183.4 )
    0.0 ( 0.0 )
        Day 85
    876.3 ( 222.5 )
    349.4 ( 71.1 )
        Day 99
    891.8 ( 125.2 )
    0.0 ( 0.0 )
    No statistical analyses for this end point

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

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    End point title
    		 Percent Change From Baseline in Free C2, Total C2, and Functional Complement Activity (CH50) [12]
    End point description
    PD set - All participants for whom at least 1 postbaseline value for pharmacodynamic parameters was available. Only participants with available data at week 16.
    End point type
    Secondary
    End point timeframe
    At week 16
    Notes
    [12] - The end point is not reporting statistics for all the arms in the baseline period. It is expected all the baseline period arms will be reported on when providing values for an end point on the baseline period.
    Justification: Data from the placebo cohorts 1 and 2 has been pooled in a single “Total placebo” group for this endpoint
    End point values
    		 ARGX-117 Cohort 1 ARGX-117 Cohort 2 Total Placebo (Cohort 1 and 2 Combined)
    Number of subjects analysed
    18
    18
    18
    Units: Percent change
    median (inter-quartile range (Q1-Q3))
        Free C2
    -98.915 (-99.031 to -98.635)
    -98.079 (-98.532 to -97.324)
    -0.669 (-13.876 to 7.625)
        Total C2
    331.82 (314.29 to 475.34)
    296.34 (219.80 to 332.00)
    331.82 (314.29 to 475.34)
        CH50
    -89.01 (-95.68 to -83.92)
    -64.33 (-69.00 to -45.27)
    296.34 (219.80 to 332.00)
    No statistical analyses for this end point

    Secondary: Incidence of Antidrug Antibodies (ADA) Against Empasiprubart

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    End point title
    		 Incidence of Antidrug Antibodies (ADA) Against Empasiprubart [13]
    End point description
    Only ADA-evaluable participants were analyzed for this outcome measure. ADA-evaluable participants were classified as treatment-boosted ADA, treatment-induced ADA, treatment-unaffected ADA, or ADA negative.
    End point type
    Secondary
    End point timeframe
    Up to 16 weeks
    Notes
    [13] - The end point is not reporting statistics for all the arms in the baseline period. It is expected all the baseline period arms will be reported on when providing values for an end point on the baseline period.
    Justification: Data from the placebo cohorts 1 and 2 has been pooled in a single “Total placebo” group for this endpoint
    End point values
    		 ARGX-117 Cohort 1 ARGX-117 Cohort 2 Total Placebo (Cohort 1 and 2 Combined)
    Number of subjects analysed
    16
    18
    18
    Units: participants
    0
    1
    0
    No statistical analyses for this end point

    Adverse events

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    Adverse events information
    Timeframe for reporting adverse events
    AEs have been reported from the start of the DBTP (Double-Blinded Treatment Period - 16 weeks) until the end of the safety follow-up period (15 months).
    Assessment type
    		 Systematic
    Dictionary used for adverse event reporting
    Dictionary name
    		 MedDRA
    Dictionary version
    24.1
    Reporting groups
    Reporting group title
    ARGX-117 Cohort 1
    Reporting group description
    		 Participants received dosing regimen 1 of ARGX-117 via intravenous (IV) infusion

    Reporting group title
    Placebo Cohort 1
    Reporting group description
    		 Participants received placebo via intravenous (IV) infusion

    Reporting group title
    ARGX-117 Cohort 2
    Reporting group description
    		 Participants received dosing regimen 2 of ARGX-117 via intravenous (IV) infusion

    Reporting group title
    Placebo Cohort 2
    Reporting group description
    		 Participants received placebo via intravenous (IV) infusion

    Serious adverse events
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Total subjects affected by serious adverse events
         subjects affected / exposed
    2 / 18 (11.11%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         number of deaths (all causes)
    0
    0
    0
    0
         number of deaths resulting from adverse events
    0
    0
    0
    0
    Cardiac disorders
    Acute coronary syndrome
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 0
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Infections and infestations
    Pneumonia
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences causally related to treatment / all
    0 / 1
    0 / 0
    0 / 0
    0 / 0
         deaths causally related to treatment / all
    0 / 0
    0 / 0
    0 / 0
    0 / 0
    Frequency threshold for reporting non-serious adverse events: 5%
    Non-serious adverse events
    		 ARGX-117 Cohort 1 Placebo Cohort 1 ARGX-117 Cohort 2 Placebo Cohort 2
    Total subjects affected by non serious adverse events
         subjects affected / exposed
    13 / 18 (72.22%)
    1 / 9 (11.11%)
    14 / 18 (77.78%)
    6 / 9 (66.67%)
    General disorders and administration site conditions
    Fatigue
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    2 / 18 (11.11%)
    2 / 9 (22.22%)
         occurrences all number
    0
    0
    2
    2
    Infusion site rash
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Oedema peripheral
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    1
    0
    Vaccination site pain
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    1
    1
    Asthenia
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Catheter site haematoma
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    0
    1
    Chest discomfort
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Chest pain
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Chills
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Feeling cold
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Injection site pain
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Pyrexia
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Immune system disorders
    Hypersensitivity
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Respiratory, thoracic and mediastinal disorders
    Cough
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    3 / 18 (16.67%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    3
    0
    Oropharyngeal pain
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    1
    0
    1
    Asthma
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Choking
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Nasal congestion
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Sneezing
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Psychiatric disorders
    Insomnia
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Investigations
    Blood urine present
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Protein urine
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    2 / 18 (11.11%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    2
    0
    Alanine aminotransferase increased
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Haemoglobin decreased
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Serum ferritin decreased
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Injury, poisoning and procedural complications
    Procedural headache
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Arthropod bite
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Contusion
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Foot fracture
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Head injury
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    0
    1
    Limb crushing injury
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    0
    1
    Skin abrasion
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Traumatic haematoma
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    0
    1
    Antinuclear antibody increased
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    0
    1
    Bilirubin urine
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Nervous system disorders
    Headache
         subjects affected / exposed
    5 / 18 (27.78%)
    1 / 9 (11.11%)
    5 / 18 (27.78%)
    2 / 9 (22.22%)
         occurrences all number
    5
    1
    5
    2
    Amnesia
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Fine motor skill dysfunction
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Somnolence
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Ear and labyrinth disorders
    Ear pain
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Eye disorders
    Eye irritation
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Gastrointestinal disorders
    Abdominal rigidity
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Diarrhoea
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Dysphagia
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Gastritis
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Skin and subcutaneous tissue disorders
    Rash
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    1 / 9 (11.11%)
         occurrences all number
    1
    0
    1
    1
    Pigmentation disorder
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    0
    1
    Rash papular
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Rash pruritic
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Urticaria
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Renal and urinary disorders
    Haematuria
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    1
    0
    0
    1
    Musculoskeletal and connective tissue disorders
    Arthralgia
         subjects affected / exposed
    1 / 18 (5.56%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    1
    1
    0
    1
    Arthritis
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    1
    0
    Muscle spasms
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Pain in extremity
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    1
    0
    Back pain
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Myalgia
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Neck pain
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Spinal pain
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Fall
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Infections and infestations
    Nasopharyngitis
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    4 / 18 (22.22%)
    3 / 9 (33.33%)
         occurrences all number
    0
    0
    4
    3
    Influenza
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    1
    0
    Urinary tract infection
         subjects affected / exposed
    2 / 18 (11.11%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    2
    0
    1
    0
    Upper respiratory tract infection
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    1
    0
    Anal fungal infection
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    COVID-19
         subjects affected / exposed
    1 / 18 (5.56%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    1
    0
    0
    0
    Gastrointestinal infection
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Lower respiratory tract infection
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0
    Paronychia
         subjects affected / exposed
    0 / 18 (0.00%)
    1 / 9 (11.11%)
    0 / 18 (0.00%)
    0 / 9 (0.00%)
         occurrences all number
    0
    1
    0
    0
    Sinusitis bacterial
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    0 / 18 (0.00%)
    1 / 9 (11.11%)
         occurrences all number
    0
    0
    0
    1
    Tooth abscess
         subjects affected / exposed
    0 / 18 (0.00%)
    0 / 9 (0.00%)
    1 / 18 (5.56%)
    0 / 9 (0.00%)
         occurrences all number
    0
    0
    1
    0

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    Substantial protocol amendments (globally)
    Were there any global substantial amendments to the protocol? Yes
    Date
    Amendment
    16 Feb 2022
    Amendment 1 (v2.0) - Revised contraception guidelines and defined sexual abstinence and unacceptable forms of contraception per Clinical Trials Facilitation and Coordination Group guidelines. The timing of pregnancy tests for women of childbearing potential was also clarified. - Clarified that a delay in the first visit (IDV1 or IMV1) to align with a participant’s IVIg dosing schedule would not result in screen failure. - Clarified that all assessments were performed before IMP administration unless otherwise specified. Added sampling for immunogenicity at screening. - Extended the safety follow-up period from 9 to 12 months and adapted the timing of the visits. - Corrected mMRC endpoint from percentage of time to proportion of participants. - Specified liver and renal exclusion cutoff values in the exclusion criteria. Also clarified that individuals who had a splenectomy were excluded from the study. - Expanded criteria for early treatment discontinuation to include the detection of a new malignancy during the DBTP and participants whose blinding code was broken. - Updated safety and monitoring criteria. - Added C-reactive protein to the collected laboratory parameters.
    12 Dec 2022
    Amendment 2 (v3.0): - Revised the definition of clinically meaningful deterioration to align with the clinical presentation of MMN. - Clarified that the investigator determined whether deterioration in objective MMN measurements necessitated retreatment with IVIg. - Updated the safety follow-up period and requirements for contraception from 12 to 15 months to reflect the half-life of empasiprubart. - Clarified that bilateral vasectomy was considered an effective form of contraception. - Clarified that the final causality assessment was made by the sponsor after careful review of all relevant information, including recommendations/suggestions from the principal investigator and IDMC. - Clarified that “stable” IVIg regimen was at least 3 months before screening or recently initiated. - Clarified that IDMC review of cohort 1 data also considered early discontinuations within the DBTP. - Clarified the timing of assessments. - Clarified the secondary endpoints of the study: mMRC, 9-HPT, EQ-5D-5L, PGI-C, HRPQ, TSQM-14, and ADA. The endpoint planned to assess the difference between the time to the first retreatment with IVIg (cycle) and the second time to retreatment with IVIg was removed because it was unlikely to be meaningful. - Replaced the full analysis set with the safety analysis set, because participants were analyzed according to the treatment received and not planned. The per protocol analysis set was deleted. - Added that interim analyses could have been performed for regulatory interactions.
    02 Mar 2023
    Amendment 3 (v4.0): - Added AEs of clinical interest. - Added 3 dosing regimen options for cohort 2. - Added details about maintaining blinding throughout cohort 2. - Updated potential risks and mitigation strategies. - Updated ANA titer reporting to ≥1:100. - Updated pregnancy follow-up and SAE reporting language and clarified that any female who became pregnant while participating in the study would discontinue IMP. - Added details for the interim analyses after the completion of cohort 1 and cohort 2. - Clarified the timeline for the final database lock. - Updated language to reflect that the EDRT would select the final dosing regimen in cohort 2, if applicable.

    Interruptions (globally)
    Were there any global interruptions to the trial? No

    Limitations and caveats
    Limitations of the trial such as small numbers of subjects analysed or technical problems leading to unreliable data.
    None reported
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