Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
Conditions
Brief summary
This is a Phase 2 study to evaluate the safety and efficacy of the subcutaneous formulation of efgartigimod in adults with CIDP.
Interventions
BIOLOGICALefgartigimod PH20 SC in stage B
Stage A: efgartigimod PH20 SC, Stage B: efgartigimod PH20 SC
OTHERplacebo in stage B
Stage A: N/A, stage B: placebo
Sponsors
argenx
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Ability to understand the requirements of the trial, provide written informed consent (include consent for the use and disclosure of research-related health information), willingness and ability to comply with the trial protocol procedures (including required trial visits) 2. Male or female patient aged 18 years or older, at the time of signing the informed consent. 3. Diagnosed with probable or definite CIDP according to criteria of the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS 2010), progressing or relapsing forms. 4. CIDP Disease Activity Status (CDAS) score ≥2 at screening. 5. INCAT score ≥2 at the first run-in visit (for patients entering run-in) or stage A baseline (for treatment-naïve patients with documented evidence for worsening on the total adjusted INCAT disability score within 3 months prior to screening). Patients with an INCAT score of 2 at trial entry must have this score exclusively from the leg disability score; for patients with an INCAT score of ≥3 at trial entry, there are no specific requirements for arm or leg scores. 6. Fulfilling any of the following treatment conditions: * Currently treated with pulsed corticosteroids, oral corticosteroids equivalent to prednisolone/prednisone ≤10mg/day, and/or IVIg or SCIg, if this treatment has been started within the last 5 years before screening, and the patient is willing to discontinue this treatment at the first run-in visit; or * Without previous treatment (treatment-naive); or * Treatment with corticosteroids and/or IVIg or SCIg discontinued at least 6 months prior to screening Note: Patients not treated with monthly or daily corticosteroids, IVIg or SCIg for at least 6 months prior to screening are considered as equal to treatment-naïve patients. 7. Women of childbearing potential who have a negative pregnancy test at screening and a negative urine pregnancy test up to Stage A baseline. 8. Women of childbearing potential must use an acceptable method of contraception from signing the ICF until the date of the last dose of IMP
Exclusion criteria
1. Pure sensory atypical CIDP (EFNS/PNS definition). 2. Polyneuropathy of other causes, including the following: Multifocal motor neuropathy; Monoclonal gammopathy of uncertain significance with anti-myelin associated, glycoprotein immunoglobulin M (IgM) antibodies; Hereditary demyelinating neuropathy; Polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin change syndromes; Lumbosacral radiculoplexus neuropathy; Polyneuropathy most likely due to diabetes mellitus; Polyneuropathy most likely due to systemic illnesses; Drug- or toxin-induced polyneuropathy. 3. Any other disease that could better explain the patient's signs and symptoms. 4. Any history of myelopathy or evidence of central demyelination. 5. Current or past history (within 12 months of screening) of alcohol, drug or medication abuse. 6. Severe psychiatric disorder (such as severe depression, psychosis, bipolar disorder), history of suicide attempt, or current suicidal ideation that in the opinion of the investigator could create undue risk to the patient or could affect adherence with the trial protocol. 7. Patients with clinically significant active or chronic uncontrolled bacterial, viral, or fungal infection at screening, including patients who test positive for an active viral infection at screening with: Active Hepatitis B Virus (HBV): serologic panel test results indicative of an active (acute or chronic) infection; Active Hepatitis C Virus (HCV): serology positive for HCV-Ab; Human Immunodeficiency Virus (HIV) positive serology associated with an Acquired Immune Deficiency Syndrome (AIDS)-defining condition or with a cluster of differentiation 4 (CD4) count ≤200 cells/mm3. 8. Total IgG level \<6 g/L at screening. 9. Treatment with the following: Within 3 months (or 5 half-lives of the drug, whichever is longer) before screening: plasma exchange or immunoadsorption, any concomitant Fc-containing therapeutic agents or other biological, or any other investigational product; Within 6 months before screening: rituximab, alemtuzumab, any other monoclonal antibody, cyclophosphamide, interferon, tumor necrosis factor-alpha inhibitors, fingolimod, methotrexate, azathioprine, mycophenolate, any other immunomodulating or immunosuppressive medications, and oral daily corticosteroids \>10 mg/day. Note: Patients using IVIg, SCIg, pulsed corticosteroids, and oral daily corticosteroids ≤10 mg/day can be included. Patients who (intend to) use prohibited medications and therapies (see protocol) during the trial. 10. Pregnant and lactating women and those intending to become pregnant during the trial or within 90 days after last IMP administration. 11. Patients with any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of clinical symptoms of CIDP. 12. Patients who received a live-attenuated vaccine fewer than 28 days before screening. Receiving an inactivated, sub-unit, polysaccharide, or conjugate vaccine any time before screening is not exclusionary. 13. Patients who have a history of malignancy unless deemed cured by adequate treatment with no evidence of recurrence for ≥3 years before the first IMP administration. Patients with the following cancer can be included anytime: Adequately treated basal cell or squamous cell skin cancer, Carcinoma in situ of the cervix, Carcinoma in situ of the breast, or Incidental histological finding of Prostate cancer (TNM \[tumor, nodes, and metastases classification\] stage T1a or T1b). 14. Patients who previously participated in a trial with efgartigimod and have received at least one administration of IMP. 15. Patients with known medical history of hypersensitivity to any of the ingredients of IMP. 16. Patients with clinical evidence of other significant serious disease or patients who underwent a recent or have a planned major surgery, or any other reason which could confound the results of the trial or put the patient at undue risk.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Stage A: Percentage of Participants With Confirmed Evidence of Clinical Improvement(ECI) | Up to 12 weeks during the open-label stage A |
| Stage B: Time to First Adjusted INCAT Deterioration Compared to Stage B Baseline | Up to 48 weeks during the randomized placebo-controlled stage B |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Medical Research Council (MRC) Sum Score | Up to 12 weeks during the open-label stage A | The Medical Research Council (MRC) Sum scores range from 0 to 60 with a lower score indicating greater muscle weakness. |
| Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in I-RODS Disability Scores | Up to 12 weeks during the open-label stage A | The Inflammatory Rasch-built Overall Disability Scale (I-RODS) score ranges from 0-100, with lower scores indicating the greatest degree of disability. |
| Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in TUG Score | Up to 12 weeks during the open-label stage A | The Timed Up and Go (TUG) score is calculated as the number of seconds needed to complete a series of actions. The longer time needed to complete this test (expressed in seconds) indicates lower mobility. |
| Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Mean Grip Strength | Up to 12 weeks during the open-label stage A | This is measured with a handheld device called a vigometer |
| Stage A: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | Up to 12 weeks during the open-label stage A | Treatment-emergent (serious) AEs expressed in number of events/100 PYFU (participant years of follow-up) |
| Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Up to 13 weeks during the open-label stage A (12 weeks + optional 1 additional week to confirm evidence of clinical improvement (ECI)) | — |
| Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Up to 13 weeks during the open-label stage A (12 weeks + optional 1 additional week to confirm evidence of clinical improvement (ECI)) | — |
| Stage A: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | Up to 12 weeks during the open-label stage A | — |
| Stage A: Changes From Stage A Baseline to Last Assessment in Stage A, in EQ-5D-5L Visual Analog Scale (VAS) Over Time | Up to 12 weeks during the open-label stage A | Scores range from 0-100 with 100 indicating the best health state. Therefore, positive changes indicate higher health-related quality of life reported by the patient. |
| Stage B: Time to CIDP Disease Progression | Up to 48 weeks during the randomized placebo-controlled stage B | Time to chronic inflammatory demyelinating polyneuropathy (CIDP) disease progression is defined by the time from first dose of double-blind IMP to the first I-RODS score decrease ≥4 points compared to Stage B baseline using the centile metric. |
| Stage B: Number of Participants With Improved Functional Level Compared to Stage B Baseline | Up to 48 weeks during the randomized placebo-controlled stage B | — |
| Stage A: Time to Initial Confirmed Evidence of Clinical Improvement (ECI) | Up to 12 weeks during the open-label stage A | — |
| Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in MRC Sum Score | Up to 48 weeks during the randomized placebo-controlled stage B | The Medical Research Council (MRC) Sum scores range from 0 to 60 with a lower score indicating greater muscle weakness. |
| Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in 24-item I-RODS Disability Score | Up to 48 weeks during the randomized placebo-controlled stage B | The Inflammatory Rasch-built Overall Disability Scale (I-RODS) score ranges from 0-100, with lower scores indicating the greatest degree of disability. |
| Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in TUG Score | Up to 48 weeks during the randomized placebo-controlled stage B | The Timed Up and Go (TUG) score is calculated as the number of seconds needed to complete a series of actions. The longer time needed to complete this test (expressed in seconds) indicates lower mobility. |
| Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Mean Grip Strength | Up to 48 weeks during the randomized placebo-controlled stage B | This is measured with a handheld device called a vigometer |
| Stage B: Time to 10% Decrease in the 24-item I-RODS | Up to 48 weeks during the randomized placebo-controlled stage B | The Inflammatory Rasch-built Overall Disability Scale (I-RODS) score ranges from 0-100, with lower scores indicating the greatest degree of disability. |
| Stage B: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | Up to 48 weeks during the randomized placebo-controlled stage B | Treatment-emergent (serious) AEs expressed in number of events/100 PYFU (participant years of follow-up) |
| Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Up to 48 weeks during the randomized placebo-controlled stage B | — |
| Stage B: Percent Changes of Serum IgG Levels Over Time | Up to 48 weeks during the randomized placebo-controlled stage B | — |
| Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | Up to 48 weeks during the randomized placebo-controlled stage B | — |
| Stage B: Changes From Stage B Baseline to Last Assessment in Stage B, in EQ-5D-5L Visual Analog Scale (VAS) Over Time | Up to 48 weeks during the randomized placebo-controlled stage B | Scores range from 0-100 with 100 indicating the best health state. Therefore, positive changes indicate higher health-related quality of life reported by the patient. |
| Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Adjusted INCAT Score | Up to 48 weeks during the randomized placebo-controlled stage B | Adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) scores range from 0-10 with a score of 10 indicating the greatest degree of disability. |
| Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Adjusted INCAT Score | Up to 12 weeks during the open-label stage A | Adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) scores range from 0-10 with a score of 10 indicating the greatest degree of disability. |
Countries
Austria, Belgium, Bulgaria, China, Czechia, Denmark, France, Georgia, Germany, Hungary, Israel, Italy, Japan, Latvia, Netherlands, Poland, Romania, Russia, Serbia, Spain, Taiwan, Turkey (Türkiye), Ukraine, United Kingdom, United States
Participant flow
Recruitment details
ARGX-113-1802 enrolled a broad and global (North America, Asia, Europe, and the rest of the world \[ROW\]) population of treatment-naïve participants and participants who were previously treated for CIDP (corticosteroids, IVIg, or SCIg) with confirmed, active disease and a wide range of disease severity. A total of 322 participants received efgartigimod PH20 SC in Stage A, and 221 participants were randomized in a 1:1 ratio to efgartigimod PH20 SC (N=111) or placebo (N=110) in Stage B.
Participants by arm
| Arm | Count |
|---|---|
| Stage A: Efgartigimod PH20 SC Participants receiving efgartigimod PH20 SC in Stage A | 322 |
| Stage B: Efgartigimod PH20 SC Participants who completed stage A and received efgartigimod PH20 SC in stage B | 111 |
| Stage B: Placebo PH20 SC Participants who completed stage A and received placebo PH20 SC in stage B | 110 |
| Total | 543 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Stage A | Adverse Event | 20 | 0 | 0 |
| Stage A | All events required for primary analysis achieved (rolled over to ARGX-1113-1902) | 22 | 0 | 0 |
| Stage A | Death | 1 | 0 | 0 |
| Stage A | Lack of Efficacy | 8 | 0 | 0 |
| Stage A | Lack of efficacy before end of Stage A | 28 | 0 | 0 |
| Stage A | Lost to Follow-up | 2 | 0 | 0 |
| Stage A | Non-compliance with study drug | 1 | 0 | 0 |
| Stage A | Other | 5 | 0 | 0 |
| Stage A | Physician Decision | 1 | 0 | 0 |
| Stage A | Prohibited medications | 2 | 0 | 0 |
| Stage A | Withdrawal by Subject | 11 | 0 | 0 |
| Stage B | Adverse Event | 0 | 3 | 0 |
| Stage B | All events required for primary analysis achieved (rolled over to ARGX-1113-1902) | 0 | 35 | 26 |
| Stage B | Death | 0 | 0 | 1 |
| Stage B | Lack of Efficacy | 0 | 0 | 1 |
| Stage B | Lost to Follow-up | 0 | 0 | 2 |
| Stage B | Other | 0 | 3 | 0 |
| Stage B | Prohibited medications | 0 | 2 | 1 |
| Stage B | Protocol Violation | 0 | 1 | 1 |
| Stage B | Sponsor decision | 0 | 0 | 1 |
| Stage B | Withdrawal by Subject | 0 | 3 | 3 |
Baseline characteristics
| Characteristic | Stage B: Efgartigimod PH20 SC | Total | Stage B: Placebo PH20 SC | Stage A: Efgartigimod PH20 SC |
|---|---|---|---|---|
| Age, Categorical Stage A <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Stage A >=65 years | 0 Participants | 75 Participants | 0 Participants | 75 Participants |
| Age, Categorical Stage A Between 18 and 65 years | 0 Participants | 247 Participants | 0 Participants | 247 Participants |
| Age, Categorical Stage B <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Stage B >=65 years | 25 Participants | 47 Participants | 22 Participants | 0 Participants |
| Age, Categorical Stage B Between 18 and 65 years | 86 Participants | 174 Participants | 88 Participants | 0 Participants |
| Age, Continuous Stage A | — | 54.0 years STANDARD_DEVIATION 13.92 | — | 54.0 years STANDARD_DEVIATION 13.92 |
| Age, Continuous Stage B | 54.5 years STANDARD_DEVIATION 13.18 | 52.9 years STANDARD_DEVIATION 13.9 | 51.3 years STANDARD_DEVIATION 14.47 | — |
| Ethnicity (NIH/OMB) Stage A Hispanic or Latino | — | 23 Participants | — | 23 Participants |
| Ethnicity (NIH/OMB) Stage A Not Hispanic or Latino | — | 288 Participants | — | 288 Participants |
| Ethnicity (NIH/OMB) Stage A Unknown or Not Reported | — | 11 Participants | — | 11 Participants |
| Ethnicity (NIH/OMB) Stage B Hispanic or Latino | 9 Participants | 13 Participants | 4 Participants | — |
| Ethnicity (NIH/OMB) Stage B Not Hispanic or Latino | 99 Participants | 201 Participants | 102 Participants | — |
| Ethnicity (NIH/OMB) Stage B Unknown or Not Reported | 3 Participants | 7 Participants | 4 Participants | — |
| Race (NIH/OMB) Stage A American Indian or Alaska Native | — | 0 Participants | — | 0 Participants |
| Race (NIH/OMB) Stage A Asian | — | 89 Participants | — | 89 Participants |
| Race (NIH/OMB) Stage A Black or African American | — | 4 Participants | — | 4 Participants |
| Race (NIH/OMB) Stage A More than one race | — | 0 Participants | — | 0 Participants |
| Race (NIH/OMB) Stage A Native Hawaiian or Other Pacific Islander | — | 1 Participants | — | 1 Participants |
| Race (NIH/OMB) Stage A Unknown or Not Reported | — | 17 Participants | — | 17 Participants |
| Race (NIH/OMB) Stage A White | — | 211 Participants | — | 211 Participants |
| Race (NIH/OMB) Stage B American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | — |
| Race (NIH/OMB) Stage B Asian | 33 Participants | 67 Participants | 34 Participants | — |
| Race (NIH/OMB) Stage B Black or African American | 1 Participants | 2 Participants | 1 Participants | — |
| Race (NIH/OMB) Stage B More than one race | 0 Participants | 0 Participants | 0 Participants | — |
| Race (NIH/OMB) Stage B Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | — |
| Race (NIH/OMB) Stage B Unknown or Not Reported | 4 Participants | 8 Participants | 4 Participants | — |
| Race (NIH/OMB) Stage B White | 73 Participants | 144 Participants | 71 Participants | — |
| Sex: Female, Male Stage A Female | — | 114 Participants | — | 114 Participants |
| Sex: Female, Male Stage A Male | — | 208 Participants | — | 208 Participants |
| Sex: Female, Male Stage B Female | 38 Participants | 79 Participants | 41 Participants | — |
| Sex: Female, Male Stage B Male | 73 Participants | 142 Participants | 69 Participants | — |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 2 / 322 | 0 / 111 | 1 / 110 |
| other Total, other adverse events | 60 / 322 | 31 / 111 | 15 / 110 |
| serious Total, serious adverse events | 21 / 322 | 6 / 111 | 6 / 110 |
Outcome results
Primary
Stage A: Percentage of Participants With Confirmed Evidence of Clinical Improvement(ECI)
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Percentage of Participants With Confirmed Evidence of Clinical Improvement(ECI) | 66.5 percentage of participants |
Primary
Stage B: Time to First Adjusted INCAT Deterioration Compared to Stage B Baseline
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Time to First Adjusted INCAT Deterioration Compared to Stage B Baseline | NA Days |
| Stage B: Placebo PH20 SC | Stage B: Time to First Adjusted INCAT Deterioration Compared to Stage B Baseline | 140.0 Days |
95% CI: [0.253, 0.614]
Secondary
Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Adjusted INCAT Score
Adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) scores range from 0-10 with a score of 10 indicating the greatest degree of disability.
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Adjusted INCAT Score | -0.9 score on a scale | Standard Deviation 1.71 |
Secondary
Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in I-RODS Disability Scores
The Inflammatory Rasch-built Overall Disability Scale (I-RODS) score ranges from 0-100, with lower scores indicating the greatest degree of disability.
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in I-RODS Disability Scores | 7.7 score on a scale | Standard Deviation 15.48 |
Secondary
Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Mean Grip Strength
This is measured with a handheld device called a vigometer
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Mean Grip Strength | dominant hand | 12.3 Kilopascal (kPa) | Standard Deviation 18.68 |
| Stage A: Efgartigimod PH20 SC | Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Mean Grip Strength | nondominant hand | 11.2 Kilopascal (kPa) | Standard Deviation 21.12 |
Secondary
Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Medical Research Council (MRC) Sum Score
The Medical Research Council (MRC) Sum scores range from 0 to 60 with a lower score indicating greater muscle weakness.
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in Medical Research Council (MRC) Sum Score | 3.8 score on a scale | Standard Error 0.41 |
Secondary
Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in TUG Score
The Timed Up and Go (TUG) score is calculated as the number of seconds needed to complete a series of actions. The longer time needed to complete this test (expressed in seconds) indicates lower mobility.
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Change From Stage A Baseline to Last Assessment in Stage A, in TUG Score | -4.3 seconds | Standard Error 0.83 |
Secondary
Stage A: Changes From Stage A Baseline to Last Assessment in Stage A, in EQ-5D-5L Visual Analog Scale (VAS) Over Time
Scores range from 0-100 with 100 indicating the best health state. Therefore, positive changes indicate higher health-related quality of life reported by the patient.
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Changes From Stage A Baseline to Last Assessment in Stage A, in EQ-5D-5L Visual Analog Scale (VAS) Over Time | 10.7 score on a scale | Standard Error 1.34 |
Secondary
Stage A: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events
Treatment-emergent (serious) AEs expressed in number of events/100 PYFU (participant years of follow-up)
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | Exposure Adjusted Occurrence of Treatment-emergent Adverse Events | 1343.1 Events/100 PYFU |
| Stage A: Efgartigimod PH20 SC | Stage A: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | Exposure Adjusted Occurrence of Treatment-emergent Serious Adverse Events | 51.2 Events/100 PYFU |
Secondary
Stage A: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20
Time frame: Up to 12 weeks during the open-label stage A
Population: The number of participants analyzed is different since it is based on the number of evaluable participants for each drug. For Ab and NAb against rHuPH20 only 316 participants were evaluable, whereas for ADA and NAb towards efgartigimod 317 participants were evaluable. IMM-A (Stage A immunogenicity analysis set): Participants from the SAF-A for whom at least 1 ADA sample during Stage A is available
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | ADA towards Efgartigimod incidence | 20 Participants |
| Stage A: Efgartigimod PH20 SC | Stage A: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | Ab towards rHuPH20 incidence | 45 Participants |
| Stage A: Efgartigimod PH20 SC | Stage A: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | NAb against Efgartigimod incidence | 1 Participants |
| Stage A: Efgartigimod PH20 SC | Stage A: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | NAb against rHuPH20 incidence | 0 Participants |
Secondary
Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time
Time frame: Up to 13 weeks during the open-label stage A (12 weeks + optional 1 additional week to confirm evidence of clinical improvement (ECI))
Population: The number analyzed in rows decreases due to participants advancing to stage B or withdrawing from the study and missing patient data. Week 13 was an optional additional week for the confirmation of the evidence of clinical improvement (ECI). PD-A (Stage A PD analysis set): Participants from the SAF-A for whom at least 1 serum PD concentration during Stage A is available.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 1 | -36.1 percent change | Standard Error 0.58 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 2 | -54.6 percent change | Standard Error 0.8 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 3 | -63.5 percent change | Standard Error 0.71 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 4 | -66.2 percent change | Standard Error 0.89 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 5 | -67.9 percent change | Standard Error 0.74 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 6 | -67.7 percent change | Standard Error 1.42 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 7 | -66.4 percent change | Standard Error 1.96 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 8 | -64.5 percent change | Standard Error 4.28 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 9 | -68.8 percent change | Standard Error 1.17 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 10 | -67.1 percent change | Standard Error 1.9 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 11 | -70.0 percent change | Standard Error 1.41 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 12 | -67.3 percent change | Standard Error 4.44 |
| Stage A: Efgartigimod PH20 SC | Stage A: Percent Changes From Stage A Baseline of Serum IgG Levels Over Time | Percent change from Baseline to Week 13 | -51.0 percent change | Standard Error 10 |
Secondary
Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time
Time frame: Up to 13 weeks during the open-label stage A (12 weeks + optional 1 additional week to confirm evidence of clinical improvement (ECI))
Population: The number analyzed in rows decreases due to participants withdrawing from the study and missing participant data. Week 13 was an optional additional week for the confirmation of the ECI. PK-A (Stage A PK analysis set): Participants from the SAF-A for whom at least 1 serum PK concentration during Stage A is available
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 1 | 14.9 ug/mL | Standard Deviation 6.92 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 2 | 19.6 ug/mL | Standard Deviation 8.55 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 3 | 19.7 ug/mL | Standard Deviation 9.62 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 4 | 18.9 ug/mL | Standard Deviation 9.96 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 5 | 18.4 ug/mL | Standard Deviation 8.38 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 6 | 19.2 ug/mL | Standard Deviation 9.62 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 7 | 17.3 ug/mL | Standard Deviation 8.89 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 8 | 18.8 ug/mL | Standard Deviation 8.93 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 9 | 17.8 ug/mL | Standard Deviation 8.84 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 10 | 17.3 ug/mL | Standard Deviation 7.62 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 11 | 20.1 ug/mL | Standard Deviation 9.64 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 12 | 20.0 ug/mL | Standard Deviation 6.89 |
| Stage A: Efgartigimod PH20 SC | Stage A: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 13 | 14.9 ug/mL | Standard Deviation 7.24 |
Secondary
Stage A: Time to Initial Confirmed Evidence of Clinical Improvement (ECI)
Time frame: Up to 12 weeks during the open-label stage A
Population: SAF-A (Stage A safety analysis set): Participants who received at least 1 dose or part of a dose of efgartigimod PH20 SC in Stage A
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage A: Time to Initial Confirmed Evidence of Clinical Improvement (ECI) | 25th percentile | 22 days |
| Stage A: Efgartigimod PH20 SC | Stage A: Time to Initial Confirmed Evidence of Clinical Improvement (ECI) | 50th percentile (median) | 43.0 days |
| Stage A: Efgartigimod PH20 SC | Stage A: Time to Initial Confirmed Evidence of Clinical Improvement (ECI) | 75th percentile | 71.0 days |
Secondary
Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in 24-item I-RODS Disability Score
The Inflammatory Rasch-built Overall Disability Scale (I-RODS) score ranges from 0-100, with lower scores indicating the greatest degree of disability.
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in 24-item I-RODS Disability Score | 0.8 score on a scale | Standard Deviation 12.33 |
| Stage B: Placebo PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in 24-item I-RODS Disability Score | -7.0 score on a scale | Standard Deviation 19.1 |
Secondary
Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Adjusted INCAT Score
Adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) scores range from 0-10 with a score of 10 indicating the greatest degree of disability.
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Adjusted INCAT Score | 0.1 score on a scale | Standard Deviation 1.08 |
| Stage B: Placebo PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Adjusted INCAT Score | 0.9 score on a scale | Standard Deviation 1.98 |
Secondary
Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Mean Grip Strength
This is measured with a handheld device called a vigometer
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Mean Grip Strength | dominant hand | 2.1 Kilopascal (kPa) | Standard Deviation 13.29 |
| Stage A: Efgartigimod PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Mean Grip Strength | nondominant hand | 2.0 Kilopascal (kPa) | Standard Deviation 17.33 |
| Stage B: Placebo PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Mean Grip Strength | dominant hand | -8.2 Kilopascal (kPa) | Standard Deviation 20.69 |
| Stage B: Placebo PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in Mean Grip Strength | nondominant hand | -6.9 Kilopascal (kPa) | Standard Deviation 21.3 |
Secondary
Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in MRC Sum Score
The Medical Research Council (MRC) Sum scores range from 0 to 60 with a lower score indicating greater muscle weakness.
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in MRC Sum Score | -0.3 score on a scale | Standard Error 0.43 |
| Stage B: Placebo PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in MRC Sum Score | -3 score on a scale | Standard Error 0.86 |
Secondary
Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in TUG Score
The Timed Up and Go (TUG) score is calculated as the number of seconds needed to complete a series of actions. The longer time needed to complete this test (expressed in seconds) indicates lower mobility.
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in TUG Score | 0.8 seconds | Standard Error 0.36 |
| Stage B: Placebo PH20 SC | Stage B: Change From Stage B Baseline to Last Assessment in Stage B, in TUG Score | 1.9 seconds | Standard Error 0.6 |
Secondary
Stage B: Changes From Stage B Baseline to Last Assessment in Stage B, in EQ-5D-5L Visual Analog Scale (VAS) Over Time
Scores range from 0-100 with 100 indicating the best health state. Therefore, positive changes indicate higher health-related quality of life reported by the patient.
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: SAF-B (Stage B safety analysis set): Participants from the SCR who received at least 1 dose or part of a dose of IMP in Stage B
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Changes From Stage B Baseline to Last Assessment in Stage B, in EQ-5D-5L Visual Analog Scale (VAS) Over Time | 0.5 score on a scale | Standard Error 1.77 |
| Stage B: Placebo PH20 SC | Stage B: Changes From Stage B Baseline to Last Assessment in Stage B, in EQ-5D-5L Visual Analog Scale (VAS) Over Time | -10.2 score on a scale | Standard Error 2.47 |
Secondary
Stage B: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events
Treatment-emergent (serious) AEs expressed in number of events/100 PYFU (participant years of follow-up)
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: SAF-B (Stage B safety analysis set): Participants from the SCR who received at least 1 dose or part of a dose of IMP in Stage B
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | treatment-emergent adverse events | 347.6 Events/100 PYFU |
| Stage A: Efgartigimod PH20 SC | Stage B: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | serious adverse events | 14.1 Events/100 PYFU |
| Stage B: Placebo PH20 SC | Stage B: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | treatment-emergent adverse events | 510.9 Events/100 PYFU |
| Stage B: Placebo PH20 SC | Stage B: Exposure Adjusted Occurrence of Treatment-emergent Adverse Events and Serious Adverse Events | serious adverse events | 19.0 Events/100 PYFU |
Secondary
Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: IMM-B (Stage B immunogenicity analysis set): Participants from the SAF-B for whom at least 1 ADA sample during Stage B is available
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | ADA towards Efgartigimod incidence | 2 participants |
| Stage A: Efgartigimod PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | Ab towards rHuPH20 incidence | 52 participants |
| Stage A: Efgartigimod PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | NAb against efgartigimod incidence | 0 participants |
| Stage A: Efgartigimod PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | NAb against rHuPH20 incidence | 5 participants |
| Stage B: Placebo PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | NAb against rHuPH20 incidence | 2 participants |
| Stage B: Placebo PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | ADA towards Efgartigimod incidence | 64 participants |
| Stage B: Placebo PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | NAb against efgartigimod incidence | 13 participants |
| Stage B: Placebo PH20 SC | Stage B: Number of Participants With Binding Antidrug Antibodies (ADA) Towards Efgartigimod or Antibodies (Ab) Against rHuPH20 and Neutralizing Antibodies (NAb) Against Efgartigimod and/or rHuPH20 | Ab towards rHuPH20 incidence | 32 participants |
Secondary
Stage B: Number of Participants With Improved Functional Level Compared to Stage B Baseline
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Number of Participants With Improved Functional Level Compared to Stage B Baseline | 50 Participants |
| Stage B: Placebo PH20 SC | Stage B: Number of Participants With Improved Functional Level Compared to Stage B Baseline | 40 Participants |
Secondary
Stage B: Percent Changes of Serum IgG Levels Over Time
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: The number analyzed in rows decreases due to participants completing the study, withdrawing from the study, and missing participant data. PD-B (Stage B PD analysis set): Participants from the SAF-B for whom at least 1 serum PD concentration during Stage B is available
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 28 | -67.9 percent change | Standard Error 1.42 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 16 | -67.4 percent change | Standard Error 1.49 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 32 | -68.5 percent change | Standard Error 1.63 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 8 | -68.2 percent change | Standard Error 1.24 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 36 | -64.7 percent change | Standard Error 2.82 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 20 | -67.8 percent change | Standard Error 1.3 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 40 | -68.0 percent change | Standard Error 1.91 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 12 | -69.8 percent change | Standard Error 1.09 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 44 | -67.8 percent change | Standard Error 1.92 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 24 | -67.2 percent change | Standard Error 1.52 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 48 | -66.6 percent change | Standard Error 1.85 |
| Stage A: Efgartigimod PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 4 | -68.2 percent change | Standard Error 1.14 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 48 | -0.9 percent change | Standard Error 7.36 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 4 | -36.7 percent change | Standard Error 1.91 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 12 | -7.1 percent change | Standard Error 2.54 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 16 | -2.1 percent change | Standard Error 3.09 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 20 | 2.0 percent change | Standard Error 3.61 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 24 | 1.7 percent change | Standard Error 4.22 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 28 | -2.3 percent change | Standard Error 4.31 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 32 | 0.6 percent change | Standard Error 5.18 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 36 | -3.6 percent change | Standard Error 4.12 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 40 | -4.2 percent change | Standard Error 4.98 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 44 | -3.6 percent change | Standard Error 6.5 |
| Stage B: Placebo PH20 SC | Stage B: Percent Changes of Serum IgG Levels Over Time | Percent change from Baseline to Week 8 | -10.9 percent change | Standard Error 2.41 |
Secondary
Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: The number analyzed in rows decreases due to participants completing the study, withdrawing from the study, and missing participant data. PK-B (Stage B PK analysis set): Participants from the SAF-B for whom at least 1 serum PK concentration during Stage B is available
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 4 | 18.4 ug/mL | Standard Deviation 10.3 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 8 | 17.2 ug/mL | Standard Deviation 9.11 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 12 | 18.1 ug/mL | Standard Deviation 9.48 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 16 | 16.9 ug/mL | Standard Deviation 9.03 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 20 | 16.8 ug/mL | Standard Deviation 8.36 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 24 | 16.0 ug/mL | Standard Deviation 7.89 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 28 | 18.5 ug/mL | Standard Deviation 10.2 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 32 | 18.0 ug/mL | Standard Deviation 9.5 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 36 | 17.9 ug/mL | Standard Deviation 10.7 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 40 | 16.2 ug/mL | Standard Deviation 8.2 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 44 | 18.1 ug/mL | Standard Deviation 10.2 |
| Stage A: Efgartigimod PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 48 | 16.3 ug/mL | Standard Deviation 8.18 |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 44 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 4 | 0.267 ug/mL | Standard Deviation 0.365 |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 28 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 8 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 40 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 12 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 32 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 16 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 48 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 20 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 36 | NA ug/mL | — |
| Stage B: Placebo PH20 SC | Stage B: Pre-dosing Efgartigimod Serum Concentrations Over Time | Week 24 | NA ug/mL | — |
Secondary
Stage B: Time to 10% Decrease in the 24-item I-RODS
The Inflammatory Rasch-built Overall Disability Scale (I-RODS) score ranges from 0-100, with lower scores indicating the greatest degree of disability.
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Time to 10% Decrease in the 24-item I-RODS | NA days |
| Stage B: Placebo PH20 SC | Stage B: Time to 10% Decrease in the 24-item I-RODS | 111 days |
Secondary
Stage B: Time to CIDP Disease Progression
Time to chronic inflammatory demyelinating polyneuropathy (CIDP) disease progression is defined by the time from first dose of double-blind IMP to the first I-RODS score decrease ≥4 points compared to Stage B baseline using the centile metric.
Time frame: Up to 48 weeks during the randomized placebo-controlled stage B
Population: mITT (modified intent-to-treat) analysis set; Participants who were randomized in Stage B and who received at least 1 dose or part of a dose of IMP in Stage B.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Stage A: Efgartigimod PH20 SC | Stage B: Time to CIDP Disease Progression | NA days |
| Stage B: Placebo PH20 SC | Stage B: Time to CIDP Disease Progression | 85 days |