Exclusion Criteria

Any coexisting condition which may interfere with the outcome assessments

• Clinical signs or symptoms suggestive for neuropathies other than MMN such as motor neuron disease or other inflammatory neuropathies

• Severe psychiatric disorder, history of suicide attempt, or current suicidal ideation that in the opinion of the investigator could create undue risk to the participant or could affect adherence with the trial protocol.

• Clinically significant uncontrolled active or chronic bacterial, viral, or fungal infection during the screening and/or IVIg monitoring period (IVMP).

• Any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of clinical symptoms of MMN or put the participant at undue risk (eg, SLE).

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

• Adequately treated basal cell or squamous cell skin cancer

• Carcinoma in situ of the cervix

• Carcinoma in situ of the breast

• Incidental histological finding of prostate cancer

• Clinical evidence of other significant serious diseases, have had a recent major surgery (including a splenectomy at any time), or who have any other condition in the opinion of the investigator, that could confound the results of the trial or put the participant at undue risk

• Prior/concomitant therapy

• Cyclophosphamide and/or rituximab and/or eculizumab and/or mycophenolate mofetil within 3 months prior to screening

• Use of an investigational product within 3 months or 5 half-lives (whichever is longer) before the first dose of the IMP.

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

• Hepatitis B virus (HBV) that is indicative of an acute or chronic infection

• Hepatitis C virus (HCV) based on HCV antibody assay

• HIV based on test results that are associated with an AIDS-defining condition

• Current or history of (ie, within 12 months of screening) alcohol, drug, or medication abuse

• Known hypersensitivity reaction to 1 of the components of the IMP or any of its excipients

• Female participants with a positive serum or urine pregnancy test, lactating females, and those who intend to become pregnant during the trial or within 12 months after last dose of the IMP

• ALT or AST ≥2 × upper limit of normal and total bilirubin ≥1.5 × upper limit of normal of the central laboratory reference range

• An estimated glomerular filtration rate of ≤60 mL/min/1.73m2