A Study to Assess the Efficacy and Safety of Empasiprubart Versus IVIg in Adults With Multifocal Motor Neuropathy

Inclusion Criteria:

• Is at least 18 years of age and the local legal age of consent for clinical studies

• Has a confirmed diagnosis of definite or probable MMN at screening according to theEFNS/PNS 2010 guidelines

• Has responded to IVIg in the past 5 years.

• Is receiving IVIg at a treatment interval of once every 2, 3, 4, or 5 weeks, and adose of 0.4 to 2.0 g/kg body weight per cycle

• Is receiving a maintenance regimen (no change in frequency, and no change in dose >10%) of IVIg for at least 8 weeks before screening (or at least 10 weeks forparticipants receiving IVIg once every 5 weeks)

• Minimum converted weekly IVIg dose of ≥0.125 g/kg

• Has documented immunization against encapsulated bacterial pathogens (N meningitidisand S pneumoniae) within 5 years of screening or is willing to receive immunizationat least 14 days before first study drug administration

Exclusion Criteria:

• Besides the indication under study, known autoimmune disease (eg, SLE) or any othermedical condition that would confound the study results or put the participant atundue risk

• Clinical signs or symptoms suggestive of neuropathies other than MMN, such as motorneuron disease (eg, bulbar signs, brisk reflexes) or other inflammatory neuropathies (eg, sensory neuropathy)