This study aims to evaluate the effectand safety of empasiprubart compared with intravenous immunoglobulin (IVIg) treatment in adults with multifocal motor neuropathy (MMN). This study will also check how empasiprubart affects the body, how it is absorbed and removed from the body, and how the immune system reacts to empasiprubart.

To Assess the Long-Term Safety and Efficacy of ION-682884 in Patients with Hereditary Transthyretin-Mediated Amyloid Polyneuropathy