A Study to Assess Efficacy and Safety of Adimanebart in Adult and Pediatric Participants With DOK7-,MUSK-, AGRN-, or LRP4- Congenital Myasthenic Syndromes (CMS)

The purpose of this study is to assess efficacy and safety of adimanebart in participants at least 12 years of age with DOK7-, MUSK-, AGRN-, or LRP4- Congenital Myasthenic Syndromes (CMS). The study aims to determine whether adimanebart is safe and can help people with CMS feel better and perform daily activities more easily. The study includes a double-blinded treatment period (DBTP) and an Open- label extension period (OLE). In the DBTP, all participants will be randomized in a 1:1 ratio to adimanebart or placebo. Participants who complete the DBTP will continue to the OLE. Additionally, participants who complete part of the active-treatment period of ARGX-119-2302 study are eligible to enroll in the OLE of this study. In the OLE, all participants will receive open-label adimanebart. After final IMP dose, the participants will enter a follow-up period and their health will be monitored. The total duration of the study is up to approximately 152 weeks (2 years and 11 months). More information can be found here: clinicaltrials.argenx.com/Comets