Congenital myasthenic syndromes (CMS) are rare inherited conditions that affect how nerves communicate with muscles. Patients typically present with muscle weakness in the first decade of life, but are often undiagnosed for prolonged periods, or misdiagnosed with other conditions, most commonly with seronegative myasthenia gravis.

CMS can be caused by changes (mutations) in one of these genes: DOK7, MUSK, AGRN or LRP4. These changes can affect how nerves and muscles communicate with each other.

The Comets study is designed to see if the investigational study drug*, adimanebart, can help people feel better and perform daily activities more easily. Researchers also want to learn about its safety in adolescents and adults with CMS.

* The investigational study drug is not approved by any health authority for use an CMS as efficacy and safety have not been established.

CMS patients may be eligible to participate if they are:

• at least 18 years old (if it concerns children, the minimum age is 12 years)
• diagnosed with DOK7-, MUSK-, AGRN-, or LRP4-CMS based on a genetic test
• taking stable CMS medications for at least 6 months or not receiving CMS medications

The patient would participate in the study for about 2 years and 11 months.

During this time, they may need to visit the study site approximately 40 times. 

The study consists of 4 phases:

• Screening period: to learn if they can join the study.
• Treatment period: participant will receive either study drug or placebo
• Open Label period: participant will receive only study drug
• Follow-up period: participant will no longer receive the study drug, and their health will be monitored

The study drug will be administered through a needle into a vein (intravenous or “IV” infusion).