Researchers are looking for people with congenital myasthenic syndrome (CMS) to participate in a phase 3 study being conducted by Catalyst Pharmaceuticals to test the experimental drug amifampridine phosphate.

Amifampridine phosphate is a potassium channel inhibitor designed to cause greater stimulation of muscle by prolonging nerve signals and is expected to help treat muscle weakness in people with CMS. The drug has shown promising results in treating patients with a related disorder called LEMS.