Catalyst Pharmaceuticals, Inc. received approval from the FDA for Firdapse (amifampridine) tablets for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults. LEMS is a rare autoimmune disorder that affects the connection between nerves and muscles and causes weakness and other symptoms in affected patients. This is the first FDA approval of a treatment for LEMS.    In people with LEMS, the body’s own immune system attacks the neuromuscular junction (the connection between n...