The FDA has approved amifampridine (Firdapse, Catalyst Pharmaceuticals, Coral Gables, FL) tablets for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in adults. This is the first FDA approval of a treatment for the rare autoimmune disorder.
Commonly occurring in patients with cancers, such as small cell lung cancer, LEMS onset often precedes or coincides with the cancer diagnosis.
The efficacy of amifampridine was studied in two clinical trials with a total of 64 adult patients who received amifampridine or placebo. The studies examined the Quantitative Myasthenia Gravis score for muscle weakness and the Subject Global Impression. For both tests, the patients who received amifampridine experienced a greater benefit than those on placebo.
The FDA granted this application Priority Review and Breakthrough Therapy designations. Amifampridine also received Orphan Drug designation, which gives incentives to assist and encourage development of drugs for rare diseases.
“There has been a long-standing need for a treatment for this rare disorder,” said Billy Dunn, MD, director of the Division of Neurology Products in the FDA Center for Drug Evaluation and Research. “Patients with LEMS have significant weakness and fatigue that can often cause great difficulties with daily activities.”
The Muscular Dystrophy Association (MDA) released a statement that they "celebrate the FDAs approval of Firdapse (amifampridine), the first FDA approved treatment for Lambert-Eaton myasthenic syndrome (LEMS). LEMS, a rare autoimmune disease, affects the connection between the nerves and muscles and causes weakness and other symptoms in affected patients, often resulting in difficulty in performing daily activities." The MDA is an umbrella organization representing more than 40 different disorders, including LEMS. Our MDA Care Centers at over 150 leading medical institutions nationwide play a key role in confirmatory diagnoses, treatment, long-term care and follow up.