According to a story from Globe Newswire, the biopharmaceutical company Catalyst Pharmaceuticals has recently announced an update to the company’s supplemental New Drug Application (sNDA) for its drug amifampridine (marketed as FIRDAPSE). Catalyst is focused on the development of treatments for rare diseases. The US Food and Drug Administration (FDA) has approved the application, which increases the maximum approved dose from 80mg to 100mg in patients that weigh over 45kg living with Lambert-Eaton myasthenic syndrome (LEMS), a rare disease. 

About Amifampridine (FIRDAPSE)

FIRDAPSE is classified as a potassium channel blocker and is the only treatment with US approval for LEMS at this juncture. The drug is believed to work by boosting the neurotransmitter acetylcholine at the neuromuscular junction, giving improved muscle function. The increased dose should give physicians more flexibility in developing a treatment regimen for individual patients.

About Lambert-Eaton Myasthenic Syndrome (LEMS)

Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disease which is characterized by weakness of the limb muscles. In this autoimmune disease, the immune system develops antibodies against an ion channel that plays a vital role in neuromuscular function. Lambert-Eaton myasthenic syndrome commonly appears as the result of cancer, often small cell lung cancer. Genetic variants are often the cause when cancer is not involved. The disease presents with muscle weakness of the upper arms and legs, with the legs usually being most affected. Other symptoms include difficulty swallowing, double vision, drooping eyelids, orthostatic hypotension, ataxia, and reduced reflexes. Weakness may be temporarily relieved after exercise; hot temperatures seem to worsen symptoms. Treatment of comorbid cancer can resolve the disease; other treatments include immune system suppressors (IVIg and prednisone) and drugs that improve neuromuscular function. To learn more about Lambert-Eaton myasthenic syndrome, click here.