Firdapse (amifampridine phosphate) a leading drug from Catalyst Pharmaceutical Partners Inc, has demonstrated superior results compared to placebo for treating symptoms associated with the rare autoimmune disorder Lambert-Eaton Myasthenic Syndrome (LEMS). LEMS is a neuromuscular disease causing progressive muscle weakness, and it is often associated with cancer. All patients in the phase III randomized “withdrawal” trial received Firdapse during a 91 day run-in period, followed by treatment with either Firdapse or placebo for two weeks. A total of 38 patients completed the 3-month run-in period and subsequent 2 week randomization period. Firdapse was superior to placebo for quantitative myasthenia gravis score and subject global impression, the primary endpoints. It was also superior to placebo for the secondary endpoint of physician’s clinical global impression of improvement. Firdapse is already approved in the EU for Lambert-Eaton Myasthenic Syndrome.
