FDA approves Ruzurgi for the treatment of Lambert-Eaton myasthenic syndrome

The FDA has approved Ruzurgi (amifampridine) tablets from Jacobus Pharmaceuticals for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in patients 6 to less than 17 years of age. This is the first FDA approval of a treatment specifically for pediatric patients with LEMS. The only other treatment approved for LEMS is only approved for use in adults.

The effectiveness of Ruzurgi for the treatment of LEMS was established by a randomized, double-blind, placebo-controlled withdrawal study of 32 adult patients in which patients were taking Ruzurgi for at least three months prior to entering the study. The study compared patients continuing on Ruzurgi to patients switched to placebo. Effectiveness was measured by the degree of change in a test that assessed the time it took the patient to rise from a chair, walk three meters, and return to the chair for three consecutive laps without pause. The patients that continued on Ruzurgi experienced less impairment than those on placebo. Effectiveness was also measured with a self-assessment scale for LEMS-related weakness that evaluated the feeling of weakening or strengthening. The scores indicated greater perceived weakening in the patients switched to placebo.

The most common side effects experienced by pediatric and adult patients taking Ruzurgi were burning or prickling sensation (paresthesia), abdominal pain, indigestion, dizziness and nausea. Side effects reported in pediatric patients were similar to those seen in adult patients. Seizures have been observed in patients without a history of seizures. Patients should inform their health care professional immediately if they have signs of hypersensitivity reactions such as rash, hives, itching, fever, swelling or trouble breathing.