Skip to Content

Firdapse FDA Approval History

Reviewed by J.Stewart BPharm. Last updated on Nov 30, 2018.

FDA Approved: Yes (First approved November 28, 2018)
Brand name: Firdapse
Generic name: amifampridine phosphate
Dosage form: Tablets
Company: Catalyst Pharmaceuticals, Inc.
Treatment for: Lambert Eaton Myasthenic Syndrome

Firdapse (amifampridine phosphate) is a nonspecific, voltage-dependent, potassium (K+) channel blocker for the treatment of Lambert Eaton myasthenic syndrome (LEMS) in adults.

  • LEMS is a rare autoimmune disease that affects approximately 1 in 100,000 people in the United States. The most common symptoms are proximal muscle weakness and fatigue, which can be life threatening when the weakness involves respiratory muscles.
  • The efficacy of Firdapse was established in two Phase 3 clinical trials where patients treated with Firdapse experienced improvements in muscle function, and reduced weakness and fatigability compared to patients receiving placebo.
  • Firdapse is taken orally in divided doses (3 to 4 times daily).
  • The most common (> 10%) adverse reactions are paresthesia, upper respiratory tract infection, abdominal pain, nausea, diarrhea, headache, elevated liver enzymes, back pain, hypertension, and muscle spasms.

Development Timeline for Firdapse

Nov 28, 2018Approval FDA Approves Firdapse (amifampridine) for Lambert-Eaton Myasthenic Syndrome
May 29, 2018Catalyst Pharmaceuticals Announces FDA Acceptance of NDA and Priority Review Status for Firdapse (amifampridine phosphate) for Lambert-Eaton Myasthenic Syndrome
Mar 29, 2018Catalyst Pharmaceuticals Announces Submission of New Drug Application for Firdapse for Treatment of Lambert-Eaton Myasthenic Syndrome
Feb 12, 2018Catalyst Pharmaceuticals Announces Plans to Resubmit New Drug Application for Firdapse
Dec  8, 2016Catalyst Pharmaceuticals Provides Update on its Clinical Trial for Patients with Congenital Myasthenic Syndromes
Apr 26, 2016Catalyst Pharmaceuticals Provides Regulatory Update on Firdapse
Feb 17, 2016Catalyst Pharmaceuticals Receives Refusal to File Letter From the FDA on Its NDA for Firdapse
Dec 17, 2015Catalyst Pharmaceuticals Completes NDA Submission to FDA for Firdapse for the Treatment of Lambert-Eaton Myasthenic Syndrome and Congenital Myasthenic Syndromes

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.