Catalyst Pharma's Lead Drug Produces Positive Phase 3 Results
By C. Rajan, contributing writer
Catalyst Pharma has just announced that its lead drug, Firdapse, demonstrated positive top-line results in a pivotal Phase 3 clinical trial for the treatment of Lambert-Eaton myasthenic syndrome (LEMS), a rare debilitating condition.
In the double blind, randomized, "withdrawal" format late stage trial, results from 38 patients treated with Firdapse met both the primary and secondary endpoints satisfactorily, while the placebo treated patients showed significant worsening of symptoms.
Patrick J. McEnany, CEO of Catalyst Pharmaceuticals, said, "These results show that Firdapse provides an important benefit to LEMS patients and continues to demonstrate a favorable safety profile. We plan to meet with the FDA in the near future to determine the fastest way to get an NDA for Firdapse approved.”
LEMS is a rare autoimmune neuromuscular disease that causes gradual muscle weakness and loss in mobility. The disease can also be life-threatening in some patients. The condition is caused by insufficient release of the essential neurotransmitter, acetylcholine, and is also accompanied by cancer in over half of the patients.
Firdapse (amifampridine phosphate or 3,4-diaminopyridine (3,4-DAP) phosphate) is a potassium channel inhibitor, which works by increasing acetylcholine release and increasing the nerve repolarization time, in turn reducing muscle weakness. Besides LEMS, Firdapse can also be effective for other neuromuscular indications, such as Myasthenia Gravis and Congenital Myasthenic Syndrome.
Firdapse has already been approved in the European Union for LEMS as an orphan drug. It is being sold in Europe by BioMarin Pharmaceutical, which out-licensed the North American rights of the drug to Catalyst in 2012.
Firdapse has received FDA’s breakthrough therapy and orphan drug designations, making it eligible for a faster review and approval process. Catalyst plans to initiate a rolling NDA submission in early-2015.
Catalyst is also planning to make Firdapse available to LEMS patients in the U.S. through an expanded access program, which allows doctors to prescribe unapproved drugs to patients in serious cases when there are no other approved drugs for the condition. Under this program, the company stated that Firdapse will be provided at no cost until sometime after approval.
McEnany added, “We are committed to the LEMS patient community and are pleased that we will be launching our expanded access program next month. This program will provide Firdapse at no charge to patients who meet the inclusion/exclusion requirements."
Firdapse has already generated a net revenue of over $9.3 million in the first half of this year in Europe, according to Reuters. Once launched in the U.S., Firdapse is likely to bring in annual sales over $100 million, says McEnany.