Catalyst Pharmaceuticals achieves positive results from second Phase 3 Clinical Trial
Catalyst Pharmaceuticals announced positive top-line results from a second Phase 3 clinical trial (LMS-003) of Firdapse® (amifampridine phosphate tablets equivalent to 10 mg amifampridine) for the symptomatic treatment of Lambert-Eaton myasthenic syndrome (LEMS). Firdapse received Breakthrough Therapy designation from the FDA in August 2013 and this clinical trial was conducted using a protocol agreed to by the FDA through the Special Protocol Assessment (SPA) process.
This trial had two prospectively defined co-primary endpoints. The first of these, quantitative myasthenia gravis score (QMG), achieved a statistically significant p-value of 0.0004, and the second, subject global impression (SGI), achieved a statistically significant p-value of 0.0003. More importantly, a clinically significant difference of 6.4 points was observed between the Firdapse and placebo groups for the QMG endpoint. Firdapse was well tolerated and showed a similar safety profile to that seen in earlier studies. All p-values reported are based on the entire intent to treat (ITT) population of patients that enrolled in this trial.
The prospectively defined secondary endpoint for the physician’s clinical global impression of improvement (CGI-I) achieved statistical significance (p-value 0.0020). Further, the exploratory endpoints had the following results: (i) the triple timed up and go (3TUG) endpoint achieved statistical significance (p-value 0.0112), (ii) the evaluation of the QMG-Limb domains endpoint achieved statistical significance (p-value 0.0010), and (iii) the most bothersome symptom (MBS) endpoint was not statistically significant, but showed a positive trend (p-value 0.0572).
“Data from the LMS-003 trial continue to demonstrate that amifampridine phosphate has a significant magnitude of effect in treating the symptoms of LEMS patients,” said Perry Shieh, MD, PhD, Associate Professor of Neurology at the David Geffen School of Medicine at UCLA, and principal investigator of this clinical trial. “The findings are especially meaningful given the need for FDA-approved therapies which may transform the lives of patients suffering from LEMS.”
“We are extremely pleased with the top-line efficacy and safety results from this second Phase 3 trial, which reinforces the potential of Firdapse to be an important treatment for patients suffering from LEMS. We look forward to presenting further data in future publications and at medical conferences. We remain on track to submit our NDA to the FDA in the first quarter of 2018,” stated Patrick J. McEnany, President and CEO of Catalyst Pharmaceuticals. “Catalyst remains committed to the development of therapies that will improve the function and lives of people with rare neurodegenerative diseases.”
“Catalyst has once again been able to demonstrate that Firdapse is able to have a positive, clinically significant effect in the symptomatic treatment of LEMS,” stated Gary Ingenito, MD, Ph.D., Chief Medical Officer of Catalyst Pharmaceuticals. “We thank all those individuals who participated in the LMS-003 trial, in order to have the possibility of an FDA approved medication accessible to the LEMS population.”