A SPA is a process by which sponsors ask the FDA to evaluate the protocol of a proposed clinical trial to determine whether it adequately addresses scientific and regulatory requirements for the purpose identified by the sponsor. A SPA agreement indicates concurrence with the adequacy and acceptability of specific critical elements of protocol design, endpoints and analysis.
Additionally, it provides a binding agreement with FDA's review division that a pivotal trial design, conduct, and planned analysis adequately addresses the scientific and regulatory objectives in support of a regulatory submission for drug approval. However, final marketing approval depends upon the results of efficacy, the safety profile, and an evaluation of the risk/benefit of treatment demonstrated in the Phase 3 clinical trial, among other requirements.
Catalyst CEO Patrick McEnany said: "Receipt of this SPA agreement is a major milestone which provides us with a clearly defined development and regulatory pathway for Firdapse in the treatment of LEMS.
"We would like to thank the FDA for its engagement and guidance in this process."
Catalyst intends to conduct its second Phase 3 trial (designated as LMS-003) at two clinical trial sites, one on the east coast of the United States and one on the west coast of the United States. This double-blind, placebo controlled withdrawal trial will include approximately 28 subjects, so that the trial is adequately powered, and will have the same co-primary endpoints as Catalyst's first Phase 3 trial evaluating Firdapse for the treatment of LEMS.
Further, the FDA has agreed to allow Catalyst to enroll patients from its expanded access program as study subjects in this second trial. Finally, after further discussion with the FDA in connection with the SPA request, this second trial will be a parallel design and not a cross-over design.
Final details of the Phase 3 clinical trial will be available at the launch of the study on www.clinicaltrials.gov. As previously reported, Catalyst expects to initiate this trial before the end of this year.