The FDA has challenged the efficacy data package for Otsuka Pharmaceutical’s Rexulti, an add-on therapy for post-traumatic stress disorder (PTSD), requesting additional studies ahead of an advisory committee meeting. Rexulti is combined with sertraline and would represent a new therapeutic option for PTSD, the first in over 20 years if approved. The agency noted the need for at least two positive controlled trials for effectiveness demonstration. The advisory committee’s deliberations will shape the path forward for this treatment candidate.