The U.S. Food and Drug Administration (FDA) has raised concerns about the effectiveness of Otsuka Pharmaceutical’s proposed treatment for post-traumatic stress disorder (PTSD), which combines its antipsychotic drug brexpiprazole with Viatris’ antidepressant, Zoloft (sertraline).
The assessment, published ahead of an independent advisory panel meeting scheduled for Friday, highlighted inconsistent clinical trial outcomes and a modest treatment benefit that may not meet the threshold for clinical significance.
Otsuka’s application to extend the use of brexpiprazole—marketed under the brand name Rexulti—relies on findings from one mid-stage and two late-stage studies. These trials compared the drug combination against Zoloft alone in adults with PTSD. However, FDA reviewers pointed out that one of the late-stage studies failed to demonstrate statistically significant results, while the mid-stage trial raised methodological and statistical concerns.
PTSD is a serious mental health disorder triggered by traumatic experiences, often manifesting in flashbacks, nightmares, and acute anxiety. While treatments exist, no new PTSD medication has been approved in the United States in over three decades, since Zoloft and GSK’s Paxil were introduced.
Brexpiprazole is currently approved in the U.S. for the treatment of schizophrenia, major depressive disorder, and agitation associated with Alzheimer’s disease. The drug is jointly developed by Otsuka and Danish pharmaceutical company Lundbeck.
Otsuka previously disclosed that the FDA had postponed its original decision—initially expected by February 8—to gather further input from the advisory panel on certain issues related to the combination therapy’s marketing application. A new decision date has not yet been announced.
If approved, this combination therapy would mark a significant milestone as the first new pharmacological treatment for PTSD approved in the U.S. in more than 30 years.
