Phase 2a results show mifepristone not efficacious for PTSD in male veterans

Key takeaways:

• Mifepristone did not demonstrate efficacy in treating PTSD in male veterans.
• Future studies may investigate mifepristone for PTSD in people without traumatic brain injury or other head trauma.

Compared with placebo, mifepristone taken daily for 1 week did not improve PTSD in male veterans over long-term follow-up, according to phase 2a data published in JAMA Network Open.

Julia A. Golier, MD, chief of psychiatry at the Veterans Affairs Medical Center in the Bronx, New York, and colleagues enrolled male veterans with chronic PTSD who had a score of at least 50 on the Clinician-Administered PTSD Scale (CAPS). For the phase 2a double-blind trial, the researchers randomly assigned 41 veterans to mifepristone 600 mg and 39 veterans to placebo. Participants took their assigned treatment every day for 7 days.

Clinical response was defined as CAPS score reduction of at least 30%.

At week 4, 38.1% of the mifepristone group and 31.1% of the placebo group responded to treatment. At 12 weeks, the response rates were 33.5% and 39.8%, respectively. The mifepristone group did not meet the clinical efficacy margin of 15% at either time point.

Analyses of efficacy in subgroups of the study cohort indicated that veterans with no history of traumatic brain injury (TBI) had a greater clinical response to mifepristone compared with placebo at both week 4 (50% vs. 27.3%) and week 12 (45.2% vs. 18.2%).

Among people with a history of TBI, the rates of clinical response to mifepristone and placebo were similar at week 4 (32% vs. 32.6%). However, the response rate in the mifepristone group was lower compared with the placebo group at week 12 (27.4% vs. 48.3%).

Safety data revealed that mifepristone was well-tolerated and elicited similar rates of study drug-related adverse events or treatment-emergent adverse events compared with the placebo group (34.1% vs. 32.5%).

Limitations included enrolling men only, dosage amount and duration of treatment and generalizability, Golier and colleagues wrote.

Moving forward, the researchers said studies should work to address these limitations, as well as further investigate the potential use of mifepristone for PTSD in male veterans without TBI.