Psychiatry · Clinical trials
Post-Traumatic Stress Disorder (PTSD) Clinical Trials
Approved therapies, the pivotal-trial endpoints they were judged on, the magnitude of benefit — and the drugs that failed their endpoints, and why.
Indication overview
About post-traumatic stress disorder (ptsd) — and why its trials are hard
PTSD is a trauma- and stressor-related disorder marked by intrusive re-experiencing, avoidance, negative alterations in cognition and mood, and hyperarousal persisting more than one month after a traumatic event. Despite high prevalence, the pharmacologic armamentarium is strikingly narrow: only two agents, the SSRIs sertraline (1999) and paroxetine (2001), carry FDA approval for PTSD, both delivering modest symptom reductions on the Clinician-Administered PTSD Scale (CAPS). Trauma-focused psychotherapies (prolonged exposure, CPT) remain first-line, and many patients receive off-label prazosin, SNRIs, or antipsychotics. The field has seen high-profile late-stage failures: MDMA-assisted therapy was rejected by the FDA in 2024, and a brexpiprazole-plus-sertraline combination was denied in 2025 after inconsistent replication. These setbacks underscore persistent challenges in trial design, functional unblinding, and reproducibility that continue to constrain novel PTSD drug development, leaving substantial unmet need for pharmacotherapies with larger effect sizes and durable benefit.
Approved therapies & pivotal evidence
What's been approved — and by how much it moved the endpoint
| Drug (brand) | Approved | Setting | Pivotal trial | Primary endpoint | Magnitude of benefit |
|---|---|---|---|---|---|
| Sertraline (Zoloft) | 1999 | Adults with PTSD; oral SSRI, first-line pharmacotherapy | Pivotal 12-week placebo-controlled trials (Brady et al. 2000, JAMA; Davidson et al. 2001) | CAPS-2 total score and CGI-I / Impact of Event Scale change from baseline | Statistically significant reduction in CAPS-2 vs placebo; responder rates roughly 53% vs 32% for placebo (unverified exact figures) |
| Paroxetine (Paxil) | 2001 | Adults with PTSD; oral SSRI, first-line pharmacotherapy | Two 12-week randomized placebo-controlled trials (Marshall et al. 2001; Tucker et al. 2001) | CAPS-2 total score and CGI-I change from baseline | Significant CAPS-2 reduction vs placebo across all three symptom clusters; LSM difference roughly 8-13 points (unverified exact figures) |
Where trials have failed
Drugs that missed their endpoint — and what contributed
The most instructive lessons in post-traumatic stress disorder (ptsd) development come from programmes that failed the endpoint that mattered.
| Drug / trial | Endpoint outcome | What contributed |
|---|---|---|
| MDMA-assisted therapy (midomafetamine) — MAPP1 and MAPP2 Phase 3 (Nature Medicine 2021, 2023); primary endpoint CAPS-5 change from baseline | Trials met CAPS-5 endpoint with large effect, but FDA issued a Complete Response Letter (rejection) in August 2024 requiring an additional Phase 3 study | Functional unblinding, concerns over expectancy bias, reports of therapist misconduct and data-integrity/ethics issues, and difficulty isolating drug from psychotherapy effect |
| Brexpiprazole + sertraline (combination) — Studies 071, 072 (and 061); primary endpoint CAPS-5 change from baseline | FDA advisory committee voted against and the agency denied approval in 2025 because a second trial failed to replicate the first | Inconsistent efficacy across pivotal trials (072 did not confirm 071), modest effect size, and insufficient substantial evidence of effectiveness |
Choosing the right endpoint
Primary endpoints that matter in post-traumatic stress disorder (ptsd) trials
- CAPS-5 (Clinician-Administered PTSD Scale for DSM-5) — Structured clinician interview; the current gold-standard primary endpoint in modern PTSD trials
- CAPS-2 / CAPS-IV — Earlier CAPS versions used in the pivotal sertraline and paroxetine registration trials
- CGI-I (Clinical Global Impression-Improvement) — Global clinician-rated responder measure used as key secondary/co-primary
- PCL-5 (PTSD Checklist) — Patient-reported symptom severity scale, common secondary endpoint
How iNGENū runs post-traumatic stress disorder (ptsd) trials
Physician-led design, built for FDA submission
Endpoint & biomarker strategy
Board-certified specialists design endpoints and patient selection aligned to current FDA guidance for this indication.
FDA-ready data
Built to ICH-GCP and 21 CFR 312.120, with direct FDA submission — data accepted by the FDA, EMA and MHRA.
Faster, lower-cost delivery
~4-week ethics via the TGA CTN scheme, up to 43.5% R&D rebate, and 80–90% below US CRO cost.
Request a fixed-milestone proposal and a tailored endpoint & feasibility summary for this indication.
Frequently asked questions
Post-Traumatic Stress Disorder (PTSD) clinical trials — FAQs
How many drugs are FDA-approved specifically for PTSD?
Why was MDMA-assisted therapy rejected by the FDA?
What is the standard primary endpoint in PTSD trials?
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