Investigational TSND-201 Shows Early and Significant Efficacy in Severe PTSD in Phase II Trial
USA: The investigational neuroplastogen TSND-201 demonstrated significant efficacy in patients with severe post-traumatic stress disorder (PTSD) in a randomized phase II trial. A statistically significant clinical improvement was observed as early as day 10 of treatment. Notably, patients in the study achieved these benefits without undergoing psychotherapy, highlighting the drug’s potential as a standalone therapeutic option for severe PTSD.
The findings, published in JAMA Psychiatry, come from the IMPACT-1 (part B) trial led by Amanda Jones of Transcend Therapeutics, New York, and colleagues. PTSD remains a debilitating condition with a substantial unmet need for rapid and durable treatments. TSND-201 (methylone) is a selective, fast-acting neuroplastogen that increases the release of serotonin, norepinephrine, and dopamine without directly stimulating 5-HT2A receptors. Earlier phase 1 studies in healthy volunteers suggested favorable tolerability.
This phase 2, multicenter, double-blind, placebo-controlled trial enrolled 65 adults aged 18 to 65 years with moderate to severe PTSD, defined by a Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) score of 35 or higher and symptoms persisting for at least six months. The study was conducted across 16 sites in the US, UK, and Ireland between late 2023 and early 2025.
Participants were randomly assigned in a 1:1 ratio to receive TSND-201 or a placebo. Treatment consisted of four once-weekly oral dosing sessions, beginning with 150 mg followed by 100 mg doses. Although dosing sessions were supervised by mental health professionals, no formal psychotherapy was delivered. Patients were monitored for six weeks after the final dose.
The primary endpoint was the change in CAPS-5 total severity score from baseline to day 64.
The researchers reported the following findings:
- TSND-201 produced a significantly greater reduction in PTSD symptom severity compared with placebo, with a least-squares mean difference of 9.64 points.
- Significant improvements were also observed in secondary outcomes, including PCL-5, Sheehan Disability Scale (SDS), and Montgomery-Åsberg Depression Rating Scale (MADRS) scores.
- Higher response and remission rates further reinforced the clinical significance of the treatment effect.
- Symptom improvement was rapid and sustained beyond the dosing period.
- TSND-201 was generally well tolerated.
- Common adverse events included headache, nausea, decreased appetite, dizziness, increased blood pressure, dry mouth, and insomnia.
- Most adverse events were mild to moderate, occurred on dosing days, and resolved within 24 hours.
- No new safety concerns were identified.
The investigators noted several limitations, including a relatively small sample size and limited representation of individuals with military-related trauma. The study also used a one-sided statistical test, though significance was maintained with two-sided analyses. Additionally, the sample size precluded a detailed assessment of predictors of treatment response.
Overall, the trial provides encouraging evidence that TSND-201 may offer a rapid, durable, and well-tolerated treatment option for severe PTSD. Larger confirmatory studies are needed to validate these results and further define their role in clinical practice.
Reference: Jones A, Warner-Schmidt J, Kwak H, et al. Efficacy and Safety of the Neuroplastogen TSND-201 for the Treatment of PTSD: A Randomized Clinical Trial. JAMA Psychiatry. Published online February 18, 2026. doi:10.1001/jamapsychiatry.2025.4625
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