OPC-34712 · program

Brexpiprazole for Post-traumatic stress disorder

Filed (NDA)DiscontinuedOtsuka Pharmaceutical Co., Ltd. (4578.T)

Brexpiprazole administered in combination with the SSRI sertraline for the treatment of post-traumatic stress disorder (PTSD) in adults, developed by Otsuka and Lundbeck. A supplemental New Drug Application (sNDA) was accepted by the FDA on 25 Jun 2024 (PDUFA target 8 Feb 2025), supported by three randomized trials: Phase 2 Trial 061 (positive), Phase 3 Trial 071 / NCT04124614 (flexible dose, met its primary CAPS-5 endpoint), and Phase 3 Trial 072 / NCT04174170 (fixed dose, did not meet its primary endpoint). On 18 Jul 2025 an FDA Psychopharmacologic Drugs Advisory Committee voted 1-10 that efficacy of concurrently-initiated brexpiprazole + sertraline was not established. The FDA issued a Complete Response Letter, announced 20 Sep 2025, stating the application did not provide substantial evidence of effectiveness and that additional adequate, well-controlled trials would be needed. Status marked discontinued to reflect that the approval path is, as of the CRL, not advancing; phase 'filed' captures the regulatory-submission state.

Development timeline

Filed (NDA)Jun 2024 – Sept 2025
  1. missedFDA issues Complete Response Letter for brexpiprazole + sertraline sNDA in PTSD
  2. FDA accepted the sNDA for brexpiprazole in combination with sertraline for adult PTSD; PDUFA target action date 8 Feb 2025.
Phase 3Aug 2023
  1. Both Phase 3 PTSD trials of brexpiprazole + sertraline completed in August 2023 (Trial 071 / NCT04124614 completed 8 Aug 2023; Trial 072 / NCT04174170 completed 15 Aug 2023). Trial 071 met its primary CAPS-5 endpoint; Trial 072 did not.

Readouts

  • 2025-09-20ReportedRegulatorymissed

    FDA issues Complete Response Letter for brexpiprazole + sertraline sNDA in PTSD

Clinical trials in Post-traumatic stress disorder

NCT04174170331-201-00072Phase 3Completedn=591

A Phase 3, Multicenter, Randomized, Double-blind Trial of Fixed-Dose Brexpiprazole as Combination Therapy With Sertraline in the Treatment of Adults With Post-traumatic Stress Disorder

Started Oct 2019· Primary completion Jul 2023· 📍 1 site across 1 country (United States)

missedprimaryChange from baseline in CAPS-5 total score at week 10 (fixed-dose brexpiprazole + sertraline vs sertraline + placebo)

Phase 3 fixed-dose Trial 072 did NOT meet its primary endpoint. Per the companies, reductions in PTSD symptoms with brexpiprazole + sertraline were directionally consistent with Trials 061 and 071, but the primary CAPS-5 endpoint was not statistically met. This negative result, alongside the positive flexible-dose Trial 071, contributed to the FDA's finding of insufficient substantial evidence.

NCT04124614331-201-00071Phase 3Completedn=450

A Phase 3, Multicenter, Randomized, Double-blind Trial of Brexpiprazole as Combination Therapy With Sertraline in the Treatment of Adults With Post-traumatic Stress Disorder

Started Oct 2019· Primary completion Jul 2023· 📍 1 site across 1 country (United States)

metprimaryChange from baseline in CAPS-5 total score at week 10 (brexpiprazole + sertraline vs sertraline + placebo) — LSM difference -5.59 (95% CI -8.79 to -2.38); CAPS-5 change -19.2 (brexpiprazole+sertraline) vs -13.6 (sertraline+placebo) (<0.001)

Phase 3 flexible-dose Trial 071 (416 randomized; 205 brexpiprazole+sertraline, 196 sertraline+placebo) met its primary endpoint: brexpiprazole + sertraline produced a statistically significant greater reduction in CAPS-5 total score vs sertraline + placebo from week 1 to week 10. Published in JAMA Psychiatry 18 Dec 2024 (doi:10.1001/jamapsychiatry.2024.3996).

Formulations

FormulationRouteRegimenPharmacokinetics
Brexpiprazole oral tablet (Rexulti)
Oral tablets in 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, and 4 mg strengths, administered once daily with or without food. In PTSD studied as combination therapy with sertraline.
OralOnce dailyt½ 91 h · Tmax 4 h · F 95%

Mechanism of action (compound-wide)

Brexpiprazole is a serotonin-dopamine activity modulator. It is a partial agonist at dopamine D2 and serotonin 5-HT1A receptors and an antagonist at serotonin 5-HT2A receptors, with additional antagonism at adrenergic alpha1B and alpha2C receptors. Relative to aripiprazole it has lower intrinsic activity at D2 and higher 5-HT1A/5-HT2A affinity. In the PTSD program it was given in combination with the SSRI sertraline (a serotonin reuptake inhibitor); the rationale was that brexpiprazole's receptor modulation augments sertraline's serotonergic action to improve PTSD symptom control. Affinity values are from the primary in vitro characterization (Maeda et al. 2014).

TargetActionAffinity
D2primaryDRD2Partial agonistKi 0.3 nM
5-HT1AHTR1APartial agonistKi 0.12 nM
5-HT2AHTR2AAntagonistKi 0.47 nM

← Full OPC-34712 compound page (identity, identifiers, all indications)

Sources

  1. Brexpiprazole as Combination Therapy With Sertraline in Treatment of Adults With PTSD (Trial 071) — ClinicalTrials.gov
  2. Brexpiprazole I: in vitro and in vivo characterization of a novel serotonin-dopamine activity modulator (Maeda et al., J Pharmacol Exp Ther 2014) — Journal of Pharmacology and Experimental Therapeutics
  3. Fixed-Dose Brexpiprazole as Combination Therapy With Sertraline in Treatment of Adults With PTSD (Trial 072) — ClinicalTrials.gov
  4. JAMA Psychiatry Publishes Results of Otsuka and Lundbeck's Phase 3 Trial of Brexpiprazole in Combination with Sertraline in Treatment of PTSD in Adults — Otsuka Pharmaceutical
  5. Otsuka and Lundbeck Announce FDA Acceptance of sNDA Filing for Brexpiprazole in Combination with Sertraline for the Treatment of Adults with PTSD — H. Lundbeck A/S
  6. Otsuka and Lundbeck Receive Complete Response Letter from U.S. FDA for sNDA of REXULTI (brexpiprazole) in Combination with Sertraline for the Treatment of Adults with PTSD — Otsuka Pharmaceutical
  7. REXULTI (brexpiprazole) tablets, for oral use — US Prescribing Information — Otsuka Pharmaceutical / FDA