SEP-363856 · program

Ulotaront (SEP-363856) for Major depressive disorder

Phase 2/3CompletedOtsuka Pharmaceutical Co., Ltd. (4578.T)

Indications for SEP-363856: Generalized anxiety disorder · Phase 2/3 Major depressive disorder · Phase 2/3

Adjunctive ulotaront for major depressive disorder — second mood indication after the lead GAD program. Phase 2/3 study (NCT05593029, n=929) completed Nov 2025; topline pending.

Data current as of

Development timeline

Phase 2/3Nov 2022 – Nov 2025
  1. Phase 2/3 adjunctive MDD study reached completion; topline results not yet disclosed.
  2. Phase 2/3 adjunctive MDD study (NCT05593029) started.

Clinical trials in Major depressive disorder

NCT05593029382-201-00001Phase 2/3Completedn=929

Phase 2/3 Trial of SEP-363856 as Adjunctive Therapy in Major Depressive Disorder

Started Nov 2022· Primary completion Nov 2025· 📍 77 sites across 7 countries (United States, Germany, Poland, Bulgaria)

Formulations

FormulationRouteRegimenPharmacokinetics
Ulotaront oral
Oral doses studied 10-100 mg (dose-proportional PK); 25 mg single oral dose in the CYP2D6 healthy-subject study; once-daily dosing supported by PK.
OralOnce dailyt½ 7 h · Tmax 2 h

Mechanism of action (compound-wide)

Dual TAAR1 agonist / 5-HT1A agonist with no appreciable D2 or 5-HT2A activity.

TargetActionAffinity
TAAR1primaryTAAR1AgonistEC50 38 nMⓘ
5-HT1AHTR1AAgonistKi 284 nMⓘ

← Full SEP-363856 compound page (identity, identifiers, all indications)

Sources

  1. A Phase I, Open-Label, Fixed Sequence Study to Investigate the Effect of CYP2D6 Inhibition on the Pharmacokinetics of Ulotaront in Healthy Subjects — Clinical Pharmacokinetics (PMC)
  2. Ulotaront adjunctive MDD Phase 2/3 (NCT05593029) — ClinicalTrials.gov
  3. Ulotaront: A TAAR1 Agonist for the Treatment of Schizophrenia (synthesis/med-chem) — ACS Med Chem Lett (PMC)