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NBI-1065845 added to a current antidepressant for major depressive disorder

A Randomized, Double-Blind, Placebo-Controlled Study to Assess the Efficacy and Safety of NBI-1065845 as Adjunctive Treatment in Subjects With Major Depressive Disorder (MDD)

Phase 3 Interventional Neurocrine Biosciences · NCT06963021

This trial will test whether adding NBI-1065845 to a stable oral antidepressant helps adults with major depressive disorder who have not had enough benefit.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment200 (estimated)
Ages18 Years and up
SexAll
SponsorNeurocrine Biosciences Industry-sponsored
Locations30 sites (Chino, California and 29 other locations)
Trial IDNCT06963021 on ClinicalTrials.gov

What this trial studies

This is a Phase 3 interventional trial comparing NBI-1065845 with placebo as an add-on to participants' ongoing oral antidepressant medication. Eligible participants have recurrent moderate or severe MDD or persistent depressive disorder and an inadequate response to oral antidepressants, with a HAM-D17 score of 22 or higher at screening and baseline. Participants must have been on a stable oral antidepressant regimen for at least 8 weeks and continue that regimen unchanged during the trial while receiving either NBI-1065845 or placebo. Symptom change will be measured using standard depression rating scales to determine whether the adjunctive therapy provides additional benefit.

Who should consider this trial

Good fit: Adults with recurrent moderate or severe major depressive disorder or persistent depressive disorder who have had an inadequate response to at least 8 weeks of a stable oral antidepressant and have a HAM-D17 score of 22 or higher are the intended candidates.

Not a fit: People whose depression is primarily due to another psychiatric disorder treated in the past year, those judged to be at imminent suicide risk, or those already responding well to their current antidepressant are unlikely to benefit from this trial.

Why it matters

Potential benefit: If successful, this could provide an effective add-on medication option for people with MDD who do not respond adequately to current oral antidepressants.

How similar studies have performed: Adjunctive pharmacologic strategies are an established approach in MDD and earlier-phase data for NBI-1065845/TAK-653 provided enough signal to progress to this Phase 3 evaluation.

Eligibility criteria

Show full inclusion / exclusion criteria 
Key Inclusion Criteria:

* Participant has a primary diagnosis of recurrent MDD (moderate or severe) or persistent depressive disorder.
* Participant has had an inadequate response to oral antidepressant treatments in the current episode of depression.
* Participant must have been taking oral antidepressants for at least 8 weeks and is willing to continue the same oral antidepressants at the same dose and frequency of administration throughout participation in the study.
* Total Hamilton Depression Rating Scale-17 Item (HAM-D17) score ≥22 at screening and at study baseline (Day 1).
* Willing and able to comply with all study procedures and restrictions in the opinion of the investigator.

Key Exclusion Criteria:

* A current or prior psychiatric disorder diagnosis in the last 1 year that was the primary focus of treatment other than MDD.
* Are considered by the investigator to be at imminent risk of suicide or injury to self or others.
* Participants depressive symptoms have previously demonstrated nonresponse to electroconvulsive therapy (ECT) in the current major depressive episode.

Where this trial is running

Chino, California and 29 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Major Depressive DisorderMDDDepressionNBI-1065845TAK-653MADRS
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.