Recruiting
Phase 2

ACP-211

Sponsor:

ACADIA Pharmaceuticals Inc.

Code:

NCT07284667

Conditions

Major Depressive Disorder (MDD)

Depressive Disorder, Treatment-Resistant

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Interventions

ACP-211

Placebo

Study Details

Brief summary:

The goal of this clinical trial is to learn if ACP-211 can help treat adults with major depressive disorder (MDD) who have not improved with antidepressant therapy (ADT), including those with treatment resistant depression (TRD).

The main questions the study aims to answer are:

  • Does ACP-211 work better than a placebo (a look-alike capsule with no medicine) to reduce symptoms of depression?
  • What adverse events do participants have when taking ACP-211?

Conditions

Major Depressive Disorder (MDD)

Depressive Disorder, Treatment-Resistant

Study ID

NCT07284667

Start date

Nov 14, 2025

Status verified date

Oct, 2026

Completion date

Sep, 2027

Anticipated

Primary completion date

Aug, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Adults ≥18 and ≤65 years of age
  • Provides written informed consent
  • Clinical diagnosis of MDD
  • History of inadequate response to at least two antidepressants, with at least one inadequate response documented during the current episode
  • Currently treated with an approved antidepressant at a stable dose prior to Screening
  • MADRS total score ≥28, CGI-S score ≥4 , and QIDS-SR16 score ≥16 at Screening and Baseline
  • Females of childbearing potential must have a negative pregnancy test and agree to use acceptable contraception; males must agree to use barrier protection and refrain from sperm donation

Exclusion Criteria:

  • Current diagnosis of certain personality disorders or persistent depressive disorder
  • Recent substance use disorders, excluding caffeine or nicotine
  • Active suicidal risk or recent suicidal attempt
  • History of schizophrenia, psychotic disorders, bipolar disorder, or MDD with psychotic features
  • Current treatment requirement for PTSD, acute stress disorder, panic disorder, or OCD
  • History of neuroleptic malignant syndrome, serotonin syndrome, or epilepsy (except single febrile seizure in infancy)
  • Allergy or sensitivity to ketamine or esketamine
  • Significant cardiovascular disease
  • Positive history of hepatitis B, hepatitis C, or HIV infection
  • Unstable diabetes or uncontrolled medical conditions
  • Positive urine drug test for an illicit drug or cannabis
  • Received neuromodulation therapies (ECT, TMS, VNS, DBS) in the current depressive episode
  • Recent initiation or change in psychotherapy

Additional inclusion/exclusion criteria apply. Participants will be evaluated at Screening to ensure that all criteria for study participation are met.

Study Design

Enrollment

153 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: ACP-211 600 mg

ACP-211 600 mg, administered orally twice weekly

experimental: ACP-211 300 mg

ACP-211 300 mg, administered orally twice weekly

placebo comparator: Placebo

Matching placebo, administered orally twice weekly

Interventions

ACP-211

ACP-211 monotherapy

Placebo

Placebo control

Primary outcome measure

  • Change From Baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score at Day 28 [ Time Frame: Baseline and Day 28 ]

Central Contacts and Locations

Central contacts

Sandy Filosi

+1(609) 250-6920sfilosi@ACADIA-Pharm.com

Lori Lykens

+1(609) 250-6917lori.lykens@acadia-pharm.com

Locations

Inland Psychiatric Medical Group

Recruiting

Chino, California, United States, 91710

Behavioral Research Specialists, LLC

Recruiting

Glendale, California, United States, 91107

Kadima Neuropsychiatry Institute

Recruiting

La Jolla, California, United States, 92037

PNS Clinical Research LLC dba ATP Clinical Research

Recruiting

Orange, California, United States, 92866

Focus Clinical Research, LLC d/b/a Alliance Clinical West Hills

Recruiting

West Hills, California, United States, 91307

Mountain View Clinical Research

Recruiting

Denver, Colorado, United States, 80209

New Access Research and Medical Services, Inc.

Recruiting

Fort Myers, Florida, United States, 33901

The Medici Medical Research

Recruiting

Hollywood, Florida, United States, 33021

Clinical Neuroscience Solutions, Inc.

Recruiting

Orlando, Florida, United States, 32801

IPTB Clinical Research

Recruiting

Tampa, Florida, United States, 33629

Neuroscience Research Institute, Inc.

Recruiting

West Palm Beach, Florida, United States, 33407

Adams Clinical, Inc.

Recruiting

Watertown, Massachusetts, United States, 02472

Vitalix Clinical, Inc.

Recruiting

Worcester, Massachusetts, United States, 01608

Precise Research Centers

Recruiting

Flowood, Mississippi, United States, 39232

St. Charles Psychiatric Associates, Inc. dba Midwest Research Group

Recruiting

Saint Charles, Missouri, United States, 63304

Alivation Research, LLC

Recruiting

Lincoln, Nebraska, United States, 68526

Redbird Research LLC

Recruiting

Las Vegas, Nevada, United States, 89134

Integrative Clinical Trials LLC

Recruiting

Brooklyn, New York, United States, 11229

Magnolia Clinical Research, LLC

Recruiting

Cary, North Carolina, United States, 27511

Neuro-Behavioral Clinical Research

Recruiting

North Canton, Ohio, United States, 44720

Baylor College of Medicine

Recruiting

Houston, Texas, United States, 77030

Olympus Clinical Research, LLC

Recruiting

Katy, Texas, United States, 77450

Family Psychiatry of The Woodlands

Recruiting

The Woodlands, Texas, United States, 77381

Aura Wellness

Recruiting

Salt Lake City, Utah, United States, 84105

More Information

Sponsor

ACADIA Pharmaceuticals Inc.

Last update posted

Oct 5, 2026

Last verified

Oct, 2026

Keywords

  • Major Depressive Disorder (MDD)
  • Depressive Disorder, Treatment-Resistant
  • Antidepressive Agents
  • Randomized Controlled Trial
  • Double-Blind Method
  • Clinical Trial, Phase II
  • Psychiatric Status Rating Scales
  • Ketamine

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-08. This information was provided to ClinicalTrials.gov by ACADIA Pharmaceuticals Inc. on 2026-10-05. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.