Actively Recruiting
Efficacy and Safety Study of ACP-211 Monotherapy in Adults With Major Depressive Disorder and Inadequate Response to Antidepressant Treatment
Led by ACADIA Pharmaceuticals Inc. · Updated on 2026-06-08
153
Participants Needed
21
Research Sites
4 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating ACP-211 as a monotherapy for adults aged 18 to 65 with major depressive disorder (MDD) who have not had sufficient improvement with antidepressant therapy, including those with treatment-resistant depression. The study aims to determine if ACP-211 is more effective than a placebo in reducing depression symptoms and to assess adverse events experienced by participants. This is a randomized, double-blind, placebo-controlled Phase 2 clinical trial sponsored by ACADIA Pharmaceuticals Inc. Participants will be assigned randomly to one of three groups: ACP-211 600 mg taken orally twice weekly, ACP-211 300 mg taken orally twice weekly, or a matching placebo taken orally twice weekly. Treatment will continue for a period up to Day 28, during which the effects of the medication on depression symptoms will be monitored and compared across groups. Throughout the study, participants will undergo assessments including the Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline and Day 28 to measure changes in depression symptoms. Additional evaluations include MADRS scores at 24 hours postdose on Day 2. Safety and adverse events will be closely monitored, and participants will be evaluated at screening to confirm eligibility. The study duration includes treatment and follow-up assessments up to approximately one month.
CONDITIONS
Brief Title
ACP-211 Monotherapy for Major Depressive Disorder With Inadequate Antidepressant Response
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Adults 18 to 65 years of age
- Provide written informed consent
- Clinical diagnosis of major depressive disorder
- History of inadequate response to at least two antidepressants, including one during the current episode
- Currently treated with an approved antidepressant at a stable dose prior to screening
- MADRS total score of 28 or higher, CGI-S score of 4 or higher, and QIDS-SR16 score of 16 or higher 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
You will not qualify if you...
- 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 major depressive disorder 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)
- Documented non-response to antidepressant therapy including ketamine or esketamine
- 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 illicit drugs or cannabis
- Received neuromodulation therapies (ECT, TMS, VNS, DBS) in the current depressive episode
- Recent initiation or change in psychotherapy
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 28 days
Participants receive ACP-211 or placebo orally twice weekly as monotherapy for major depressive disorder.
Approximately 4 visits (in-person) during treatment
Trial Site Locations
Total: 21 locations
1
University of Alabama at Birmingham
Birmingham, Alabama, United States, 35294
Actively Recruiting
2
Inland Psychiatric Medical Group
Chino, California, United States, 91710
Actively Recruiting
3
Kadima Neuropsychiatry Institute
La Jolla, California, United States, 92037
Actively Recruiting
4
PNS Clinical Research LLC dba ATP Clinical Research
Orange, California, United States, 92866
Actively Recruiting
5
Mountain View Clinical Research
Denver, Colorado, United States, 80209
Actively Recruiting
6
The Medici Medical Research
Hollywood, Florida, United States, 33021
Actively Recruiting
7
Sandhill Research, LLC/DBA Accel Research Sites
Largo, Florida, United States, 33777
Active, Not Recruiting
8
Clinical Neuroscience Solutions, Inc.
Orlando, Florida, United States, 32801
Actively Recruiting
9
IPTB Clinical Research
Tampa, Florida, United States, 33629
Actively Recruiting
10
Neuroscience Research Institute, Inc.
West Palm Beach, Florida, United States, 33407
Actively Recruiting
11
Vitalix Clinical, Inc.
Worcester, Massachusetts, United States, 01608
Actively Recruiting
12
St. Charles Psychiatric Associates, Inc. dba Midwest Research Group
Saint Charles, Missouri, United States, 63304
Actively Recruiting
13
Redbird Research LLC
Las Vegas, Nevada, United States, 89134
Actively Recruiting
14
CenExel Hassman Research Institute, LLC
Marlton, New Jersey, United States, 08053
Active, Not Recruiting
15
Integrative Clinical Trials LLC
Brooklyn, New York, United States, 11229
Actively Recruiting
16
Magnolia Clinical Research, LLC
Cary, North Carolina, United States, 27511
Actively Recruiting
17
Neuro-Behavioral Clinical Research
North Canton, Ohio, United States, 44720
Actively Recruiting
18
Baylor College of Medicine
Houston, Texas, United States, 77030
Actively Recruiting
19
Dynamed Clinical Research LP d/b/a DM Clinical Research
Houston, Texas, United States, 77081
Active, Not Recruiting
20
Olympus Clinical Research, LLC
Katy, Texas, United States, 77450
Actively Recruiting
21
Family Psychiatry of The Woodlands
The Woodlands, Texas, United States, 77381
Actively Recruiting
Research Team
S
Sandy Filosi
L
Lori Lykens
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
3
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