Major Depressive Disorder (MDD)Phase 2NORLIGHTNCT07284667
ACP-211 Monotherapy for Major Depressive Disorder With Inadequate Antidepressant Response
A Phase 2 study testing ACP-211 in people with Major Depressive Disorder (MDD) and Depressive Disorder, Treatment-Resistant, run by ACADIA Pharmaceuticals Inc. at 28 sites in United States.
Trial 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). Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Major Depressive Disorder (MDD), Depressive Disorder, Treatment-Resistant
- What is being tested?
- ACP-211
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 153 participants
- Where
- 28 sitesUnited States
- Study dates
- 14 Nov 2025to Sep 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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 ≥14 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
Who cannot join
- 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)
Show all 14Show fewer
- 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.
Trial locations and contacts
28 sites in 1 country. Contact the study team or a site near you to ask about taking part.
28 sites in 1 country
United States28 sites, 24 recruiting
- Withdrawn
University of Alabama at Birmingham
Birmingham, Alabama, 35294
- Recruiting
Integrative Clinical Trials LLC
Brooklyn, New York, 11229
- Recruiting
Magnolia Clinical Research, LLC
Cary, North Carolina, 27511
- Recruiting
Inland Psychiatric Medical Group
Chino, California, 91710
- Recruiting
Mountain View Clinical Research
Denver, Colorado, 80209
- Recruiting
Precise Research Centers
Flowood, Mississippi, 39232
- Recruiting
New Access Research and Medical Services, Inc.
Fort Myers, Florida, 33901
- Recruiting
Behavioral Research Specialists, LLC
Glendale, California, 91107
- Recruiting
The Medici Medical Research
Hollywood, Florida, 33021
- Recruiting
Baylor College of Medicine
Houston, Texas, 77030
- Withdrawn
Dynamed Clinical Research LP d/b/a DM Clinical Research
Houston, Texas, 77081
- Recruiting
Olympus Clinical Research, LLC
Katy, Texas, 77450
- Recruiting
Kadima Neuropsychiatry Institute
La Jolla, California, 92037
- Withdrawn
Sandhill Research, LLC/DBA Accel Research Sites
Largo, Florida, 33777
- Recruiting
Redbird Research LLC
Las Vegas, Nevada, 89134
- Recruiting
Alivation Research, LLC
Lincoln, Nebraska, 68526
- Withdrawn
CenExel Hassman Research Institute, LLC
Marlton, New Jersey, 08053
- Recruiting
Neuro-Behavioral Clinical Research
North Canton, Ohio, 44720
- Recruiting
PNS Clinical Research LLC dba ATP Clinical Research
Orange, California, 92866
- Recruiting
Clinical Neuroscience Solutions, Inc.
Orlando, Florida, 32801
- Recruiting
St. Charles Psychiatric Associates, Inc. dba Midwest Research Group
Saint Charles, Missouri, 63304
- Recruiting
Aura Wellness
Salt Lake City, Utah, 84105
- Recruiting
IPTB Clinical Research
Tampa, Florida, 33629
- Recruiting
Family Psychiatry of The Woodlands
The Woodlands, Texas, 77381
- Recruiting
Adams Clinical, Inc.
Watertown, Massachusetts, 02472
- Recruiting
Focus Clinical Research, LLC d/b/a Alliance Clinical West Hills
West Hills, California, 91307
- Recruiting
Neuroscience Research Institute, Inc.
West Palm Beach, Florida, 33407
- Recruiting
Vitalix Clinical, Inc.
Worcester, Massachusetts, 01608
About this study
Official title: A Double-Blind, Placebo-Controlled, Parallel Group, Efficacy and Safety Study of ACP-211 Monotherapy in Adults With Major Depressive Disorder and Inadequate Response to Antidepressant Treatment
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?
- Being tested
- ACP-211, Placebo
- 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
- Medical subject headings
- Depressive Disorder, Major, Depressive Disorder, Treatment-Resistant
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ACP-211Drug
ACP-211 monotherapy
PlaceboDrug
Placebo control
| Study group | Role | What they receive |
|---|---|---|
| ACP-211 600 mg | Experimental | ACP-211 600 mg, administered orally twice weekly Receives: Drug: ACP-211 |
| ACP-211 300 mg | Experimental | ACP-211 300 mg, administered orally twice weekly Receives: Drug: ACP-211 |
| Placebo | Placebo comparator | Matching placebo, administered orally twice weekly Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change From Baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score at Day 28
The MADRS is a clinician-rated scale that assesses the severity of depressive symptoms. It consists of 10 items, each scored from 0 (no symptoms) to 6 (severe symptoms), resulting in a total score range of 0 to 60. Higher scores indicate greater depression severity.
Measured: Baseline and Day 28
Secondary outcomes (7)
Change From Baseline in MADRS Total Score at Day 2
The MADRS is a clinician-rated scale that assesses the severity of depressive symptoms. It consists of 10 items, each scored from 0 (no symptoms) to 6 (severe symptoms), resulting in a total score range of 0 to 60. Higher scores indicate greater depression severity.
Measured: Baseline and Day 2 (24 hours postdose)
Change From Baseline in MADRS Total Score at Scheduled Postbaseline Visits
Measured: Baseline through Day 28
Change From Baseline in Clinical Global Impression-Severity (CGI-S) Score at Scheduled Postbaseline Visits
The CGI-S is a clinician-rated assessment of illness severity scored on a 7-point scale ranging from 1 (normal, not at all ill) to 7 (among the most extremely ill). Higher scores indicate greater illness severity.
Measured: Baseline through Day 28
Proportion of Subjects in Remission at Scheduled Postbaseline Visits (MADRS ≤10)
Measured: Up to Day 28
Proportion of Subjects With Response at Scheduled Postbaseline Visits (≥50% Reduction From Baseline in MADRS Total Score)
Measured: Up to Day 28
Proportion of Subjects With Sustained Response From Day 2 Through Day 28
Subjects achieving sustained response, defined as a ≥50% reduction from Baseline in MADRS total score, with onset by Day 2 and maintained through the end of the double-blind treatment period.
Measured: Day 2 through Day 28
Proportion of Subjects With Clinical Global Impression of Improvement (CGI-I) Score of 1 or 2 at Scheduled Postbaseline Visits
The CGI-I is a clinician-rated assessment of change in illness relative to Baseline. Scores range from 1 (very much improved) to 7 (very much worse). This outcome evaluates subjects with a score of 1 (very much improved) or 2 (much improved).
Measured: Up to Day 28
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2025
- Study start14 Nov 2025
- Primary completionAug 2027 (estimated)
- Study completionSep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Major Depressive Disorder (MDD)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 153 participants (estimated)
Sponsor and investigators
- Lead sponsor
- ACADIA Pharmaceuticals Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07284667
- Sponsor's protocol ID
- ACP-211-002
- Acronym
- NORLIGHT
- Status last verified
- Nov 2026
- First submitted
- 9 Dec 2025
- Last updated
- 5 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Double-Blind, Placebo-Controlled, Parallel Group, Efficacy and Safety Study of ACP-211 Monotherapy in Adults With Major Depressive Disorder and Inadequate Response to Antidepressant Treatment
- ClinicalTrials.gov ID
- NCT07284667
- Acronym / sponsor ID
- NORLIGHT / ACP-211-002
- 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
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 153 participants (estimated)
- Lead sponsor
- ACADIA Pharmaceuticals Inc.Industry (pharma, biotech, devices)
- Study start
- 14 Nov 2025 (actual)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Sep 2027 (estimated)
- First posted
- 16 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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?
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| ACP-211 600 mg | Experimental | Drug: ACP-211ACP-211 600 mg, administered orally twice weekly |
| ACP-211 300 mg | Experimental | Drug: ACP-211ACP-211 300 mg, administered orally twice weekly |
| Placebo | Placebo comparator | Drug: PlaceboMatching placebo, administered orally twice weekly |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- 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
Key exclusion criteria (14 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ACP-211ACP-211 monotherapy | Drug | ACP-211 300 mg, ACP-211 600 mg |
| PlaceboPlacebo control | Drug | Placebo |
Primary outcome
Change From Baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score at Day 28
Time frame: Baseline and Day 28
The MADRS is a clinician-rated scale that assesses the severity of depressive symptoms. It consists of 10 items, each scored from 0 (no symptoms) to 6 (severe symptoms), resulting in a total score range of 0 to 60. Higher scores indicate greater depression severity.
7 secondary outcomes
Change From Baseline in MADRS Total Score at Day 2
Time frame: Baseline and Day 2 (24 hours postdose)
Change From Baseline in MADRS Total Score at Scheduled Postbaseline Visits
Time frame: Baseline through Day 28
Change From Baseline in Clinical Global Impression-Severity (CGI-S) Score at Scheduled Postbaseline Visits
Time frame: Baseline through Day 28
Proportion of Subjects in Remission at Scheduled Postbaseline Visits (MADRS ≤10)
Time frame: Up to Day 28
Proportion of Subjects With Response at Scheduled Postbaseline Visits (≥50% Reduction From Baseline in MADRS Total Score)
Time frame: Up to Day 28
Proportion of Subjects With Sustained Response From Day 2 Through Day 28
Time frame: Day 2 through Day 28
Proportion of Subjects With Clinical Global Impression of Improvement (CGI-I) Score of 1 or 2 at Scheduled Postbaseline Visits
Time frame: Up to Day 28
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Nov 2026.
- Individual participant dataSharing planned: No
Related trials for Major Depressive Disorder (MDD)
Not yet recruiting
Preventive and Personalized Digital Emotion Regulation Skills Intervention to Reduce Depression and Anxiety in Youths With Adverse Childhood Experiences
Adverse Childhood Experience, Depression / Major Depressive Disorder
RecruitingPhase 4
Biomarker-Guided Antidepressant Selection
Depression - Major Depressive Disorder, Treatment-resistant Depression (TRD)
Recruiting
Targeting Network Dysfunction in Apathy of Late-life Depression Using Digital Therapeutics
Major Depressive Disorder, Apathy
Not yet recruiting
Acute Intermittent Hypoxia Therapy for Depression
Major Depressive Disorder (MDD)
RecruitingPhase 2
Psilocybin With Pimavanserin Compared to Psilocybin Alone for the Treatment of Major Depressive Disorder
Major Depressive Disorder
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
28 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing ACP-211 in people with Major Depressive Disorder (MDD) and Depressive Disorder, Treatment-Resistant, run by ACADIA Pharmaceuticals Inc. at 28 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 5 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 28 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sandy Filosi (+1(609) 250-6920, sfilosi@ACADIA-Pharm.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change From Baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score at Day 28 (time frame: Baseline and Day 28). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Nov 2026.