ALTO-207 in Adults With Treatment-resistant Depression (TRD)

April 23, 2026 updated by: Alto Neuroscience

A Randomized, Double-blind, Placebo-controlled Trial of ALTO-207 in Adults With Treatment-resistant Depression

The purpose of this trial is to measure depressive symptoms following treatment with ALTO-207 compared with placebo in participants with TRD.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
178

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United Kingdom
      • Antrim, United Kingdom
        • Not yet recruiting
        • Site 7419
      • Birmingham, United Kingdom
        • Not yet recruiting
        • Site 7411
      • Bristol, United Kingdom
        • Not yet recruiting
        • Site 7414
      • Cardiff, United Kingdom
        • Not yet recruiting
        • Site 7412
      • Exeter, United Kingdom
        • Not yet recruiting
        • Site 7418
      • London, United Kingdom
        • Not yet recruiting
        • Site 7415
      • Nottingham, United Kingdom
        • Not yet recruiting
        • Site 7413
      • Oxford, United Kingdom
        • Not yet recruiting
        • Site 7410
      • Prescot, United Kingdom
        • Not yet recruiting
        • Site 7402
      • Sheffield, United Kingdom
        • Not yet recruiting
        • Site 7416
  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35294
        • Not yet recruiting
        • Site 7074
      • Dothan, Alabama, United States, 36345
        • Not yet recruiting
        • Site 7173
    • Arizona
      • Phoenix, Arizona, United States, 85012
        • Recruiting
        • Site 7000
    • California
      • Chino, California, United States, 91710
        • Not yet recruiting
        • Site 7153
      • Oakland, California, United States, 94610
        • Not yet recruiting
        • Site 7156
      • Oceanside, California, United States, 92056
        • Recruiting
        • Site 7082
      • Palo Alto, California, United States, 94304
        • Not yet recruiting
        • Site 7159
      • Sacramento, California, United States, 95655
        • Not yet recruiting
        • Site 7016
      • San Diego, California, United States, 92123
        • Recruiting
        • Site 7144
      • Valley Village, California, United States, 91607
        • Not yet recruiting
        • Site 7171
    • Florida
      • Saint Augustine, Florida, United States, 32086
        • Recruiting
        • Site 7152
    • Georgia
      • Albany, Georgia, United States, 31707
        • Recruiting
        • Site 7148
      • Atlanta, Georgia, United States, 30060
        • Not yet recruiting
        • Site 7146
      • Peachtree Corners, Georgia, United States, 30078
        • Not yet recruiting
        • Site 7064
      • Savannah, Georgia, United States, 31406
        • Recruiting
        • Site 7141
    • Indiana
      • Indianapolis, Indiana, United States, 46202
        • Not yet recruiting
        • Site 7169
    • Maryland
      • Annapolis, Maryland, United States, 21401
        • Recruiting
        • Site 7151
      • Pikesville, Maryland, United States, 21208
        • Not yet recruiting
        • Site 7054
    • Massachusetts
      • Worcester, Massachusetts, United States, 01606
        • Not yet recruiting
        • Site 7166
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • Not yet recruiting
        • Site 7155
      • Bloomfield Hills, Michigan, United States, 48302
        • Recruiting
        • Site 7154
    • New York
      • Amherst, New York, United States, 14226
        • Not yet recruiting
        • Site 7170
      • Cedarhurst, New York, United States, 11516
        • Not yet recruiting
        • Site 7055
      • Lewiston, New York, United States, 14214
        • Not yet recruiting
        • Site 7162
      • Syracuse, New York, United States, 13210
        • Not yet recruiting
        • Site 7157
    • North Carolina
      • Charlotte, North Carolina, United States, 28287
        • Recruiting
        • Site 7143
    • Ohio
      • Cincinnati, Ohio, United States, 45215
        • Recruiting
        • Site 7029
      • Garfield Heights, Ohio, United States, 44125
        • Not yet recruiting
        • Site 7158
    • Rhode Island
      • East Providence, Rhode Island, United States, 02914
        • Not yet recruiting
        • Site 7172
    • Texas
      • Dallas, Texas, United States, 75243
        • Not yet recruiting
        • Site 7176
      • Fort Worth, Texas, United States, 76104
        • Not yet recruiting
        • Site 7160
      • Galveston, Texas, United States, 77555
        • Not yet recruiting
        • Site 7150
      • Houston, Texas, United States, 77007
        • Not yet recruiting
        • Site 7175
      • Houston, Texas, United States, 77030
        • Recruiting
        • Site 7145
      • Irving, Texas, United States, 75062
        • Recruiting
        • Site 7161
    • Virginia
      • Fairfax, Virginia, United States, 22030
        • Not yet recruiting
        • Site 7177
    • Washington
      • Seattle, Washington, United States, 98004
        • Not yet recruiting
        • Site 7128
    • West Virginia
      • South Charleston, West Virginia, United States, 25303
        • Not yet recruiting
        • Site 7163

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male and female participants, ages 18 to 75 years, inclusive, at the time of signing the ICF.
  • Prior diagnosis of MDD without psychotic symptoms (in the current episode) and have confirmatory diagnosis of current MDD (moderate to severe).
  • Failure to respond (<50% improvement) to at least 2-5 antidepressant treatments (including the current treatment)
  • Currently taking a stable dose of at least 1 but no more than 2 oral antidepressants at baseline

Exclusion Criteria:

  • Evidence of unstable medical condition
  • Concurrent use of any prohibited medications or substance use disorder
  • Diagnosed bipolar disorder or a psychotic disorder or symptoms
  • Significant current PTSD symptoms or history of PTSD
  • Clinically significant current impulse control difficulties
  • Has a history of hypersensitivity or allergic reaction to ALTO-207 or any of its components/excipients
  • Concurrent or recent participation in another clinical trial for mental illness involving an investigational product or device

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: Placebo
Drug: Placebo
Matching Placebo
Experimental: ALTO-207
Drug: ALTO-207
ALTO-207 BID

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in the MADRS total score
Time Frame: Change from baseline up to 8 weeks
Montgomery Asberg Depression Rating Scale (MADRS) is a clinician-administered scale designed to measure depression severity and detects changes due to antidepressant treatment. The MADRS evaluates the following 10 items: apparent sadness, reported sadness, inner tension, reduced sleep, reduced appetite, concentration difficulties, lassitude, inability to feel, pessimistic thoughts, and suicidal thoughts. Each item is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.
Change from baseline up to 8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in response (≥50% improvement) raters based on MADRS
Time Frame: Change from baseline up to 8 weeks
Montgomery Asberg Depression Rating Scale (MADRS) is a clinician-administered scale designed to measure depression severity and detects changes due to antidepressant treatment. The MADRS evaluates the following 10 items: apparent sadness, reported sadness, inner tension, reduced sleep, reduced appetite, concentration difficulties, lassitude, inability to feel, pessimistic thoughts, and suicidal thoughts. Each item is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition.
Change from baseline up to 8 weeks
Change in the Clinician-administered CGI-S score over time from Baseline to Week 8
Time Frame: Change from baseline up to 8 weeks
The Clinician Global Impression-Severity scale (CGI-S) is a 7-point global assessment scale that measures the clinician's impression of the severity of illness exhibited by a participant, rating according to: 1=normal (not at all ill); 2=borderline ill; 3=mildly ill; 4=moderately ill; 5=markedly ill; 6=severely ill; and 7=among the most extremely ill participants. Higher scores represent a more severe condition.
Change from baseline up to 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Alto Neuroscience

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 31, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 23, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 28, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 28, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 23, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ALTO-207-201

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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