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ALTO-207 for adults with treatment-resistant depression

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

Phase 2 Interventional Alto Neuroscience · NCT07553637

This trial will test whether ALTO-207 reduces depressive symptoms more than placebo in adults whose depression has not improved after at least two antidepressant treatments.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment178 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorAlto Neuroscience Industry-sponsored
Locations48 sites (Birmingham, Alabama and 47 other locations)
Trial IDNCT07553637 on ClinicalTrials.gov

What this trial studies

This Phase 2 interventional trial compares ALTO-207 to placebo in adults with treatment-resistant depression. Eligible participants are ages 18–75 with moderate-to-severe major depressive disorder who have failed to respond (<50% improvement) to 2–5 prior antidepressant treatments and are on a stable dose of one to two oral antidepressants. Participants at U.S. outpatient sites will receive ALTO-207 or matched placebo and depressive symptoms will be measured periodically using standard rating scales. The trial is sponsored by Alto Neuroscience and conducted at sites in Alabama and Arizona.

Who should consider this trial

Good fit: Adults 18–75 with a current moderate-to-severe major depressive episode who have not improved sufficiently after 2–5 antidepressant treatments and who are on a stable dose of one to two oral antidepressants are the intended participants.

Not a fit: People with bipolar disorder, psychotic disorders, significant PTSD symptoms, current substance use disorder, unstable medical conditions, or known allergy to ALTO-207 would be excluded and are unlikely to benefit from participating.

Why it matters

Potential benefit: If successful, ALTO-207 could provide an additional effective treatment option to reduce symptoms for people with treatment-resistant depression.

How similar studies have performed: ALTO-207 and related compounds are relatively novel with limited published clinical data, so this approach remains experimental.

Eligibility criteria

Show full inclusion / exclusion criteria 
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

Where this trial is running

Birmingham, Alabama and 47 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 Treatment-resistant Depression
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.