A Phase 2a Study to Evaluate the Safety and Tolerability of GM-2505 in Patients With MDD

A Phase 2a Study to Evaluate the Safety and Tolerability of Two Repeated Doses of GM-2505 at a 2-Week Interval in Patients With Major Depressive Disorder.

A Phase 2a Study to Evaluate the Safety and Tolerability of GM-2505 in Patients With MDD (NCT06236880) is a Phase 2 interventional studying Major Depressive Disorder, sponsored by Gilgamesh Pharmaceuticals. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

This is a three-part Phase 2a study. The aim of Part A is to assess the safety and tolerability and preliminary antidepressant efficacy in patients with MDD who are not currently on an antidepressant therapy. The aim of Part B is to assess the antidepressant efficacy, safety and tolerability in patients with MDD who are partial responders while on a current and adequate single SSRI or SNRI treatment. Part C aims to replicate the monotherapy findings of Part A, but with a lower control group dose.

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Major Depressive Disorder and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 124 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Major Depressive Disorder subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Key Who May Qualify: 1. Patients are male or female, of any ethnic origin. 2. Patients are aged between 18 to 65 years, inclusive. 3. Patients meet the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for recurrent MDD without psychotic features, as assessed with the Mini-International Neuropsychiatric Interview (MINI) at Screening. 4. Current moderate to severe MDD diagnosis confirmed with a MADRS-SIGMA 5. Concomitant depression therapy: 1. (Part A) Patients need to be stable and must not have taken any SSRI or SNRI for at least 6 weeks prior to Screening and must be willing to avoid starting a new pharmacological treatment for MDD until the end of the study procedures and assessments. Discontinuing current treatment is not allowed if done for the purposes of achieving eligibility for this study. 2. (Part B) Patients need to be on stable treatment with any SSRI or SNRI for at least 6 weeks prior to screening and must be willing to remain on the SSRI or SNRI for the duration of the trial 3. Patients receiving any form of psychotherapy or counselling must have been receiving therapy at Screening and must be willing to remain in therapy until the end of the study procedures and assessments. Key Who Should NOT Join This Trial: 1. Patient has current or past primary DSM-5 diagnosis of a psychotic disorder or MDD with psychotic features, bipolar, or related disorders. A current diagnosis of PTSD, complex PTSD and borderline personality disorder are exclusionary. Other psychiatric disorders besides MDD should not be the primary disorder. 2. In first degree relatives, a history of schizophrenia, psychosis, bipolar disorder, delusional disorder, paranoid personality disorder or schizoaffective disorder. 3. Current or prior (six weeks before Screening) use of any SSRI/SNRI medication (Part A only). ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Key Inclusion Criteria: 1. Patients are male or female, of any ethnic origin. 2. Patients are aged between 18 to 65 years, inclusive. 3. Patients meet the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for recurrent MDD without psychotic features, as assessed with the Mini-International Neuropsychiatric Interview (MINI) at Screening. 4. Current moderate to severe MDD diagnosis confirmed with a MADRS-SIGMA 5. Concomitant depression therapy: 1. (Part A) Patients need to be stable and must not have taken any SSRI or SNRI for at least 6 weeks prior to Screening and must be willing to avoid starting a new pharmacological treatment for MDD until the end of the study procedures and assessments. Discontinuing current treatment is not allowed if done for the purposes of achieving eligibility for this study. 2. (Part B) Patients need to be on stable treatment with any SSRI or SNRI for at least 6 weeks prior to screening and must be willing to remain on the SSRI or SNRI for the duration of the trial 3. Patients receiving any form of psychotherapy or counselling must have been receiving therapy at Screening and must be willing to remain in therapy until the end of the study procedures and assessments. Key Exclusion Criteria: 1. Patient has current or past primary DSM-5 diagnosis of a psychotic disorder or MDD with psychotic features, bipolar, or related disorders. A current diagnosis of PTSD, complex PTSD and borderline personality disorder are exclusionary. Other psychiatric disorders besides MDD should not be the primary disorder. 2. In first degree relatives, a history of schizophrenia, psychosis, bipolar disorder, delusional disorder, paranoid personality disorder or schizoaffective disorder. 3. Current or prior (six weeks before Screening) use of any SSRI/SNRI medication (Part A only). 4. Current or prior (five weeks before Screening) use of any monoamine oxidase inhibitor (\[MAO-I\]; including phenelzine, tranylcypromine, isocarboxazid, iproniazid, selegiline, rasagiline, the reversible MAO-I moclobemide and the antibiotic linezolid).or any tricyclic antidepressant

Treatments Being Tested

DRUG

GM-2505

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

MAC Clinical Research

Manchester, United Kingdom

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06236880), the sponsor (Gilgamesh Pharmaceuticals), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06236880 clinical trial studying?

Who can participate in NCT06236880?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06236880?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06236880. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06236880. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.