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Study on the Effects of Mebufotenin (GH001) for Patients with Treatment-Resistant Depression

Fast replyInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a treatment for treatment-resistant depression, a condition where patients do not respond to typical depression treatments. The treatment being tested is called Mebufotenin, also known by its code name GH001. Mebufotenin is administered as an inhalation powder using a vaporization device called the Volcano Medic 2. The purpose of the study is to determine the safety and effectiveness of GH001 in improving symptoms of depression in patients who have not found relief with other treatments.

The study is designed to compare the effects of GH001 with a placebo. Participants will receive a single day of individualized dosing, which means the amount of medication is tailored to each person. The study will initially be conducted in a double-blind manner, meaning neither the participants nor the researchers will know who is receiving the actual medication or the placebo. This part of the study will last for seven days. After this, there will be an open-label extension, where all participants will have the opportunity to receive GH001, and both the participants and researchers will know they are receiving the active treatment.

The trial aims to assess changes in depressive symptoms using a tool called the Montgomery-Åsberg Depression Rating Scale (MADRS), which helps measure the severity of depression. The study will monitor changes from the start of the trial to the end of the seven-day double-blind phase. The overall goal is to see if GH001 can provide significant improvement in depressive symptoms for those with treatment-resistant depression.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the trial

    Upon joining the trial, you will be informed about the study's purpose and procedures. You will be asked to provide informed consent, confirming your understanding and willingness to participate.

  2. Step 2

    Initial assessment

    An initial assessment will be conducted to confirm your eligibility. This includes verifying that you meet the criteria for treatment-resistant depression (TRD) and are between 18 and 64 years old.

  3. Step 3

    Randomized treatment phase

    You will be randomly assigned to receive either the study medication, GH001, or a placebo. This phase is double-blind, meaning neither you nor the researchers will know which treatment you are receiving.

    The medication is administered as an inhalation powder. The dosing regimen is individualized and occurs over a single day.

  4. Step 4

    Monitoring and assessment

    Your depressive symptoms will be monitored using a scale called MADRS (Montgomery-Åsberg Depression Rating Scale) to assess changes from the baseline to day 7.

    Regular check-ins will be scheduled to ensure your safety and to evaluate the treatment's effectiveness.

  5. Step 5

    Open-label extension

    After the initial 7-day period, you may enter an open-label extension phase where all participants receive the study medication, GH001, regardless of the initial group assignment.

    This phase allows further observation of the medication's effects over a longer period.

  6. Step 6

    Completion of the trial

    Upon completing the trial, a final assessment will be conducted to evaluate your overall response to the treatment.

    You will receive information about the study's findings and any follow-up care if necessary.

Who can join the trial?

6 criteria

  • Must be between 18 and 64 years old at the time of giving consent to participate.
  • Must have treatment-resistant depression (TRD), which means depression that hasn't improved after trying at least two different antidepressant medications.
  • Must meet the criteria for Major Depressive Disorder (MDD) as defined by the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). This includes having either a single episode or recurrent episodes of depression without psychotic features, confirmed by a structured interview called the Mini-International Neuropsychiatric Interview (MINI).
  • The current episode of depression must have lasted 2 years or less.
  • The current depressive episode must be considered "valid" based on a specific interview method used to assess the state and traits of depression.
  • Must have shown less than 25% improvement in symptoms after trying between two and four different oral antidepressant treatments during the current episode of depression.

Who cannot join the trial?

10 criteria

  • Patients who have a history of severe allergic reactions to the study medication or its ingredients cannot participate.
  • Patients with a current diagnosis of another major psychiatric disorder, such as schizophrenia or bipolar disorder, are excluded.
  • Patients who have a significant medical condition that might interfere with the study, such as uncontrolled diabetes or heart disease, cannot join.
  • Patients who are currently pregnant or breastfeeding are not allowed to participate.
  • Patients who have used certain medications or treatments that might interfere with the study results, such as other antidepressants, within a specific time frame before the study starts, are excluded.
  • Patients with a history of substance abuse or dependence within the past year cannot participate.
  • Patients who have participated in another clinical trial within a certain period before this study are not eligible.
  • Patients who are unable to comply with the study procedures or follow-up visits are excluded.
  • Patients who have a history of suicidal behavior or thoughts that are considered a risk by the study team cannot join.
  • Patients who have a history of non-compliance with medical treatment or who are unlikely to complete the study are excluded.
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Investigated drugs

GH001 is a medication being tested in this clinical trial for its potential to help people with treatment-resistant depression. This means it is being studied to see if it can improve symptoms of depression in patients who have not responded well to other treatments. The trial is designed to find out how effective GH001 is in reducing depressive symptoms over a short period. Participants will receive this medication in a carefully controlled setting to see if it can make a significant difference in their mood and overall mental health.

What is already known about the treatment

GH001 – GH001 is administered as a single-day individualized dosing regimen, designed to be taken by patients with treatment-resistant depression. Currently, it is being studied in a Phase 2b clinical trial to assess its safety and effectiveness in improving depressive symptoms. The main therapeutic indication for GH001 is treatment-resistant depression, a condition where patients do not respond to standard antidepressant treatments. At the molecular level, GH001 is believed to work by modulating neurotransmitter systems in the brain, which are involved in mood regulation. It falls under the pharmacological classification of investigational drugs, as it is still undergoing clinical evaluation.

Investigated diseases

Treatment-resistant depression (TRD) – Treatment-resistant depression is a form of major depressive disorder that does not respond to standard treatments, such as antidepressant medications and psychotherapy. It is characterized by persistent depressive symptoms despite trying multiple treatment strategies. The progression of TRD involves ongoing feelings of sadness, hopelessness, and a lack of interest or pleasure in activities. Patients may experience changes in sleep patterns, appetite, and energy levels. The condition can lead to difficulties in daily functioning and maintaining relationships. Over time, the lack of response to treatment can exacerbate the severity of symptoms.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-510047-37-00Protocol codeGH001-TRD-201Estimated enrolment81 patientsSponsorGH Research Ireland Limited

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).