Major Depressive DisorderPhase 2NCT06236880
A Phase 2a Study to Evaluate the Safety and Tolerability of GM-2505 in Patients With MDD
A Phase 2 study testing GM-2505 in people with Major Depressive Disorder, run by AbbVie at 1 site in United Kingdom.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Major Depressive Disorder
- What is being tested?
- GM-2505
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 126 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 31 Jan 2024to 27 Jul 2026
- Phase
- Phase 2
- Are there results?
- None posted in the registry
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
- Patients are male or female, of any ethnic origin.
- Patients are aged between 18 to 65 years, inclusive.
- 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.
- Current moderate to severe MDD diagnosis confirmed with a MADRS-SIGMA
- Concomitant depression therapy:
- (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.
- (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
- 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.
Who cannot join
- 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.
- In first degree relatives, a history of schizophrenia, psychosis, bipolar disorder, delusional disorder, paranoid personality disorder or schizoaffective disorder.
- Current or prior (six weeks before Screening) use of any SSRI/SNRI medication (Part A only).
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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.
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.
- Conditions
- Major Depressive Disorder
- Being tested
- GM-2505
- Keywords
- MDD, Adjunctive, antidepressant, 5HT2a agonist
- Medical subject headings
- Depressive Disorder, Major
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GM-2505Drug
IV
| Study group | Role | What they receive |
|---|---|---|
| Low Dose to High Dose of GM-2505 | Experimental | Not described Receives: Drug: GM-2505 |
| Moderate Dose to High Dose of GM-2505 | Experimental | Not described Receives: Drug: GM-2505 |
| Experimental very low dose to very low dose of GM-2505 | Active comparator | Not described Receives: Drug: GM-2505 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and Tolerability (Part A, B, and C)
The primary objective of this study is to evaluate the safety and tolerability of two doses of GM-2505 administered to MDD patients at a 2-week interval between doses.
Measured: 99 Days
MADRS Score (Part B and C)
The estimated difference between Arm 1 and Arm 2 in the changes from baseline in MADRS-SIGMA total score
Measured: 29 Days
Secondary outcomes (4)
MADRS-SIGMA total score (Part A)
Change in MADRS-SIGMA total score between Baseline and Day 29 and comparison of Day 1 low dose vs moderate dose at Day 14
Measured: Days 14 and 29
MADRS-SIGMA total score (Part B and C)
MADRS-SIGMA scores (change from baseline)
Measured: All additional timepoints
MADRS-SIGMA total score (Part B and C)
Response and Remission
Measured: Days 14, 29, 43, 71, and 99
PK of GM-2505 (Part C)
Assess the pharmacokinetics of GM-2505 at very low, moderate, and high doses
Measured: Day 16
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Feb 2024
- Study start31 Jan 2024
- Primary completion27 Jul 2026
- Study completion27 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Major Depressive DisorderStudies of the same condition, open and under way.
- More trials run by AbbVieThe sponsor's other registered studies.
- 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
- 126 participants (actual)
Sponsor and investigators
- Lead sponsor
- AbbVie
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Gerard Marek, MD, Study chair, Gilgamesh Pharmaceuticals
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06236880
- Sponsor's protocol ID
- GM-2505-201
- Other IDs
- 2023-000846-40, M26-286, 2023
- Status last verified
- Oct 2026
- First submitted
- 23 Jan 2024
- Last updated
- 19 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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.
- ClinicalTrials.gov ID
- NCT06236880
- Acronym / sponsor ID
- GM-2505-201
- Conditions
- Major Depressive Disorder
- Keywords
- MDD, Adjunctive, antidepressant, 5HT2a agonist
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 126 participants (actual)
- Lead sponsor
- AbbVieIndustry (pharma, biotech, devices)
- Study start
- 31 Jan 2024 (actual)
- Primary completion
- 27 Jul 2026 (actual)
- Study completion
- 27 Jul 2026 (actual)
- First posted
- 1 Feb 2024 (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.
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.
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 |
|---|---|---|
| Low Dose to High Dose of GM-2505 | Experimental | Drug: GM-2505 |
| Moderate Dose to High Dose of GM-2505 | Experimental | Drug: GM-2505 |
| Experimental very low dose to very low dose of GM-2505 | Active comparator | Drug: GM-2505 |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Patients are male or female, of any ethnic origin.
- Patients are aged between 18 to 65 years, inclusive.
- 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.
- Current moderate to severe MDD diagnosis confirmed with a MADRS-SIGMA
- Concomitant depression therapy:
Key exclusion criteria (4 listed)
- 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.
- In first degree relatives, a history of schizophrenia, psychosis, bipolar disorder, delusional disorder, paranoid personality disorder or schizoaffective disorder.
- Current or prior (six weeks before Screening) use of any SSRI/SNRI medication (Part A only).
- 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
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 |
|---|---|---|
| GM-2505IV | Drug | Experimental very low dose to very low dose of GM-2505, Low Dose to High Dose of GM-2505, Moderate Dose to High Dose of GM-2505 |
Primary outcome
Safety and Tolerability (Part A, B, and C)
Time frame: 99 Days
The primary objective of this study is to evaluate the safety and tolerability of two doses of GM-2505 administered to MDD patients at a 2-week interval between doses.
MADRS Score (Part B and C)
Time frame: 29 Days
The estimated difference between Arm 1 and Arm 2 in the changes from baseline in MADRS-SIGMA total score
4 secondary outcomes
MADRS-SIGMA total score (Part A)
Time frame: Days 14 and 29
MADRS-SIGMA total score (Part B and C)
Time frame: All additional timepoints
MADRS-SIGMA total score (Part B and C)
Time frame: Days 14, 29, 43, 71, and 99
PK of GM-2505 (Part C)
Time frame: Day 16
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Oct 2026.
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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. This study is not recruiting at the moment.
Gerard Marek, MD study chair
Gilgamesh Pharmaceuticals
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing GM-2505 in people with Major Depressive Disorder, run by AbbVie at 1 site in United Kingdom.
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 8 inclusion and 4 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: finished, as of the sponsor's last update on 19 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. 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. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety and Tolerability (Part A, B, and C) (time frame: 99 Days). The study lists 2 primary outcomes in all. 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 19 Oct 2026.