Efficacy of Brenipatide (LY3537031) as Adjunctive Therapy to Delay Relapse in Adults with Major Depressive Disorder

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What is this study about?

Major Depressive Disorder is a condition that causes persistent feelings of sadness, loss of interest, and difficulty functioning in daily life. In this study, participants who are already taking a stable medication for depression may receive an added treatment called Brenipatide, which is given as a small injection under the skin, or they may receive a harmless comparison substance called placebo. The added treatment is intended to work together with the existing medication to help keep symptoms from returning.

The purpose of the study is to see whether adding Brenipatide can delay the time it takes for depression symptoms to come back compared with the placebo. Participants are randomly assigned to one of the two groups, and neither the participants nor the study staff know which injection is being given. After the first dose, participants return for regular check‑ins over several months, during which they are monitored for any return of depressive symptoms, known as a relapse, and for any side effects.

1 randomization and receipt of study medication

after you join the study, you are randomly assigned to receive either brenipatide or a matching placebo.

the medication is supplied in a pre‑filled syringe for subcutaneous injection (injection under the skin). the specific dose is defined by the study protocol.

2 initial injection and instructions

you receive the first injection of the assigned product at the clinic.

study staff provide written and verbal instructions on how to prepare and administer the injection at home, how to store the syringe, and how to record each dose.

3 regular self‑administration of medication

you inject the medication according to the schedule described in the study instructions.

the injection is given subcutaneously using the pre‑filled syringe; the exact frequency (for example, daily or weekly) is specified by the study protocol.

4 scheduled clinic visits for assessments

you attend clinic visits at intervals set by the study (for example, weekly or monthly).

during each visit, study staff check your health, record any side effects, and evaluate the effectiveness of the treatment using questionnaires and clinical measures.

5 monitoring for relapse criteria

the study tracks the number of days from randomization until you meet any relapse criterion for major depressive disorder.

if relapse is identified, the study may end for you early, and appropriate medical care will be provided.

6 continuation of stable standard‑of‑care medication

you continue any existing medication for major depressive disorder that was stable before entering the study.

no changes to this background treatment are made unless required for safety.

7 study completion or early termination

the study continues until the planned end date or until you experience relapse, whichever occurs first.

at study end, you may receive a summary of your participation and any follow‑up recommendations.

Who Can Join the Study?

Have a diagnosis of major depressive disorder (MDD), which means you experience a persistent low mood and loss of interest that lasts for weeks or months.
Be taking a stable standard of care (SoC) medication for MDD, meaning your regular depression medicine has been at the same dose for a set period of time.
Be able to stay in the study for its entire length and attend all required study visits.
Be willing and able to give yourself the study medication by self‑inject as instructed by the study staff.
Be able to store and use the provided blinded study intervention, which means you will not know whether the injection contains the active drug or a harmless placebo.
Be able to keep a study diary, either on a device or on paper, to record daily information as requested.
Be able to complete the required questionnaires during the study.
Be an adult (18 years or older) and can be male or female.

Who Cannot Join the Study?

If you have ever been diagnosed with schizophrenia (a serious mental illness that can cause loss of touch with reality), another psychotic disorder, bipolar disorder (a condition that causes extreme mood swings), borderline personality disorder (a condition with unstable emotions and relationships), or any eating disorder (such as anorexia or bulimia), you cannot join the study.
If you have type 1 diabetes mellitus (a disease where the body cannot produce insulin), or have ever had ketoacidosis (a dangerous buildup of acids in the blood), a hyperosmolar state (very high blood sugar causing severe dehydration), or have been in a coma (a deep unconscious state), you cannot join the study.
If you have moderate or severe substance or alcohol use disorder (a pattern of drug or alcohol use that causes problems) within the past 180 days, you cannot join the study.
If you are currently actively suicidal or are considered at a significant risk for suicide, you cannot join the study.
If you have taken part in another clinical study and received an active treatment, or it is unclear whether you received an active treatment, within the last 90 days or within five half-lives (the time it takes for a drug to reduce to half its amount) of that treatment—whichever period is longer—you cannot join the study.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country
Center For Pediatric And Adolescent Medicine Of The Johannes Gutenberg University Mainz	Mainz	Germany
Pharmakologisches Studienzentrum Chemnitz GmbH	Chemnitz	Germany
Hospital Universitario De Salamanca	Salamanca	Spain
Diamond Clinic Sp. z o.o.	Cracow	Poland
ClinHouse Centrum Medyczne	Zabrze	Poland

Other Sites

Site Name	City	Country
General Hospital Of Thessaloniki Papageorgiou	Thessaloniki	Greece
Eginitio Hospital	Athens	Greece
Somni bene Institut fuer medizinische Forschung und Schlafmedizin Schwerin GmbH	Schwerin	Germany
University General Hospital Attikon General Hospital Of West Attica H Agia Varvara	Chaidari	Greece
Argolida General Hospital		Greece
Pan-Arcadian General Hospital Of Tripoli Evangelistria	Tripoli	Greece
Universitaetsklinikum Aachen	Aachen	Germany
ZNS Siegen	Siegen	Germany
ISPG – Institut für Studien zur Psychischen Gesundheit	Mannheim	Germany
Multidisciplinary Mental Health Hospital of Attiki		Greece
Hospital Universitario Araba	Vitoria	Spain
Hospital Universitario Infanta Leonor	Madrid	Spain
Euromedis Sp. z o.o.	Szczecin	Poland
Revit Sp. z o.o.	Bialystok	Poland
Centrum Medyczne Luxmed Sp. z o.o.	Lublin	Poland
Instituto De Neuropsiquiatria Y Adiciones	Barcelona	Spain
NZOZ Psychiatrycznej Mentis	Leszno	Poland
MentalMEDIC	Bielsko-Biala	Poland
Medical Concierge Centrum Medyczne	Warsaw	Poland
Private Practice – Dr. Małgorzata Wojtanowska-Bogacka	Poznan	Poland
Hospital Clinic de Barcelona	Barcelona	Spain
Hospital Provincial de Zamora	Zamora	Spain
Ginemedica Sp. z o.o.	Wroclaw	Poland
Nidsluzmhyfc Bbxzwsebm	Bielefeld	Germany
Fjidbbbada Gciu	Offenbach Am Main	Germany
Hvaote Pjfhp Syon	Barcelona	Spain
Hpevihyo Vijr dbexapip	Barcelona	Spain
Hyllpdoi Dh Lv Snnmv Cbks I Sndo Pfg	Barcelona	Spain
Cphlevj Bnbsp Ktiigertary Pietuwvu Sus z ospd	Gdansk	Poland

Trial status

Country	Status	Recruitment Start
Germany	Not yet recruiting	01.06.2026
Greece	Not yet recruiting	01.06.2026
Poland	Not yet recruiting	01.06.2026
Spain	Not yet recruiting	01.06.2026

Trial locations

Investigated drugs:

LY3537031

Brenipatide is an experimental drug being tested for people with major depressive disorder. It is provided as a liquid that is injected under the skin (subcutaneous injection). In the study, participants keep taking their usual antidepressant medicines, and Brenipatide is added on to see if it can help delay the return of depressive symptoms. The medication contains a new active ingredient called LY3537031, which is not yet approved for regular use. The trial will compare how well participants do with Brenipatide versus a placebo.

Major Depressive Disorder – Major Depressive Disorder is a mental health condition marked by persistent low mood, loss of interest, and feelings of worthlessness. It often starts with a period of sadness that lasts longer than typical feelings. Over time the symptoms can become more constant, affecting sleep, appetite, and concentration. The condition may fluctuate, with some days feeling slightly better and others feeling worse. Without appropriate support, the low mood can continue for weeks or months, making daily activities harder.

Trial ID:

2025-522308-25-00

Protocol code:

J2S-MC-GZMH

Trial Phase:

Therapeutic confirmatory (Phase III)

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Efficacy of Brenipatide (LY3537031) as Adjunctive Therapy to Delay Relapse in Adults with Major Depressive Disorder

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?