Don't give up on finding alternatives for your depression

Consider a research study evaluating
a new option for people with depression
who have tried 2 or more medications
without sufficient improvement.

About the Study

The Cleo Study is evaluating an oral study medication, an oral esketamine tablet, to see if it may reduce symptoms of depression. If you have tried at least 2 medications for your depression and have not seen sufficient improvement, the Cleo Study may be an option. If you qualify for the study, you would continue taking your current depression medication along with the oral study medication.

Who can participate in the study?

You may be able to participate in the Cleo Study if you:*

  • Are 18 to 65 years old
  • Have been diagnosed with depression, also known as major depressive disorder (MDD)
  • Have tried at least 2 medications for depression without sufficient improvement
  • Have had depression symptoms for at least 12 weeks
  • Are on a stable dose of antidepressant medication for at least 4-5 weeks

*Other criteria will apply.

Why Participate

If you qualify and enroll, you will receive:

  • All study-related care, including assigned study medication, at no cost
  • Close monitoring of your depression by an experienced study team
  • The opportunity to advance medical science for depression that does not respond adequately to other medications

Your participation is voluntary, and you may choose to withdraw from the study at any time.

About Depression

Major Depressive Disorder (MDD), also referred to as clinical depression, is a medical condition where feelings of sadness or other symptoms last longer than 2 weeks at a time and interfere with your daily life.1


People living with depression often experience:

  • A loss of interest in activities
  • Changes in sleep, appetite, energy level, and concentration
  • Difficulty keeping up with their daily routine
  • Feelings of isolation


Up to one-third of individuals diagnosed with depression do not adequately respond to existing treatments for their symptoms, so there is a need for new therapies.2 This inadequate response can be referred to as treatment-resistant depression, generally defined as having tried at least 2 medications for depression with little or no improvement in symptoms.


  1. Depression. Overview. National Institute of Mental Health. Accessed September 21, 2020.
  2. Rush AJ., Trivedi MH., Wisniewski SR., et al Acute and longer-term outcomes in depressed outpatients requiring one or several treatment steps: a STAR*D report. Am J Psychiatry. 2006;163:1905–1917.

Frequently Asked Questions

This section will help answer some of the important questions you may have.

About the Cleo Study

Why is this clinical research study being conducted?

The Cleo Study is designed to find out how effective the study therapy is at improving depressive symptoms for people who have tried other treatments for major depressive disorder without sufficient improvement. It will enroll about 120 people suffering from major depressive disorder.

What can I expect if I participate in the Cleo Study?

If you are eligible and decide to join the Cleo Study, your participation will last 6 to 10 weeks and include:

  • A Screening Period of up to 28 days to see if you qualify for the study
  • A Treatment Period of 4 weeks, during which you will receive the oral study medication or placebo
    • You will continue to take your current depression medication during this time
  • A Follow-up Period of 2 weeks to check on your health after you finish taking the oral study medication

How do I decide if this clinical research study is right for me?

Deciding to participate in a clinical research study is an important and personal decision. Before you agree to participate, the study team will review all aspects of the clinical research study with you. You will be given a document called an Informed Consent Form that provides, in writing, the clinical research study’s purpose, assessments, procedures, benefits, risks, and precautions. You will have the opportunity to ask questions and are encouraged to speak with your own physician to decide if taking part is right for you.

Is there a placebo in this study?

Yes, there is a 1 in 2 (50%) chance you will receive the oral study medication and a 1 in 2 (50%) chance you will receive placebo. A placebo looks like the investigational medication but is an inactive substance. It is sometimes used in clinical research studies to evaluate the safety and effectiveness of the treatment. Regardless of whether you receive the oral study medication or placebo, you will continue taking your current medication for depression.

Can I withdraw from the study after I have started?

Yes, your participation in any clinical research study is completely voluntary. If you decide to participate in a clinical research study, you are always free to withdraw at any time for any reason without any penalty or effect on your future medical care.

Does my doctor need to give me permission to participate?

Your doctor does not have to give you permission to participate. However, you are encouraged to talk to your doctor about participating in the study. With your permission, the study doctor will keep your regular doctor updated about your condition during the study. You will also remain on your current depression medication prescribed by your regular doctor.

Who can I contact with more questions?

If you have questions or want more information, please contact:


Will my personal information be kept private?

Yes, the information you provide will not be shared with anyone who is not directly associated with this clinical research study without your permission (except as required by law) or as set forth in the informed consent.

Will I be paid for taking part or reimbursed for travel?

The study staff can give you more information about compensation and transportation.

How many people will participate?

About 120 people will participate in the Cleo Study.

Who is the study sponsor?

The study sponsor is Clexio Biosciences Ltd.

About Clinical Research

What is a clinical research study?

Clinical research studies help scientists and doctors explore whether a medical strategy, medication, or device is safe and effective for people. Before a strategy, medication, or device can be prescribed to treat a certain condition, it must go through several phases of clinical research.

There is no guarantee the oral study medication will improve your condition, but what we learn from this study may help provide future treatment options for people who have tried at least 2 medications for depression with little or no improvement in their symptoms.

Who oversees clinical research studies?

To help ensure that a clinical research study is ethical, and that participants’ rights are protected, Institutional Review Boards (IRB) or Ethics Committees (EC) review study protocols.

Contact Us

If you are interested in participating or would like more information, please fill out the form below