RecruitingPHASE2INTERVENTIONAL

ALTO-207 in Adults With Treatment-resistant Depression (TRD)

This important study is looking for adults aged 18 to 75 who have depression that hasn't gotten better with standard treatments. This type of depression is sometimes called 'treatment-resistant depression'. We are testing a new medicine, ALTO-207, to see if it can help reduce depressive symptoms. Participants will either receive ALTO-207 or a placebo (a dummy pill with no active medicine) to compare their effects. The main goal is to understand if ALTO-207 is effective in improving mood and reducing the impact of depression. This research could help find new ways to treat people who struggle with depression that hasn't responded to existing options.

At a glance

Status

Recruiting

Phase

PHASE2

Sponsor

Alto Neuroscience

Enrolment target

178

Start

01 May 2026

Estimated completion

01 Dec 2027

Treatment-resistant Depression (TRD)

What is this study about?

This study is particularly important for people living in the UK who have struggled to find effective help for their depression. We understand that it can be very frustrating and disheartening when depression doesn't improve with treatments that work for others. This research is trying to find new options for people in this situation. The medicine being tested is called ALTO-207.

Researchers want to see if ALTO-207 can help reduce the symptoms of depression, such as low mood, loss of interest, and tiredness, in people who haven't felt better after trying other anti-depressant medicines. To do this, some people in the study will receive ALTO-207, while others will receive a 'placebo'. A placebo looks exactly like the study medicine but contains no active ingredients. This helps researchers work out if any improvements are genuinely due to ALTO-207 or other factors.

By taking part, you could contribute to developing new and effective treatments for depression. We hope that the findings from this study will help doctors better manage depression that is currently difficult to treat, offering new hope for many people.

Key takeaways

This study is for adults with depression that hasn't responded well to other treatments.
It's testing a new medicine, ALTO-207, against a placebo (dummy pill).
Participation involves regular clinic visits and health checks.
You might experience side effects, and there's no guarantee of benefit.
You can withdraw from the study at any time.
Your participation could help others with hard-to-treat depression.

Who may be eligible?

This study is open to adults aged 18 to 75, both men and women. To be considered, you must have been diagnosed with depression without any psychotic symptoms (like hallucinations or delusions) in your current episode. Your depression needs to be considered moderate to severe, and other treatments haven't helped enough.

Specifically, you should have tried at least two, but possibly up to five, different antidepressant treatments that haven't worked well for you (meaning your symptoms didn't improve by at least half). You should also be taking one or two oral antidepressants at a stable dose when you join the study.

There are some reasons why you wouldn't be able to join. For example, if you have other serious uncontrolled health problems, use certain prohibited medications or substances, or have been diagnosed with bipolar disorder or a psychotic disorder. If you have severe symptoms of post-traumatic stress disorder (PTSD), significant problems with impulse control, or a history of allergic reactions to ALTO-207 or its components, you also cannot participate. Finally, if you're currently in another medical study for a mental health condition, you wouldn't be eligible for this one.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 75 years old?
Have you been diagnosed with depression (not bipolar) that doctors say is moderate to severe?
Have at least two different antidepressant medicines not worked well enough for you?
Are you currently taking one or two antidepressant medicines at a stable dose?
Do you *not* have other serious untreated medical conditions or uncontrolled mood disorders like bipolar or psychosis?
Do you *not* have a severe allergy to ALTO-207 or its ingredients?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll have regular visits to the clinic where study staff will check how you are feeling and any side effects. You'll be given either the study medicine (ALTO-207) or a placebo, which you'll take as instructed. Throughout the study, you'll answer questions about your mood and symptoms, and possibly have certain medical tests to monitor your health.

The study involves several follow-up appointments to track your progress and well-being. The total length of your participation in the study will be explained in detail by the study team, but it typically involves several weeks to months of treatment and monitoring. All aspects of your participation, including medication, assessments, and visits, will be carefully explained to you before you make a decision.

Potential risks and benefits

While we hope ALTO-207 will help improve your depression, there's no guarantee you'll receive the active drug or that it will benefit you. Any new medicine carries a risk of side effects, which the study team will discuss in detail. Possible side effects could range from mild to more serious. You will be closely monitored for any reactions. Your safety and well-being are our top priority, and you are free to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (48)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Site 7074
Verified postcode
Birmingham, United States· Not yet recruiting
Site 7173
Verified postcode
Dothan, United States· Not yet recruiting
Site 7000
Verified postcode
Phoenix, United States· Recruiting
Site 7153
Verified postcode
Chino, United States· Not yet recruiting
Site 7156
Verified postcode
Oakland, United States· Not yet recruiting
Site 7082
Verified postcode
Oceanside, United States· Recruiting
Site 7159
Verified postcode
Palo Alto, United States· Not yet recruiting
Site 7016
Verified postcode
Sacramento, United States· Not yet recruiting
Site 7144
Verified postcode
San Diego, United States· Recruiting
Site 7171
Verified postcode
Valley Village, United States· Not yet recruiting
Site 7152
Verified postcode
Saint Augustine, United States· Recruiting
Site 7148
Verified postcode
Albany, United States· Recruiting

Common questions

What is 'treatment-resistant depression'?

This means your depression hasn't gotten significantly better after trying two or more different antidepressant treatments.

What is a placebo?

A placebo is a 'dummy pill' that looks like the study medicine but contains no active ingredients. It helps researchers fairly compare the new medicine.

Will I know if I'm getting ALTO-207 or the placebo?

No, during the main part of the study, neither you nor the study team will know who is getting which. This is to make sure results are fair.

Can I stop taking part in the study if I change my mind?

Yes, you can choose to leave the study at any time, for any reason, without needing to explain why, and it won't affect your future medical care.

Will this study cost me anything?

No, your participation in the study, including all study-related visits and medications, will not cost you anything.

How to find out more

Alto Neuroscience

clinical@altoneuroscience.com 650-200-0412 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.