RecruitingPHASE2INTERVENTIONAL

Study of REGN13335 in Adult Participants With Pulmonary Arterial Hypertension (PAH)

This study is exploring an experimental new drug called REGN13335 for adults living with Pulmonary Arterial Hypertension (PAH). PAH is a serious condition affecting the blood vessels in the lungs. The main goal is to find out how safe and well REGN13335 works when people are already taking other medicines for their PAH. Researchers will also be checking for any side effects and how the body handles the new drug. This is a Phase 2 study, meaning it's an earlier stage for checking effectiveness and safety in a larger group of people, after initial safety tests. The study aims to gather important information that could help develop new treatments for PAH.

At a glance

Status

Recruiting

Phase

PHASE2

Sponsor

Regeneron Pharmaceuticals

Enrolment target

Start

06 May 2026

Estimated completion

17 Sep 2028

Pulmonary Arterial Hypertension (PAH)

What is this study about?

This study is about a new, experimental drug called REGN13335. It's being tested in adults who have a condition called Pulmonary Arterial Hypertension, often shortened to PAH. PAH is a serious type of high blood pressure that affects the arteries in your lungs and the right side of your heart. It can make you feel breathless and tired.

The main purpose of this research is to see how safe REGN13335 is and how well it works when people are already taking other medicines for their PAH. Researchers want to understand if this new drug can make a difference. They will also be looking closely at any side effects people might experience while taking REGN13335. Another important part of the study is to see how the body processes the drug and if the body creates 'antibodies' against it, which could make the drug less effective.

This kind of study is called a 'Phase 2' trial. This means the drug has already passed initial safety tests and is now being given to a larger group of people with the condition to learn more about its effects. People joining this study will either receive REGN13335 or a 'placebo' (a dummy treatment). This helps researchers compare the effects accurately. The aim is to gather enough information to decide if REGN13335 has the potential to become a new treatment option for PAH in the future.

Key takeaways

This study is testing a new drug, REGN13335, for adults with PAH.
It aims to check the safety and effectiveness of REGN13335 when added to existing PAH medicines.
Participants will either receive REGN13335 or a placebo.
The study will closely monitor for side effects and how the drug affects the body.
It's a Phase 2 trial, focusing on gathering more information on effectiveness and safety.
Participation involves regular clinic visits and health assessments.

Who may be eligible?

To join this study, adults must have been officially diagnosed with a specific type of PAH (called Group 1 PH) and be experiencing mild to moderate symptoms that affect their daily life. You also need to be on a steady dose of other PAH medicines before starting the study, and your lung blood pressure measurements would need to meet certain levels.

There are also reasons why someone might not be able to join. For example, if you have other types of high blood pressure in the lungs (not Group 1 PH), or if you have certain heart conditions, severe lung diseases, or issues with bleeding. The research team will do several checks to make sure the study is a safe and suitable option for you.

It’s important to remember that these are just some of the main points; the study has many other detailed rules about who can and cannot take part. The study doctors and nurses will explain everything fully.

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.

Have you been diagnosed with Group 1 Pulmonary Arterial Hypertension (PAH)?
Are you currently taking other medicines for your PAH at a steady dose?
Do you experience mild to moderate daily symptoms from your PAH?
Are you aged 18 or over?
Do you NOT have other serious heart or lung conditions?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you will have regular visits to the clinic. These visits will involve various checks and tests to monitor your health, your PAH, and how you are reacting to the study medication. These may include blood tests, physical examinations, and other specific PAH-related tests such as a '6-minute walk test', where you walk as far as you can in six minutes to measure your exercise ability.

You will be given either the experimental drug REGN13335 or a placebo (a treatment with no active drug) to take. There will be specific instructions on how and when to take your medication. Throughout the study, the research team will keep a close eye on you, including checking for any side effects. After finishing the course of treatment, there will likely be follow-up visits to ensure your well-being. The total length of your participation, including treatment and follow-up, will be several months, but the specific duration will be explained by the study team.

Potential risks and benefits

Taking part in a clinical trial may offer potential benefits, such as gaining access to a new experimental treatment before it's widely available and receiving close medical attention from specialist doctors and nurses. However, there are also potential risks involved. The experimental drug REGN13335 could cause side effects, some of which might be serious or currently unknown. You might also receive a placebo instead of the active drug, meaning your PAH might not be directly treated by the study medicine. It is crucial to remember that you are free to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (6)

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

University of Colorado Denver
Verified postcode
Aurora, United States· Recruiting
P. Stradins Clinical University hospital
Verified postcode
Riga, Latvia· Recruiting
Gachon University Gil Medical Center
Unverified
Namdong-gu, South Korea· Recruiting
Asan Medical Center
Verified postcode
Seoul, South Korea· Recruiting
Seoul National University Hospital
Verified postcode
Seoul, South Korea· Recruiting
Imperial College Healthcare NHS Trust, Hammersmith Hospital
Verified postcode
London, United Kingdom· Recruiting

Common questions

What is Pulmonary Arterial Hypertension (PAH)?

PAH is a type of high blood pressure that specifically affects the arteries in your lungs and the right side of your heart, making it harder for blood to flow through your lungs.

What does 'experimental drug' mean?

It means the drug is still being tested and hasn't been approved for general use yet. Researchers are trying to find out if it's safe and effective.

What is a 'placebo'?

A placebo is a dummy treatment that looks like the real drug but contains no active medicine. It helps researchers compare the effects of the active drug.

What is a 'Phase 2' study?

Phase 2 means the drug has passed initial safety tests and is now being given to a larger group of people with the condition to see how well it works and if there are particular side effects.

Will I still take my regular PAH medicines if I join?

Yes, if you join this study, it's expected that you will continue taking your usual PAH medicines at a stable dose, as the study is looking at REGN13335 alongside existing treatments.

How to find out more

Clinical Trials Administrator

clinicaltrials@regeneron.com 844-734-6643 Official trial record

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