RecruitingPHASE1, PHASE2INTERVENTIONAL

A Study of HS235 for Treatment of Pulmonary Arterial Hypertension (PAH) in Adults

This research is looking at a new treatment called HS235 for adults with Pulmonary Arterial Hypertension (PAH). PAH is a serious lung condition where blood pressure in the arteries leading to the lungs becomes too high. The study wants to find out if HS235 is safe, what effects it has on the body, and if it can help people feel better when used alongside their current PAH medications. Some participants will receive HS235, while others will get a placebo (a dummy drug with no active ingredients). This is a 'Phase 1b/2' study, meaning it's an early-stage trial that first checks safety and then looks for signs of effectiveness and the right dose. Participants will be carefully monitored throughout.

At a glance

Status

Recruiting

Phase

PHASE1, PHASE2

Sponsor

35Pharma Inc

Enrolment target

Start

19 Aug 2026

Estimated completion

01 Nov 2028

Pulmonary Arterial Hypertension

What is this study about?

This study is about a new medication called HS235 for adults who have a specific type of high blood pressure in the lungs, known as Pulmonary Arterial Hypertension (PAH). PAH makes it harder for the heart to pump blood through the lungs, causing symptoms like breathlessness and tiredness.

The main goal of this research is to see if HS235 is safe for people with PAH and how their bodies react to it. It also aims to find out if this new drug can help improve their health and symptoms when added to the treatments they are already taking. Some people in the study will receive HS235, while others will be given a placebo (a substance that looks like the drug but has no active ingredients) to compare the effects fairly.

This is an important step in finding new ways to treat PAH. By understanding how HS235 works and if it helps, researchers hope to develop better treatments for people living with this condition.

Key takeaways

This study tests a new drug, HS235, for adults with Pulmonary Arterial Hypertension (PAH).
It aims to check safety, how the drug works, and if it helps improve health.
Participants will receive either HS235 or a placebo, alongside their usual PAH medicines.
Close medical monitoring will be provided throughout your participation.
Participation is voluntary, and you can withdraw at any time.
This is an early-stage study, so potential benefits and risks are still being evaluated.

Who may be eligible?

To join this study, you must be an adult aged 18 or older. You should have been diagnosed with a specific type of high blood pressure in your lungs called WHO Group 1 Pulmonary Arterial Hypertension (PAH) and be experiencing symptoms. You also need to be taking at least two approved medications for your PAH, plus diuretics (water pills), and these treatments should be stable.

There are also some physical requirements, such as a certain body weight and a minimum walking distance you can cover in six minutes. Doctors will also check specific measurements related to your lung blood pressure during screening tests. You must be able to attend all study appointments and follow the study instructions carefully.

However, you cannot join if you have other types of high blood pressure in the lungs (Groups 2, 3, 4, or 5), or if you've been in hospital recently for a serious medical issue or surgery. Certain heart conditions, kidney problems, liver problems, or a history of stroke in the last 90 days would also mean you couldn't take part. You also can't have participated in a previous study using a similar type of drug.

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 an adult aged 18 or older?
Do you have WHO Group 1 Pulmonary Arterial Hypertension (PAH)?
Are you currently taking at least two approved PAH medications and diuretics?
Can you attend regular study visits and follow instructions?
Have you *not* had any major surgery or hospitalisation in the last 4 weeks?
Have you *not* had a stroke in the last 90 days or certain other heart/lung conditions?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you would first go through a screening process to check if the study is right for you. This involves medical exams, tests, and discussions about your health. If you qualify, you will be randomly assigned to either receive the new medication, HS235, or a placebo, which looks identical but contains no active drug. Neither you nor your study doctor will know which one you are receiving – this is to ensure the results are fair and unbiased.

You will continue to take your usual PAH medications throughout the study. You will have regular visits to the study clinic where the research team will monitor your health, check for any side effects, and perform various tests. These tests might include blood samples, physical examinations, and possibly more walking tests to see how the treatment is affecting you. The total duration of your involvement in the study, including the follow-up, will be explained fully by the study team.

Potential risks and benefits

Taking part in a clinical trial means you'll be closely monitored by medical professionals, and you might have early access to a new medication that could potentially help your condition. However, there's no guarantee that HS235 will be effective for you, and it might not improve your health more than your current treatments. There are also potential risks, as the new medication could cause side effects that are currently unknown or that are different from those of your usual medications. All potential risks and side effects will be fully explained before you decide to join. Remember, you can choose to leave the study at any time, for any reason, without it affecting your usual medical care.

Locations (4)

Investigational Site-102
Verified postcode
Tampa, United States· Recruiting
Investigational Site-104
Verified postcode
Providence, United States· Recruiting
Investigational Site-305
Verified postcode
Barcelona, Spain· Recruiting
Investigational Site-903
Verified postcode
London, United Kingdom· Recruiting

Common questions

What is Pulmonary Arterial Hypertension (PAH)?

PAH is a serious condition where the blood vessels in the lungs become narrow, causing high blood pressure in the arteries leading from the heart to the lungs. This makes the heart work harder and can cause breathlessness and tiredness.

What is a 'placebo'?

A placebo is a 'dummy' treatment that looks exactly like the actual study medication but contains no active drug. It's used in studies to fairly compare the effects of the new medication.

What does 'randomized, double-blind' mean?

It means participants are randomly chosen to receive either the study drug or the placebo. 'Double-blind' means neither you nor your study doctor will know which treatment you are getting, to keep the study fair.

Will I have to stop my current PAH medications?

No, you will continue to take your usual PAH medications throughout the study. HS235, or the placebo, will be added to your current treatment plan.

How long will I be in the study?

The study team will provide you with full details on the expected duration of your participation, including all follow-up appointments, during your initial consultation.

How to find out more

US GSK Clinical Trials Call Center

gskclinicalsupporthd@gsk.com 877-379-3718 Official trial record

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