Research offers a different path for PAH patients

People living with pulmonary arterial hypertension (PAH) often struggle with activities that once took little-to-no effort. Simple things, like playing with your dog or bringing in the groceries, may now cause you to stop and catch your breath.

As part of this study, medical professionals will provide study-required monitoring of your PAH and overall health.

Do I Qualify?

About PAH

Pulmonary arterial hypertension (PAH) is a type of high blood pressure that affects arteries in the lungs. Symptoms of PAH may include shortness of breath, fatigue, dizziness or fainting, and chest pressure or pain.

Although progress has been made in developing medications for PAH, many people are still affected by the disease. As a result, there is still a need for medications that can help treat and slow the progression of the disease.

Who is eligible to be in the UNISUS Study?

To pre-qualify for this study, you must be:

At least 18 years of age, and

Diagnosed with PAH

All study-required visits, tests, and medications will be provided at no cost. In addition, reimbursement for study-required travel may be available.

About the UNISUS Study

The UNISUS research study is dedicated to people with PAH. The study will compare the effectiveness and safety of a higher dose of an investigational medication against a lower dose.

The investigational medication has been approved for other uses by the FDA at a lower dose. The doctors are evaluating the safety and effectiveness of the investigational medication in people with PAH.

The results of the UNISUS Study will provide more information about the investigational medication’s effectiveness and safety when it is given at a higher dose to adults with PAH.

What is my role in the study as a participant?

If you are eligible and agree to be in this study, you will be randomly assigned (by chance) to receive either the higher or lower dose of the investigational medication as well as a matching placebo. A placebo looks like the investigational medication and is given in the same manner but does not have any active medication. You have an equal chance of being assigned to receive either dose of the investigational medication. If you are currently taking medicine to treat your PAH, you may be able to continue taking it while in the study.

Neither you, the study doctor, or the study staff will know which study medication dose you’ll be receiving. However, in case of an emergency, that information can be provided to your study doctor.

You will take 2 tablets (study medication + placebo) once a day as instructed by the study doctor while you are in the study.

After completing the study treatment period, you will continue into the study treatment extension period which will consist of two phases. During the first phase, you will receive either a higher or lower dose of the investigational medication along with a matching placebo for 4 weeks. During the last phase called the open-label phase, all participants that have received the lower dose will have the option to receive the higher (target) dose.

Your total study participation may last 3 to 6 years; however, you are free to withdraw from the study at any time. During your study participation, you will be asked to attend regular study clinic visits to evaluate your health. You will also receive phone calls from the study staff to discuss the study and check in on how you are feeling.

What are the potential benefits and risks related to the UNISUS Study?

While it's possible that your PAH could improve as a participant in this study, that cannot be guaranteed. Your condition may also stay the same or worsen. However, your study participation may help people with PAH in the future.

It is possible that you could experience one or more side effects during this study. Before you begin the study, the study doctor will talk you through the potential study-related risks and side effects.

This study has been approved by an independent review board that is responsible for patient safety. Because participation in this study could affect your health, you will be closely monitored throughout the study. Study researchers designed a protocol that explains the study in detail, and the protocol must be followed exactly as written.


For additional information about clinical studies please see the FAQ section.

Short Study Summary

Medical condition

Pulmonary Arterial Hypertension (PAH)

Study Duration

3 to 6 years


This is a global study which will enroll approximately 900 participants across North America, South America, Europe, and Asia-Pacific.



Frequently Asked Questions

Clinical studies evaluate whether a medicine, treatment, or device is safe and effective for humans.

Clinical studies are scientific studies in which investigational medicines and treatments are tested to make sure they are safe and effective for people who may need them. They are one of the most important steps in bringing potential medications to patients.

Clinical research adds to medical knowledge and helps bring potential medications to people with medical conditions. In order to make potential medications available to the public they need be studied in clinical trials.

Clinical trials rely on the participation of volunteers in order to succeed. On average, it can take up to 8 years for an investigational medication to reach the public.

All investigational medical treatments and medications have gone through clinical trials to make sure that they are safe and effective.

Clinical studies can be sponsored, or funded, by pharmaceutical companies, academic medical centers, volunteer groups, or health care providers.

Every clinical study is led by a principal investigator, who is often a medical doctor. Clinical studies also have a research team that may include doctors, nurses, social workers, and other health care professionals.

Phase I
The first study in humans. These are small studies with 20-100 participants, mostly in healthy volunteers.

The main objectives are to investigate:
• Safety of the study medication
• How the study medication is absorbed by the body and what dosage should be used
• How the study medication is removed from the body
• Potential side effects

Phase II
Small studies with around 100-500 participants.

The main objectives are to investigate:
• Ongoing safety
• Whether the study medication works for a particular disease
• The best dose of the study medication

Phase III
Large studies with around 500 or more participants. These are the main studies for final approval by health authorities.

The main objectives are to investigate:
• Safety and side effects in bigger populations
• Whether the study medication works for a particular disease
• How the treatment compares to already existing standard therapies

Phase IV
Large studies in patients after the study medication has been approved by regulatory authorities for prescription
use (or public use if it isn't a medicine that requires a prescription).

The main objectives are to investigate:
• Side effects during day-to-day use in the population
• Risks and benefits over a longer period of time

Before taking part in a trial, you will be asked to read and sign an informed consent document to ensure:

1. You agree to volunteer
2. You understand the study, including all the study procedures, risks and potential side effects of the study medication.
3. You understand that you can leave the study at any time for any reason.

During the consenting process, you will have the opportunity to ask the site staff any questions you may have. Taking part in a clinical trial typically involves taking tests to determine if you are a match for the study. If you qualify, you will visit the clinic regularly to receive the investigational medication, undergo tests or procedures, and assess your disease. The study staff will monitor your progress and well-being.