Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 3INTERVENTIONAL

Trial to Evaluate Parenteral Treprostinil and Riociguat on Right Ventriculo-vascular Coupling and Morphology in Those With Advanced PAH

Q: What is the NCT04062565 clinical trial studying?

The purpose of this study is to determine if there is a greater effect to patients with advanced pulmonary arterial hypertension (PAH) by using a combination of two drugs, Treprostinil and Riociquat versus Treprostinil alone The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Q: Who can participate in NCT04062565?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

Q: How do I contact the trial site for NCT04062565?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Q: Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Q: Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

A Prospective Trial to Evaluate Up-front Parenteral Treprostinil and Riociguat on Right Ventriculo-vascular Coupling and Morphology in Patients With Advanced Pulmonary Arterial Hypertension (IIR-3810)

Trial to Evaluate Parenteral Treprostinil and Riociguat on Right Ventriculo-vascular Coupling and Morphology in Those With Advanced PAH (NCT04062565) is a Phase 3 interventional studying Pulmonary Arterial Hypertension, sponsored by University of Arizona. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

What Stage of Research Is This?

Phase 3 trials confirm efficacy and safety in large patient groups (often 300–3,000+) and form the evidence base for an FDA approval submission. For Pulmonary Arterial Hypertension, Phase 3 studies typically randomize participants between the investigational treatment and either a placebo or current standard of care. A successful Phase 3 result is the threshold most treatments need to clear before regulatory approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 20 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

Who May Qualify: - WHO Category I PAH - Resting mPAP ≥ 25 mmHg with a wedge pressure of ≤ 15mmHg during right heart catheterization. - Need for parenteral TRE as determined by the PH specialist caring for the patient Who Should NOT Join This Trial: - Patients with a mean arterial pressure \<60, and/or requiring vasopressor support - Patients whom expected device (i.e. ECMO, RVAD) assistance or early pulmonary transplantation (within 3 months) seems inevitable - Patients with a left ventricular ejection fraction \<50% or clinical, echocardiographic, and/or catheterization data consistent with heart failure with preserved ejection fraction (HFpEF) and/or moderate-severe aortic or mitral valve abnormality - Patients with severe restrictive lung disease (FVC\<70% predicted) and/or obstructive lung disease (FEV1 \<70% predicted and FEV1/FVC \<70%). - Patients with a history of pulmonary embolism within the last three months or evidence of chronic pulmonary embolism. - Patients with a known contraindication to right heart catheterization. - Patients whom have received active or previous pulmonary vasoactive medication within the previous 12 weeks. - PAH associated with significant venous or capillary involvement (PCWP \> 15 mmHg), known pulmonary veno-occlusive disease, and pulmonary capillary hemangiomatosis. - Pulmonary Hypertension belonging to groups 2 to 5 of the WHO classification. - Moderate to severe hepatic impairment, i.e., Child-Pugh Class B or C. - Estimated creatinine clearance \< 30 mL/min - Serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) \> 1.5 times the upper limit of normal. - Hemoglobin \< 75% of the lower limit of the normal range. - Acute or chronic physical impairment (other than dyspnea), limiting the ability to comply with study requirements. - Pregnant or breast-feeding. - Females must either abstain from intercourse (when it is in line with their preferred and usual lifestyle), or ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * WHO Category I PAH * Resting mPAP ≥ 25 mmHg with a wedge pressure of ≤ 15mmHg during right heart catheterization. * Need for parenteral TRE as determined by the PH specialist caring for the patient Exclusion Criteria: * Patients with a mean arterial pressure \<60, and/or requiring vasopressor support * Patients whom expected device (i.e. ECMO, RVAD) assistance or early pulmonary transplantation (within 3 months) seems inevitable * Patients with a left ventricular ejection fraction \<50% or clinical, echocardiographic, and/or catheterization data consistent with heart failure with preserved ejection fraction (HFpEF) and/or moderate-severe aortic or mitral valve abnormality * Patients with severe restrictive lung disease (FVC\<70% predicted) and/or obstructive lung disease (FEV1 \<70% predicted and FEV1/FVC \<70%). * Patients with a history of pulmonary embolism within the last three months or evidence of chronic pulmonary embolism. * Patients with a known contraindication to right heart catheterization. * Patients whom have received active or previous pulmonary vasoactive medication within the previous 12 weeks. * PAH associated with significant venous or capillary involvement (PCWP \> 15 mmHg), known pulmonary veno-occlusive disease, and pulmonary capillary hemangiomatosis. * Pulmonary Hypertension belonging to groups 2 to 5 of the WHO classification. * Moderate to severe hepatic impairment, i.e., Child-Pugh Class B or C. * Estimated creatinine clearance \< 30 mL/min * Serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) \> 1.5 times the upper limit of normal. * Hemoglobin \< 75% of the lower limit of the normal range. * Acute or chronic physical impairment (other than dyspnea), limiting the ability to comply with study requirements. * Pregnant or breast-feeding. * Females must either abstain from intercourse (when it is in line with their preferred and usual lifestyle), or * Use 2 medically acceptable, highly effective forms of contraception for the duration of study, and at least 30 after discontinuing study drug. * Known concomitant life-threatening disease with a life expectancy \< 12 months. * Body weight \< 40 kg and/or \>150 kg. * Any condition that prevents compliance with the protocol or adherence to therapy. * Concurrent therapy with strong CYP3A4 inhibitors/inducers (i.e. protease inhibitors, azole antibiotics, macrolides), theophylline, and any medication in the PI's opinion may substantially potentiate the hypotensive effect of RIO. * Treatment with nitrates of any kind within the 4 weeks prior to enrollment. * Known hypersensitivity to drugs of the same class as TRE and/or RIO, or any of their excipients. * Planned treatment, or treatment, with another investigational drug within 1 month prior to randomization. * Recent (\<6 months) hemoptysis and/or history of severe hemoptysis requiring intervention (bronchial artery embolization).

Treatments Being Tested

DRUG

Treprostinil Injectable Product

Injection

DRUG

Riociguat Pill

Tablet

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

University of Arizona

Tucson, Arizona, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04062565), the sponsor (University of Arizona), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT04062565 clinical trial studying?

The purpose of this study is to determine if there is a greater effect to patients with advanced pulmonary arterial hypertension (PAH) by using a combination of two drugs, Treprostinil and Riociquat versus Treprostinil alone The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT04062565?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT04062565?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT04062565. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04062565. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.