A Study of the Efficacy and Safety of Frespaciguat (MK-5475) in Participants With Pulmonary Arterial Hypertension (INSIGNIA-PAH: Phase 2/3 Study of an Inhaled sGC Stimulator in PAH) (MK-5475-007)
Public ClinicalTrials.gov record NCT04732221. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A Phase 2/3, Multicenter, Randomized, Double-blind, Placebo-Controlled, Adaptive Design Study to Evaluate the Efficacy and Safety of MK-5475 in Adults With Pulmonary Arterial Hypertension
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This is a two-part (Phase 2/Phase 3) study of frespaciguat, an inhaled soluble guanylate cyclase stimulator, in participants with pulmonary arterial hypertension (PAH). The first part (Phase 2) will assess three different doses of frespaciguat compared to placebo in a base period of 12 weeks, followed by comparison of three different doses of frespaciguat during an optional 40 month extension period. The treatment dose with the best efficacy and safety profile in the phase 2 cohort base period will be selected for use in the second part (Phase 3) of the study. The primary hypothesis of Phase 2 is that at least one frespaciguat dose is superior to placebo in reducing pulmonary vascular resistance (PVR) from baseline at week 12. The purpose of the second part (Phase 3) of the study is to confirm the efficacy, safety, and tolerability of frespaciguat at the selected dose compared to placebo during a 12 week base period followed by an extension period of up to 5 years. The primary hypothesis of Phase 3 is that frespaciguat is superior to placebo in increasing 6-minute walk distance (6MWD) from baseline at week 12. Due to sponsor's decision this phase/part was not conducted.
Study identification
- NCT ID
- NCT04732221
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2, Phase 3
- Enrollment
- 168 participants
Conditions and interventions
Eligibility (public fields only)
- Age range
- 18 Years to 75 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- May 18, 2021
- Primary completion
- Jan 3, 2024
- Completion
- Jul 1, 2024
- Last update posted
- May 24, 2025
2021 – 2024
United States locations
- U.S. sites
- 26
- U.S. states
- 18
- U.S. cities
- 25
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| University of California San Diego Health-Pulmonary Critical Care ( Site 0061) | La Jolla | California | 92037-7381 | — |
| University of California Davis Health-Internal Medicine: Pulmonary, Critical Care and Sleep Medicine | Sacramento | California | 95817 | — |
| UCSF Helen Diller Medical Center at Parnassus Heights ( Site 0063) | San Francisco | California | 94143 | — |
| University of Colorado - Denver ( Site 0003) | Aurora | Colorado | 80045 | — |
| Cardiovascular Institute of North Colorado - Banner Health ( Site 0013) | Greeley | Colorado | 80631 | — |
| Georgetown University Hospital ( Site 0025) | Washington D.C. | District of Columbia | 20007 | — |
| University of Miami Hospital-Division of Pulmonary & Critical Care ( Site 0053) | Miami | Florida | 33136 | — |
| AdventHealth Orlando ( Site 0040) | Orlando | Florida | 32803 | — |
| Tampa General Hospital ( Site 0058) | Tampa | Florida | 33606 | — |
| Indiana University Health Methodist Hospital ( Site 0045) | Indianapolis | Indiana | 46202-1239 | — |
| University of Iowa Hospital and Clinics ( Site 0009) | Iowa City | Iowa | 52242 | — |
| University of Kansas Medical Center ( Site 0038) | Kansas City | Kansas | 66160 | — |
| University of Kentucky ( Site 0006) | Lexington | Kentucky | 40536 | — |
| Norton Pulmonary Specialists ( Site 0048) | Louisville | Kentucky | 40202 | — |
| University of Maryland ( Site 0032) | Baltimore | Maryland | 21201 | — |
| Washington University School of Medicine ( Site 0066) | St Louis | Missouri | 63110 | — |
| University of Nebraska Medical Center ( Site 0041) | Omaha | Nebraska | 68198 | — |
| University of New Mexico, Health Sciences Center ( Site 0028) | Albuquerque | New Mexico | 87131 | — |
| Clinical Trials Unit at Eastowne Medical Office Building ( Site 0019) | Chapel Hill | North Carolina | 27514 | — |
| AnMed Health ( Site 0033) | Anderson | South Carolina | 29621 | — |
| Statcare Pulmonary Consultants ( Site 0067) | Knoxville | Tennessee | 37934 | — |
| University of Texas Southwestern Medical Center at Dallas ( Site 0012) | Dallas | Texas | 75390 | — |
| Houston Methodist Research Institute ( Site 0036) | Houston | Texas | 77030 | — |
| The University of Texas Health Science Center at Houston ( Site 0054) | Houston | Texas | 77030 | — |
| Sentara Norfolk General Hospital ( Site 0014) | Norfolk | Virginia | 23507 | — |
| West Virginia University-WVU Heart and Vascular Institute ( Site 0051) | Morgantown | West Virginia | 26506 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
Non-U.S. locations
This page focuses on the U.S. directory. The official record also lists 65 non-U.S. sites.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04732221, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted May 24, 2025 · Synced Sep 27, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04732221 live on ClinicalTrials.gov.