Independent directory Public ClinicalTrials.gov records United States
ClinicalTrials.gov record
Completed Phase 2Phase 3 Interventional Results available

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)

ClinicalTrials.gov ID: NCT04732221

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.

ClinicalTrials.gov public records Last synced Jul 23, 2026, 10:20 AM EDT

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

Study identification

NCT ID
NCT04732221
Recruitment status
Completed
Study type
Interventional
Phase
Phase 2, Phase 3
Lead sponsor
Merck Sharp & Dohme LLC
Industry
Enrollment
168 participants

Conditions and interventions

Interventions

  • Frespaciguat Drug
  • Placebo to Frespaciguat Drug

Drug

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 Jul 23, 2026

Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.

Open the official record

The complete protocol, eligibility criteria, and contact information for NCT04732221 live on ClinicalTrials.gov.

View official ClinicalTrials.gov record →