Effects of the Combination of Bosentan and Sildenafil Versus Sildenafil Monotherapy on Pulmonary Arterial Hypertension (PAH) (Compass-2)

Effects of Combination of Bosentan and Sildenafil Versus Sildenafil Monotherapy on Morbidity and Mortality in Symptomatic Patients With Pulmonary Arterial Hypertension - A Multicenter, Double-blind, Randomized, Placebo-controlled, Parallel Group, Prospective, Event Driven Phase IV Study

COMPASS-2 is a Phase 4, prospective, randomized, double-blind, placebo-controlled, event-driven study evaluating the effect of bosentan on the time to first confirmed morbidity/mortality event in patients with symptomatic PAH already receiving sildenafil therapy. Patients must have been receiving doses of sildenafil equal to or greater than 20 mg t.i.d. for at least 12 weeks prior to being randomized.

The study continued until the predefined target number of morbidity/mortality events was reached.

Study Overview

• Status: Completed
• Conditions: Pulmonary Arterial Hypertension
• Intervention / Treatment: Drug: bosentan; Drug: placebo

• Study Type: Interventional
• Enrollment (Actual): 334
• Phase: Phase 4

Contacts and Locations

Study Locations

• Brazil
  • Belo Horizonte, Brazil, 30430-142
    • Hospital Madre Teresa
  • Porto Alegre, Brazil, 90020-090
    • CHSCPA
  • Sao Paulo, Brazil, 05403-000
    • Hospital das Clinicas - FMUSP
  • Sao Paulo, Brazil, 04012-909
    • Instituto Dante Pazzanese
  • Sao Paulo, Brazil, 04023-062
    • UNIFESP - Pneumologia
  • CE
    • Fortaleza, CE, Brazil, 60864-190
      • Hospital de Messejana
  • DF
    • Brasília, DF, Brazil, 70840-050
      • Hospital Universitario de Brasilia
  • MG
    • Belo Horizonte, MG, Brazil, 30130-100
      • Hospital das Clinicas - UFMG
• Czech Republic
  • Praha, Czech Republic, 128 08
    • Vseobecna Fakultni Nemocnice
  • Praha, Czech Republic, 140 21
    • Kardiologicka klinika Videnska
• Denmark
  • Copenhagen, Denmark, 2100
    • Rigshospitalet
• Germany
  • Giessen, Germany, 35392
    • Universitätsklinikum Giessen und Marburg, Standort Giessen Zentrum für Innere Medizin
  • Hannover, Germany, 30625
    • Medizinische Hochschule Hannover
  • Heidelberg, Germany, 69120
    • Medizinische Klinik der Universitat Innere Medizin III
  • Loewenstein, Germany, 74245
    • Klinik Löwenstein GmbH
  • Regensburg, Germany, 93053
    • Universitätsklinikum Regensburg
• Greece
  • Athens, Greece, 12462
    • University General Hospital "Attikon"
  • Athens, Greece, 11528
    • General Hospital Alexandra
  • Patras, Greece
    • Rio University Hospital
• Portugal
  • Coimbra, Portugal, 3000-076
    • Universidade de Coimbra
  • Lisbon, Portugal, 1649-035
    • Hospital de Santa Maria
• Saudi Arabia
  • Riyadh, Saudi Arabia, 11159
    • Riyadh Military Hospital
• Slovakia
  • Bratislava, Slovakia
    • NUSCH, a.s.
  • Kosice, Slovakia
    • Východoslovenský Ústav Srdcových A Cievnych Chorôb, A.S.
• Spain
  • Las Palmas de Gran Canaria, Spain, 35016
    • Hospital Universitario Insular de Gran Canaria
  • Madrid, Spain, 28041
    • Hospital Universitario 12 Octubre
• Sweden
  • Gothenburg, Sweden
    • Sahlgrenska University Hospital
• United Kingdom
  • Sheffield, United Kingdom, S102JF
    • Royal Hallamshire Hospital
• United States
  • California
    • La Jolla, California, United States, 92037-7381
      • UCSD Medical Center, Thornton Hospital
    • Los Angeles, California, United States, 90073
      • Greater Los Angeles VA Medical Center
    • Sacramento, California, United States, 95817
      • University of California (UC) Davis Health System
    • San Francisco, California, United States, 94143
      • UCSF
  • Colorado
    • Denver, Colorado, United States, 80220
      • University of Colorado Health Sciences Center
  • Connecticut
    • Farmington, Connecticut, United States, 06030
      • University of Connecticut
    • New Haven, Connecticut, United States, 06520-8057
      • Yale University School of Medicine, Dept. of Internal Medicine, Pulmonary & Critical Care
  • Florida
    • Clearwater, Florida, United States, 33756
      • Bay Area Chest Physicians
    • Gainesville, Florida, United States, 30067
      • Shands Hospital at the University of Florida
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic Jacksonville
    • Jacksonville, Florida, United States, 32209
      • University of Florida - Jacksonville
  • Georgia
    • Mineola, Georgia, United States, 30067
      • Winthrop University Hospital
  • Iowa
    • Iowa City, Iowa, United States, 52242
      • University of Iowa Pulmonary Hypertension Program
  • Kansas
    • Kansas City, Kansas, United States, 66160
      • University of Kansas Medical Center
  • Kentucky
    • Lexington, Kentucky, United States, 40536-0294
      • UK Medical Center - University of Kentucky
  • Maryland
    • Baltimore, Maryland, United States, 21205
      • Johns Hopkins University
    • Baltimore, Maryland, United States, 21201-1595
      • University of Maryland - School of Medicine
  • Massachusetts
    • Boston, Massachusetts, United States, 02111
      • TUFTS - New England Medical Center
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan Cardiology
    • Detroit, Michigan, United States, 48201
      • Harper University Hospital - Wayne State University
    • Grand Rapids, Michigan, United States, 49525
      • Spectrum Health Research Department
  • Minnesota
    • Minneapolis, Minnesota, United States, 55455
      • University of Minnesota Department of Medicine - Cardiovascular Division
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic
  • Missouri
    • Chesterfield, Missouri, United States, 63017
      • St. Luke's Hospital
    • St. Louis, Missouri, United States, 63110
      • Washington University
  • New Hampshire
    • Lebanon, New Hampshire, United States, 03756-0001
      • Dartmouth Hitchcock Medical Center
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke University Medical Center (DUMC)
  • Ohio
    • Cincinnati, Ohio, United States, 45219
      • Lindner Clinical Trials Center
    • Cleveland, Ohio, United States, 44195
      • The Cleveland Clinic Foundation
    • Columbus, Ohio, United States, 43210
      • Ohio State University - Pulmonary Clinical Trials Office - Martha Morehouse Medical Plaza
  • Oregon
    • Portland, Oregon, United States, 97220
      • The Oregon Clinic - Pulmonary and Critical Care Medicine
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15212
      • Allegheny General Hospital
    • Pittsburgh, Pennsylvania, United States, 15213
      • University of Pittsburgh Medical Center - Presbyterian Cardiovascular Institute
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina (MUSC)
    • Lexington, South Carolina, United States, 29072
      • Mid Carolina Internal Medicine
    • Spartanburg, South Carolina, United States, 29303
      • South Carolina Pharmaceutical Research
  • Texas
    • Galveston, Texas, United States, 77555-0561
      • University of Texas Medical Branch
    • Houston, Texas, United States, 77030
      • Baylor Clinic
  • Virginia
    • Falls Church, Virginia, United States, 22042-3300
      • Inova Fairfax Hospital
  • Wisconsin
    • Milwaukee, Wisconsin, United States, 53226
      • Froedtert Memorial Lutheran Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Signed informed consent prior to initiation of any study-mandated procedure

2. Males or females >=12 years of age (except for countries where this age limit is contrary to specific regulatory requirements).

   - Women of childbearing potential must have a negative pretreatment pregnancy test and must use a reliable method of contraception during study treatment and for at least 3 months after study treatment termination.

   ·Reliable methods of contraception are:

   O Barrier type devices (e.g., female condom, diaphragm, contraceptive sponge) only in combination with a spermicide.

   O Intrauterine devices. O Oral, transdermal, injectable or implantable contraceptives only in combination with a barrier method.

   • Hormone-based contraceptives alone, regardless of the route of administration, are not considered as reliable methods of contraception.

   • Abstention, rhythm method, and contraception by the partner alone are not acceptable methods of contraception.

     • Women not of childbearing potential are defined as postmenopausal (i.e., amenorrhea for at least 1 year), or documented surgically or naturally sterile.
3. Patients with symptomatic PAH

4. Patients with the following types of PAH belonging to WHO Group I:

   • Idiopathic (IPAH)
   • Familial (FPAH)

   • Associated with (APAH):

     i. Collagen vascular disease with normal left ventricular function (ejection fraction (EF) > 50%) ii. Congenital systemic-to-pulmonary shunts at least 2 years post surgical repair iii. Drugs and toxins

5. PAH diagnosed by right heart catheter showing:

   • Mean pulmonary arterial pressure (mPAP) >= 25 mm Hg AND
   • Pulmonary capillary wedge pressure (PCWP) =< 15 mm Hg or left ventricular end diastolic pressure (LVEDP) =< 15 mmHg If both PCWP and LVEDP are available then the LVEDP value is retained for inclusion.
6. Treatment with a stable dose of sildenafil equal to or greater than 20 mg t.i.d. for at least 12 weeks prior to randomization (no sildenafil dosage adjustment should occur in this period) 7)150 m =< 6-minute walk test (6MWT) =< 480 m, documented by 2 tests with second 6MWT within 15% of first 6MWT distance or a third test required

Exclusion Criteria :

1. PAH belonging to WHO group II-V
2. PAH associated with portal hypertension and HIV infection
3. PAH associated with thyroid disorders, glycogen storage disease, Gaucher disease, hereditary hemorrhagic telangiectasia, hemoglobinopathies, myeloproliferative disorders and splenectomy
4. PAH associated with significant venous or capillary involvement (PCWP > 15 mmHg): pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis
5. Persistent pulmonary hypertension of the newborn
6. Significant valvular disease with valvular lesions to be excluded by echocardiogram within 2 years prior to randomization (i.e. patients with tricuspid or pulmonary insufficiency secondary to PAH can be included)
7. Restrictive lung disease: total lung capacity (TLC) < 60% of normal predicted value (see Appendix 3)
8. Obstructive lung disease: forced expiratory volume/forced vital capacity (FEV1/FVC) < 0.5
9. Moderate to severe hepatic impairment, i.e., Child-Pugh Class B or C
10. Known HIV infection
11. Acute or chronic impairment (other than dyspnea), limiting the ability to comply with study requirements or that may interfere with the safety or the evaluation of the study, such as chronic infection, chronic renal failure etc.
12. Psychotic, addictive or other disorder limiting the ability to provide informed consent or to comply with study requirements
13. Pregnancy or breast-feeding
14. Condition that prevents compliance with the protocol or adherence to therapy
15. Systolic blood pressure < 85 mmHg
16. Body weight < 40 kg
17. Hemoglobin <75% of the lower limit of the normal range
18. Aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) > 1.5 times the upper limit of normal ranges
19. Known hypersensitivity or history of drug-related adverse events with bosentan (e.g. increase in liver function test results), or any of the excipients of its formulation
20. Receipt of an investigational product other than sildenafil within 3 months before start of study treatment
21. Treatment with endothelin receptor antagonists (ERAs), prostanoids or phosphodiesterase (PDE) 5 inhibitors other than sildenafil within 3 months prior to randomization

22. Concomitant systemic treatment within 1 week prior to randomization with

    • calcineurin inhibitors (e.g., cyclosporine A and tacrolimus), sirolimus and everolimus
    • glibenclamide (glyburide)
    • both cytochrome P2C9 (CYP2C9) and cytochrome P3A4 (CYP3A4) (e.g., fluconazole, amiodarone, voriconazole)
    • combination of drugs that inhibit CYP2C9 and CYP3A4
23. Treatment with nitrates and alpha-blockers at time of randomization
24. In the opinion of the investigator - patients in need for treatment with any prostanoid up to Visit 4
25. Significant left ventricular dysfunction

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: B; Placebo	Drug: placebo; Matching bosentan placebo/b.i.d.
Experimental: A; Bosentan	Drug: bosentan; bosentan/62.5 mg tablet/b.i.d. for 4 weeks then bosentan/125 mg tablet/b.i.d.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to First Confirmed Morbidity/Mortality Event up to the End of Study	Kaplan-Meier estimate of percentage of participants without a morbidity/mortality event. A morbidity/mortality event is defined as the occurrence of a) death, b) hospitalization for worsening or complication of PAH or intravenous prostanoid initiation, c) atrial septostomy, d) lung transplantation, or e) worsening PAH, defined as "moderately" or "markedly" worsened PAH symptoms using a patient global self-assessment (PGSA) scale AND initiation of inhaled or subcutaneous prostanoids or the disease progression package (open-label bosentan). If a patient replied "no change" or "mildly worse" on the PGSA, a decrease in 6MWT of 20% versus last visit or 30% versus baseline is also required to confirm the event.	From baseline to end of study, approximately 86 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to First Confirmed Death, Hospitalization for Worsening or Complication of PAH or Initiation of Intravenous Prostanoids, Atrial Septostomy, or Lung Transplantation	Kaplan-Meier estimate of percentage of participants without an event of death, hospitalization (for worsening or complication of PAH or initiation of intravenous prostanoids), atrial septostomy or lung transplantation. Time to first confirmed death, hospitalization (for worsening or complication of PAH or initiation of intravenous prostanoids), atrial septostomy or lung transplantation from baseline to end of study was confirmed by an independent Clinical Endpoint Committee.	Baseline to end of study, approximately 86 months
Change From Baseline to Week 16 in 6 Minute Walk Test (6MWT)	The 6MWT is a non-encouraged test, which measures the distance covered over a 6 minute walk; the patient is instructed to walk as far as possible in a 30 m long flat corridor, back and forth around two cones, with the permission to slow down, rest, or stop if needed. Areas were to be well ventilated with air temperature controlled between 20 °C and 23 °C (68 °F to 76 °F). The test was to be administered at the same time of day and by the same tester throughout the study. The tester measured the distance walked by non-encouraged patients during the timed 6 minute period.	From baseline to week 16
Number of Participants With Improved, No Change, or Worsened World Health Organisation Functional Class From Baseline to Week 16	Class I: no limitation of usual physical activity (PA) which does not increase dyspnea, fatigue, chest pain, or presyncope. Class II: mild limitation of PA. No discomfort at rest. Normal PA increases dyspnea, fatigue, chest pain, or presyncope. Class III: marked limitation of PA. No discomfort at rest. Less than ordinary activity increases dyspnea, fatigue, chest pain, or presyncope. Class IV: unable to perform any PA and who may have signs of right ventricular failure. Dyspnea and/or fatigue may be present at rest and symptoms are increased by almost any PA.	From baseline to Week 16
Time to Death of All Causes From Baseline to End of Study	Kaplan-Meier estimate of percentage of participants without a mortality event.Time to death due to any cause.	Baseline to End of Study, approximately 86 months
Adjusted Percentage Ratio From Baseline in N-terminal Pro-B-type Natriuretic Peptide (NT-pro-BNP)	Blood sampling for the measurement of NT-pro-BNP was performed and the plasma concentrations of NT-pro-BNP were determined by a certified centralized laboratory.	Baseline to Month 20
Change From Baseline to Week 16 in Borg Dyspnea Index	The Borg dyspnea index was evaluated immediately after the 6MWT to obtain a rating of dyspnea at the end of the exercise using a scale from 0 ('Nothing at all') to 10 ('Very, very severe - maximal').	Baseline to Week 16
Change From Baseline to Week 16 in the EuroQol 5 Dimensions (EQ-5D) Questionnaire Calculated Score	The EQ-5D questionnaire is a patient-reported outcome consisting of a 5 dimensional descriptive system and a visual analog scale (VAS). The descriptive system asks respondents to describe their health status. Health is defined in 5 dimensions: (1) mobility, (2) self care, (3) usual activities, (4) pain or discomfort, and (5) anxiety or depression. Each dimension is divided into 3 levels, indicating (a) no problem, (b) some or moderate problems, or (c) extreme problems. Respondents record their problem(s) in each of the 5 dimensions. Combinations of these levels define a total of 243 health states. A health state defined by the descriptive system of EQ-5D can be described by a 5-digit number with full health is indicated by 11111 and poorest health state by 33333. The EQ-5D calculated score was derived by re-assigning local scores for answers to each question and combining these local scores into a global score with ranges from 0 (worst possible outcome) to 1 (best possible outcome).	From baseline to Week 16
Change From Baseline to Week 16 in the EuroQol 5 Dimensions (EQ-5D) Visual Analogue Scale Score	The EQ-5D questionnaire is a patient-reported outcome consisting of a 5 dimensional descriptive system and a visual analog scale (VAS) together with brief demographic questions. EQ-5D VAS asks respondents to rate their perception of their overall health on a vertical visual analogue scale with 'best imaginable health state' set at 100 and 'worst imaginable health state' set at 0.	Baseline to Week 16
Patient Global Self Assessment (PGSA) Status at Week 16	The PGSA is a questionnaire that allows the patient to compare his/her PAH status in response to the question "How do you feel about your PAH today compared with your last visit?" asked by the investigator. Patients use a seven-point scale to respond: markedly better, moderately better, mildly better, no change, markedly worse, moderately worse, or mildly worse.	Week 16

Collaborators and Investigators

• Sponsor: Actelion

Publications and helpful links

General Publications

• McLaughlin V, Channick RN, Ghofrani HA, Lemarie JC, Naeije R, Packer M, Souza R, Tapson VF, Tolson J, Al Hiti H, Meyer G, Hoeper MM. Bosentan added to sildenafil therapy in patients with pulmonary arterial hypertension. Eur Respir J. 2015 Aug;46(2):405-13. doi: 10.1183/13993003.02044-2014. Epub 2015 Jun 25.

Helpful Links

• Tracleer for PAH approval page at Drugs@FDA.gov

Study record dates

Study Major Dates

• Study Start: May 1, 2006
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: March 16, 2006
• First Submitted That Met QC Criteria: March 16, 2006
• First Posted (Estimated): March 17, 2006

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 31, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Keywords: Pulmonary Hypertension; sildenafil; Randomized Controlled Trial; Pulmonary Arterial Hypertension; endothelin receptor antagonist; Combination Drug Therapy; Multicenter Study; Antihypertensive Agents; bosentan; Tracleer; Outcome Assessment; Phosphodiesterase type 5 inhibitor (PDE5i)
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Respiratory Tract Diseases; Lung Diseases; Hypertension, Pulmonary; Pulmonary Arterial Hypertension; Hypertension; Familial Primary Pulmonary Hypertension; Molecular Mechanisms of Pharmacological Action; Antihypertensive Agents; Endothelin Receptor Antagonists; Bosentan
• Other Study ID Numbers: AC-052-414; COMPASS-2 (Other Identifier: Actelion Pharmaceuticals Ltd)