A Study to Evaluate Efficacy and Safety of Macitentan 75 mg in Inoperable or Persistent/Recurrent Chronic Thromboembolic Pulmonary Hypertension

Study Overview
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Brief Summary
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The purpose of the study is to evaluate the effect of macitentan 75 mg versus placebo on exercise capacity at Week 28 in participants with chronic thromboembolic pulmonary hypertension (CTEPH).

Detailed Description
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CTEPH is one of the leading causes of severe pulmonary hypertension (PH), classified within World Health Organization (WHO) group 4 PH. It is a rare, progressive pulmonary vascular disease that if left untreated, leads to progressively increasing pulmonary vascular resistance (PVR) and eventually right ventricle failure and death. Histopathologic findings including endothelial cell dysfunction and distal pulmonary arterial remodeling are shared between PAH and CTEPH, and PH-specific therapies (that is, riociguat) have shown efficacy in inoperable and persistent/recurrent CTEPH. The endothelin receptor antagonist macitentan offers a different mode of action and addresses an important unmet medical need for an alternative treatment option in this indication. This study will assess the effect of macitentan 75 mg on exercise capacity in CTEPH. The total duration of the study is approximately 6 years. The study comprises of a screening period (at least 14 days and up to 60 days), a double-blind (DB) treatment period (28 weeks [minimum duration] up to 3.5 years), an open-label (OL) extension period (starts at end-of-DB-treatment [EODBT] and will end for all participants 104 weeks after the last participant has completed DB Week 28). The DB period consists of an 8-week up-titration phase and a maintenance phase. The maintenance phase is divided into a 28-week fixed duration part, at the end of which primary endpoint is assessed, and a variable duration part. The duration of the DB period for an individual participant depends on the timepoint of entry into the study and whether a CEC-confirmed clinical worsening event occurred. Participants who discontinue DB study intervention during the 28-week fixed duration part will be followed until Week 28 in a post-treatment observation period (PTOP).

Official Title
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A Prospective, Randomized, Double-blind, Multicenter, Placebo-controlled, Parallel Group, Adaptive Phase 3 Study With Open-label Extension to Evaluate Efficacy and Safety of Macitentan 75 mg in Inoperable or Persistent/Recurrent Chronic Thromboembolic Pulmonary Hypertension

Conditions
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Chronic Thromboembolic Pulmonary Hypertension

Intervention / Treatment
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* Drug: Macitentan
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chronic thromboembolic pulmonary hypertension (CTEPH) (World Health Organization [WHO] Group 4) fulfilling one of the following criteria: a) inoperable due to the localization of the obstruction being surgically inaccessible (that is, distal disease), b) persistent/recurrent CTEPH after balloon pulmonary angioplasty (BPA), and deemed inoperable due to the localization of the obstruction being surgically inaccessible (that is, distal disease), c) persistent/recurrent CTEPH after rescue pulmonary endarterectomy (PEA) 6-minute walk distance (6MWD) greater than or equal to (>=) 100 meter (m) and less than or equal to (<=) 450 meters (m), documented by an eligibility and a baseline 6-minute walk test (6MWT). The baseline 6MWD must not differ by more than 15 percent (%) from the eligibility test World Health Organization functional class (WHO FC) >= II Participants are to receive riociguat as per local standard of care, unless it is contraindicated or unavailable Exclusion Criteria: Acute pulmonary embolism within 3 months prior to or during Screening Planned balloon pulmonary angioplasty (BPA) during the fixed duration part of the double-blind period Significant obstructive and restrictive lung disease Acute or chronic conditions (other than dyspnea) that limit the ability to comply with study requirements, in particular with 6MWT (for example, intermittent claudication). Symptomatic coronary artery disease requiring an intervention within 3 months prior to or during Screening or anticipated during the fixed duration part of the study Decompensated cardiac failure if not under close supervision Known and documented life-threatening cardiac arrhythmias Acute myocardial infarction within 6 months prior to, or during Screening Cerebrovascular events (including transient ischemic attack) within 3 months prior to, or during Screening Known or suspicion of pulmonary veno-occlusive disease (PVOD) Administration of ERAs, intravenous prostacyclins / prostacyclin analogs, or investigational treatment within 90 days prior to Randomization Change in dose or initiation of Phosphodiesterase type-5 (PDE-5) inhibitors, oral, inhaled or subcutaneous (SC) prostacyclins / prostacyclin analogues, prostacyclin receptor agonists or riociguat, a) within 90 days prior to Randomization, or b) anticipated during the fixed duration part of the double-blind [DB] period Hypotension, that is, systolic blood pressure (SBP) less than (<) 90 millimeters of mercury (mmHg) or diastolic blood pressure (DBP) <50 mmHg at Screening. Severe renal dysfunction with an estimated Glomerular Filtration Rate <30 milliliters per minute per 1.73 meter square (mL/min/1.73 m^2) using the Chronic Kidney Disease Epidemiology Collaboration formula at Screening Known moderate to severe hepatic impairment, defined as Child-Pugh Class B or C, based on records that confirm documented medical history Serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) greater than or equal to (>=) 1.5*upper limit of normal (ULN) at Screening Hemoglobin <100 g/L (<10 gram per deciliter [g/dL]) at Screening

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Macitentan<br>Participant will receive macitentan at a dose of 10 milligram (mg) once daily (OD) for 4 weeks, followed by a dose of macitentan 37.5 mg for another 4 weeks and continue with the target dose of macitentan 75 mg. Participants who have reached the target dose of 75 mg, completed the Double-blind (DB) period up to Week 28 (either on treatment or in Post-treatment observation period [PTOP]) at minimum, may be eligible for transitioning into the Open label (OL) extension period once all participants have completed the DB part of the study, or earlier if they experienced a Clinical event committee (CEC) confirmed clinical worsening event. | Drug: Macitentan<br>* Participants will receive Macitentan film-coated tablets orally od.<br>* Other names: Opsumit;|
| Experimental: Placebo<br>Participants will receive placebo tablets matching the macitentan 10 mg, macitentan 37.5mg and macitentan 75 mg tablets, respectively. Participants who completed the DB period as per protocol either on treatment or in PTOP are eligible for transitioning to the OL extension period and will receive macitentan 75 mg after an 8-week double-dummy uptitration (macitentan 10 mg for 4 weeks, followed by 37.5 mg for another 4 weeks). | Drug: Macitentan<br>* Participants will receive Macitentan film-coated tablets orally od.<br>* Other names: Opsumit;Drug: Placebo<br>* Participant will receive matching placebo tablets orally od.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change From Baseline to Week 28 in 6- minute Walk Distance [6MWD] | Change from baseline to week 28 in 6MWD as measured by 6-minute walk test [6MWT]) will be reported. The purpose of the six-minute walk test (6MWT) is to quantify exercise tolerance and capacity. This standardized test measures the distance an individual is able to walk over a total of six minutes on a hard, flat surface. The goal is for the individual to walk as far as possible in 6 minutes. | Baseline up to Week 28 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to Clinical Worsening up to End-of double-blind-treatment (EODBT) Period | Time to first Clinical Event Committee (CEC) confirmed clinical worsening up to EODBT will be reported. Clinical worsening is defined as the occurrence of at least one of the following events: 1) All-cause death; 2) Heart and/or lung transplantation; 3) Unplanned pulmonary hypertension (PH)-related hospitalization; 4) PH-related deterioration from baseline identified by at least one of the following: a) Persistent increase in World Health Organization functional class (WHO FC) that cannot be explained by another cause (for example, viral infection); b) Persistent deterioration by at least 15 percent (%) in exercise capacity; as measured by the 6MWD; c) New or worsening signs or symptoms of right heart failure; 5) Rescue pulmonary endarterectomy (PEA) and/or balloon pulmonary angioplasty (BPA) procedure due to worsening of PH. | Up to EODBT (variable duration per participant, up to 3.5 years) | 
| Number of Participants with Improvement in WHO Functional Class (WHO FC) From Baseline to Week 28 | Improvement in WHO FC from baseline to Week 28 will be calculated for each participant. WHO FC test is used to assess disease severity. Four functional classes (FC) are defined from FC I (no limitation of physical activity) to FC IV (inability to carry out any physical activity without symptoms). Improvement is considered when a participant changes from a higher class to a lower class. | Baseline up to Week 28 | 
| Change From Baseline to Week 28 in Pulmonary Arterial Hypertension - Symptoms Based on (PAH-SYMPACT) - Cardiopulmonary Symptom Domain Score | The Cardiopulmonary Symptoms domain consists of 6 items (shortness of breath, fatigue, lack of energy, swelling in ankles or legs, swelling in stomach area and cough) reported on a 5-point Likert scale (from 0 to 4). The value 0 means no symptom and value 4 corresponds to very severe symptoms. The symptoms part of the PAH-SYMPACT will be administered daily over a 7-day period. The recall period of symptom items is the last 24 hours. An average Cardiopulmonary Symptoms domain score is determined based on the daily scores of the 6 items. Questionnaires to be completed at site at screening for training purpose. PAH-SYMPACT to be performed at home, during the 7-day period prior to the scheduled visit. | Baseline up to Week 28 | 
| Change from Baseline to Week 28 in PAH-SYMPACT - Cardiovascular Symptom Domain Score | The Cardiovascular Symptoms domain consists of 5 items (heart palpitations [fluttering], rapid heartbeat, chest pain, chest tightness, and lightheadedness) reported on a 5-point Likert scale (from 0 to 4). The value 0 corresponds to no symptoms and value 4 corresponds to very severe symptoms. The symptoms part of the PAH-SYMPACT will be administered daily over a 7-day period. The recall period of symptom items is the last 24 hours. An average Cardiovascular Symptoms domain score is determined based on the daily scores of the 5 items. Questionnaires to be completed at site at screening for training purpose. PAH-SYMPACT to be performed at home, during the 7-day period prior to the scheduled visit. | Baseline up to Week 28 | 
| Change from baseline to Week 28 in Euro Quality of life-5-Dimension-5-Level (EQ-5D-5L) Utility Score | The EQ-5D-5L is a generic measure of health status. The EQ-5D-5L is a 5-item questionnaire that assesses 5 domains including mobility, self-care, usual activities, pain/discomfort and anxiety/depression plus a visual analog scale rating health today with anchors ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). | Baseline up to Week 28 | 
| Change From Baseline to Week 28 in Accelerometer-assessed Proportion of Time Spent in Moderate to Vigorous Physical Activity | Change from baseline to week 28 in accelerometer-assessed proportion of time spent in moderate to vigorous physical activity will be assessed. | Baseline up to Week 28 |