CompRehensive Phenotypic Characterization of Patients With Scleroderma-Associated ILD and PH

Inclusion Criteria: * Patients who have scleroderma ILD will be defined as having a total lung capacity of less than 80% predicted and CT evidence of fibrosis. The degree of fibrosis will be scored by a radiologist using the CT comparative scoring method of Wells et al (13). * Pulmonary Hypertension (PH) as defined as resting mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg with a wedge pressure of ≤ 15 mmHg during right heart catheterization. * Stable ILD as evident by a stable FEV1 and FVC for 3 months prior to the initiation of the study, and be pulmonary arterial hypertension (PAH)-targeted treatment naïve. Exclusion Criteria: * 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\<40% predicted) and/or obstructive lung disease (FEV1 \<55% predicted and FEV1/FVC \<70%). * Patients with radiographic combined pulmonary fibrosis/emphysema (CPFE) will also be excluded if imaging shows predominant emphysema and/or obstruction is moderately severe (FEV1\<30%) * 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. * Patients with a contraindication to exercise testing based on American Heart Association/American College of Cardiology (AHA/ACC) guidelines. * PAH associated with significant venous or capillary involvement (PCWP \> 15 mmHg), known pulmonary veno-occlusive disease, and pulmonary capillary hemangiomatosis. * Persistent pulmonary hypertension of the newborn. * Pulmonary Hypertension belonging to groups 2 to 5 of the Venice 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. * Systolic blood pressure \< 100 mmHg. * Acute or chronic physical impairment (other than dyspnea), limiting the ability to comply with study requirements. * Pregnant or breast-feeding. * Known concomitant life-threatening disease with a life expectancy \< 12 months. * Body weight \< 40 kg. * Any condition that prevents compliance with the protocol or adherence to therapy. * Treatment with endothelin receptor antagonists (ERAs) within 3 months prior to randomization. * Systemic treatment within 4 week prior to randomization with cyclosporine A or tacrolimus, everolimus, sirolimus (calcineurin or mammalian target of rapamycin (mTOR) inhibitors). * Treatment with cytochrome P3A (CYP3A) inducers within 4 weeks prior to randomization * Known hypersensitivity to drugs of the same class as the study drug, or any of their excipients. * Planned treatment, or treatment, with another investigational drug within 1 month prior to randomization