Bardoxolone Methyl in Patients With Connective Tissue Disease-associated Pulmonary Arterial Hypertension - CATALYST

This study assesses the safety and efficacy of bardoxolone methyl relative to placebo in patients with connective tissue disease-associated pulmonary arterial hypertension to determine the recommended dose range and evaluate the change from baseline in 6-minute walk distance (6MWD) following 24 weeks of study participation.

This double-blind, randomized, placebo-controlled trial will study the safety, tolerability, and efficacy of bardoxolone methyl in qualified patients with World Health Organization Group I Connective Tissue Disease Pulmonary Arterial Hypertension (WHO Group I CTD-PAH).

Qualified patients will be randomized 1:1 to either bardoxolone methyl or placebo to be administered once daily for 24 weeks. Patients randomized to placebo will remain on placebo throughout the study. Patients randomized to bardoxolone methyl will start at 5 mg and will dose-escalate to 10 mg at Week 4 unless contraindicated clinically. Dose de-escalation is permitted during the study if indicated clinically.

All patients in the study will follow the same visit and assessment schedule. Following randomization, patients will be scheduled to be assessed in person during treatment at Weeks 1, 2, 4, 6, 8, 16, and 24 and by telephone contact on Days 3, 10, 21, 31, 38, 84, and 140. Patients will also be scheduled to be assessed at an in person follow up visit at Week 28, four weeks after the end of treatment.

Study Sponsor, originally Reata Pharmaceuticals, Inc., is now Reata Pharmaceuticals, Inc., a wholly owned subsidiary of Biogen.

Eligibility Criteria:
Inclusion Criteria:

* BMI \> 18.5 kg/m2;
* Symptomatic pulmonary hypertension WHO/NYHA FC class II and III;
* WHO Group I PAH associated with connective tissue disease;
* Had a diagnostic right heart catheterization performed and documented within 36 months prior to Day 1 that confirmed a diagnosis of PAH according to all the following criteria:

  * Mean pulmonary artery pressure ≥ 25 mm Hg (at rest);
  * Pulmonary capillary wedge pressure (PCWP) ≤ 15 mm Hg;
  * Pulmonary vascular resistance \> 240 dyn.sec/cm5 or \> 3 mm Hg/liter (L)/minute;
* Has BNP level ≤ 400 pg/mL;
* Had an average 6MWD ≥ 150 meters on two consecutive tests performed on different days prior to randomization, with both tests measuring within 15% of one another;
* Has been receiving no more than two (2) approved disease-specific PAH therapies. PAH therapy must have been at a stable dose for at least 90 days prior to Day 1. No additions or changes should be made to PAH therapies and doses should remain stable for the duration of the study;
* Has maintained a stable dose for 30 days prior to Day 1 if receiving any of the following therapies that may affect PAH: vasodilators (including calcium channel blockers), digoxin, L-arginine supplementation, or oxygen supplementation. No additions or changes should be made to therapies and doses should remain stable for the duration of the study;
* If receiving treatment for CTD with prednisone or any other drugs, doses must remain stable for at least 30 days prior to Day 1 and for the duration of the study Had pulmonary function tests (PFTs) within 90 days prior to Day 1 with total lung capacity ≥ 65% (predicted);
* Had a ventilation-perfusion (V/Q) lung scan, spiral/helical/electron beam computed tomography (CT), or pulmonary angiogram prior to Day 1 that shows no evidence of thromboembolic disease (i.e., should note normal or low probability for pulmonary embolism). If V/Q scan was abnormal (i.e., results other than normal or low probability), then a confirmatory CT or selective pulmonary angiography must exclude chronic thromboembolic pulmonary hypertension;
* Has adequate kidney function defined as an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2 as measured by the central lab;
* Willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures;
* Evidence of a personally signed and dated informed consent document indicating that the patient (or a legally acceptable representative) has been informed of all pertinent aspects of the study prior to initiation of any patient-mandated procedures

Exclusion Criteria:

* Participation in other investigational clinical studies involving interventional products being tested or used in a way different from the approved form or when used for an unapproved indication within 30 days prior to Day 1;
* Initiation of an exercise program for cardio-pulmonary rehabilitation within 90 days prior to Day 1 or planned initiation during the study;
* Stopped receiving any PAH chronic therapy within 60 days prior to Day 1;
* Received a dose of prednisone \> 20 mg/day (or equivalent dose if other corticosteroid) within 30 days prior to Day 1;
* Received intravenous (iv) or subcutaneous (sc) prostacyclin/prostacyclin analogues within 90 days prior to Day 1;
* Received intravenous inotropes within 30 days prior to Day 1;
* Has uncontrolled systemic hypertension as evidenced by sitting systolic blood pressure (BP) \> 160 mm Hg or sitting diastolic BP \> 100 mm Hg during Screening after a period of rest;
* Has systolic BP \< 90 mm Hg during Screening after a period of rest;
* Has a history of clinically significant left-sided heart disease and/or clinically significant cardiac disease, including but not limited to any of the following:

  * Congenital or acquired valvular disease if clinically significant apart from tricuspid valvular insufficiency due to pulmonary hypertension;
  * Pericardial constriction;
  * Restrictive or congestive cardiomyopathy;
  * Left ventricular ejection fraction \< 40% per echocardiogram (ECHO) within 90 days of Day 1;
  * Symptomatic coronary artery disease within the last 3 years;
* Acutely decompensated heart failure within 30 days prior to Day 1, per investigator assessment;
* Has more than two of the following clinical risk factors for left ventricular diastolic dysfunction:

  * Age \> 65 years;
  * BMI ≥ 30 kg/m2;
  * History of systemic hypertension;
  * History of type 2 diabetes;
  * History of atrial fibrillation;
  * History of atrial septostomy within 180 days prior to Day 1;
  * History of uncontrolled obstructive sleep apnea;
* Has a history of portal hypertension or chronic liver disease, including hepatitis B and/or hepatitis C (with evidence of recent infection and/or active virus replication) defined as mild to severe hepatic impairment (Child-Pugh Class A-C);
* Serum aminotransferase (ALT or AST) levels \> 1.5X the upper limit of normal (ULN) at Screening;
* Hemoglobin (Hgb) concentration \< 8.5 g/dL at Screening;
* Diagnosis of Down syndrome;
* History of malignancy within 5 years prior to screening, with the exception of localized skin or cervical carcinomas;
* Untreated or uncontrolled active bacterial, fungal, or viral infection;
* Known or suspected active drug or alcohol abuse, per investigator judgment;
* Use of Herbalife supplements within 14 days prior to Day 1;
* Major surgery within 30 days prior to Day 1 or planned to occur during the course of the study;
* Unwilling to practice acceptable methods of birth control (both males who have partners of childbearing potential and females of childbearing potential) during screening, while taking study drug, and for at least 30 days after the last dose of study drug is ingested;
* Use of inhaled nitric oxide within 7 days prior to Screening and Day 1 visits, excluding acute vasodilator testing during diagnostic cardiac catheterization;
* Women who are pregnant or breastfeeding;
* Any disability or impairment that would prohibit performance of the 6MWT;
* Any abnormal laboratory level that, in the opinion of the investigator, would put the patient at risk by trial enrollment;
* Patient is, in the opinion of the investigator, unable to comply with the requirements of the study protocol or is unsuitable for the study for any reason;
* Known hypersensitivity to any component of the study drug;
* Unable to communicate or cooperate with the investigator because of language problems, poor mental development, or impaired cerebral function.