Open-label, Clinical Study to Evaluate the Safety and Tolerability of TreT in Subjects With PAH Currently Using Tyvaso

Inclusion Criteria

• •1. Subject voluntarily gave informed consent to participate in the study.
• •2. Subject was aged 18 years or older at the time of signing informed consent.
• •3. Women of childbearing potential were those who had experienced menarche and who had not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or were not postmenopausal (defined as amenorrhea for at least 12 consecutive months). WOCBP must have been nonpregnant (as confirmed by a urine pregnancy test at Screening prior to initiating study medication), nonlactating, and did 1 of the following:
• •1. Abstained from intercourse (when it was in line with their preferred and usual lifestyle), or
• •2. Used 2 medically acceptable, highly effective forms of contraception for the duration of study, and at least 30 days after discontinuing TreT. Medically acceptable, highly effective forms of contraception included approved hormonal contraceptives (oral, injectable, and implantable), intrauterine devices or systems, and barrier methods (such as a condom or diaphragm) when used with a spermicide.
• •4. Males with a partner of childbearing potential must have used a condom for the duration of treatment and for at least 48 hours after discontinuing TreT.
• •5. Subject was diagnosed with PAH as defined by the following World Health Organization (WHO) Group 1 categories:
• •1. Idiopathic/familial
• •2. Associated with unrepaired or repaired congenital systemic-to-pulmonary shunts (repaired ≥5 years prior to Screening)
• •3. Associated with collagen vascular disease
• •4. Associated with human immunodeficiency virus
• •5. Associated with appetite suppressant/other drug or toxin use
• •6. Subject must have started Tyvaso ≥3 months prior to the Baseline Visit and was currently on a stable regimen (no change in dose within 30 days of Baseline Visit) of Tyvaso (6 to 12 breaths QID).
• •7. Baseline 6MWD ≥150 m.
• •8. If the subject was currently receiving other approved background therapy (eg, endothelin receptor antagonist or phosphodiesterase type 5 inhibitor or both), the subject must have been on a stable dose with no additions or discontinuations for a minimum of 30 days prior to Screening.
• •9. The subject had evidence of forced expiratory volume in 1 second (FEV1) ≥60% and FEV1/forced vital capacity ratio ≥60% during the 6 months prior to enrollment.
• •10. In the opinion of the Investigator, the subject was able to communicate effectively with study personnel, and was considered reliable, willing, and likely to be cooperative with protocol requirements, including all study visits.