A Study of Fixed Dose Combination of Macitentan/Tadalafil (10 mg/20 mg) Compared to the Reference Free Combination of Macitentan and Tadalafil in Healthy Adult Participants

A Single-center, Open-label, Single-dose, Randomized, 3-way Crossover Phase 1 Study in Healthy Adult Participants to Assess the Bioequivalence of the Combination of Macitentan/Tadalafil (10 mg/20 mg) Administered as a Fixed Dose Combination Formulation Compared to the Reference Free Combination of 10 mg Macitentan (Opsumit®) and 20 mg Tadalafil (Adcirca®) as Well as the Food Effect of the Fixed-dose Combination Formulation

The purpose of this study is to demonstrate bioequivalence on the primary pharmacokinetic (PK) parameters between macitentan and tadalafil administered as a fixed dose combination (FDC) (test) of macitentan/tadalafil and the co- administered free combination (reference) of macitentan (Opsumit) and tadalafil (Adcirca) in fasted conditions in healthy adult participants; and to evaluate the effect of food on the primary PK parameters of macitentan and tadalafil administered as an FDC of macitentan/tadalafil in fed versus fasted conditions in healthy adult participants.

Inclusion Criteria:

• Healthy on the basis of physical examination and medical history, performed at screening. If there are any abnormalities, they must be considered not clinically relevant and this determination must be recorded in the participant's source documents and initialed by the investigator
• Systolic blood pressure (SBP) between 100 and 145 millimeters of mercury (mm Hg) (inclusive), diastolic blood pressure (DBP) between 50 and 90 mm Hg (inclusive), and pulse rate between 45 and 90 beats per minute (inclusive) at screening, supine for at least 5 minutes and after 3 minutes of standing
• Twelve-lead electrocardiogram (ECG) without clinically relevant abnormalities, at the discretion of the investigator, measured after the participant is supine for at least 5 minutes, at screening
• A woman must agree not to donate eggs (ova, oocytes) for the purposes of assisted reproduction during the study and for a period of 30 days after the last study intervention intake
• Willing and able to adhere to the lifestyle restrictions specified in this protocol

Exclusion Criteria:

• Known allergies, hypersensitivity, or intolerance to macitentan, tadalafil, or drug of the same class, or its excipients
• History or clinical evidence of any disease and/or existence of any surgical or medical condition which might interfere with the absorption, distribution, metabolism, or excretion of the study intervention(s) (appendectomy and herniotomy allowed, cholecystectomy not allowed)
• Veins unsuitable for intravenous puncture on either arm (example, veins that are difficult to locate, access, or puncture, and veins with a tendency to rupture during or after puncture)
• Known hereditary degenerative retinal disorders, including retinitis pigmentosa