A Study of Macitentan and Tadalafil as a Fixed Dose Combination and the Free Combination in Healthy Adult Participants

Single-center, Open-label, Single-dose, 2-period, Randomized, Crossover Phase 1 Study to Demonstrate Bioequivalence of Tadalafil Administered as a Fixed Dose Combination Formulation of Macitentan/Tadalafil (10 mg/40 mg) and as the Free Combination of 10 mg Macitentan (Opsumit) and 40 mg Tadalafil (Adcirca), and to Assess the Effect of Food on the Pharmacokinetics of the Fixed Dose Formulation of Macitentan/Tadalafil (10 mg/40 mg) in Healthy Adult Participants

The purpose of this study is to demonstrate bioequivalence on the primary pharmacokinetic (PK) parameters of tadalafil administered as an fixed dose combination (FDC) (test) of macitentan/tadalafil (10 milligram [mg]/40 mg) and coadministered as a free combination (reference) of 10 mg macitentan (Opsumit) and 40 mg Canada-sourced tadalafil (Adcirca) in fasted conditions in healthy adult participants (Group 1) and to evaluate the effect of food on the primary PK parameters of macitentan and tadalafil administered as an FDC of macitentan/tadalafil (10 mg/40 mg) in healthy adult participants (Group 2).

Inclusion Criteria:

• Body mass index (BMI; weight [kilogram]/height^2 [m^2]) between 18.5 and 30.0 kilogram per meter square (kg/m^2), inclusive, and body weight not less than 50.0 kg at screening
• Healthy on the basis of physical examination, and medical and surgical history, performed at screening. If there are abnormalities, the participant may be included only if the investigator judges the abnormalities to be not clinically significant. This determination must be recorded in the participant's source documents and initialed by the investigator
• Healthy on the basis of clinical laboratory tests performed at screening. If the results of hematology, coagulation, or biochemistry assessments are outside the normal reference ranges, the participant may be included only if the investigator judges the abnormalities or deviations from normal to be not clinically significant. This determination must be recorded in the participant's source documents and initialed by the investigator
• Systolic blood pressure (SBP) between 100 and 145 millimeter of Mercury (mmHg), diastolic blood pressure (DBP) between 50 and 90 mmHg, and pulse rate between 45 and 99 beats per minute (bpm; inclusive), preferably measured on the right arm, after the participant is supine for at least 5 minutes, at screening
• 12-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

Exclusion Criteria:

• Female participant who is breastfeeding at screening and plans to breastfeed throughout the study
• Known allergy, hypersensitivity, or intolerance to any active substance or drugs of the same class, or any excipient of the drug formulation(s)
• 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 treatment(s) (appendectomy and herniotomy allowed, cholecystectomy not allowed)
• Any loss of vision in 1 or both eyes
• Known hereditary degenerative retinal disorders, including retinitis pigmentosa