Effect of Selexipag on Daily Life Physical Activity of Patients With Pulmonary Arterial Hypertension.

This study is designed as exploratory with the purpose to generate hypotheses on new
endpoints

Inclusion Criteria:

- Male or female between 18 and 75 years old inclusive.

- Women of childbearing potential must have a negative serum pregnancy test at planned
visits and use an acceptable method of birth control from screening up to 30 days
after study treatment discontinuation.

- Symptomatic pulmonary arterial hypertension (PAH) belonging to one of the following
subgroups only:

- Idiopathic

- Heritable

- Drug or toxin induced

- Associated with one of the following: connective tissue disease; HIV infection;
corrected simple congenital heart disease.

- With the following hemodynamic characteristics assessed by right heart catheterization
(RHC) prior to randomization:

- Mean pulmonary artery pressure (mPAP) ≥ 25 mmHg

- Pulmonary vascular resistance (PVR) ≥ 240 dyn•sec/cm5 (or 3 Wood Units)

- Pulmonary artery wedge pressure (PCWP) or left ventricular end-diastolic pressure
(LVEDP) ≤ 15 mmHg.

- Treatment with an endothelin receptor antagonist (ERA) for at least 90 days and on a
stable dose for 30 days prior to randomization.

- If an ERA is given in combination with a phosphodiesterase-5 (PDE-5) inhibitor or
soluble guanylate cyclase (sGC) stimulator, these treatments must be ongoing for at
least 90 days and on a stable dose for 30 days prior to randomization.

- WHO functional class (FC) II or III at randomization

- 6-minute walk distance (6MWD) ≥ 100 m at screening.

- Ability to walk without a walking aid.

- Valid baseline data for daily life physical activity (DLPA) and PAH-SYMPACT®.

Exclusion Criteria:

- Patients on a PAH-specific monotherapy targeting the nitric oxide pathway (i.e. PDE-5
inhibitor or sGC stimulator).

- Patients treated with prostacyclin, prostacyclin analog or selexipag within 3 months
prior to screening.

- Any hospitalization during the last 30 days prior to screening.

- Severe coronary heart disease or unstable angina.

- Documented severe hepatic impairment or severe renal insufficiency at screening.

- Participation in a cardio-pulmonary rehabilitation program based on exercise training
within 8 weeks prior to screening

- Any factor or condition likely to affect full participation in the study or compliance
with the protocol (such as adherence to protocol mandated procedures), as judged by
the investigator.