Study of Efficacy and Safety of LTP001 in Pulmonary Arterial Hypertension

Inclusion Criteria:

• History of PAH belonging to one of the following subgroups of the ClinicalClassification Group 1 (WHO):

• participants with idiopathic pulmonary arterial hypertension (IPAH)

• Hereditary pulmonary arterial hypertension

• Congenital heart disease (surgically repaired at least 12 months prior toscreening)

• drug or toxin induced (for example, anorexigen, or methamphetamine use).

• Resting mean pulmonary arterial pressure (mPAP) > 25 mmHg; pulmonary capillary wedgepressure (PCWP) or left ventricular end diastolic pressure < 15 mmHg, as determinedby right heart catheterization within 20 days of randomization.

• Pulmonary Vascular Resistance > 6 Wood units (480 dynes s/cm-5), as determined byright heart catheterization within 20 days of randomization.

• WHO Functional Class II-III

• 6MWD must be between 150 and 550 m (inclusive). The qualifying test needs to bewithin 20 days of randomization. To meet the above criterion additional six minutewalk test (6MWT) may be performed up to a maximum of 3 tests in total prior todosing; the minimal time difference between two tests should be at least 4 h.

• Standard of care therapy which is stable at least 6 weeks prior to RHC andqualifying 6MWT assessment within 20 days of randomization. Standard of careincludes one or more of the following treatments:

• prostacyclin analogues and receptor agonists (if I.V., dose adjustments must bewithin 20% of initial stable dose)

• endothelin receptor antagonists (ERAs)

• phosphodiesterase type 5 inhibitors (PDE5i)

• soluble guanylate cyclase (sGC) stimulators

Exclusion Criteria:

• Participants with pulmonary hypertension (PH) in the Clinical Classification Groups 2-5 (WHO), and any PAH Group 1 subgroups not covered by Inclusion Criterion #4.

• Participants with a history of left sided heart disease, chronic left sided heartfailure, congenital or acquired valvular disease compromising left ventricularfunction and/or pulmonary venous hypertension or symptomatic coronary disease (non-symptomatic, revascularized coronary artery disease would be acceptable).

• Participants with obstructive lung disease defined as: FEV1/FVC < 60% and FEV1 < 60%of predicted value after bronchodilator administration as well as participants withmoderate or severe restrictive lung disease: Total Lung Capacity < 70% of predictedvalue. Testing must have occurred within 24months of screening. If historicaltesting is not available, then lung function testing must be conducted during thescreening period.

• Acute or chronic impairment (other than dyspnea), which would limit the ability tocomply with study requirements, including interference with physical activity andexecution of study procedures such as 6MWT (e.g., angina pectoris, claudication,musculoskeletal disorder, multiple sclerosis, need for walking aids).