Evatanepag is primarily used in the treatment of pulmonary arterial hypertension (PAH). It functions as a selective prostacyclin receptor agonist, helping to dilate blood vessels and reduce blood pressure in the lungs, thereby improving exercise capacity and delaying disease progression. This makes it a valuable therapeutic option for patients suffering from PAH, particularly those who may not respond well to other treatments. Additionally, its oral administration offers a convenient alternative to more invasive therapies, enhancing patient compliance and quality of life.