This clinical trial is focused on studying a condition known as Pulmonary Arterial Hypertension (PAH). PAH is a type of high blood pressure that affects the arteries in the lungs and the right side of the heart. The study will investigate a treatment called KER-012, which is a solution for injection. KER-012 is a recombinant fusion protein, meaning it is a specially designed protein that combines parts from different sources to help treat the disease. The trial will compare the effects of KER-012 with a placebo, which is a substance with no active medication, to see how well KER-012 works in combination with other PAH therapies that participants are already receiving.

The purpose of the study is to evaluate the safety and effectiveness of KER-012 in improving the condition of patients with PAH. Participants will receive either KER-012 or a placebo, and the study will monitor changes in their health over time. The trial will last for a period of up to 96 weeks, during which participants will have regular check-ups to assess their response to the treatment. The main focus will be on how KER-012 affects the blood flow in the lungs and the ability of participants to perform physical activities, such as walking.

Throughout the study, researchers will also keep track of any side effects or adverse reactions that participants may experience. This will help determine the overall safety of KER-012. The study aims to provide valuable information on whether KER-012 can be a beneficial addition to existing PAH treatments, potentially improving the quality of life for those living with this challenging condition.