Vardenafil Inhaled for Pulmonary Arterial Hypertension PRN Phase 2B Study is testing a new inhaled medicine called RT234 for people with a lung condition called pulmonary arterial hypertension (PAH). PAH makes it hard to exercise because it affects the heart and lungs. This study checks if RT234 can help people breathe easier and exercise better.

Key Points to Consider:

• The study is for adults 18-80 years old with PAH.
• Participants must be able to walk and exercise without extra oxygen.
• No major changes in PAH treatment for 3 months before starting the study.

In the study, participants will take one inhaled dose of RT234 and do exercise tests, such as the six-minute walk test. These tests measure how well their heart and lungs are working. The study also checks for any side effects. People cannot join if they have uncontrolled asthma, certain heart problems, or need oxygen to exercise. This study helps to see if RT234 can safely improve exercise abilities for people with PAH.