This study is testing a medicine called **inhaled treprostinil** to see if it helps people with **Idiopathic Pulmonary Fibrosis (IPF)**, a lung disease that makes it hard to breathe. The study will compare inhaled treprostinil to a **placebo**, a substance with no active medication, to check for changes in breathing capacity over 52 weeks. Participants are given the medicine or placebo to inhale 4 times a day, starting with a low dose and increasing as tolerated. You will have to visit the clinic 6 times over the year. Researchers will check your lung function, overall health, and any side effects. At the end of the study, you might continue with the medicine in an open-label extension, where you know you're getting the actual drug.

• This study lasts for one year with 6 clinic visits.
• Participants take inhaled treprostinil or placebo daily.
• Check if you're eligible: age 40+, non-pregnant, and other health criteria.