This study is testing a medicine called *inhaled treprostinil* for people with *Idiopathic Pulmonary Fibrosis* (IPF). IPF is a lung disease that makes it hard to breathe. The study compares treprostinil with a fake treatment called a placebo to see which works better over one year (52 weeks). People in the study will take the medicine by breathing it in several times a day, starting with 3 breaths and possibly increasing up to 12 breaths as their bodies get used to it.

The study will have 6 clinic visits at different weeks to check how well the lungs are working and to see if there are any bad side effects. People who finish the study might be able to continue in a follow-up study. To join, you must be at least 40 years old and have a confirmed IPF diagnosis. Women must not be pregnant or breastfeeding, and both men and women need to use birth control during the study.

• The study lasts 52 weeks with 6 clinic visits.
• Participants will use an inhaler multiple times a day.
• Potential to join a follow-up study after completion.