At the beginning of the study, your baseline condition will be assessed. This includes measurements that will serve as reference points for comparison throughout the trial.

Your exercise capacity will be measured using a 6-minute walk test. This test measures how far you can walk in 6 minutes. You will perform this test twice during the initial assessment, with at least 4 hours between the two tests.

Blood samples will be collected to measure NT-proBNP, a substance in your blood that can indicate how well your heart is functioning.

A questionnaire called Living With Pulmonary Fibrosis will be completed to assess your symptoms and how they affect your daily life.

You will be randomly assigned to receive either the study medication treprostinil palmitil inhalation powder or a placebo. A placebo looks identical to the study medication but contains no active ingredient.

Neither you nor your medical team will know which treatment you are receiving. This is called a double-blind study design.

The study medication or placebo will be provided as an inhalation powder in capsules. The capsules may contain different dosage strengths: 80 micrograms, 160 micrograms, 320 micrograms, or 640 micrograms.

You will inhale the powder using a special inhaler device.

You will take the assigned treatment by inhalation according to the prescribed schedule. The exact frequency of administration will be provided by your study team.

During this period, regular assessments of your exercise capacity will be performed using the 6-minute walk test. These tests will be conducted at specific time points to measure changes from your baseline.

Blood samples will be collected at regular intervals to measure NT-proBNP levels and to determine the concentration of the study medication in your blood.

You will continue to complete the Living With Pulmonary Fibrosis questionnaire at scheduled visits to track changes in your symptoms.

If you are taking other medications for your underlying lung condition or PDE5 inhibitors (medications that help relax blood vessels in the lungs), you should continue taking them at the same dose throughout the study.

At week 22, your exercise capacity will be measured using the 6-minute walk test. This test will be performed at a specific time called trough exposure, which means at the time when the medication level in your body is at its lowest point before the next dose.

This measurement will be compared to your baseline to determine any changes in your walking ability.

At week 24, the main assessment of the study will take place. Your exercise capacity will be measured using the 6-minute walk test at a time called peak exposure, which means when the medication level in your body is at its highest.

This measurement will be compared to your baseline to evaluate the effect of the treatment on your ability to walk.

Blood samples will be collected to measure NT-proBNP levels. The change from your baseline will be assessed, and it will be determined whether your levels have improved.

You will complete the Living With Pulmonary Fibrosis questionnaire again, and the change in your symptom scores from baseline will be evaluated.

Throughout the entire 24-week period, any worsening of your condition or significant health events will be monitored and recorded.

After completing the 24-week treatment period and all required assessments, your participation in the main part of the study will be finished.

Final evaluations will be performed to ensure your safety and to collect all necessary data.