A Randomized, Double-Blind, Placebo-Controlled, Phase 2b Study Evaluating the Safety and Efficacy of Pirfenidone Solution for Inhalation (AP01) in Subjects with Progressive Pulmonary Fibrosis (PPF) (MIST Devpro)

Patients with progressive pulmonary fibrosis will inhale an experimental drug through a nebuliser to see if it can slow the scarring that stiffens their lungs and makes breathing increasingly difficult. This matters because pulmonary fibrosis is a relentless, life-shortening disease with limited treatment options. The oral version of pirfenidone is already approved for some forms of interstitial lung disease, but it can cause severe side effects and many patients cannot tolerate it. Delivering the drug directly to the lungs via inhalation—using the eFlow® nebuliser—may allow a lower dose to reach scarred tissue more efficiently, potentially reducing side effects while maintaining or improving effectiveness. The study is a phase 2b trial, meaning it will test multiple doses against a placebo over 52 weeks in patients who are already on standard treatment. If the inhaled formulation proves safe and effective, it could offer a new, better-tolerated option for thousands of people with progressive pulmonary fibrosis. This would not change daily life for most people, but for those affected, it could mean slower disease progression, preserved lung function, and more time before the disease forces them onto oxygen or a transplant list. The trial will also measure how the drug behaves in the body, providing data needed for larger phase 3 studies.