Plain language summary: Clinical study of BI 1015550 as a potential treatment for idiopathic pulmonary fibrosis.

WHAT IS THIS SUMMARY ABOUT?: This plain language summary describes the main findings from a trial in people with idiopathic pulmonary fibrosis (also called IPF) that was recently published in the . IPF is a rare disease, where the lungs become more and more scarred, with breathing and oxygen uptake becoming increasingly difficult. This trial looked at the medication BI 1015550 as a potential treatment for IPF. It compared BI 1015550 to placebo (a dummy drug that does not contain any active ingredients) to investigate the effectiveness of the drug in treating people with IPF. The study also looked at the additional medical issues (referred to as adverse events) reported during the study. Some participants took approved treatments to reduce scarring (nintedanib or pirfenidone), and some did not.

WHAT WERE THE RESULTS?: Overall, 147 people with IPF from 22 countries took part in the trial. The results showed that BI 1015550 prevented lung function from decreasing in people with IPF. There was no difference in the percentage of patients with medical issues rated as severe by the study physician with BI 1015550 or placebo. However, more people treated with BI 1015550 had diarrhoea. Among those treated with BI 1015550, 13 participants stopped their treatment due to medical issues, whereas treatment was not stopped due to medical issues for any participants treated with placebo.

WHAT DO THE RESULTS MEAN?: These results provide evidence that BI 1015550 prevents lung function from worsening in people with IPF. Further clinical studies will be conducted in the future to test BI 1015550 in a larger group of people with IPF and other forms of lung scarring that get worse over time, and for a longer time period.