A Study to Test Whether Nerandomilast Helps People With Lung Fibrosis Related to Rheumatic Diseases

Adults 18 years of age and older or above legal age with lung fibrosis related to systemic autoimmune rheumatic disease can participate in this study. People can only take part if they show no improvement in lung function after standard treatment with immunosuppressant medicine. The main purpose of this study is to find out how a medicine called nerandomilast affects the lungs in people with systemic autoimmune rheumatic disease. Participants are put into 2 groups randomly, which means by chance. One group takes nerandomilast tablets and the other group takes placebo tablets. Placebo tablets look like nerandomilast tablets but do not contain any medicine. Participants take a tablet 2 times a day for at least 26 weeks and up to 1 year. Participants continue immunosuppressant treatment for their underlying rheumatic disease. Participants are in the study for about 7.5 to 13 months depending on when they join the study. During this time, they visit the study site about 9 to 10 times. At study visits, participants have lung function tests. At select visits, chest imaging is performed. Participants fill in questionnaires about their symptoms and quality of life. The results between the 2 groups are compared to see whether the treatment works. The doctors also regularly check participants' health and take note of any unwanted effects.