This study is for adults with systemic sclerosis (also called scleroderma), a condition that affects skin and organs like the lungs. The research aims to see if a medicine called Avenciguat (BI 685509) can help improve lung function and symptoms of scleroderma. Participants are randomly divided into two groups: one group takes Avenciguat tablets, and the other takes a placebo (a pill that looks the same but has no medicine). The study lasts at least 11 months, but the total time can vary, as participants continue until the last person completes the 11-month treatment. At first, participants visit the study site every 2 weeks, but over time, the visits become less frequent. After the initial treatment period, visits occur every 3 months. During the study, participants will undergo lung tests and fill out questionnaires about their symptoms. Doctors will also check their skin and overall health.

• Study duration varies, but treatment is at least 11 months.
• Visits start every 2 weeks, then every 3 months after initial period.
• Participants may receive compensation for their time and travel.