BI-765250

This study is open to adults with plaque psoriasis. The main purpose of this study is to find out whether people with plaque psoriasis can tolerate a medicine called BI 765250. Another purpose is to check whether BI 765250 can improve participants' skin condition.
Participants are divided into 5 groups. Each group gets a different dose of BI 765250 or placebo as an infusion or injection for 12 weeks. Placebo infusions and injections look like BI 765250 but do not contain any medicine. It is decided by chance, who gets BI 765250 and who gets placebo. During the first 2 weeks, participants get the study medicine as an infusion into a vein once a week. Afterwards, they get the study medicine as an injection under the skin every 2 or 4 weeks. In total, every participant gets up to 5 injections.
Participants are in the study for about 8 months. During this time, they visit the study site 23 times. On 2 of the visits, participants stay overnight at the study site, once for 2 nights and once for 1 night. The doctors collect information on any health problems of the participants. They also regularly check participants' skin condition.