BI-3000202

This study is open to adults with systemic lupus erythematosus (SLE). The purpose of this study is to find out whether a medicine called BI 3000202 helps people with SLE. The study tests different doses of BI 3000202 and aims to find the best dose for people with this condition.
Participants are put into 5 groups randomly, which means by chance. 4 groups get different doses of BI 3000202, and 1 group gets a placebo. Placebo tablets look like BI 3000202 tablets but do not contain any medicine. Participants take the tablets for 1 year. All participants also continue their regular treatment for SLE.
Participants are in the study for a bit longer than 1 year. During this time, they visit the study site regularly. Doctors check the participants' health and take note of any unwanted effects. They also compare the results between the groups to see if the treatment works.

The purpose of this study is to find out how quickly and to what extent BI 3000202 is processed in the body.
The purpose of Part A is to find out how 3000202 moves through and exits the body of healthy people. The purpose of Part B is to find out how much BI 3000202 gets into the blood when participants take it as a tablet compared with when they get it as an infusion.
Adults between 18 and 55 years of age can take part if the study doctor determines they are healthy.
The doctors regularly check participants' health. To assess the study endpoints, the study staff takes blood, urine, and stool samples.