A Study to Test BI 767551 in People With Mild to Moderate Symptoms of COVID-19

This study is open to adults with mild to moderate symptoms of COVID-19 (coronavirus disease). The purpose of this study is to find out whether a medicine called BI 767551 helps people with COVID-19. BI 767551 is an antibody against the coronavirus. The study has 2 parts. Part 1 wants to find out the best dose of BI 767551 given as infusion into a vein. It also tests how BI 767551 is taken up by the body when taken via an inhaler. Participants are put into 4 groups by chance. Participants get BI 767551 or placebo once. * 1 group gets a high dose of BI 767551 as an infusion into a vein * 1 group gets a low dose of BI 767551 as an infusion into a vein * 1 group gets BI 767551 via an inhaler * 1 group gets placebo both as an infusion into a vein and via an inhaler The placebo infusion and inhaler look like the BI 767551 infusion and inhaler but do not contain any medicine. Doctors check how BI 767551 reduces the amount of coronavirus. Once the best dose of BI 767551 is found, part 2 of the study tests BI 767551 in a larger group of people. Also, in part 2, the participants get BI 767551 or placebo as an infusion into a vein once. In this part, doctors will check how many people need to be treated in a hospital or die. The results will be compared between the groups. For each part, participants are in the study for about 13 weeks. During this time, they visit the study site about 8 times and get about 3 remote visits. The doctors also regularly check participants' health and take note of any unwanted effects of BI 767551.