A Study to Test How Well Different Doses of BI 3706674 Are Tolerated by People With Advanced Cancer in the Stomach and Oesophagus

This study is no longer open to new participants. It was a study in adults with advanced cancer in the stomach and oesophagus. This is a study for people for whom previous treatment was not successful or no treatment exists. In this study, BI 3706674 is given to humans for the first time. The purpose of this study is to find a suitable dose of BI 3706674 that people with advanced cancer can tolerate when taken alone. Another purpose is to check whether BI 3706674 can make tumours shrink. BI 3706674 blocks growth signals and may prevent the tumour from growing. Participants take BI 3706674 as a tablet when starting treatment. Different doses of BI 3706674 are tested during this study. If there is benefit for the participants and if they can tolerate it, the treatment is given up to the maximum duration of the study. During this time, participants visit the study site regularly. The total number of visits depends on how they respond to and tolerate the treatment. Doctors record any unwanted effects and regularly check the general health of the participants.