A Study to Find the Best Dose of BI 1387446 Alone or in Combination With Ezabenlimab (BI 754091) in Patients With Different Types of Advanced or Metastatic Cancer (Solid Tumors)

This is a study in adults with advanced cancer (solid tumours) in whom previous treatment was not successful. The study tests 2 medicines called BI 1387446 and BI 754091. Both medicines may help the immune system fight cancer. In this study, BI 1387446 is given to humans for the first time. The purpose of this study is to find out the highest dose of BI 1387446 alone and in combination with BI 754091 the participants can tolerate. BI 1387446 is injected directly into the tumour. Participants get BI 1387446 injections every week at the beginning and then every 3 weeks. Some participants get BI 754091 in addition to BI 1387446. BI 754091 is given as an infusion into a vein every 3 weeks. As long as they benefit from treatment and can tolerate it, participants can stay in the study for up to 2 years and 8 months. During this time, they visit the study site regularly. At these visit, doctors record any unwanted effects. The doctors also regularly check participants' health.