There were no notable safety findings with BI 907828 45 mg q3w, the recommended dose for expansion (RDE) for BI 907828 monotherapy. Nine of the 15 pts who received doublet therapy were evaluable for response; four had a confirmed partial response (PR; 30 mg, n = 1; 45 mg, n = 3), two biliary tract carcinoma, one urothelial carcinoma, and one myxoid liposarcoma; one had an unconfirmed PR (30 mg) with adenocarcinoma (primary site intrahepatic cholangiocarcinoma). Four pts with liposarcoma and gastric cancer had stable disease. The doublet combination of BI 907828 plus ezabenlimab showed a manageable safety profile and early signs of anti-tumor activity.