This study focuses on patients with HER2-mutated or overexpressed/amplified solid tumors, which are types of cancer where a specific protein called HER2 is either altered or present in higher amounts than normal. The study will test a new medication called zongertinib (also known as BI 1810631) that is given as a film-coated tablet taken by mouth.

The purpose of this research is to evaluate how well zongertinib works in treating various types of advanced cancers that have changes in the HER2 protein. This is an open-label study, which means all participants will receive the active medication. The medication will be given to patients who have already received at least one previous treatment for their advanced cancer.

During the study, participants will take the medication and be monitored for how their cancer responds to the treatment. The study will also look at how long any improvements last and track any side effects that may occur. Participants will also complete questionnaires about their physical functioning and quality of life during the treatment period, which may last up to 15 months.