Brightline-2: A Phase IIa/IIb, Open-label, Single-arm, Multi-centre Trial of Brigimadlin (BI 907828) for Treatment of Patients With Locally Advanced / Metastatic, MDM2 Amplified, TP53 Wild-type Biliary Tract Adenocarcinoma, Pancreatic Ductal Adenocarcinoma, or Other Selected Solid Tumours

Inclusion Criteria:

* Diagnosis of a solid tumour which meets the criteria for an open trial cohort:

* Cohorts 1 and 1-CN (biliary tract adenocarcinoma): Locally advanced or metastatic biliary tract adenocarcinoma (intra- and extrahepatic cholangiocarcinoma, gallbladder cancer, and ampullary cancer).Patients must have unresectable disease and have received all available conventional therapies known to confer clinical benefit for their disease based on local approved standards; or (in the opinion of the investigator) patients are unlikely to tolerate or derive clinically meaningful benefit from appropriate standard of care therapy.

* Cohort 2 (pancreatic ductal adenocarcinoma): Locally advanced or metastatic pancreatic ductal adenocarcinoma. Patients must have unresectable disease and have received all available conventional therapies known to confer clinical benefit for their disease based on local approved standards.

* Cohort 3 (lung adenocarcinoma): Locally advanced or metastatic lung adenocarcinoma. Patients must have unresectable disease and have received all available conventional therapies known to confer clinical benefit for their disease based on local approved standards.

* Cohort 4 (urothelial bladder cancer): Locally advanced or metastatic urothelial bladder cancer. Patients must have unresectable disease and have received all available conventional therapies known to confer clinical benefit for their disease based on local approved standards.

* Written pathology report / molecular profiling report indicating Mouse double minute 2 homolog (MDM2) amplification or a copy number ≥8 and tumor protein 53 (TP53) wild-type status. This must have been confirmed with a tissue-based test. A test with liquid biopsy is not accepted.

* Archival tissue (formalin fixed paraffin embedded \[FFPE\] tumour blocks or slides) must be provided for retrospective confirmation of MDM2 amplification and TP53 status.

* Presence of at least 1 measurable target lesion according to Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1.

* Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1.

* Patient must be willing to donate mandatory blood samples for the pharmacokinetics, pharmacodynamics, and biomarker analyses

* Adequate organ function

* All toxicities related to previous anti-cancer therapies have resolved to ≤Common Terminology Criteria for Adverse Events (CTCAE) Grade 1 prior to trial treatment administration (except for alopecia and amenorrhea / menstrual disorders which can be of any grade and peripheral neuropathy which must be ≤CTCAE Grade 2).

* Life expectancy ≥3 months at the start of treatment in the opinion of the investigator.

* Provision of signed and dated, written informed consent form (ICF) in accordance with ICH-GCP and local legislation prior to any trial-specific procedures, sampling, or analyses.

* Male or female patients ≥18 years old at the time of signature of the ICF. Women of childbearing potential (WOCBP) and men able to father a child must be ready and able to use 2 medically acceptable methods of birth control per ICH M3 (R2) that result in a low failure rate of less than 1% per year when used consistently and correctly beginning at screening, during trial participation, and until 6 months and 12 days after last dose for women and 102 days after last dose for men. A list of contraception methods meeting these criteria is provided in the patient information.

Exclusion Criteria:

* Previous administration of brigimadlin (BI 907828) or any other MDM2-p53 or mouse double minute 4 (MDMX, MDM4)-p53 antagonist.

* Active bleeding, significant risk of haemorrhage (e.g. previous severe gastrointestinal bleeding, previous haemorrhagic stroke at any time), or current bleeding disorder (e.g. haemophilia, von Willebrand disease).

* Major surgery (major according to the investigator's assessment) performed within 4 weeks prior to start of trial treatment or planned within 6 months after screening (e.g. hip replacement).

* Clinically significant previous or concomitant malignancies in the opinion of the investigator affecting the efficacy and/or outcome of the trial.

* Patients who must or intend to continue the intake of restricted medications or any drug considered likely to interfere with the safe conduct of the trial.

* Currently enrolled in another investigational device or drug trial.

* Any history of, or concomitant condition that, in the opinion of the investigator, would compromise the patient's ability to comply with the trial or interfere with the evaluation of the safety and efficacy of the trial drug.

* Patients not expected to comply with the protocol requirements or not expected to complete the trial as scheduled (e.g. chronic alcohol or drug abuse or any other condition that, in the investigator's opinion, makes the patient an unreliable trial participant).

Further exclusion criteria apply.