A Study to Find a Suitable Dose of BI 765883 and to Test Whether it Helps People With Advanced Pancreatic Cancer When Taken Alone or Together With Chemotherapy

This study is open to adults with advanced pancreatic cancer for whom previous treatment was not successful or no treatment exists. The purpose of this study is to find the highest dose of BI 765883 that people with advanced pancreatic cancer can tolerate when taken alone or together with chemotherapy. Another purpose is to check whether BI 765883 helps people with advanced pancreatic cancer. In this study, BI 765883 is given to humans for the first time. Participants receive either BI 765883 alone or BI 765883 in combination with chemotherapy. Participants can stay in the study as long as they benefit from treatment and can tolerate it. At study visits, doctors collect information on any health problems of the participants and check the severity of participants' cancer.

Inclusion Criteria: 1. Signed and dated written informed consent in accordance with ICH-GCP and local legislation prior to admission to the trial 2. Of legal adult age (according to local legislation) at screening 3. Male or female patients. Women of childbearing potential (WOCBP) and men able to father a child must be willing and able to use highly effective 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. 4. Histologically or cytologically confirmed Pancreatic ductal adenocarcinoma (PDAC) 5. Eastern Cooperative Oncology Group (ECOG) performance status ≤1 6. Life expectancy ≥3 months in the opinion of the investigator 7. Archived tumor tissue from a tissue core biopsy (e.g. paraffin-embedded formalin-fixed tissue blocks), OR fresh tumor tissue available for retrospective biomarker analysis; in both cases, a minimum of at least two core needle biopsies (18 gauge or greater) is required. Only non-significant risk procedures per the investigator's judgment will be used to obtain any biopsies specified in this study in cases where a fresh tumor biopsy is required. 8. Patients with at least 1 target lesion that can be accurately measured per RECIST version 1.1 Further inclusion criteria apply. Exclusion Criteria: 1. Previous exposure to trial drug (BI 765883) 2. Any prior gemcitabine and/or paclitaxel therapy (for combination therapy cohorts) 3. Known hypersensitivity to the study medications or their excipients (including gemcitabine and nab-paclitaxel) 4. Any contraindications to gemcitabine or nab-paclitaxel according to the current approved local labels (combination therapy) 5. Currently enrolled in another investigational device or drug trial, or less than 28 days since ending another investigational device or drug trial(s) or receiving other investigational treatment(s) 6. Any serious concomitant disease or medical condition affecting compliance with trial requirements or which are considered relevant for the evaluation of the efficacy or safety of the trial drug, such as neurologic, psychiatric, infectious disease, active ulcers (gastrointestinal tract, skin), inflammatory bowel disease or bowel infection, or laboratory abnormality that may increase the risk associated with trial participation or trial drug administration, and in the judgment of the Investigator, would make the patient inappropriate for entry into the trial. 7. Prior radiotherapy or systemic therapy within 14 days prior to treatment start 8. History or presence of cardiovascular abnormalities such as uncontrolled hypertension, congestive heart failure NYHA classification of ≥III or IV, unstable angina or poorly controlled arrhythmia which are considered as clinically relevant by the Investigator Further exclusion criteria apply.