This study is open to adults with advanced cancer of the colon, rectum, stomach, or pancreas, that is the cancer cannot be removed by surgery or has spread. People can take part in this study if their previous treatment was not successful, or no other treatment exists.

The study aims to find the highest dose for the study medicine called BI 765049 that people with advanced cancer can tolerate. Another purpose is to find the most suitable dose and best way of administration of BI 765049 for further clinical development. BI 765049 may help the immune system fight cancer.

Participants receive BI 765049 at least once every 3 weeks. Participants may continue to get BI 765049 treatment as long as they benefit from treatment and can tolerate it. Participants in this study also get additional medication before and after treatment with BI 765049 for better tolerability. If participants take this medication at home, they have daily phone visits.

Participants regularly visit the study site. The study visits include several overnight stays at the hospital. At the visits, study doctors check participants' health, take necessary laboratory tests, and note any unwanted effects. Unwanted effects are any health problems that the doctors think were caused by the study medicine or treatment. To find the highest dose of BI 765049 that participants can tolerate, researchers look at the number of participants with certain severe health problems. These are severe health problems that happen within the time from when a person first receives the intended target dose, until one week after they receive it for the second time.

Inclusion criteria:

• For all patients, signed and dated informed consent form (ICF)2/main ICF describing the study in accordance with International Council on Harmonisation Good Clinical Practice (ICH-GCP) and local legislation prior to any trial-specific procedures, sampling, or analyses.
• Patient must be ≥18 years of age and at least at the legal age of consent in countries where it is greater than 18 years at the time of signature on the ICFs (ICF1/screening ICF and ICF2/main ICF).
• In US: Patients with a histologically or cytologically confirmed diagnosis of colorectal carcinoma (CRC), gastric carcinoma (GC), or pancreatic ductal adenocarcinoma (PDAC).
• In Europe: Patients with a histologically or cytologically confirmed diagnosis of CRC.
• Patients with advanced, unresectable, and/or metastatic disease. Further inclusion criteria apply.

Exclusion criteria:

• Patient with a history of a major surgery within 28 days prior to first dose of BI 765049 (major according to the Investigator's and/or Medical Monitor's assessment).

• Previous or concomitant malignancies other than the one treated in this trial within the last 5 years except:

  • Effectively treated non-melanoma skin cancers
  • Effectively treated carcinoma in situ of the cervix
  • Effectively treated ductal carcinoma in situ
  • Other effectively treated malignancy that is considered cured by local treatment"

• Patient with known leptomeningeal disease or spinal cord compression due to disease.

• Patient requiring anticoagulant treatment which cannot be safely interrupted, if medically needed based on the opinion of the Investigator.

Further exclusion criteria apply.

Once the criteria in section "Time Frame" are fulfilled, researchers can use the following link https://www.clinicalstudies.boehringer-ingelheim.com/msw/datasharing to request access to the clinical study documents regarding this study, and upon a signed "Document Sharing Agreement".

Furthermore, researchers can request access to the clinical study data, for this and other listed studies, after the submission of a research proposal and according to the terms outlined in the website.

One year after the approval has been granted by major Regulatory Authorities and after the primary manuscript has been accepted for publication, or after termination of the development program.

For study documents - upon signing of a "Document Sharing Agreement". For study data - 1. after the submission and approval of the research proposal (checks will be performed by the sponsor and/or the independent review panel, including checking that the planned analysis does not compete with sponsor's publication plan); 2. and upon signing of a legal agreement.