Inclusion Criteria

        Master Protocol:

          -  Provision of signed and dated, written Master informed consent form (ICF) prior to any
             trial-specific procedures, sampling, or analyses.

          -  Patient ≥18 years of age at the time of signature of the ICF.

          -  Eastern Cooperative Oncology Group (ECOG) score: 0 or 1.

          -  Patient must agree to a pre-treatment biopsy (if archival tissue is not available) and
             on-treatment tumour biopsy.

          -  Life expectancy of at least 12 weeks after the start of the treatment according to the
             Investigator's judgement.

          -  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 (that result in a low failure rate of less than 1% per year when used
             consistently and correctly) during trial participation and for at least 6 months after
             the last administration of trial medication.

        Module A:

        - Histologically confirmed diagnosis of one of the following cohorts:

          -  Cohort 1 GEC - Locally advanced, unresectable or metastatic gastric adenocarcinoma or
             gastro oesophageal adenocarcinoma (GEC) (defined as primary tumour localisation below
             the gastro oesophageal junction (GEJ) with prior anti-PD-1 or anti-PD-L1 based treated
             tumour.

          -  Cohort 2 Patients with secondary resistance to anti-PD-1 or anti-PD-L1 based therapy:
             Any advanced or metastatic solid tumour with previously anti-PD-1 or anti-PD-L1 based
             treatment who progressed after achieving benefit

          -  Cohort 3 Patients with primary resistance to anti-PD-1 or anti-PD-L1 based therapy:
             Select advanced or metastatic solid tumour types with previous anti-PD- 1/PD-L1 based
             treated tumour without achieving benefit.

          -  All patients must have measurable lesions according to RECIST v1.1

          -  Patient must agree to pre- and on-treatment tumour biopsies. If archived tumour tissue
             is available from the last treatment failure, sections may be supplied instead of a
             pre-treatment biopsy.

        Module C:

          -  Histologically confirmed diagnosis of one of the following cohorts:

               -  Cohort 1: GEC: Locally advanced, unresectable or metastatic gastric
                  adenocarcinoma or GEC.

               -  Cohort 2: Patients with secondary resistance to anti-PD-1 or anti-PD-L1 based
                  therapy: Any advanced or metastatic solid tumour (excluding NSCLC and melanoma)
                  with previously anti-PD-1 or anti-PD-L1 based treatment which progressed after
                  achieving benefit.

               -  Cohort 3: Patients with primary resistance to anti-PD-1 or anti-PD-L1 based
                  therapy: Select advanced or metastatic solid tumour types with previous
                  anti-PD-1/PD-L1 based treated tumour without achieving benefit.

               -  Cohort 4: Locally advanced, unresectable or metastatic second line or greater,
                  microsatellite stable (MSS) colorectal cancer.

               -  Cohort 5: Advanced Endometrial cancer: Endometrial carcinoma that is pMMR
                  (Mismatch Repair-Proficient)/MSS and is advanced, recurrent, or persistent and
                  has relapsed or is refractory to curative therapy.

          -  All patients must have at least one measurable lesion according to RECIST v1.1

          -  Further inclusion criteria apply

        Exclusion Criteria

        Master Protocol:

          -  Any investigational treatment anti-tumour treatment within 4 weeks or within 5
             half-life periods (whichever is shorter) prior to the initiation of trial treatment.

          -  More than one anti-PD-(L)1-based treatment regimen prior to entering study

          -  Major surgery ('major' according to the Investigator's assessment) performed within 12
             weeks prior to first trial treatment or planned within 12 months after screening,
             e.g., hip replacement.

          -  Known history of severe hypersensitivity reactions to other mAbs or known
             hypersensitivity to the trial drugs or their excipients.

          -  Presence of central nervous system (CNS) metastases, unless treated and asymptomatic
             and off corticosteroids and/or anticonvulsant therapy for at least 2 weeks prior to
             start of treatment.

          -  Immunosuppressive corticosteroid doses (>10 mg prednisone daily or equivalent) within
             4 weeks prior to the first dose of study treatment.

          -  Active autoimmune disease or a documented history of autoimmune disease, except
             vitiligo or resolved childhood asthma/atopy. Patients who were permanently
             discontinued from previous anti-PD-1 or anti-PD-L1 therapy because of a immune-related
             adverse event (irAE).

        Module A:

        - Previous treatment with an anti-LAG-3 Agent

        Module C:

          -  Unresolved, Grade >1 toxicity before the start of treatment with the study drug except
             for hair loss (alopecia) and hypothyroidism that requires thyroid hormone supplements
             but is asymptomatic under therapy.

          -  Significant cardiovascular/cerebrovascular diseases (i.e. uncontrolled hypertension,
             unstable angina, history of infarction within past 6 months, congestive heart failure
             > New York Heart Association [NYHA] II)

          -  History of severe haemorrhagic or thromboembolic event in the past 12 months

          -  Known inherited predisposition to bleeding or to thrombosis, in the opinion of the
             investigator - Further exclusion criteria apply