Main Inclusion Criteria:

          -  Signed informed consent prior to any procedures

          -  Phase Ib part: Adult patients with advanced melanoma, endometrial carcinoma,
             pancreatic or TNBC, with measurable or non-measurable disease who have progressed
             despite standard therapy or are intolerant of standard therapy, or for whom no
             standard therapy exists.

          -  Phase II part: Adult patients with advanced solid tumors who have received standard
             therapy (no more than 3 prior lines of treatment) or are intolerant of standard
             therapy, have progressed following their last prior therapy, and fit into one of the
             following groups:

               -  Group 1: TNBC who did not receive prior anti-PD-1/PD-L1 treatment

               -  Group 2: Pancreatic adenocarcinoma who did not receive prior anti-PD-1/PD-L1
                  treatment

               -  Group 3: Endometrial carcinoma who did not receive prior anti-PD-1/PD-L1
                  treatment

               -  Group 4: Melanoma who progressed on prior anti-PD-1/PD-L1 treatment.

        Main Exclusion Criteria:

          -  Patients with the following:

               -  Symptomatic central nervous system (CNS) metastases or those requiring local
                  CNS-directed therapy.

               -  Abnormal liver, renal, or blood lab values.

               -  Impaired cardiac function or clinically significant cardiac disease.

               -  Active autoimmune disease or documented autoimmune disease within 3 years of
                  screening.

               -  Active infection requiring antibiotic therapy.

               -  Known HIV, active hepatitis B or C virus.

               -  Concurrent malignant disease.

          -  Patients who received systemic anticancer therapy, major surgery, or radiotherapy
             within 2 weeks of study treatment, or live vaccines within 4 weeks of study treatment.

          -  Patients requiring chronic treatment with systemic steroid therapy or any
             immunosuppressive therapy.

          -  Patients who used hematopoietic colony-stimulating growth factors within 2 weeks of
             study treatment.