Inclusion Criteria:

          -  Be ≥ 18 years of age at the time the ICF is signed.

          -  Consent to submission of archival tumor tissue, if available.

          -  Adequate bone marrow, hepatic, and renal function.

          -  ECOG performance status of 0 or 1.

          -  Life expectancy of at least 6 months.

          -  Measurable disease per RECIST v1.1.

        Phase 1 only:

        • Patients must have an advanced/metastatic solid tumor that is refractory to or has
        progressed following prior treatment and has no satisfactory alternative treatment options.

        Patient enrolled in Phase 2 will have one of several specific tumor types with advanced or
        recurrent or metastatic disease following prior therapy.

        Exclusion Criteria:

          -  Active second malignancy that may interfere with the safety or efficacy assessments of
             this study

          -  Symptomatic and/or untreated central nervous system (CNS) metastases or leptomeningeal
             disease or with primary tumor of CNS origin. Patients must be clinically stable for at
             least 4 weeks without steroid treatment

          -  Received anticancer treatment ≤ 14 days prior to receiving study treatment (≤ 28 days
             prior in case of checkpoint inhibitor or other antibody therapies)

          -  Received prior radiopharmaceutical therapy or radioembolization, or prior extensive
             external beam radiation therapy (EBRT) to bone marrow or any prior EBRT to kidney, or
             received any EBRT within 2 weeks prior to administration of study treatment

          -  Ongoing adverse effects from anticancer treatment > Grade 1, with the exception of
             alopecia

          -  Known incompatibility with contrast media for CT or PET scans. Infection requiring
             systemic antibiotics within 2 weeks prior to administration of study treatment

          -  Impaired cardiac function or clinically significant cardiac disease

          -  Severe urinary incontinence, voiding dysfunction, or urinary obstruction

          -  Minor surgery ≤ 5 days, or major surgery ≤ 21 days, prior to administration of study
             treatment.

          -  Any other condition that may increase the risk associated with study participation or
             interfere with its interpretation.

          -  Refusal to use highly effective method of contraception, as applicable

          -  Pregnant or breastfeeding

          -  Any other condition that may increase the risk associated with study participation or
             interfere with its interpretation.