Inclusion Criteria:

          1. Male or female patients age ≥ 18 years of age at the time of informed consent

          2. HLA-A*0201 positive, confirmed by central laboratory

          3. MAGE-A4 positive tumor confirmed by the central laboratory

          4. Histologically confirmed diagnosis of metastatic/unresectable NSCLC, esophageal,
             gastric, urothelial, and HNSCC cancers are eligible

          5. Prior Treatments:

               -  Arms A1 and A2 — patients must be relapsed from, refractory to, or intolerant to
                  all approved classes of therapy for their disease. There is no limit on the
                  number of prior therapies

               -  Arms B1 and B2 — patients must have experienced disease progression or drug
                  intolerance in the unresectable/metastatic setting following at least one line of
                  chemotherapy AND one line of immune therapy as designated by the standard of care
                  for a particular disease. There is no limit on the number of prior therapies.

               -  Special consideration: NSCLC patients with known mutations (ie, EGFR, ROS, ALK,
                  B-Raf proto-oncogene serine/threonine kinase [BRAF]) must have experienced
                  disease progression or drug intolerance following at least one line of small
                  molecule targeted therapy and following platinum-based chemotherapy.

          6. Disease amenable to pre-treatment biopsy if no archival tissue available

          7. Measurable disease to RECIST v.1.1 criteria

        Exclusion Criteria:

          1. Impaired baseline organ function as evaluated by out-of-range laboratory values

          2. History of severe hypersensitivity reactions (eg, anaphylaxis) to monoclonal
             antibodies

          3. Clinically significant cardiac disease or impaired cardiac function

          4. Presence of symptomatic or untreated central nervous system (CNS) metastases

          5. Active infection requiring systemic antibiotic therapy

          6. Known history of human immunodeficiency virus infection (HIV)

          7. Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection

          8. Malignant disease, other than that being treated in this study

          9. Patients receiving systemic steroid therapy or any other systemic immunosuppressive
             medication. Local steroid therapies are acceptable

         10. Systemic anti-cancer therapy within 2 weeks of the first dose of study drug.

         11. Major surgery within 2 weeks of the first dose of study drug

         12. Radiotherapy within 2 weeks of the first dose of study drug, with the exception of
             palliative radiotherapy to a limited field

         13. Use of hematopoietic colony-stimulating growth factors (eg, G-CSF, GM-CSF, M-CSF) ≤ 2
             weeks prior to start of study drug

         14. Pregnant, likely to become pregnant, or lactating women