Key Inclusion Criteria:  Unresectable and/or metastatic solid tumors that have received standard-of-care (SOC) therapies previously and have no other SOC options available Confirmed HLA-A*02:01 haplotype Confirmed MAGE-A4 expression Radiologically measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 Life expectancy of >/=12 weeks Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 Absence of rapid disease progression, threat to vital organs or non-irradiated lesions >2 cm in diameter at critical sites No significant ongoing toxicity from prior anticancer treatment Adequate hematological function Adequate liver function Adequate renal function If applicable, willingness to use contraceptive measures.  Key Exclusion Criteria:  History or clinical evidence of CNS primary tumors or metastases Another invasive malignancy in the last 2 years Uncontrolled hypertension Significant cardiovascular disease Known active or uncontrolled bacterial, viral, fungal, mycobacterial, parasitic or other infection Current or past history of CNS disease Dementia or altered mental status that would prohibit informed consent Active auto-immune disease or flare within 6 months prior to start of study treatment Expected need for regular immunosuppressive therapy or with systemic corticosteroids Insufficient washout from prior anti-cancer therapy Prior treatment with a bispecific T-cell engaging or adoptive cell therapy.