Clinical Trials

Inclusion Criteria: - Patient must be >=10 years of age at the time of signing the informed consent. - Patient has a diagnosis of synovial sarcoma confirmed by histology. - Patient has advanced (metastatic or unresectable) synovial sarcoma. - In substudy 1, patient with metastatic synovial sarcoma who is newly diagnosed or previously untreated. - In substudy 2, at the time of treatment, patient has received/completed treatment with anthracycline or anthracycline with ifosfamide for advanced (metastatic or inoperable) disease and progressed. - Male or female. Contraception requirements will apply at the time of leukapheresis and treatment. - Patient must be positive for Human leukocyte antigen (HLA)-A*02:01, HLA-A*02:05, and/or HLA-A*02:06 alleles by a validated test in a designated central laboratory. - Patients tumor has been pathologically reviewed by a designated central laboratory with confirmed positive NY-ESO-1 expression. - Performance status: Eastern Cooperative Oncology Group of 0-1. - Patient must have adequate organ function and blood cell counts 7 days prior to leukapheresis. - Female patients of childbearing potential must have a negative urine or serum pregnancy test. - Patient has measurable disease according to RECIST v1.1. - Supportive radiotherapy has not affected >25 percent of bone marrow. Exclusion Criteria: - In substudy 1, patient has been previously treated for metastatic synovial sarcoma. - Central nervous system metastases. - Any other prior malignancy that is not in complete remission. - Previous treatment with genetically engineered NY-ESO-1-specific T cells. - Previous NY-ESO-1 vaccine or NY-ESO-1 targeting antibody. - Prior gene therapy using an integrating vector. - Previous allogeneic hematopoietic stem cell transplant. - Clinically significant systemic illness: serious active infections or significant cardiac, pulmonary, hepatic or other organ dysfunction, that in the judgment of the Investigator would compromise the Patient ''s ability to tolerate protocol therapy or significantly increase the risk of complications, or, prior or active demyelinating disease. - Patient has history of chronic or recurrent (within the last year prior to leukapheresis) severe autoimmune or immune mediated disease requiring steroids or other immunosuppressive treatments. - Uncontrolled intercurrent illness. - Current active liver or biliary disease. - Pregnant or breastfeeding females (due to risk to fetus or newborn). - Prior/concomitant therapy: any prior treatment-related toxicities must be Common terminology criteria for adverse events <=Grade 1 at the time of initiating study intervention (except for non-clinically significant toxicities). - Other standard of care lines of therapy are allowed only if guidelines and washout periods are followed. - Patient has active infection as defined in the protocol. - Patient has known psychiatric or substance abuse disorders that would interfere with cooperating with the requirements of the study. - Patient had major surgery <=28 days of first dose of study intervention.