Inclusion Criteria

• Participant must be 18 years or older at the time of signing the informed consent form (ICF).
• Histologically confirmed primary central nervous system (CNS) lymphoma (PCNSL) prior to screening, as assessed by local pathology.
• Transplant-ineligible based on physician's assessment and meeting at least one of the following criteria: age ≥65 years or HCT-CI (Hematopoietic Cell Transplantation-specific Comorbidity Index) score ≥3.
• Participant must be suitable, per investigator, to receive a high dose methotrexate (HD-MTX) based treatment regimen.
• Prior to signing ICF, anti-cancer therapy for the treatment of PCNSL must be limited to HD-MTX based standard of care regimens with a minimum of 4 and maximum of 6 doses of MTX. Corticosteroids used as part of standard-of-care management for PCNSL symptom control are permitted prior to ICF signature but must be discontinued at the time of ICF signature. For medical conditions other than PCNSL, non-therapeutic corticosteroids use may be permitted on study.
• Prior to ICF enrollment, participant's disease must be sensitive to prior high-dose methotrexate-based (HD-MTX) regimens, as demonstrated by a complete response (CR, no remaining signs of PCNSL) or a partial response (PR, signs of PNCSL mostly gone) per Investigator's assessment, based on the International Primary CNS Lymphoma Collaborative Group (IPCG) criteria.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2.
• Individuals of childbearing potential (IOCBP) must have a negative highly sensitive pregnancy test within 24 hours prior to the start of study intervention.

Exclusion Criteria

• Participant has a diagnosis of secondary CNS lymphoma due to systemic disease.
• Primary intraocular lymphoma (PIOL)/ Primary vitreoretinal lymphoma (PVRL), isolated cerebrospinal fluid (CSF) disease, or a relapsed or refractory PCNSL.
• Any significant medical condition including the presence of laboratory abnormalities, which places the participant at unacceptable risk if he/she was to participate in the study based on investigator's judgement.
• History of another primary malignancy that has not been in remission for ≥2 years.
• Prior treatment with CAR T-cell or any other gene therapy product that utilizes human genome-editing technology.
• History of or active human immunodeficiency virus (HIV).
• Active hepatitis B or active hepatitis C.
• Active autoimmune disease requiring immunosuppressive therapy.
• History of prior allogeneic transplant, or solid organ transplant requiring immunosuppressive therapy.
• Other protocol-defined Inclusion/Exclusion criteria apply.