A Study to Evaluate Tabelecleucel in Participants With Epstein Barr Virus (EBV) Associated Diseases

Inclusion Criteria:

* Diagnosis of EBV+ disease.
* Eastern Cooperative Oncology Group performance status ≤ 3 for participants aged ≥ 16 years; Lansky score ≥ 20 for participants from ≥ 1 year to \< 16 years.
* Adequate organ function test results, unless organ dysfunction is considered to be due to the underlying EBV-associated disease by the investigator.

Cohort-specific Inclusion Criteria:

* For participants with CNS PTLD:

  * R/R or newly diagnosed EBV+ CNS PTLD for whom the standard. first-line therapy is inappropriate, as determined by the investigator. The CNS PTLD is histologically confirmed by at least biopsy-proven EBV+ CNS PTLD or positive CSF cytology with or without radiographically measurable intracranial disease with EBV detected in CSF.
  * Participants with R/R disease must have had at least one prior line of systemic therapy and one of the following: radiographic disease progression per Lugano Classification during or after treatment or failure to achieve a CR or PR (defined by Lugano radiographic criteria) after standard first-line therapy.
  * Participant may have systemic and CNS disease or CNS disease only.

Exclusion Criteria:

* Currently active Burkitt, T-cell, natural killer/T-cell lymphoma/LPD, Hodgkin, plasmablastic, transformed lymphoma, active hemophagocytic lymphohistiocytosis, or other malignancies requiring systemic therapy.
* Serious known active infections, defined as ongoing uncontrolled adenovirus infection or infections requiring systemic therapy at the time of enrollment, or known history of human immunodeficiency virus (HIV) infection.
* Suspected or confirmed Grade ≥ 2 acute graft-versus-host disease (GvHD) per the Center for International Blood and Marrow Transplant Research (CIBMTR) consensus grading system or extensive chronic GvHD per National Institutes of Health (NIH) consensus criteria at the time of the enrollment.
* Need for vasopressor or ventilatory support at the time of enrollment.
* Prior therapy (in order of increasing washout period) prior to enrollment as follows:

  * Within 4 weeks or 5 half-lives (whichever is shorter) for any investigational product and/ or any chemotherapy (systemic or intrathecal), targeted small molecule therapy, or antibody/biologic therapy. Note: prior anti-CD20 antibody use is permitted within the washout period if a subsequent disease response assessment indicates disease progression.
  * Within 8 weeks: prior tabelecleucel (\> 8 weeks prior to enrollment) is permitted if response was obtained or if usual protocol-directed therapeutic options were not exhausted, for cellular therapies (chimeric antigen receptor therapies directed at T-cells or T-cell subsets, donor lymphocyte infusion, other CTLs or virus-specific T-cells); and/or therapies which could impact tabelecleucel function (anti-thymocyte globulin, alemtuzumab).
  * Any prior treatment with EBV-CTLs with the exception of tabelecleucel as above
* Women who are breastfeeding or pregnant.
* Unwilling to comply with protocol specified contraceptive/reproductive restrictions from enrollment through 90 days after the last treatment.
* Inability or unwillingness to comply with all study procedures.
* Ongoing need for daily steroids of \> 0.5 mg/kg prednisone or glucocorticoid equivalent, ongoing methotrexate, or extracorporeal photopheresis (for participants with CNS disease, protocol-specified dexamethasone is permitted and concludes by the time of enrollment).
* Any conditions that may put the study outcomes at undue risk (life expectancy \< 60 days or any life-threatening illness, medical condition, or organ system dysfunction).