A Phase 3 Study of Tabelecleucel for Participants With Epstein-Barr Virus-Associated Post-Transplant Lymphoproliferative Disease After Failure With Rituximab or Rituximab and Chemotherapy

Inclusion Criteria

• Prior SOT of kidney, liver, heart, lung, pancreas, small bowel, or any combination of these (C-SOT); or prior allogeneic HCT (C-HCT).
• A diagnosis of locally assessed, biopsy-proven EBV+ PTLD.
• Availability of appropriate partially HLA-matched and restricted tabelecleucel has been confirmed by the sponsor.
• Measurable, 18F-deoxyglucose (FDG)-avid (Deauville score ≥ 3) systemic disease using Lugano Classification response criteria by positron emission tomography (PET)-diagnostic computed tomography (CT). Magnetic resonance imaging (MRI) may be used when PET-CT is contraindicated, mandated by local practice, or when disease status cannot be assessed adequately in the investigator's opinion and is confirmed by the Sponsor. For participants with treated CNS disease, a head diagnostic CT and/or brain/spinal MRI as clinically appropriate will be required to follow CNS disease response per Lugano Classification response criteria.
• Treatment failure to CD20-directed antibody, i.e. rituximab or interchangeable commercially available biosimilar monotherapy (SOT-R or HCT cohort) or rituximab plus any concurrent or sequentially administered chemotherapy regimen (SOT-R+C) for treatment of PTLD.
• Males and females of any age.
• Eastern Cooperative Oncology Group performance status ≤ 3 for participants aged ≥ 16 years; Lansky score ≥ 20 for participants < 16 years.
• For C-HCT only: If allogeneic HCT was performed as treatment for an acute lymphoid or myeloid malignancy, the underlying primary disease for which the participant underwent transplant must be in morphologic remission.
• Adequate organ function.
• Absolute neutrophil count ≥ 1000/μL, (C-SOT) or ≥ 500/μL (C-HCT), with or without cytokine support.
• Platelet count ≥ 50,000/μL, with or without transfusion or cytokine support. For C-HCT, platelet count < 50,000/μL but ≥ 20,000/μL, with or without transfusion support, is permissible if the participant has not had grade ≥ 2 bleeding in the prior 4 weeks (where grading of the bleeding is determined per the National Cancer Institute's Common Terminology Criteria for Adverse Events [CTCAE], version 5.0).
• Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin each < 5 × the upper limit of normal; however, ALT, AST, and total bilirubin each ≤ 10 × upper limit of normal is acceptable if the elevation is considered by the investigator to be due to EBV and/or PTLD involvement of the liver as long as there is no known evidence of significant liver dysfunction.
• Participant or participant's representative is willing and able to provide written informed consent.

Exclusion Criteria

• Currently active Burkitt, T-cell, NK/T-cell lymphoma/LPD, Hodgkin, plasmablastic, transformed lymphoma, active hemophagocytic lymphohistiocytosis, or other malignancies requiring systemic therapy.
• Daily steroids of > 0.5 mg/kg prednisone or glucocorticoid equivalent, ongoing methotrexate, or extracorporeal photopheresis.
• Untreated CNS PTLD or CNS PTLD for which the participant is actively receiving CNS-directed chemotherapy (systemic or intrathecal) or radiotherapy at enrollment. NOTE: Participants with previously treated CNS PTLD may enroll if CNS-directed therapy is complete.
• Suspected or confirmed grade ≥ 2 graft-versus-host disease (GvHD) per the Center for International Blood and Marrow Transplant Research consensus grading system at enrollment.
• Ongoing or recent use of a checkpoint inhibitor agent (eg, ipilimumab, pembrolizumab, nivolumab) within 3 drug half-lives from the most recent dose to enrollment.
• For C-HCT: active adenovirus viremia.
• Need for vasopressor or ventilatory support.
• Antithymocyte globulin or similar anti-T cell antibody therapy ≤ 4 weeks prior to enrollment.
• Treatment with Epstein-Barr virus cytotoxic T lymphocytes or chimeric antigen receptor T cells directed against B cells within 8 weeks of enrollment (C-SOT or C-HCT), or unselected donor lymphocyte infusion within 8 weeks of enrollment (C-HCT only).
• Female who is breastfeeding or pregnant or female of childbearing potential or male with a female partner of childbearing potential unwilling to use a highly effective method of contraception.
• Inability to comply with study-related procedures.
• Any medical condition or organ system dysfunction that in the investigator';s opinion, could compromise the participant's safety or ability to complete the study.