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

The purpose of this study is to determine the clinical benefit and characterize the safety profile of tabelecleucel for the treatment of Epstein-Barr virus-associated post-transplant lymphoproliferative disease (EBV+ PTLD) in the setting of (1) solid organ transplant (SOT) after failure of rituximab (SOT-R) and rituximab plus chemotherapy (SOT-R+C) or (2) allogeneic hematopoietic cell transplant (HCT) after failure of rituximab.

This is a multicenter, open-label, phase 3 study to assess the efficacy and safety of tabelecleucel for the treatment of EBV+ PTLD in the setting of SOT-R and SOT-R+C (Cohort \[C\]-SOT) or HCT after failure of rituximab (C-HCT). SOT-R further included participants: 1. who did not receive chemotherapy and did not have a documented medical reason not to receive chemotherapy (SOT-Ro) or 2. who were considered chemotherapy ineligible/inappropriate (SOT-R-Ci) Combined population (SOT-R-Ci, SOT-R+C, and HCT) and (SOT-R-Ci and SOT-R+C) who received commercial product, or a product manufactured using a comparable process version (PV) were also used for analysis of outcomes. Enrollment will be preceded by confirmation of availability of partially human leukocyte antigen (HLA) matched and restricted tabelecleucel for the participant. Study procedures and product administration will be the same for each cohort. Tabelecleucel will be administered in cycles lasting 5 weeks (35 days). During each cycle, participants will receive intravenous tabelecleucel at a dose of 2 × 10\^6 cells/kg on Days 1, 8, and 15, followed by observation through Day 35. Treatment will continue until maximal response, unacceptable toxicity, initiation of non protocol therapy, or failure of tabelecleucel with up to 2 different HLA restrictions (C-SOT) or up to 4 different HLA restrictions (C-HCT). The study includes a total of 5 years of follow-up for disease and survival status for participants enrolled before or after 09 October 2023 to reach the initial sample size of 33 participants in both cohorts. For all other participants enrolled after 09 October 2023 and after the initial sample of 33 participants in both cohorts has been reached in both cohorts, the follow-up will be every 3 months, up to 12 months, as assessed on anniversary of Cycle 1 Day 1. For responders, the follow-up will be 12 months from the date of initial response.