Administration of LMP-Specific Cytotoxic T-Lymphocytes to Patients with Relapsed EBV-Positive Lymphoma Post Allogeneic STEM CELL Transplant

Epstein Barr virus (EBV) associated tumors in the immunocompetent host express the type II latency antigens LMP1 and LMP2 which can serve as potential targets for immunotherapy. For many patients with chronic active EBV (CAEBV) and/or relapsed EBV+ Non Hodgkin Lymphoma (NHL) or Hodgkin Lymphoma (HL) the only potential curative option is allogeneic hematopoietic stem cell transplant (allo-HSCT). However, relapse rates remain high (>50%) and the risk of inducing graft versus host disease (GvHD) after DLI limits the broad application of this approach. We hypothesized that the administration of donor-derived cytotoxic T lymphocytes (CTLs) directed to LMP1/2 (LMP-CTL) would rapidly restore LMP-specific T-cell immunity and prevent relapse in these high-risk patients without increasing the incidence of GvHD. LMP-CTLs were expanded using donor monocytes and EBV transformed lymphoblastoid cell lines, transduced with an adenoviral vector encoding either LMP2 (n=4) or DLMP1 and LMP2 (n=11).  Characterization of CTL lines at cryopreservation revealed CD4+ and CD8+ cells which were predominantly effector and effector memory phenotype. CTL lines had LMP2 (+/-LMP1) specific activity as determined by ELISPOT and cytotoxicity assays. Fifteen patients (n=5 HL, n=4 B-cell CAEBV/NHL, n=6 T-cell CAEBV/NHL) received 2 infusions of CTLs (dose range: 0.4-3x10e8/m2) approximately 100 days post HSCT. No immediate toxicities related to CTL infusions were observed. Infusion of LMP-CTLs resulted in a maximum 2.5 fold increase in the frequency of LMPs precursors as detected by IFNγ eliSPOT assay. No patient developed de novo GVHD post CTLs. GVHD was seen in 4 patients with a pre-existing history (1 patient with DLBCL experienced grade II skin GvHD controlled with steroids, 2 patients (1 NK-T and 1 HL) showed signs of grade I GvHD promptly controlled with steroids. 1patient with DLBCL developed grade III GvHD after weaning immune suppression and subsequently developed sepsis and died 10 months after an HLA matched-unrelated HSCT). 13 patients were in remission at the time of CTL infusion and 12/13 of these patients remained in remission for a median of 30 months post CTLs (range 6-90 months). One patient with NK/T cell NHL relapsed 6 months post CTLs and died of progressive disease. Two patients (1HL and 1 T-cell CAEBV) received CTLs for relapsed disease after HSCT and both died of disease. Disease progression in the patient with HL, was likely due to  immune-escape since tumor biopsies obtained  post CTL were EBV-negative. In conclusion, donor-derived LMP-CTLs seem to be well tolerated in high-risk patients with CAEBV and/or EBV+ lymphoma post HSCT. Furthermore, the use of donor-derived tumor-directed T-cells as adjuvant therapy post HSCT may restore LMP-specific T-cell immunity and prevent relapse in this high-risk patient population.