Rapidly-Generated EBV-Specific T Cells (Ebvst-Cells) to Treat Type 2 Latency Lymphoma

Up to ~30% of Hodgkin and non-Hodgkin lymphomas carry the EBV genome and express the viral latency proteins EBNA-1, LMP-1, LMP-2 and BARF-1 in a pattern known as Type 2 latency. We have previously shown that EBVSTs specific for Type 2 latency antigens can be expanded from the peripheral blood of lymphoma patients by stimulation with dendritic cells and lymphoblastoid cell lines modified with an adenoviral vector encoding LMP1 and LMP2 and induce clinical responses in over 50% of patients with active disease (Bollard et al J Clin Oncol 2014). To broaden the applicability of this strategy we have sought to shorten the manufacture time and simplify the process, by removing viral-vector components from our manufacturing process and replacing these components with dendritic cells or peripheral blood mononuclear cells pulsed with peptide libraries (pepmixes) spanning the antigens of interest. Responder T-cells are subsequently expanded by restimulation with the same pepmixes presented on autologous, activated T-cells together with HLA-negative K562 costimulatory cells in the presence of cytokines. We initially used IL4 and IL7 but subsequently modified the manufacturing to use IL7 and IL15 with the goal of overcoming T-cell anergy and enhancing the specificity of patient-derived EBVSTs. EBVSTs manufactured using IL7/15 are polyclonal comprising both CD4+ and CD8+ cells and generate VSTs with enhanced proliferative capacity, antigen specificity, and cytotoxicity. The manufacturing time is 3–4 weeks compared with 3–4 months with the original product. We have infused EBVSTs manufactured using both cytokine combinations into 24 patients with multiply-relapsed, EBV-positive lymphoma as adjuvant therapy after stem cell transplantation or chemotherapy in 14 patients and as treatment for disease in 10 patients. No patients had any adverse events attributed to the cell infusion. Of patients in remission at the time of infusion, 2 with IL-4/7-grown EBVSTs and 12 with IL-15/7 grown EBVSTs remain in remission with follow up of 2 to 30 months. Of patients with disease at the time of infusion, one receiving IL-4/7-grown EBVSTs had stable disease and 3 had progressive disease, while of 6 patients with IL-15/7-grown EBVSTs, two had CRs (sustained for 18 + and 6 + months), two had PRs, one had stable disease and one progressed. We are continuing to enroll patients with IL7/15 product and plan to add PD-1 inhibition in patients who have partial responses.