Phase I Clinical Trial of 4-1BB-based Adoptive T-Cell Therapy for Epstein-Barr Virus (EBV)-positive Tumors

Although adoptive cell therapy using Ag-specific T cells has been tested successfully in the clinic, the production of these T cells has been challenging. By applying our simple and practical 4-1BB-based method for the generation of Ag-specific CD8(+) T cells, here we determined the maximum tolerated dose, toxicity profile, immunologic responses, and clinical efficacy of autologous Epstein-Barr virus (EBV)/LMP2A-specific CD8(+) T cells (EBV-induced Natural T cell; EBViNT) in patients with relapsed/refractory EBV-positive tumors. This was a single-center, phase I, dose-escalation trial study evaluating 4 escalating dosing schedules of single injected EBViNT. CD8(+) T-cell responses against different LMP2A peptides in each patient were determined, and the most effective peptides were used to produce EBViNT. The produced autologous EBViNTs were single infused to patients with EBV-associated malignancy who had failed to standard treatments and were of HLA-A02 or A24 type. Of 11 patients enrolled, 8 patients received a single infusion of EBViNT: 4 with nasopharyngeal carcinomas, 1 with Hodgkin lymphoma, 2 with extranodal NK/T lymphomas, and 1 with diffuse large B-cell lymphoma. Single infusion of EBViNT was well tolerated by all the patients and generated objective antitumor responses in 3 of them. EBViNT infusion induced 2 waves of interferon-gamma response: 1 approximately 1 week and the other 4-8 weeks after the treatment. The strength of the second wave was related to the efficacy of the treatment. The current trial shows that EBViNT therapy is safe and may provide a new option for treating EBV-positive recurrent cancer patients resistant to conventional therapy.