Adoptive cell therapy (ACT) for cancers using autologous tumor-infiltrating lymphocytes (TILs) can induce immune responses and antitumor activity in metastatic melanoma patients. Here, we aimed to assess the safety and antitumor activity of ACT using expanded TILs following concurrent chemoradiotherapy (CCRT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC). Twenty-three newly diagnosed, locoregionally advanced NPC patients were enrolled, of whom 20 received a single-dose of TIL infusion following CCRT. All treated patients were assessed for toxicity, survival and clinical and immunologic responses. Correlations between immunological responses and treatment effectiveness were further studied. Only mild adverse events (AEs), including Grade 3 neutropenia (1/23, 5%) consistent with immune-related causes, were observed. Nineteen of 20 patients exhibited an objective antitumor response, and 18 patients displayed disease-free survival longer than 12 mo after ACT. A measurable plasma Epstein-Barr virus (EBV) load was detected in 14 patients at diagnosis, but a measurable EBV load was not found in patients after one week of ACT, and the plasma EBV load remained undetectable in 17 patients at 6 mo after ACT. Expansion and persistence of T cells specific for EBV antigens in peripheral blood following TIL therapy were observed in 13 patients. The apparent positive correlation between tumor regression and the expansion of T cells specific for EBV was further investigated in four patients. This study shows that NPC patients can tolerate ACT with TILs following CCRT and that this treatment results in sustained antitumor activity and anti-EBV immune responses. A larger phase II trial is in progress.
Keywords: ACT, adoptive cell therapy; CCRT, concurrent chemoradiotherapy; CR, complete response; DFS, disease-free survival, EBNA1; EBV, Epstein–Barr virus; EBV-CTLs, EBV-specific cytotoxic T cells; ELISPOT, enzyme-linked immunospot; Epstein–Barr virus nuclear antigen 1; FACS, fluorescence-activated cell sorting; GMP, good manufacturing practices; LMP1, latent membrane protein-1; LMP2, latent membrane protein-2; NPC, nasopharyngeal carcinoma; PBMCs, peripheral blood mononuclear cells; PD, progressive disease; PR, partial response; REP, rapid expansion protocol; SFCs, spot-forming cells; TILs, tumor-infiltrating lymphocytes; adoptive cell therapy; nasopharyngeal carcinoma; tumor-infiltrating lymphocytes.