Addition of Low-Dose Decitabine to Anti-PD-1 Antibody Camrelizumab in Relapsed/Refractory Classical Hodgkin Lymphoma.

PURPOSE: Anti-programmed death-1 (PD-1) monotherapy induces a high response rate in patients with relapsed/refractory classic Hodgkin lymphoma (cHL), but complete remission (CR) is infrequently observed. As decitabine is known to boost T-cell function, we assessed the safety and efficacy of anti-PD-1 camrelizumab alone versus decitabine-primed camrelizumab in patients with relapsed/refractory cHL. METHODS: This two-arm, open-label, phase II study enrolled patients with relapsed/refractory cHL who had received at least two lines of previous therapy. Anti-PD-1 treatment-naïve patients were randomly assigned (1:2) to camrelizumab (200 mg) monotherapy or decitabine (10 mg/d, days 1 to 5) plus camrelizumab (200 mg, day 8) combination therapy every 3 weeks. Patients who were previously treated with anti-PD-1 were assigned combination therapy. Primary end point was CR rate and safety. RESULTS: Overall, 86 patients were enrolled and evaluated for response, with a median follow-up of 14.9 months. In anti-PD-1-naïve patients, CR rate was 32% (six of 19 patients) with camrelizumab monotherapy versus 71% (30 of 42 patients) who were administered decitabine plus camrelizumab (P = .003). At the time of analysis, the response duration rate at 6 months was 76% on camrelizumab monotherapy versus 100% on decitabine plus camrelizumab. For patients who were previously treated with anti-PD-1, 28% achieved CR and 24% partial response after decitabine plus camrelizumab. Ten patients maintained a response at more than 6 months and 81% of responders were estimated to have a response at more than 1 year. For both treatments, the most common adverse events were clinically inconsequential cherry hemangiomas and leukocytopenia that were self-limiting. CONCLUSION: CR rate in patients with relapsed/refractory cHL who were clinically naïve to PD-1 blockade was significantly higher with decitabine plus camrelizumab than with camrelizumab alone. Decitabine plus camrelizumab may reverse resistance to PD-1 inhibitors in patients with relapsed/refractory cHL.

Genome-Wide Analysis of Epstein-Barr Virus Isolated from Extranodal NK/T-Cell Lymphoma, Nasal Type.

BACKGROUND: Extranodal natural killer (NK) cell/T-cell lymphoma (NKTCL), a rare type of non-Hodgkin's lymphoma, has strongly been associated with Epstein-Barr virus (EBV) infection. However, there are no EBV genomes isolated from NKTCL, and the roles the variations of EBV strains play in the pathogenesis of NKTCL are still unclear. MATERIALS AND METHODS: In this study, whole EBV genomes from eight primary NKTCL biopsy specimens were obtained using next-generation sequencing, designated NKTCL-EBV1 to NKTCL-EBV8. RESULTS: Compared with the six mostly referenced EBV strains, NKTCL-EBVs closely resemble the GD1 strain but still harbor 2,072 variations, including 1,938 substitutions, 58 insertions, and 76 deletions. The majority of nonsynonymous mutations were located in latent and tegument genes. Moreover, the results from phylogenetic analysis of whole NKTCL genomes and specific genes demonstrated that all the NKTCL-EBVs were related to Asian EBV strains. Based on the amino acid changes in certain residues of latent membrane protein 1 (LMP1) and EBV-determined nuclear antigen 1 (EBNA1), all the NKTCL-EBVs were sorted to China 1 and V-val subtype, respectively. Furthermore, changes in CD4+ and CD8+ T-cell epitopes of EBNA1 and LMP1 may affect the efficacy for a cytotoxic T lymphocyte (CTL)-based therapy. CONCLUSION: This is the first large study to our knowledge to obtain EBV genomes isolated from NKTCL and show the diversity of EBV genomes in a whole genome level by phylogenetic analysis. IMPLICATIONS FOR PRACTICE: In this study, the full-length sequence of Epstein-Barr virus (EBV) isolated from eight patients with nasal natural killer/T-cell lymphoma (NKTCL) was determined and further compared with the sequences previously reported isolated from other malignancies. Phylogenetic analysis showed that NKTCL-EBV strains are close to other Asian subtypes instead of non-Asian ones, leading to the conclusion that EBV infections are more likely affected by different geographic regions rather than particular EBV-associated malignancies. Therefore, these data have implications for the development of effective prophylactic and therapeutic vaccine approaches targeting the personalized or geographic-specific EBV antigens in these aggressive diseases.

Immediate and substantial evolution of T-cell repertoire in peripheral blood and tumor microenvironment of patients with esophageal squamous cell carcinoma treated with preoperative chemotherapy.

Preoperative chemotherapy could decrease tumor size and improve overall survival for esophageal squamous cell carcinoma (ESCC), and moreover, rational combination of chemotherapy and immunotherapy could increase likelihood of inducing an effective antitumor immune response. However, the immunologic impact of chemotherapeutic drugs originally chosen for cancer treatment due to the direct toxicity is poorly understood. We assess the effect of a combination of clinically approved chemotherapeutic drugs [paclitaxel-nedaplatin (PTX-NDP)] on T-cell receptor (TCR) repertoires of peripheral T cells and tumor-infiltrating lymphocytes (TILs) from five patients with primary ESCC. We found that PTX-NDP therapy induced immediate and substantial changes in clonotype frequencies of peripheral T cells and TILs, and moreover, compared with clonal amplification, clonal contraction was more likely to occur in more abundant clones in patients with ESCC. Significant increases in TCR diversity were observed in peripheral T cells but not in TILs after PTX-NDP therapy. Reconstruction of posttreatment TILs was not merely a result of local expansion or contraction of pretreatment TILs, but also-at least in part-a consequence of the migration of peripheral T cells into the chronically inflamed tumor microenvironment. Our findings uncover further insight into T-cell immune response modulated with chemotherapy, providing for theoretical bases for rational combination strategy of chemotherapy and immunotherapy.

Mutation analysis of the EBV-lymphoblastoid cell line cautions their use as antigen-presenting cells.

Lymphoblastoid cell lines (LCLs) have been widely used as professional antigen-presenting cells (APCs). However, neoantigen-loaded LCLs could induce nonspecific T-cell response, which could be due to expression of both Epstein-Barr virus (EBV) antigens and nonsynonymous mutations arising in LCLs. Since the number of passages could influence mutational characteristics of LCLs, and moreover extensive proliferation of LCLs in vitro is necessary to activate T cells for immunotherapy, we comprehensively profiled mutational characteristics by comparing eight sets of B cells and matched high-passage LCLs using whole-exome sequencing in order to assess the effect of nonsynonymous mutations arising in LCLs on nonspecific T-cell response. We found 315 nongermline mutations (approximately 40mut/subject) randomly distributed across all chromosomes including 18 mutations in immunoglobulin V and J genes in eight LCLs, of which 137 candidate neoantigens (approximately 17mut/subject) were identified. The underlying mutational processes linked to EBV-transformed LCLs could be attributed to activation induced cytidine deaminase gene expression which contributes to cytosine mutation clusters in LCLs through cytosine deamination. Pathways significantly enriched by nonsilent mutations of each LCL were totally different among all LCLs. In conclusion, high-passage LCLs may not be suitable to serve as APCs due to random nonsilent mutations, particularly for presentation of neoantigens of low immunogenicity, although further experimental proofs are needed.