CD19 CAR-T treatment shows limited efficacy in r/r DLBCL with double expression and TP53 alterations.

OBJECT: Autologous CD19 chimeric antigen receptor T-cell therapy (CAR-T) significantly modifies the natural course of chemorefractory diffuse large B-cell lymphoma (DLBCL). However, 25% to 50% of patients with relapsed/refractory DLBCL still do not achieve remission. Therefore, investigating new molecular prognostic indicators that affect the effectiveness of CAR-T for DLBCL and developing novel combination therapies are crucial. METHODS: Data from 73 DLBCL patients who received CD19 CAR-T (Axi-cel or Relma-cel) were retrospectively collected from Shanghai Tongji Hospital of Tongji University, The Second Affiliated Hospital Zhejiang University School of Medicine, and The Affiliated People's Hospital of Ningbo University. Prior to CD19 CAR-T-cell transfusions, the patients received fludarabine and cyclophosphamide chemotherapy regimen. RESULTS: Our study revealed that relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL) patients with both Double-expression (MYC > 40% and BCL2 > 50%) and TP53 alterations tend to have a poorer clinical prognosis after CAR-T therapy, even when CAR-T therapy is used in combination with other therapies. However, CAR-T therapy was found to be effective in patients with only TP53 alterations or DE status, suggesting that their prognosis is in line with that of patients without TP53 alterations or DE status. CONCLUSIONS: Our study suggests that r/r DLBCL patients with both DE status and TP53 alterations treated with CAR-T therapy are more likely to have a poorer clinical prognosis. However, CAR-T therapy has the potential to improve the prognosis of patients with only TP53 alterations or DE status to be similar to that of patients without these abnormalities.

Anti-CD79b/CD3 bispecific antibody combined with CAR19-T cells for B-cell lymphoma treatment.

CD19 CAR-T (chimeric antigen receptor-T) cell immunotherapy achieves a remission rate of approximately 70% in recurrent and refractory lymphoma treatment. However, the loss or reduction of CD19 antigen on the surface of lymphoma cells results in the escape of tumor cells from the immune killing of CD19 CAR-T cells (CAR19-T). Therefore, novel therapeutic strategies are urgently required. In this study, an anti-CD79b/CD3 bispecific antibody (BV28-OKT3) was constructed and combined with CAR19-T cells for B-cell lymphoma treatment. When the CD19 antigen was lost or reduced, BV28-OKT3 redirected CAR19-T cells to CD79b+ CD19- lymphoma cells; therefore, BV28-OKT3 overcomes the escape of CD79b+ CD19- lymphoma cells by the killing action of CAR19-T cells in vitro and in vivo. Furthermore, BV28-OKT3 triggered the antitumor function of CAR- T cells in the infusion product and boosted the antitumor immune response of bystander T cells, markedly improving the cytotoxicity of CAR19-T cells to lymphoma cells in vitro and in vivo. In addition, BV28-OKT3 elicited the cytotoxicity of donor-derived T cells toward lymphoma cells in vitro, which depended on the presence of tumor cells. Therefore, our findings provide a new clinical treatment strategy for recurrent and refractory B-cell lymphoma by combining CD79b/CD3 BsAb with CAR19-T cells.

Prognostic impact of peripheral eosinophil counts in patients with diffuse large B-cell lymphoma receiving chimeric antigen receptor T-cell therapy.

BACKGROUND AIMS: Chimeric antigen receptor (CAR) T-cell therapy is a breakthrough treatment for patients with relapsed or refractory diffuse large B-cell lymphoma. However, many patients do not achieve remission or relapse after remission. Previous studies have demonstrated that eosinophils have synergistic anti-tumor effects with CD8+T cells and pre-CAR T-eosinophil counts are associated with the efficacy of CAR T cells. METHODS: We retrospectively analyzed the eosinophil counts of patients with diffuse large B-cell lymphoma and found it changed remarkably pre- and post-CAR T-cell therapy. RESULTS: Patients who achieved complete remission after CAR T-cell infusion had greater post-CAR T-eosinophil counts than those who did not. Kaplan-Meier curves showed that patients with greater eosinophil counts during the second month after CAR T-cell infusion had superior progression-free survival and overall survival compared with those with lower eosinophil counts. CONCLUSIONS: For patients who responded to CAR T-cell therapy, eosinophil counts also can be used to predict 6-month duration of response. In conclusion, the post-CAR T-eosinophil count is associated with the prognosis of patients treated with CAR T-cell therapy and can be used to clinically identify patients who can achieve longer remission after CAR T-cell infusion.

Risk of HBV reactivation in relapsed or refractory diffuse large B-cell lymphoma patients receiving Bruton tyrosine kinase inhibitors therapy.

Background: Bruton tyrosine kinase inhibitors (BTKis) interrupt B-cell receptor signaling and thereby could potentially reactivate hepatitis B virus (HBV). However, data about the risk for HBV reactivation (HBVr) of BTKis in relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL) patients are sparse. Methods: A total of 55 R/R DLBCL patients receiving BTKis therapy in the Tongji Hospital of Tongji University were enrolled. Patient clinical characteristics, treatment outcomes and details of HBVr were collected and analyzed, aiming to demonstrate the risk of HBVr in R/R DLBCL patients post BTKis therapy and the efficacy of BTKis in HBV-associated R/R DLBCL patients. Results: Of 55 R/R DLBCL patients treated with ibrutinib (N=38) and zanubrutinib (N=17), 4 were with chronic HBV infection (HBsAg positive), 26 with resolved HBV infection (HBsAg negative and HBcAb positive) and 25 without HBV infection (HBsAg negative and HBcAb negative). In resolved HBV infection group, 2 patients developed HBVr after the use of ibrutinib and zanubrutinib respectively. Neither of them developed HBV-related hepatitis. Our finding showed that the incidence of HBVr in resolved HBV infection group was 7.69% (95% CI, 0.9-25.1%). In this study, Overall response rate (ORR) was 70.9%. 1-year overall survival (OS) rate was 80.0%. Median progression-free survival (PFS) was 4 months (95% CI, 3-5 months). In addition, HBV infection was not associated with response rates or survival among R/R DLBCL patients post BTKis treatments. Conclusion: Our study suggested that HBV infection do not affect the efficacy of BTKis' treatment. However, R/R DLBCL patients with resolved HBV infection are at a moderate risk of developing HBVr throughout BTKis treatment. Patients should be screened for HBVr during BTKis therapy.

Risk of HBV Reactivation in Patients With Resolved HBV Infection Receiving Anti-CD19 Chimeric Antigen Receptor T Cell Therapy Without Antiviral Prophylaxis.

Background: Chimeric antigen receptor (CAR) T-cell therapy has emerged as a novel treatment modality for hematologic malignancies and is predicted to experience widespread use in the near future. However, not all risks associated with this novel approach are well defined. There are few data in the risk of HBV reactivation and limited experience in management in patients with resolved HBV infection who undergo CAR-T cell therapy. Methods: We performed a post-hoc analysis of a prospective clinical trial of anti-CD19 CAR-T (CART19) cell therapy in patients with relapsed or refractory (r/r) B-cell malignancies, and aimed at exploring the actual risk of HBV reactivation in a cohort of patients with resolved HBV infection receiving CART19 cell therapy in the absence of antiviral prophylaxis. Results: In this study, we investigated the risk of HBV reactivation after CART19 cell therapy in 30 consecutive patients with B-cell malignancies and resolved HBV infection without antiviral prophylaxis, in the Tongji Hospital of Tongji University. In this cohort, two patients developed HBV reactivation 2 months and 14 months after CAR-T cell infusion, respectively, the latter of whom developed severe hepatitis. These findings showed that the incidence of HBV reactivation was 6.67% (95% CI, 0.8-22.1). Specifically, none of the 21 patients who were HBsAb positive (0.0%) versus two of nine patients who were HBsAb negative (22.2%) experienced HBV reactivation (p = 0.03), suggesting HbsAb seronegativity at baseline is a possible risk factor in this population. Although use of tocilizumab or corticosteroids has been associated with increased risk of HBV reactivation, none of the patients who received these agents had HBV reactivation in this study. Conclusion: This is the first and largest study to assess the true incidence of HBV reactivation in patients with resolved HBV infection receiving CART19 cell therapy without antiviral prophylaxis. This study highlights that this population are at risk of developing HBV reactivation and indicates that close monitoring of HBV DNA is required in the absence of antiviral prophylaxis. In addition, antiviral prophylaxis is recommended in the HBsAb-negative subpopulation.

Different sites of extranodal involvement may affect the survival of patients with relapsed or refractory non-Hodgkin lymphoma after chimeric antigen receptor T cell therapy.

Factors associated with complete and durable remissions after anti-CD19 chimeric antigen receptor T (CAR-T) cell immunotherapy for relapsed or refractory non-Hodgkin lymphoma (r/r NHL) have not been well characterized. In this study, we found that the different sites of extranodal involvement may affect response, overall survival (OS), and progression-free survival (PFS) in patients with r/r NHL treated with anti-CD19 CAR-T cells. In a cohort of 32 treated patients, 12 (37.5%) and 8 (25%) patients exhibited soft tissue lymphoma and bone marrow (BM) infiltrations, respectively, and 13 (41%) patients exhibited infiltration at other sites. The factors that may affect prognosis were identified through multivariable analysis. As an independent risk factor, soft tissue infiltration was the only factor significantly correlated with adverse prognosis (P < 0.05), whereas other factors did not reach statistical significance. Furthermore, the site of extranodal tumor infiltration significantly and negatively affected OS and PFS in patients with r/r NHL treated with anti-CD19 CAR-T cell therapy. PFS and OS in patients with BM involvement were not significantly different from those of patients with lymph node involvement alone. Thus, anti-CD19 CAR-T cell therapy may improve the prognosis of patients with BM infiltration.

Chimeric antigen receptor T-cell therapy: a promising treatment modality for relapsed/refractory mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a distinct histological type of B-cell lymphoma with a poor prognosis. Several agents, such as proteasome inhibitors, immunomodulatory drugs, and inhibitors of B cell lymphoma-2 and Bruton's tyrosine kinase have shown efficacy for relapsed or refractory (r/r) MCL but often have short-term responses. Chimeric antigen receptor (CAR) T-cell therapy has emerged as a novel treatment modality for r/r non-Hodgkin's lymphoma. However, long-term safety and tolerability associated with CAR T-cell therapy are not defined well, especially in MCL. In this report, we described a 70-year-old patient with r/r MCL with 48-month duration of follow-up who achieved long-term remission after CAR T-cell therapy. CAR T-cell-related toxicities were also mild and tolerated well even in this elderly patient. This report suggested that CAR T-cell therapy is a promising treatment modality for patients with MCL, who are generally elderly and have comorbid conditions.

SIRT1 inhibition impairs non-homologous end joining DNA damage repair by increasing Ku70 acetylation in chronic myeloid leukemia cells.

Most chemotherapeutic agents for leukemia are DNA damaging agents. However, DNA lesions can be repaired by activities of DNA repair systems. Increasing evidence have shown that enhanced DNA damage repair capacity contributes to chemotherapy resistance in leukemia cells. Thus, targeting DNA repair mechanisms is a promising strategy for novel leukemia treatment. SIRT1 expressions were downregulated by lentivirus-delivered SIRT1 shRNA in myeloid leukemia cells. SIRT1 mRNA and protein levels were analyzed by real-time PCR and Western blot, respectively. Flow cytometry was carried out to analyze cell cycle progression, apoptosis and DNA damage repair efficiency. DNA damage levels were assessed by alkaline comet assay, and H2AX phosphorylation was analyzed by immunoblotting and immunofluorescence. A mouse leukemia model was established by transplanting lentivirus-infected K562 cells containing SIRT1 shRNA into sublethally irradiated NOD/SCID mice, and tumorigenesis was evaluated by detecting tumor weights and mice survival. SIRT1 expressions were upregulated in myeloid leukemic patients. Downregulation of SIRT1 by RNAi promoted etoposide-induced DNA damage in myeloid leukemia cells accompanied by reduced NHEJ activity, and increased Ku70 acetylation. Furthermore, SIRT1 knockdown resulted in cell cycle arrest, induction of apoptosis and reduction of K562 cell proliferation accompanied by enhanced p53 and FOXO1 acetylation in K562 cells after etoposide treatment. Importantly, SIRT1 downregulation reduced the tumorigenesis ability of K562 cells in mouse xenografts following chemotherapy treatment. These results revealed that SIRT1 promotes the NHEJ repair pathway by deacetylating Ku70 in K562 cells, suggesting that SIRT1 is a novel therapeutic target for treating myeloid leukemia.

SIRT1 downregulation enhances chemosensitivity and survival of adult T-cell leukemia-lymphoma cells by reducing DNA double-strand repair.

Most chemotherapy drugs used for the treatment of adult T-cell leukemia-lymphoma (ATL) cause cell death directly by inducing DNA damage, which can be repaired via several DNA repair pathways. Enhanced activity of DNA damage repair systems contributes to ATL resistance to chemotherapies. Targeting DNA repair pathways is a promising strategy for the sensitization of ATL cells to chemotherapeutic drugs. in the present study, inhibition of SIRT1 deacetylase by shRNA sensitized Jurkat cells to etoposide by reducing the activity of non-homologous end joining (NHEJ) and homologous recombination (HR). Silencing of SIRT1 deacetylase by shRNA resulted in enhanced apoptosis and cell cycle arrest, while reduced colony formation of Jurkat cells after etoposide treatment was accompanied by elevated acetylation of FOXO1. Furthermore, inhibition of SIRT1 led to decreased activity of DNA damage repair by NHEJ and HR, accompanied by increased Ku70 acetylation. Furthermore, SIRT1 downregulation prolonged the survival time of Jurkat-xenografted mice. These results suggested that SIRT1 promotes DNA double­strand repair pathways in Jurkat cells by deacetylating Ku70, and increases cell proliferation by deacetylating FOXO1. The results suggest that SIRT1 is a potential target for the development of combinatorial treatment for ATL.

Colony-stimulating factors for chemotherapy-related febrile neutropenia are associated with improved prognosis in adult acute lymphoblastic leukemia.

Colony-stimulating factors (CSF) have been widely used to prevent febrile neutropenia associated with chemotherapy. Due to the high intensity of chemotherapy in acute lymphoblastic leukemia (ALL), CSF as a crucial component of supportive care has played a significant role in the therapy. However, the effectiveness of CSF in treatment has not been identified by large clinical trials until now. The aim of the present study was to evaluate the effect of CSF on the long-term outcome of adult ALL patients. A comprehensive search strategy has been conducted, which covered the Cochrane Central Register of Controlled Trials, PubMed and Web of Science. The result includes seven randomized controlled trials containing a total of 753 patients. The administration of CSF significantly reduced the mortality at the end of the follow-up (RR, 0.85; 95% CI, 0.75-0.95), the mortality at day 30 (RR, 0.41; 95% CI, 0.23-0.74) and the number of patients with infection or severe infections (RR, 0.8; 95% CI, 0.7-0.9 and RR, 0.48; 95% CI, 0.3-0.75). The addition of CSF also marginally increased the number of patients achieving CR (RR, 1.14; 95% CI, 1.05-1.23). The use of CSF also shortened the duration of neutropenia (median days, 8-17 to 12.5-24). In conclusion, CSFs can be administered to ALL patients during myelosuppressive chemotherapy, particularly in the induction phase.