Purpose: CD19-specific chimeric antigen receptor (CAR)-T cell therapy is effective against refractory or relapsed (R/R) B-cell lymphoma, but the efficacy is hindered by the existence of PD-1/PD-L1 pathway. Experimental Design: Here we generated a novel anti-CD19 CAR expressing PD-1/CD28 chimeric switch-receptor (CD19-PD-1/CD28-CAR). We then conducted a phase 1b study to evaluate safety and efficacy of CD19-PD-1/CD28-CAR T cells in the treatment of PD-L1+ B-cell lymphoma. Results: We found that CD19-PD-1/CD28-CAR T cells had superior T-cell proliferation, cytokine production, and sequentially, capability of killing PD-L1⁺ B-cell lymphoma cells in vitro and in vivo relative to the prototype CD19-CAR T cells. Among total of 17 adult patients with R/R lymphoma received the CAR-T therapy, 10 patients had objective response (58.8%), including 7 patients with complete remission (41.2%). At a median follow-up 15 months, median overall survival for all patients was not reached. Remarkably, no severe neurological toxicity or cytokine-release syndrome was observed. Conclusions: This first-in-human study demonstrates the tolerability, safety, and encouraging efficacy of CD19-PD-1/CD28-CART in PD-L1+ large B-cell lymphoma.

Chimeric antigen receptor T (CAR T) cell therapy has demonstrated efficacy in the treatment of haematologic malignancies. However, the accompanying adverse events, the most common of which is cytokine release syndrome (CRS), substantially limit its wide application. Due to its unique physiological characteristics, CRS in CAR T-cell treatment for B-cell non-Hodgkin lymphoma (B-NHL) may exhibit some special features. Although existing guidelines had greatly promoted the recognition and management of CRS, many recommendations are not fully applicable to B-NHL. Therefore, it is imperative to identify responses that are specific to CRS observed following CAR T treatment for B-NHL. Based on underlying biological processes and known pathophysiological mechanisms, we tentatively propose a new model to illustrate the occurrence and evolution of CAR T-cell-therapy-related CRS in B-NHL. In this model, tumour burden and bone marrow suppression are considered determinants of CRS. Novel phenomena after CAR T-cell infusion (such as local inflammatory response) are further identified. The proposed model will help us better understand the basic biology of CRS and recognize and manage it more rationally.

Clinical trials have confirmed that chimeric antigen receptor (CAR) T cell therapies are revolutionizing approaches for treating several relapsed or refractory hematological tumors. Cytokine release syndrome (CRS) is an adverse event with high incidence during CAR-T treatment. A further understanding of the characteristics and related risk factors of CRS is important for effective management. A total of 142 patients with relapsed or refractory acute lymphocyte leukemia (ALL), lymphoma, or multiple myeloma (MM) received lymphodepletion chemotherapy followed by infusion of CAR-T cells. The characteristics of CRS at different time points after treatment were monitored and risk factors were analyzed. The incidence of CRS for ALL, lymphoma, and multiple myeloma were 82%, 90%, and 90% respectively. Fever was observed on a median of day 3 for ALL, day 1 for lymphoma, and day 8.5 for MM after CAR-T cell infusion, and the duration was different between grade 1–2 CRS and grade 3–5 CRS. Disease types, peak concentration of IL-6, and CRP were associated with CRS. For patients with ALL, numbers of lymphoblast in bone marrow before lymphodepletion, peak concentration of IL-6, and CRP were independent risk factors of CRS. Clinical stage of lymphoma patients and high tumor burden in marrow of MM patients were independent risk factors of CRS. In conclusion, the characteristics and risk factors of CRS in different B-cell hematological tumors are different and should be managed individually during CAR-T cell therapy.

Exosomes derived from tumor cells (TEXs) are involved in both immune suppression, angiogenesis, metastasis and anticancer stimulatory, but the biological characteristics and role of diffuse large B cell lymphoma (DLBCL)-derived exosomes have been less investigated. Exosomes (EXOs) were isolated from OCI-LY3, SU-DHL-16, and Raji cells and biological characteristics of EXOs were investigated using electron microscopy, flow cytometry analysis, and Western blot analysis. The protein expression of EXOs was determined by an antibody array. Next, the communication between EXOs and lymphoma cell, stromal cell, dendritic cells (DCs), and T cells was evaluated. Finally, effect of DLBCL TEXs on tumor growth in vivo was investigated. We demonstrated that EXOs derived from DLBCL cell lines displayed malignancy molecules such as c-Myc, Bcl-2, Mcl-1, CD19, and CD20. There was a different protein expression pattern between DLBCL TEXs and Burkitt lymphoma TEXs. DLBCL TEXs were easily captured by DCs and lymphoma cells, and mainly acted as an immunosuppressive mediator, evidenced by induction of apoptosis and upregulation of PD-1 in T cells. Furthermore, the TEXs stimulated not only cell proliferation, migration of stromal cells but also angiogenesis. As a result, the TEXs promoted tumor growth in vivo. On other hand, DLBCL TEXs did not induce apoptosis of DCs. After pulsed with the TEXs, DCs could stimulate clonal expansion of T cells, increase the secretion of IL-6 and TNFα, and decrease the production of immunosuppressive cytokine IL-4 and IL-10. The T cells from tumor bearing mice immunized by TEX were shown to possess superior antilymphoma potency relative to immunization of tumor lysates. This study provides the framework for novel immunotherapies targeting TEXs in DLBCL.

Background: Coronavirus disease 2019 (COVID-19) is a novel infectious viral disease, which lacks well-established diagnostic laboratory parameters that could be used to evaluate disease severity, thromboembolism or cardiovascular events and to predict clinical prognosis. Coagulation cascade and platelet functions have not been well studied in the COVID-19 patients. Methods: A total of 178 patients enrolled in Wuhan Huoshenshan Hospital were included for the study. Blood platelets and coagulation functions were analyzed in COVID-19 patients with non-severe and severe subgroups. Other biochemical laboratory parameters were also analyzed. Results: Forty-nine (27.5%) out of 178 patients were diagnosed with severe disease in this study, and 129 patients with non-severe disease. Severe disease group had significant lower platelet count 186.00 (103.50–249.00) ×10⁹/L than 251.00 (202.00–317.00) ×10⁹/L of non-severe group, p = 0.000. Severe group also had significantly abnormal coagulation parameters than non-severe group: prothrombin time (PT) 14.55 (13.40–16.53) s vs. 12.70 (12.15–13.59) s, p = 0.000; international normalized ratio (INR) 1.21 (1.13–1.36) vs. 1.06 (1.01–1.13), p = 0.000; thrombin time (TT) 16.35 (15.69–17.47) s vs. 15.68 (14.79–16.69) s, p = 0.011; D-Dimer 1.05 (0.68–5.90) mg/L vs. 0.42 (0.28–0.79) mg/L, p = 0.000; While the liver function parameter alanine aminotransferase (ALT) and aspartate aminotransferase (AST) didn’t show significance between two groups, ALT 30.80 (19.00–58.30) IU/L vs. 28.80 (15.75–50.15) IU/L, p = 0.487; AST 27.80 (19.30–40.55) IU/L vs. 22.6 (16.7–32.03) IU/L, p = 0.102. Disseminated intravascular coagulation (DIC) rate was 6.1% in severe group while 0% in non-severe group. Survival rate of severe disease group was worse than non-severe group, 85.7% vs. 100%, p = 0.000. Thrombocytopenia correlated with coagulation function, DIC rate and survival. Six out of 7 death case had thrombocytopenia during hospitalization, and platelet count decreased subsequently until death. Thrombocytopenia occurred within 1 week after admission in 6 recovered patients. And increased platelet levels followed by positive SARS-CoV-2 IgM/IgG and negative coronavirus nucleic acid tested in 8 recovered patients. Conclusions: Low platelet count is associated with abnormal coagulation function and increased risk of DIC, severe disease manifestation and increased mortality in patients with COVID-19.