Characteristics and recognition of early infections in patients treated with commercial anti-CD19 CAR-T cells

The characteristics of infections following chimeric antigen receptor T (CAR-T) cells targeting CD19 in real-word population are obscure. We analyzed infections' characteristics in the first month among consecutive patients with diffuse large B-cell lymphoma (DLBCL) (n = 60, median age, 69.3 years), treated with commercial CAR-T cells. ECOG performance status (PS) was 2-3 in most patients (58%). Infections were observed in 45% of patients (16, 27%, bacterial infections, and 14, 23%, viral infections). Bacterial infection included clinically documented infection in 7 (Pneumonia, n = 5; periodontal infection, n = 1; and cellulitis, n = 1) and microbiology documented infection (MDI) in 9 patients (Gram-negative rod, n = 5; Gram-positive cocci, n = 3, bacteremia; polymicrobial, n = 1). The most common viral infection was cytomegalovirus (CMV) reactivation (n = 10, 17%) leading to initiation of anti-CMV treatment in 6 (60%) among these patients. None had CMV disease. In univariate analysis, immune effector cell-associated neurotoxicity syndrome (ICANS) was associated with higher incidence of bacterial infection (OR=4.5, P = .018), while there was a trend for lower incidence of bacterial infections in patients with chemosensitive disease to bridging therapy (OR=0.375, P = .074). Age or PS was not associated with increased risk of bacterial infection. Increase in C-reactive protein (CRP) prior to fever onset was associated with microbiologically documented infections. We conclude that infections are common in the first month following CAR-T-cell administration, however, were not increased in elderly patients or those presenting with poorer PS. Increase in CRP prior to fever onset could support infection over cytokine release syndrome.     

Non-invasive cell-tracking methods for adoptive T cell therapies

Adoptive T cell therapies (ACT) have demonstrated groundbreaking results in blood cancers and melanoma. Nevertheless, their significant cost, the occurrence of severe adverse events, and their poor performance in solid tumors are important hurdles hampering more widespread applicability. In vivo cell-tracking allows instantaneous and non-invasive monitoring of the distribution, tumor homing, persistence, and redistribution to other organs of infused T cells in patients. Furthermore, cell-tracking could aid in the clinical management of patients, allowing the detection of non-responders or severe adverse events at an early stage. This review provides a concise overview of the main principles and potential of cell-tracking, followed by a discussion of the clinically relevant labeling strategies and their application in ACT.     

Universal chimeric Fcγ receptor T cells with appropriate affinity for IgG1 antibody exhibit optimal antitumor efficacy

Developing universal CARs with improved flexible targeting and controllable activities is urgently needed. While several studies have suggested the potential of CD16a in tandem with monoclonal antibodies to construct universal CAR-T cells, the weak affinity between them is one of the limiting factors for efficacy. Herein, we systematically investigated the impact of Fcγ receptor (FcγR) affinity on CAR-T cells properties by constructing universal CARs using Fcγ receptors with different affinities for IgG1 antibodies, namely CD16a, CD32a, and CD64. We demonstrated that the activities of these universal CAR-T cells on tumor cells could be redirected and regulated by IgG1 antibodies. In xenografted mice, 64CAR chimeric Jurkat cells with the highest affinity showed significant antitumor effects in combination with herceptin in the HER2 low expression U251 MG model. However, in the CD20 high expression Raji model, 64CAR caused excessive activation of CAR-T cells, which resulted in cytokine release syndrome (CRS) and the decline of antitumor activity, and 32CAR with a moderate affinity brought the best efficacy. Our work extended the knowledge about FcγR-based universal CAR-T cells and suggested that only the FcγRCAR with an appropriate affinity can offer the optimal antitumor advantages of CAR-T cells.     

The advances in therapy of blastic plasmacytoid dendritic cell neoplasm

Introduction: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive myeloid malignancy that contributes to <1% of all hematologic neoplasms. Before the introduction of various targeted agents, the therapeutic approach was based on regimens used for acute lymphoblastic or myeloid leukemia and non-Hodgkin’s lymphoma (e.g. hyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone alternating with high dose methotrexate and cytarabine) and CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) -based regimens) followed by allogeneic stem cell transplantation for eligible patients. Given that this disease primarily affects older patients, there is a significant barrier to using these highly toxic regimens, even though these regimens are usually associated with the most durable response

Areas covered: In this review, we briefly discuss outcomes with the use of leukemia-based induction regimens as well as the use of stem cell transplant. We also review low-intensity chemotherapeutic regimens. Finally, we will describe both preclinical and early clinical data regarding novel targeted strategies for treating BPDCN without the use of cytotoxic chemotherapy, with a focus on the use of CD123 directed therapy.

Expert opinion: While the current standard treatment for BPDCN is acute leukemia-based regimen followed by hematopoietic stem cell transplantation for transplant-eligible patients, there are very promising results for CD123 directed therapies. The future of BPDCN treatment may include targeted therapies without the need for cytotoxic chemotherapy.     

CAR-T细胞治疗产品非临床药效学研究关注点

CAR-T细胞（Chimeric Antigen Receptor T Cells,CAR-T）是一种表达嵌合抗原受体的基因工程T细胞,也称"活的药物",可以增强基因工程T细胞的特异性,能够以MHC （主要组织相容性复合体,Major Histocompatibility Complex,MHC）非依赖性的方式高度靶向肿瘤抗原,是治疗肿瘤的一种新手段。最近,临床上使用CAR-T细胞治疗复发、难治性血液恶性肿瘤和多发性骨髓瘤取得了很好的疗效;同时,采用CAR-T细胞治疗实体瘤的研发也在积极开展。根据所构建的CAR-T细胞不同的适应证和作用原理,构建不同的动物肿瘤模型,研究CAR-T细胞在动物模型的抗肿瘤活性,可以对CAR-T细胞进行概念验证性研究并证明其体内药效学活性,为临床研究提供有力的数据支持。