The efficacy and safety of CAR-T cell therapy in patients with refractory ALL and concomitant HBV infection

Infectious complications of chimeric antigen receptor (CAR) T-cell therapies

CAR T-cells have revolutionized the treatment of many hematological malignancies. Thousands of patients with lymphoma, acute lymphoblastic leukemia, and multiple myeloma have received this "living medicine" and achieved durable remissions. Their place in therapy continues to evolve, and there is ongoing development of new generation CAR constructs, CAR T-cells against solid tumors and CAR T-cells against chronic infections like human immunodeficiency virus and hepatitis B. A significant fraction of CAR T-cell recipients, unfortunately, develop infections. This is in part due to factors intrinsic to the patient, but also to the treatment, which requires lymphodepletion (LD), causes neutropenia and hypogammaglobulinemia and necessarily increases the state of immunosuppression of the patient. The goal of this review is to present the infectious complications of CAR T-cell therapy, explain their temporal course and risk factors, and provide recommendations for their prevention, diagnosis, and management.

Donor-Derived CD7 CAR-T Therapy Followed by Allogeneic Hematopoietic Stem Cell Transplantation for Acute T-Lymphocytic Leukemia Associated With Hepatitis B: A Case Report

The use of chimeric antigen receptor T cells (CAR-Ts) is effective in the treatment of hematological malignancies. It has been reported that HBV is reactivated after CAR-T immunotherapy for refractory/relapsed hematological malignant B-cell tumors. However, there is little literature on donor-derived CAR-T therapy combined with allogeneic hematopoietic stem cell transplantation in hepatitis B patients with acute T-lymphocytic leukemia. We report the case of one patient with hepatitis B associated with relapsed/refractory acute T-lymphocytic leukemia (T-ALL) treated with donor-derived CD7 CAR-T therapy and allogeneic hematopoietic stem cell transplantation. During treatment, the copy number of hepatitis B virus continuously decreased, and AST, ALT, DBIL and TBIL remained within the controllable ranges. CD7-negative MRD recurred 4.5 months after transplantation, and the flow cytometry results became negative after immunosuppressive reduction. Seven months after transplantation, the patient had complete remission, and the copy number of hepatitis B virus decreased to below 10². This is the first study on the safety and effectiveness of donor-derived CD7 CAR-T therapy bridging to allogeneic hematopoietic stem cell transplantation in a patient with relapsed/refractory acute T-lymphocytic leukemia and hepatitis B.

Cytomegalovirus Retinitis and Retinal Detachment following Chimeric Antigen Receptor T Cell Therapy for Relapsed/Refractory Multiple Myeloma

Cytomegalovirus (CMV) retinitis is a rare end-organ disease of CMV infection and is a marker of severe immunosuppression, especially in human immunodeficiency virus (HIV)-positive patients. In multiple myeloma (MM) patients, CMV retinitis has been reported in the post-transplant setting, with an incidence lower than 0.2%, and in patients receiving lenalidomide. Here, we describe the first case of CMV retinitis in myeloma patients following B-cell maturation antigen (BCMA)-targeted chimeric antigen receptor T (BCMA CAR-T) cell therapy. In addition to CMV, the patient developed multiple infections including a mouth ulcer, pneumonia, and fungal enteritis. While the complete remission (CR) status of MM was maintained, he regained a visual acuity of 20/1000 after appropriate ophthalmologic treatment. This single case illustrates the potential of BCMA CAR-T therapy to induce profound humoral immunosuppression, and demonstrates an imperative need for an established standard of monitoring and prophylaxis of post-CAR-T infections.

CAR-T cell therapy and infection: a review

Introduction: Chimeric antigen receptor T-cell therapy (CAR-T cell therapy) is a novel immunotherapy with promising results in the treatment of relapsed or refractory B cell malignancies. Patients undergoing CAR-T cell therapy are at increased risk of infection due to prior immunosuppression, lymphodepleting chemotherapy, treatment of unique toxicities with tocilizumab and/or steroids, on-target effects of hypogammaglobulinaemia, and prolonged cytopenias.Areas covered: A narrative review of infections (PubMed, August 2020) occurring in patients undergoing CAR-T cell therapy is described, and the evidence for infection prevention strategies is presented.Expert commentary: The rapid adoption of CAR-T cell therapy into clinical practice presents many challenges for the diagnosis, management, and prevention of infection. Ongoing surveillance of the spectrum of infectious complications and effectiveness of prophylaxis is required to support safe and effective patient care.