Autologous stem cell transplantation as bridging therapy followed by CD19 CAR-T cells in relapsed-refractory large B cell lymphoma

How I treat refractory/relapsed diffuse large B-cell lymphomas with CD19-directed chimeric antigen receptor T cells

Chimeric antigen receptor (CAR) T cells targeting CD19 represent a promising salvage immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), offering ~40% of long-term responses. In everyday clinical practice, haematologists involved in CAR T cell treatment of patients with R/R DLBCL have to deal with diagnostically complex cases and difficult therapeutic choices. The availability of novel immunotherapeutic agents for R/R DLBCL and recent advances in understanding CAR T-cell failure mechanisms demand a rational approach to identify the best choice for bridging therapy and managing post-CAR T-cell therapy relapses. Moreover, positron emission tomography/computerised tomography may result in false-positive interpretation, highlighting the importance of post-treatment biopsy. In this review, we discuss all above issues, presenting four instructive cases, with the aim to provide criteria and new perspectives for CAR T-cell treatment of DLBCL.

Case report: Cryoablation as a novel bridging strategy prior to CAR-T cell therapy for B cell malignancies with bulky disease

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a powerful immunotherapy in relapsed/refractory (R/R) hematological malignancies, especially in R/R B-cell acute lymphocytic leukemia (B-ALL), non-Hodgkin lymphoma (NHL), and multiple myeloma (MM). To prevent disease progression and reduce tumor burden during CAR-T cell manufacturing, bridging therapies prior to CAR-T cell infusion are crucial. At present, it has been demonstrated that targeted therapy, radiotherapy and autologous stem cell transplantation (ASCT) could serve as effective bridging strategies. However, whether cryoablation could serve as a novel bridging strategy is unknown. In this paper, we report 2 cases of R/R B cell malignancies with bulky disease that were successfully treated with a combination of cryoablation and CAR-T cell therapy. Patient 1 was a 65-year-old female who was diagnosed with R/R MM with extramedullary disease (EMD). She was enrolled in the anti-BCMA CAR-T cell clinical trial. Patient 2 was a 70-year-old man who presented with a subcutaneous mass in the right anterior thigh and was diagnosed with primary cutaneous diffuse large B cell lymphoma, leg type (PCLBCL-LT) 1 year ago. He failed multiline chemotherapies as well as radiotherapy. Thus, he requested anti-CD19 CAR-T cell therapy. Unfortunately, they all experienced local progression during CAR-T cell manufacturing. To rapidly achieve local tumor control and reduce tumor burden, they both received cryoablation as a bridging therapy. Patient 1 achieved a very good partial response (VGPR) 1 month after CAR-T cell infusion, and patient 2 achieved a partial response (PR) 1 month after CAR-T cell infusion. In addition, adverse effects were tolerable and manageable. Our study demonstrated the favorable safety and efficacy of combination therapy with cryoablation and CAR-T cell therapy for the first time, and it also indicates that cryoablation could serve as a novel therapeutic strategy for local tumor control in B cell malignancies.

Cytopenia after chimeric antigen receptor T cell immunotherapy in relapsed or refractory lymphoma

Background

Patients with relapsed or refractory (R/R) lymphomas have benefited from chimeric antigen receptor (CAR)-T-cell therapy. However, this treatment is linked to a high frequency of adverse events (AEs), such as cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and hematologic toxicity. There has been increasing interest in hematological toxicity in recent years, as it can result in additional complications, such as infection or hemorrhage, which remain intractable.

Methods

We conducted a retrospective, single-institution study to evaluate the patterns and outcomes of cytopenia following CAR-T-cell infusion and potential associated factors.

Results

Overall, 133 patients with R/R lymphoma who received CAR-T-cell therapy from June, 2017 to April, 2022 were included in this analysis. Severe neutropenia, anemia and thrombocytopenia occurred frequently (71, 30 and 41%, respectively) after CAR-T-cell infusion. A total of 98% of severe neutropenia and all severe thrombocytopenia cases occurred in the early phase. Early severe cytopenia was associated with CRS incidence and severity, as well as peak inflammatory factor (IL-6, C-reactive protein (CRP), and ferritin) levels. In multivariate analysis, prior hematopoietic stem cell transplantation (HSCT), baseline hemoglobin (HB), and lymphodepleting chemotherapy were independent adverse factors associated with early severe cytopenia. In addition, 18% and 35% of patients had late neutrophil- and platelet (PLT)-related toxicity, respectively. In multivariate analysis, lower baseline PLT count was an independent factor associated with late thrombocytopenia. More severe cytopenia was associated with higher infection rates and poorer survival.

Conclusions

This research indicates that improved selection of patients and management of CRS may help to decrease the severity of cytopenias and associated AEs and improve survival following CAR-T-cell therapy.

Clinical Trial Registration

https://www.clinicaltrials.gov/ct2/show/NCT03196830, identifier NCT03196830.

Combination strategies to optimize the efficacy of chimeric antigen receptor T cell therapy in haematological malignancies

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the therapeutic landscape of haematological malignancies. However, resistance and relapse remain prominent limitations, and they are related to the limited persistence and efficacy of CAR T cells, downregulation or loss of tumour antigens, intrinsic resistance of tumours to death signalling, and immune suppressive microenvironment. Rational combined modality treatments are regarded as a promising strategy to further unlock the antitumor potential of CAR T cell therapy, which can be applied before CAR T cell infusion as a conditioning regimen or in ex vivo culture settings as well as concomitant with or after CAR T cell infusion. In this review, we summarize the combinatorial strategies, including chemotherapy, radiotherapy, haematopoietic stem cell transplantation, targeted therapies and other immunotherapies, in an effort to further enhance the effectiveness of this impressive therapy and benefit more patients.