Intensive Debulking Chemotherapy Improves the Short-Term and Long-Term Efficacy of Anti-CD19-CAR-T in Refractory/Relapsed DLBCL With High Tumor Bulk

A single-day polychemotherapy regimen with proteasome inhibitor combinations for relapsed/refractory myeloma in the era of novel therapies

PCAB (prednisone, cyclophosphamide, doxorubicin, carmustine) is a single-day regimen previously used for induction and now in relapsed/refractory multiple myeloma (RRMM). We retrospectively analysed the outcomes of 85 patients from five Australian centres. These included 30 patients (35.3%) who received PCAB with one additional agent (bortezomib most frequently). Median age of the patients was 65 years (37-80), with a median of four (1-8) prior lines of therapy. ORR was 37% (CR 4.9%). Median progression free survival and overall survival were 4.4 months (95% CI 3.5-6.7) and 7.4 months (95% CI 6.4-10.2), respectively. Extramedullary disease (EMD) was associated with shorter survival. Grade 3 or 4 cytopenia and febrile neutropenia occurred in 76.2% and 39.1%, respectively, with six (7.1%) treatment-related mortalities. Median inpatient stay was 3.3 days/28-day cycle (IQR 0.6-13), and for patients who died, a median of 20.2% of days alive were spent inpatient (IQR 6.4-39.1%). Three patients were successfully bridged to CAR T-cell therapy using PCAB, despite being penta-exposed and having EMD. PCAB may be considered as a useful salvage therapy amongst other polychemotherapy regimens in late relapse. Further studies is warranted to investigate and define its role as a bridging therapy to novel therapeutics.

Several factors that predict the outcome of large B-cell lymphoma patients who relapse/progress after chimeric antigen receptor (CAR) T-cell therapy can be identified before cell administration

AIM

The aim of this study was to analyse the outcomes of patients with large B-cell lymphoma (LBCL) treated with chimeric antigen receptor T-cell therapy (CAR-Tx), with a focus on outcomes after CAR T-cell failure, and to define the risk factors for rapid progression and further treatment.

METHODS

We analysed 107 patients with LBCL from the Czech Republic and Slovakia who were treated in ≥3rd-line with tisagenlecleucel or axicabtagene ciloleucel between 2019 and 2022.

RESULTS

The overall response rate (ORR) was 60%, with a 50% complete response (CR) rate. The median progression-free survival (PFS) and overall survival (OS) were 4.3 and 26.4 months, respectively. Sixty-three patients (59%) were refractory or relapsed after CAR-Tx. Of these patients, 39 received radiotherapy or systemic therapy, with an ORR of 22% (CR 8%). The median follow-up of surviving patients in whom treatment failed was 10.6 months. Several factors predicting further treatment administration and outcomes were present even before CAR-Tx. Risk factors for not receiving further therapy after CAR-Tx failure were high lactate dehydrogenase (LDH) levels before apheresis, extranodal involvement (EN), high ferritin levels before lymphodepletion (LD) and ECOG PS >1 at R/P. The median OS-2 (from R/P after CAR-Tx) was 6.7 months (6-month 57.9%) for treated patients and 0.4 months (6-month 4.2%) for untreated patients (p < 0.001). The median PFS-2 (from R/P after CAR-Tx) was 3.2 months (6-month 28.5%) for treated patients. The risk factors for a shorter PFS-2 (n = 39) included: CRP > limit of the normal range (LNR) before LD, albumin < LNR and ECOG PS > 1 at R/P. All these factors, together with LDH > LNR before LD and EN involvement at R/P, predicted OS-2 for treated patients.

CONCLUSION

Our findings allow better stratification of CAR-Tx candidates and stress the need for a proactive approach (earlier restaging, intervention after partial remission achievement).

Biomarkers of outcome in patients undergoing CD19 CAR-T therapy for large B cell lymphoma

CD19-directed autologous chimeric antigen receptor T cell (CAR-T) therapy has transformed the management of relapsed/refractory (R/R) large B cell lymphoma (LBCL). Initially approved in the third line and beyond setting, CAR-T is now standard of care (SOC) for second-line treatment in patients with refractory disease or early relapse (progression within 12 months) following primary chemoimmunotherapy. Despite becoming SOC, most patients do not achieve complete response, and long-term cure is only observed in approximately 40% of patients. Accordingly, there is an urgent need to better understand the mechanisms of treatment failure and to identify patients that are unlikely to benefit from SOC CAR-T. The field needs robust biomarkers to predict treatment outcome, as better understanding of prognostic factors and mechanisms of resistance can inform on the design of novel treatment approaches for patients predicted to respond poorly to SOC CAR-T. This review aims to provide a comprehensive overview of clinical, molecular, imaging, and cellular features that have been shown to influence outcomes of CAR-T therapy in patients with R/R LBCL.

Advanced strategies in improving the immunotherapeutic effect of CAR-T cell therapy

Chimeric antigen receptor (CAR-T) cell therapy is a newly developed immunotherapy strategy and has achieved satisfactory outcomes in the treatment of hematological malignancies. However, some adverse effects related to CAR-T cell therapy have to be resolved before it is widely used in clinics as a cancer treatment. Furthermore, the application of CAR-T cell therapy in the treatment of solid tumors has been hampered by numerous limitations. Therefore, it is essential to explore novel strategies to improve the therapeutic effect of CAR-T cell therapy. In this review, we summarized the recently developed strategies aimed at optimizing the generation of CAR-T cells and improving the anti-tumor efficiency of CAR-T cell therapy. Furthermore, the discovery of new targets for CAR-T cell therapy and the combined treatment strategies of CAR-T cell therapy with chemotherapy, radiotherapy, cancer vaccines and nanomaterials are highlighted.

CAR-T cell therapy: Where are we now, and where are we heading?

Chimeric antigen receptor (CAR)-T-cell therapies have exhibited remarkable efficacy in the treatment of hematologic malignancies, with 9 CAR-T-cell products currently available. Furthermore, CAR-T cells have shown promising potential for expanding their therapeutic applications to diverse areas, including solid tumors, myocardial fibrosis, and autoimmune and infectious diseases. Despite these advancements, significant challenges pertaining to treatment-related toxic reactions and relapses persist. Consequently, current research efforts are focused on addressing these issues to enhance the safety and efficacy of CAR-T cells and reduce the relapse rate. This article provides a comprehensive overview of the present state of CAR-T-cell therapies, including their achievements, existing challenges, and potential future developments.

Cytopenias following anti-CD19 chimeric antigen receptor (CAR) T cell therapy: a systematic analysis for contributing factors

BACKGROUND

Cytopenia is one of the most common adverse events following the CAR-T cell infusion, affecting the quality of life and potentially leading to life-threatening bleeding and infection. This study aimed to systematically review the cytopenias following anti-CD19 CAR-T therapy and further analyse the contributing factors.

METHODS

Databases including PubMed, MEDLINE, Embase and Cochrane were systematically searched on 8 May 2022. A random-effect meta-analysis was used to estimate the incidence of cytopenia, and subgroup analyses were applied to explore heterogeneity.

RESULTS

A total of 68 studies involving 2950 patients were included in this study. The overall incidence of all grade anaemia, thrombocytopenia, neutropenia, leukopoenia, lymphocytopenia and febrile neutropenia was 65%, 55%, 78%, 62%, 70% and 27%, respectively, and the corresponding cytopenias of grade 3 or worse were 33%, 31%, 61%, 45%, 46%, and 21%, respectively. Subgroup analysis showed increased incidence of cytopenias in subgroups with lower median age, proportion of males (<65%) and proportion of bridging therapy (<80%) and in the subgroup with a median line of prior therapy ≥3. In terms of disease and therapeutic target, cytopenias were more frequent in ALL patients and in dual-target CAR-T therapies (targeting CD19 in combination with other targets). Furthermore, CAR-T products manufactured by lentiviral vectors and those with the costimulatory domain of CD28 were more likely to cause haematological toxicity. No significant differences were observed in cytopenia between patients treated with CAR-T products with murine and humanized scFv.

CONCLUSION

In conclusion, neutropenia is the most frequent cytopenia after CAR-T therapy, both in all grades or grade ≥3. The incidence of cytopenias following CAR-T therapy is influenced by the age, sex, disease and number of prior therapy lines of the patients, as well as the target and costimulatory domain of CAR-T cells, and viral vectors used for manufacturing.KEY MESSAGESNeutropenia is the most frequent cytopenia after CAR-T therapy.The clinical characteristics of the patients, the design of CAR-T cells and the protocol of CAR-T treatment can influence the occurrence of cytopenias following the CAR-T therapy.

CAR T-Cell Therapy Predictive Response Markers in Diffuse Large B-Cell Lymphoma and Therapeutic Options After CART19 Failure

Immunotherapy with T cells genetically modified with chimeric antigen receptors (CARs) has shown significant clinical efficacy in patients with relapsed/refractory B-cell lymphoma. Nevertheless, more than 50% of treated patients do not benefit from such therapy due to either absence of response or further relapse. Elucidation of clinical and biological features that would predict clinical response to CART19 therapy is of paramount importance and eventually may allow for selection of those patients with greater chances of response. In the last 5 years, significant clinical experience has been obtained in the treatment of diffuse large B-cell lymphoma (DLBCL) patients with CAR19 T cells, and major advances have been made on the understanding of CART19 efficacy mechanisms. In this review, we discuss clinical and tumor features associated with response to CART19 in DLBCL patients as well as the impact of biological features of the infusion CART19 product on the clinical response. Prognosis of DLBCL patients that fail CART19 is poor and therapeutic approaches with new drugs are also discussed.

CAR-T Cells Shoot for New Targets: Novel Approaches to Boost Adoptive Cell Therapy for B Cell-Derived Malignancies

Chimeric antigen receptor (CAR)-T cell therapy is undeniably a promising tool in combating various types of hematological malignancies. However, it is not yet optimal and a significant number of patients experience a lack of response or relapse after the treatment. Therapy improvement requires careful analysis of the occurring problems and a deeper understanding of the reasons that stand behind them. In this review, we summarize the recent knowledge about CAR-T products' clinical performance and discuss diversified approaches taken to improve the major shortcomings of this therapy. Especially, we prioritize the challenges faced by CD19 CAR-T cell-based treatment of B cell-derived malignancies and revise the latest insights about mechanisms mediating therapy resistance. Since the loss of CD19 is one of the major obstacles to the success of CAR-T cell therapy, we present antigens that could be alternatively used for the treatment of various types of B cell-derived cancers.

Systematic review and meta-analysis of the association between bridging therapy and outcomes of chimeric antigen receptor T cell therapy in patients with large B cell lymphoma

BACKGROUND

The existing evidence about the impact of bridging therapy (BT) on chimeric antigen receptor (CAR)-T cell therapy in patients with large B cell lymphoma (LBCL) is conflicting. Therefore, we reviewed all available evidence to examine the association between BT and CAR-T therapy outcomes by systematic review and meta-analysis approach.

METHODS

Two reviewers independently searched Embase, PubMed, Web of Science, and Cochrane library to identify all records that described BT for LBCL treated with CAR-T. We then applied a fixed- or random-effects meta-analysis to estimate the pooled hazard ratios (HRs) and rate ratio (RRs) for efficacy and safety endpoints and assessed differences across various BT modalities. The Newcastle-Ottawa Scale was used to evaluate study quality.

RESULTS

Twenty-six reports from 24 studies involving 2014 patients were included in the analysis. Pooled results showed that patients requiring BT had significantly worse 1-year overall survival rate (RR = 0.76, 95% confidence interval [CI] 0.68-0.85, P < 0.001), 1-year progression-free survival rate (RR = 0.71, 95% CI 0.60-0.85, P < 0.001), progression-free survival (HR = 1.35, 95% CI 1.07-1.69, P = 0.01), overall response rate (RR = 0.88, 95% CI 0.81-0.95, P = 0.001), complete response rate (RR = 0.78, 95% CI 0.65-0.93, P = 0.005), and grade ≥3 immune effector cell-associated neurotoxicity syndrome (RR = 1.43, 95% CI 1.10-1.87, P = 0.007), and tended to have poorer overall survival (HR = 1.42, 95% CI 0.99-2.02, P = 0.056) and grade ≥3 cytokine release syndrome (RR = 1.59, 95% CI 0.92-2.75, P = 0.096). Prolonged cytopenias were the common toxicity event associated with BT. Radiotherapy may serve as a promising BT option that can provide safe and effective disease control for patients with LBCL before CAR-T infusion. The inconsistency of patient baselines in the current study hindered further comparisons between different BT modalities. Most of the available evidence was rated as low quality because of concerns over low comparability.

CONCLUSION

BT appears to be associated with comparatively poor efficacy and safety outcomes after CAR-T infusion. However, due to the considerable heterogeneity between the BT and non-BT cohorts at disease baseline, no definitive conclusions can be made for the true impact of BT on CAR-T until further randomized studies are conducted.