A good response of refractory mantel cell lymphoma to haploidentical CAR T cell therapy after failure of autologous CAR T cell therapy

Be cautious to adopt a second CAR T-cell infusion after failure of CD19/CD22 cocktail CAR T-cell therapy in relapsed/refractory B-NHL

Chimeric antigen receptor (CAR) T-cell infusion (CTI) therapy has emerged as a breakthrough therapy in relapsed/refractory B-cell non-Hodgkin's lymphoma (R/R B-NHL), but a substantial number of patients still suffer treatment failure. Data on disease history, subsequent salvage therapies, and outcomes of patients who face treatment failure after the first CTI (CTI1) have not been reported in detail or systematically studied. Here, a retrospective analysis was performed on a total of 61 R/R B-NHL patients in whom salvage therapies were adopted after CTI1 treatment failure, with their clinical characteristics, subsequent management and outcomes described in detail. The results suggested that second-time CTI (CTI2) used as salvage therapy after failure of CTI1 could achieve a better transient overall response rate (ORR) than other salvage treatments (non-CTI2) in only a minority of patients (8/27 vs. 2/34, P=0.014). Nevertheless, the non-CTI2 group showed better event-free survival (EFS) (P = 0.007) and overall survival (OS) (P = 0.048) than the CTI2 group, with a median follow-up of 6.7 months vs. 4.7 months. In addition, univariate and multivariate analyses showed that only the status of the tumor at disease onset was an independent risk factor for survival; salvage therapy after CTI1 treatment failure was not. The adverse effects of CTI2 treatment were generally similar to those of non-CTI2 treatment, but the infection-related mortality was considerably higher. In conclusion, the prognosis of patients who fail CTI1 therapy is very poor regardless of the subsequent salvage therapies, and clinicians should be cautious about adopting CTI2 treatment after failure of treatment with the CD19/22 cocktail CTI1 in R/R B-NHL. Large-scale prospective studies are warranted, and new strategies are urgently needed to prevent treatment failure and improve the survival of B-cell lymphoma patients in future.

New hopes and challenges in targeted therapy and immunotherapy for primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is non-Hodgkin's lymphoma (NHL) confined to the central nervous system. Most of the patients eventually develop relapsed/refractory (R/R) PCNSL, and the overall prognosis for PCNSL remains dismal. Recently, gene sequencing, transcriptome sequencing, and single-cell sequencing platforms have provided a large amount of data revealing the mechanisms underlying the pathogenesis and drug resistance in PCNSL, including the activation of the NF-κB signaling pathway in tumor cells, tumor heterogeneity, and the immunosuppressive tumor microenvironment. Advances in molecular pathology studies for PCNSL have led to identifying new therapeutic targets and developing novel drugs. New therapeutic strategies, such as creating small molecule targeted agents, immunomodulatory drugs, immune checkpoint inhibitors, and chimeric antigen receptor T (CAR-T) cell therapy, have brought new hope for patients with PCNSL, especially for R/R PCNSL. This review presents recent advances in the treatment of PCNSL, reviews and discusses the efficacy and challenges of targeted therapy and immunotherapy, and provides an outlook on the future development of PCNSL treatment strategies.

Synergistic effect of chimeric antigen receptor modified with Bcl-2 on enhanced solid tumour targeting

Engineered T cells expressing chimeric antigen receptors (CARs) have shown remarkable therapeutic effects on haematological malignancies. However, CART cells are less effective on solid tumours mainly due to their weak persistence, which might be caused by activation-induced cell death (AICD). To overcome this limitation, CART cell with the antigen, Epidermal growth factor receptor variant III (EGFRvIII), targeting was modified to carry the anti-apoptotic molecule B cell lymphoma 2 (Bcl-2), and the final construct was named as EGFRvIII·CART-Bcl2 cells. Compared with the EGFRvIII·CART cells, EGFRvIII·CART-Bcl2 cells revealed higher capacities of proliferation, anti-apoptosis and tumour cell killing in vitro. Moreover, EGFRvIII·CART-Bcl2 cells had a longer persistence rate and exerted better anti-tumour effects than EGFRvIII·CART cells in cervical carcinoma xenograft model. Taken together, our findings suggest that incorporating anti-apoptotic molecules into CART cells may enhance its therapeutic effects against solid tumours.

Current status and prospects of hematopoietic stem cell transplantation in China

ABSTRACT

Hematopoietic stem cell transplantation (HSCT) is a highly effective and unique medical procedure for the treatment of most hematological malignancies. The first allogeneic transplantation was performed by E. Donnall Thomas in 1957. Since then, the field has evolved and expanded worldwide. The first successful allogenic HSCT (allo-HSCT) in China was conducted in 1981. Although the development of allo-HSCT in China lagged, China has since made considerable contributions to the process of HSCT worldwide, with more than 10,000 HSCTs performed annually. In particular, haploid HSCT (haplo-HSCT) technology represented in the Beijing Protocol has demonstrated similar efficacy to human leukocyte antigen-matched HSCT and has gradually become the pre-dominant choice for allo-HSCT in China. Currently, the number of haplo-HSCT procedures exceeds 5000 per year, and the Beijing Protocol has been greatly improved by implementing updated individualized strategies for controlling complications, relapse, and infection management. In addition, innovative haplo-HSCT technologies developed by different medical transplantation centers, such as Soochow, Zhejiang, Fujian, Chongqing, and Anhui, have emerged, providing inspiration for the refinement of global practice. This review will focus on the current activity in this field and highlight important trends that are vital in China's allo-HSCT process, examining the current viewpoint and future directions.

iNKT: A new avenue for CAR-based cancer immunotherapy

Chimeric antigen receptor (CAR) T cell is a T lymphocyte-based immunotherapy, which achieves great successes in treating blood malignancies and provides new hope to cue advanced cancer patients. Invariant natural killer T (iNKT) cells are a kind of special T lymphocytes characterized by expressing invariant TCR of Vα24Vβ11 to recognize CD1d-presented glycolipid antigens, which bridge innate and adaptive immune responses. iNKT cells themselves show strong anti-tumor effect in tumor models via CD1d-mediated killing of CD1d-positive tumor cells and immunosuppressive TAMs and MDSCs, and are closely related to the prognosis of cancer patients. iNKT cells are not restricted to polymorphic human leukocyte antigen (HLA) and can prevent Graft versus Host Disease (GvHD), which makes it to be an ideal CAR vector for allogeneic therapy. Although CAR-iNKT was developed and verified by several different teams and attracts more and more attentions, many obstacles are still needed to be resolved before obtaining CAR-iNKT therapeutics. In this review, we summarized the current status of clinical application of iNKT cells and the latest achievements of CAR-iNKT cells, which provides new insight in CAR-iNKT development and usages.

Engineered CAR-T and novel CAR-based therapies to fight the immune evasion of glioblastoma: gutta cavat lapidem

INTRODUCTION

The field of cancer immunotherapy has achieved great advancements through the application of genetically engineered T cells with chimeric antigen receptors (CAR), that have shown exciting success in eradicating hematologic malignancies and have proved to be safe with promising early signs of antitumoral activity in the treatment of glioblastoma (GBM).

AREAS COVERED

We discuss the use of CAR T cells in GBM, focusing on limitations and obstacles to advancement, mostly related to toxicities, hostile tumor microenvironment, limited CAR T cells infiltration and persistence, target antigen loss/heterogeneity and inadequate trafficking. Furthermore, we introduce the refined strategies aimed at strengthening CAR T activity and offer insights in to novel immunotherapeutic approaches, such as the potential use of CAR NK or CAR M to optimize anti-tumor effects for GBM management.

EXPERT OPINION

With the progressive wide use of CAR T cell therapy, significant challenges in treating solid tumors, including central nervous system (CNS) tumors, are emerging, highlighting early disease relapse and cancer cell resistance issues, owing to hostile immunosuppressive microenvironment and tumor antigen heterogeneity. In addition to CAR T cells, there is great interest in utilizing other types of CAR-based therapies, such as CAR natural killer (CAR NK) or CAR macrophages (CAR M) cells for CNS tumors.

CAR19/22 T cell therapy in adult refractory Burkitt's lymphoma

The treatment of refractory Burkitt's lymphoma (BL) is still a challenge. Although CAR-T cell therapy has achieved good responses in diffuse large B cell lymphoma, there is no case series report about the efficacy of CAR-T cell therapy in adult Burkitt's lymphoma. In this study, we evaluate the efficacy and safety of CAR19/22 T cell therapy in six refractory Burkitt's lymphoma cases with poor genetic prognostic factors. After CAR-T cell therapy, five cases had grade 1 and one had grade 3 cytokine release syndrome. Three patients achieved an objective response (3/6 50%), including two partial remission and one complete remission. One CR patient received allogeneic hematopoietic stem cell transplantation (HSCT) and one PR patient received CAR22/19-T cells following auto-HSCT, and they were still in remission at 37 and 22 months of follow-up, respectively. Interestingly, patients with bulky disease (case 2, 4 and 5) had higher levels of serum IL-2R, which was secreted by regulatory T cells, lower CAR lentiviral amplification and poorer prognosis with shorter survival time than cases with non-bulky disease. It is suggested that high tumor burden, more immune suppressive cells and limited CAR-T cell expansion might affect the efficacy of CAR-T cell therapy. CAR-T cell therapy in adult BL patients whose best response cannot achieve CR may need to bridge to other treatments (such as HSCT) early.

Immunotherapy for advanced hepatocellular carcinoma, where are we?

A couple of molecular-targeting medications, such as Lenvatinib, are available for the treatment of hepatocellular carcinoma (HCC) in addition to Sorafenib in an advanced stage. Approval for the use of immune check-point inhibitors, such as Nivolumab and Pembrolizumab has shifted the paradigm of current HCC treatment, and the monotherapy or in combination with Lenvatinib or Sorafenib has significantly extended overall survival or progression-free survival in a large portion of patients. A combination of programmed cell death ligand-1 (PD-L1) inhibitor Atezolizumab with a vascular endothelial growth factor (VEGF) inhibitor, Bevacizumab, has recently achieved promising outcome in unresectable HCC patients. Other immunotherapy, such as chimeric antigen receptor T (CAR-T) cell therapy has achieved an evolutional success in hematologic malignancies, and has extended its use in deadly solid tumors, such as HCC. Although there exist various barriers, novel approaches are developed to move potential adoptive T cell therapy strategies, including cytokine-induced killer (CIK) cells, tumor-infiltrating lymphocytes (TIL), T cell receptor (TCR) T cells, CAR-T cells, to clinical application.

Mantle Cell Lymphoma: Which Patients Should We Transplant?

PURPOSE OF REVIEW

Mantle cell lymphoma is a CD5+ non-Hodgkin lymphoma associated with suboptimal outcome. Young, fit patients are generally offered intensive induction followed by autologous hematopoietic cell transplantation (AHCT) in first remission. Some patients may not benefit from this strategy.

RECENT FINDINGS

Recent studies have investigated the role of AHCT in the modern era. First, an analysis of the National Cancer Database demonstrated improved progression-free survival (PFS) for consolidative AHCT. Second, a multi-center study associated consolidative AHCT with improved PFS even after propensity-weighted analysis. Improved overall survival (OS) for certain subgroups was suggested. Third, patients with p53 mutations derive little benefit from AHCT. Finally, retrospective series suggest certain high-risk patients may be considered for allogenic HCT. AHCT consolidation in first remission is associated with improved PFS even after adjustment for disease severity. An overall survival benefit has not been definitively shown. Patients with p53 mutations should be treated with novel agents.

Donor-Derived CD123-Targeted CAR T Cell Serves as a RIC Regimen for Haploidentical Transplantation in a Patient With FUS-ERG+ AML

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) following chemotherapy is part of standard treatment protocol for patients with acute myeloid leukemia (AML). FUS-ERG+ AML is rare but has an extremely poor prognosis even with allo-HSCT in remission, possibly due to its a leukemia stem cell (LSC)-driven disease resulting in chemotherapy resistance and a novel therapy is urgently required. It has been reported that FUS-ERG-positive AML expresses CD123, a marker of LSC, in some cases. CD123-targeted CAR T cell (CART123) is promising immunotherapy, but how to improve the complete remission (CR) rate and rescue potential hematopoietic toxicity still need to explore.

Case Presentation: We used donor-derived CART123 as part of conditioning regimen for haploidentical HSCT (haplo-HSCT) in a patient with FUS-ERG+ AML who relapsed after allogeneic transplantation within 3 months, resists to multi-agent chemotherapy and donor lymphocyte infusion (DLI) and remained non-remission, aiming to reduce these chemotherapy-resistant blasts and rescue potential hematopoietic toxicity. The blasts in BM were reduced within 2 weeks and coincided with CAR copies expansion after CART123 infusion. The patient achieved full donor chimerism, CR with incomplete blood count recovery, and myeloid implantation.

Conclusion: Our results hints that CART123 reduces the chemotherapy-resistant AML blasts for FUS-ERG+ AML without affecting the full donor chimerism and myeloid implantation.

Understanding the Mechanisms of Resistance to CAR T-Cell Therapy in Malignancies

Taking advantage of the immune system to exert an antitumor effect is currently a novel approach in cancer therapy. Adoptive transfer of T cells engineered to express chimeric antigen receptors (CARs) targeting a desired antigen has shown extraordinary antitumor activity, especially in refractory and relapsed B-cell malignancies. The most representative in this respect, as well as the most successful example, is CD19 CAR T-cell therapy in B-cell acute lymphoblastic leukemia (B-ALL). However, with the widespread use of CAR T-cell therapy, problems of resistance and relapse are starting to be considered. This review provides a comprehensive picture of the mechanisms of resistance to CAR T-cell therapy from three aspects, namely, CAR T-cell factors, tumor factors, and tumor microenvironment factors, offering insights for improving CAR T-cell therapy.

[Risk - adapted intensive induction therapy, autologous stem cell transplantation, and rituximab maintenance allow to reach a high 7-year survival rate in patients with mantle cell lymphoma]

Mantle cell lymphoma (MCL) is aggressive B-cell neoplasm diagnosed predominantly among older men. R-CHOP-like regimens allow to achieve high response rate, but the overall survival (OS) are disappointingly short - 3-4 years. An addition of high - dose cytarabine to the upfront therapy and autoSCT significantly improved outcomes but remain feasible largely for medically fit patients. Based on the activity and good tolerance of gemcitabine - oxaliplatin schemes in relapsed and refractory MCL patients, we developed an alternative first - line course for patients who are not eligible for R-HD-MTX-AraC.

AIM

Assess toxicity and efficacy of R-DA-EPOCH/ R-HD-MTX-AraC and R-DA-EPOCH/R-GIDIOX schemes, autoSCT and R-maintenance in untreated MCL patients.

MATERIALS AND METHODS

47 untreated MCL patients from 6 centers were enrolled in prospective study between April 2008 and September 2013. All patients have stage II-V; ECOG 0-3; median age 55 years (29-64); Male/Female 76%/24%. MIPIb: 28% low, 33% intermediate and 39% high risk. Following 1st R-EPOCH patients were assigned to receive either R-DA-EPOCH/ R-HD-MTX-AraC or R-DA-EPOCH/ R-GIDIOX regimen. In the absence of renal failure, hematological toxicity grade 4 more than 3 days and severe infections patients received R-HD-MTX-AraC scheme (R 375 mg/m2 Day 0, Methotrexate 1000 mg/m2/24 hours Day 1, AraC 3000 mg/m2 q 12 hrs Days 2-3). Patients who had at least one of these complications received R-GIDIOX scheme (R 375 mg/m2 day 0, gemcitabine 800 mg/m2 days 1 and 4, ifosfamide 1000 mg/m2 days 1-5, dexamethasone 10 mg/m2 IV days 1-5, irinotecan 100 mg/m2 day 3, oxaliplatin 120 mg/m2 day 2). Subsequently these courses were alternating with R-DA-EPOCH in each arm of the protocol. Depending on the time of achieving CR patients received 6 or 8 courses, unless they progressed on therapy. Those patients who achieved PR/CR/CRu underwent autoSCT (BEAM-R). Post - transplant R-maintenance was administered for 3 years (R - 375 mg/m2 every 3 months).

RESULTS

29/47 patients were treated on R-HD-MTX-AraC arm (median 50 years; MIPIb: 35.7% low, 28.6% intermediate, 35.7% high risk) and 18/47 patients were on R-GIDIOX arm (median 60 years; MIPIb: 16.7% low, 38.9% intermediate, 44.4% high risk). In R-HD-MTX-AraC arm CR rate was 96.5%. In R-GIDIOX arm OR and CR rates were 94.4% and 77.7% respectively. Main hematological toxicity of R-GIDIOX was leukopenia gr. 4 occurred in 74.1%. With median follow - up of 76 months, the estimated 7-years OS and EFS in R-HD-MTX-AraC arm are 76% and 57% respectively. In R-GIDIOX arm the estimated 7-years OS and EFS are 59% and 44%, respectively. There are no statistical differences in EFS (p=0.47) and OS (p=0.06) between two arms.

CONCLUSIONS

The use of a risk - adapted strategy allowed 95.7% of patients achieve PR/CR/CRu, performed autoSCT and begun R-maintenance therapy with rituximab. None of the patients needed a premature discontinuation of therapy because of unacceptable toxicity. The performance of autoSCT and R-maintenance apparently allowed to partially offset differences in the intensity of induction therapy and to maintain comparable results of therapy in both induction arms.