[CHIMERIC ANTIGEN RECEPTOR T CELLS (CAR-T CELLS) THERAPY FOR B-CELL HEMATOLOGICAL MALIGNANCIES - FROM THE ISRAELI SOCIETY OF HEMATOLOGY AND TRANSFUSION MEDICINE]

INTRODUCTION

Using immunotherapy to fight cancer, and specifically, the use of engineered T-cells expressing a chimeric receptor against an antigen found on malignant cells (chimeric antigen receptor, CAR-T cells) constitutes a significant breakthrough in the treatment of the disease. In recent years, several CAR-T therapies have been approved in Europe and the USA, and some are already approved and funded through the national health basket in Israel, for the indications of diffuse large B-cell lymphoma, mantle cell lymphoma and B-cell acute lymphoblastic leukemia, after the failure of at least two lines of treatment. The treatment with CAR-T cells achieves prolonged remissions and even long-term cure of patients who had a very poor prognosis. However, the treatment involves significant side effects, and requires specific expertise in the management of patients both during the period of preparation for cell transplantation, and following the treatment. During the immediate post-infusion period, the most common adverse reactions are cytokine release syndrome (CRS) which stems from the activation of the immune system, and neurological toxicity that can accompany CRS. These effects require close monitoring, grading their severity, and providing anti-cytokine therapy or steroid therapy until control of symptoms is achieved. Later effects can be persistent cytopenias, immune over-activation, and prolonged immune deficiency. Treatments for additional indications and new CAR-T constructs are being developed and will allow more effective and safer treatment. This article summarizes the principles for CAR-T administration that, as currently provided in Israel, include the short- and long-term follow-up of the patients.

Cellular Therapy in Chronic Lymphocytic Leukemia: Have We Advanced in the Last Decade?

BACKGROUND

Chronic lymphocytic leukemia (CLL) is a heterogeneous B-cell malignancy, affecting mainly older adults. Despite the recent introduction of multiple targeted agents, CLL remains an incurable disease. Cellular therapy is a promptly evolving area that has developed over the last decades from such standard of care as hematopoietic cell transplantation (HCT) to the novel treatment modalities employing genetically engineered immune cells.

SUMMARY

Tailoring the proper treatment for each patient is warranted and should take into account the disease biology, patient characteristics, and the available treatment modalities. Nowadays, the most broadly applied cellular therapies for CLL management are HCT and chimeric antigen receptor-T (CAR-T) cells. However, CAR-T cell therapy is currently not yet approved in CLL, and the appropriate sequencing for the administration of these agents remains to be clarified.

KEY MESSAGES

The current review will discuss various available cellular treatment options, their advances and limitations, as well as the optimal timing for the employment of such therapies in CLL patients.

Response Rates of Extra-Nodal Diffuse Large B Cell Lymphoma to anti CD19-CAR T Cells - a Real Word Retrospective Multi-Center Study

Chimeric antigen receptor T-cells (CAR-T) are widely used for the treatment of relapsed/refractory Diffuse large B cell lymphoma (DLBCL). The data for CAR-T cell therapy in patients with extra-nodal(EN) lymphoma is restricted. We included 126 consecutive patients with DLBCL treated with commercially available CAR-T cells (tisagenlecleucel, n=100, 79.4% and axicabtagene ciloleucel, n=26, 20.6%). At lymphodepletion, 72/126(57%) had EN disease, 42/126(33%) patients had nodal disease (ND)-only and 12/126(10%) showed no disease assessed by PET-CT. There were no significant differences in CAR-T related toxicities and in the median PFS between EN patients and ND [10.76(95% CI: 7.8-13.6) vs 14.1 (95% CI:10-18.1) months, p =0.126)]. Similarly, median OS was not significantly different [15.36 (95% CI 12.5-18.2) vs. 18.4 (95% CI 14.8-22.1) months, p =0.100]. Subgroup analysis according to the number of EN involved sites showed that median PFS and OS were significantly higher in patients with <3 EN sites [12.3 months (95% CI 9-15.5)] vs 4.28 months (95% CI 0.6-7.9), p=0.010] compared to patients with >2 EN sites, respectively [16.5 months (95% CI 13.4-19.6) vs 8.7 months (95% CI 4.6-12.8), p=0.05]. In multivariate cox regression analysis, increased number sites of EN disease and high LDH at lymphodepletion negatively impacted PFS (p=0.021 and <0.001, respectively), while sex, type of product administered, age and performance status did not predict PFS and OS. Of note, all the patients with involvement of gastrointestinal tract (n= 9), urinary tract (n= 9), or pharynx (n= 3) at lymphodepletion, progressed or had an early relapse. In conclusions, patients with >2 EN sites at lymphodepletion have significantly worse clinical outcomes compared to patients with < 3 EN sites. Patients with specific sites of EN disease may demonstrate grim prognosis.

Thrombosis in vasculitic disorders-clinical manifestations, pathogenesis and management

Inflammation and coagulation are known to affect each other in many ways. Vasculitis represents a group of disorders where blood vessels (small, medium, large or variable) are infiltrated with inflammatory cells. Accumulating evidence in the literature suggests both clinical and physiological association between vasculitis and thrombosis. Vasculitis-associated thrombosis involves arteries and veins, and a tight connection has been reported between the activity of vasculitis and the appearance of thrombosis. Pathophysiology of these relations is complex and not completely understood. While thrombophilic factors are associated with vasculitis, it remains unclear whether a true association with clinical thrombosis is present. Furthermore, several factors leading to hemostasis, endothelial injury and induction of microparticles were described as possibly accounting for thrombosis. Management of thrombosis in vasculitis patients is challenging and should be further assessed in randomized controlled studies. The current review describes clinical manifestations, pathogenesis and management of thrombosis associated with different vasculitides.

Host effects contributing to cancer therapy resistance

There are several approaches for the management of malignant disease. However, tumor resistance to therapy is still a major challenge in the clinic. Efflux transporters, genetic responses and enzyme activity in tumor cells are examples of the main modalities that account for resistance to therapy. In addition, emerging evidence suggests that the host also plays a significant role in promoting therapy resistance. Recruitment of different host cell types to the treated tumor site occurs in response to a range of therapies, including chemotherapy, radiation and even targeted drugs. This host response may have a protective effect on the tumor cells, not only negating anti-tumor activity, but also promoting a resistant tumor. In this review, we focus on host-tumor interactions leading to therapy resistance with special emphasis on different host cells and secreted factors within the tumor microenvironment. The development of novel inhibitors that block the host response to therapy could be used as a treatment strategy to enhance therapy outcomes and survival.

Treatment of T cell lymphoblastic lymphoma in children and adolescents: Israel Society of Pediatric Hematology Oncology retrospective study

BACKGROUND

Survival in T cell lymphoblastic lymphoma has improved over the past 30 years, largely due to treatment protocols derived from regimens designed for children with acute lymphoblastic leukemia.

OBJECTIVES

To assess the outcome of the NHL-BFM-95 protocol in children and adolescents hospitalized during the period 1999-2006.

METHODS

We conducted a retrospective multi-institutional, non-randomized study of children and adolescents up to age 21 with T cell lymphoma admitted to pediatric departments in six hospitals in Israel, with regard to prevalence, clinical characteristics, pathological characteristics, prognostic factors, overall survival (OS) and event-free survival (EFS). All patients had a minimal follow-up of one year after diagnosis. The study was based on the NHL-BFM-95 protocol.

RESULTS

At a median follow-up of 4 years (range 1-9 years), OS and EFS for all patients was 86.5% and 83.8%, respectively. OS was 86.7% and 83.3% for patients with stage III and stage IV, respectively, and EFS was 83.3% and 83.3%, respectively. EFS was 62.5% for Arab patients and 89.7% for Jewish patients (P = 0.014). Patients who did not express CD45 antigen showed superior survival (P = 0.028). Five patients (13.5%) relapsed, four of whom died of their disease. Death as a consequence of therapy toxicity was documented in one patient while on the re-induction protocol (protocol IIA).

CONCLUSIONS

Our study shows that OS and EFS for all patients was 86.5% and 83.8%, respectively.