Management of cytokine release syndrome and neurotoxicity in chimeric antigen receptor (CAR) T cell therapy

Safety of Axicabtagene Ciloleucel for the Treatment of Relapsed or Refractory Large B-Cell Lymphoma

BACKGROUND

Diffuse large B-cell lymphoma is the most common type of non-Hodgkin lymphoma. Recent advances in immunotherapy have resulted in the development of chimeric antigen receptor-modified T-cell (CAR-T) therapy, such as axicabtagene ciloleucel (axi-cel). However, axi-cel administration is not without risks of toxicity.

PATIENTS AND METHODS

This retrospective study of 37 patients with relapsed or refractory diffuse large B-cell lymphoma evaluated the incidence and severity of common and severe safety events after axi-cel treatment in a real-world setting. Ninety percent of patients had received 3 or more prior lines of therapy (median prior therapies 3, range 2-7) before receiving CAR-T therapy, and 32.4% had relapsed after prior stem-cell transplantation.

RESULTS

All but one patient experienced cytokine release syndrome (CRS) of any grade (97.3%). Of those 36 patients, 83.3% experienced maximum CRS grade of 1 or 2, occurring after a median of 27 hours and persisting for a median of 6 days. Twenty-seven patients (73.0%) experienced neurotoxicity of any grade. Of those 27 patients, 96.3% experienced maximum neurotoxicity grade of 2 or higher, occurring after a median of 145 hours (6 days) and persisting for a median of 7 days. All 10 patients aged 65 or older had neurotoxicity of grade 2 or higher, compared to 59.3% (11/27) under age 65 (P = .02). Patients with baseline Eastern Cooperative Oncology Group performance status score of 2 were significantly more likely to have shorter time to neurotoxicity compared to patients with performance status of 0 (P = .01).

CONCLUSION

With more real-life experience and data, we will be able to define and refine management of toxicities unique to CAR-T therapy.

Cluster of differentiation 19 chimeric antigen receptor T-cell therapy in pediatric acute lymphoblastic leukemia

Chimeric antigen receptor (CAR) T cells have an unprecedented positive curative effect for hematological malignances. Most notably, cluster of differentiation 19 (CD19) CAR T-cell therapy for pediatric acute lymphoblastic leukemia is associated with a high complete remission rate and has aroused considerable attention in the medical field. However, it also causes a series of adverse reactions and increases the risk of recurrence. The present review examines the results of CD19 CAR T-cell therapy and lists its adverse effects. In addition, some of the mechanisms of recurrence are characterized and applicable strategies to address this challenging problem are proposed.

The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of multiple myeloma

Outcomes in multiple myeloma (MM) have improved dramatically in the last two decades with the advent of novel therapies including immunomodulatory agents (IMiDs), proteasome inhibitors and monoclonal antibodies. In recent years, immunotherapy for the treatment of MM has advanced rapidly, with the approval of new targeted agents and monoclonal antibodies directed against myeloma cell-surface antigens, as well as maturing data from late stage trials of chimeric antigen receptor CAR T cells. Therapies that engage the immune system to treat myeloma offer significant clinical benefits with durable responses and manageable toxicity profiles, however, the appropriate use of these immunotherapy agents can present unique challenges for practicing physicians. Therefore, the Society for Immunotherapy of Cancer convened an expert panel, which met to consider the current role of approved and emerging immunotherapy agents in MM and provide guidance to the oncology community by developing consensus recommendations. As immunotherapy evolves as a therapeutic option for the treatment of MM, these guidelines will be updated.

Ligand-Induced Degradation of a CAR Permits Reversible Remote Control of CAR T Cell Activity In Vitro and In Vivo

Chimeric antigen receptor (CAR)-modified T cells are endowed with novel antigen specificity and are most often administered to patients without an engineered mechanism to control the CAR T cells once infused. "Suicide switches" such as the small molecule-controlled, inducible caspase-9 (iCas9) system afford the ability to selectively eliminate engineered T cells; however, these approaches are designed for all-or-none, irreversible termination of an ongoing immune response. In order to permit reversible and adjustable modulation, we have created a CAR that is capable of on-demand downregulation by fusing the CAR to a previously developed ligand-induced degradation (LID) domain. Addition of a small molecule ligand triggers exposure of a cryptic degron within the LID domain, resulting in proteasomal degradation of the CAR-LID fusion protein and loss of CAR on the surface of T cells. This fusion construct allowed for reversible and "tunable" inhibition of CAR T cell activity in vitro. Delivery of the triggering molecule in CAR-LID-treated tumor-bearing mice temporarily reduced CAR activity through modulation of CAR surface expression. The ability to more flexibly modulate CAR T cell expression through a small molecule provides a platform for controlling possible adverse side effects, as well as preclinical investigations of CAR T cell biology.

The novel multi-cytokine inhibitor TO-207 specifically inhibits pro-inflammatory cytokine secretion in monocytes without affecting the killing ability of CAR T cells

Cancer immunotherapy using chimeric antigen receptor–armed T (CAR T) cells have been shown to improve outcomes significantly in patients with hematological malignancies. However, cytokine release syndrome (CRS) remains a risk. CRS is characterized by the excessive activation of CAR T cells and macrophages. Signs and symptoms of CRS are usually resolved after steroid administration, but steroids abrogate the expansion and persistence of CAR T cell populations. Tocilizumab is a humanized monoclonal antibody (mAb) that attenuates CRS without significant loss of CAR T cell activity. However, interleukin-6 (IL-6)/IL-6 receptor (IL-6R) blockade alone cannot relieve CRS symptoms fully, and novel treatments are needed to prevent or cure CRS. TO-207 is an N-benzoyl-L-phenylalanine derivative that significantly inhibits inflammatory cytokine production in human monocyte and macrophage-specific manner. We investigated whether TO-207 could inhibit cytokine production without impairing CAR T cell function in a CRS-simulating co-culture system.

Adverse Events of Novel Therapies for Hematologic Malignancies: What Emergency Physicians Should Know

In the past decade, rapid advances in therapeutic target discovery in hematologic malignancies have led to many clinical studies demonstrating efficacy of novel agents. Between 2014 and 2018, Food and Drug Administration approvals of new drugs and agents have increased, with greater than 2 dozen novel agents. Rapidly identifying the risk profiles of these cancer therapeutics that may present with acute toxicities and understanding the timing, sequence, duration, and treatment of disease processes are the most important challenges faced by practitioners in emergency medicine, even in nononcologic centers. The emergency medicine literature lags behind rapid advances in oncology, and guidelines for rapid recognition and management of these emerging entities are not familiar. In this Review Article, we discuss the most recent and clinically relevant developments in the arena of hematologic malignancies, further expanding on drug toxicities and their clinical presentations and offering suggestions for management. Specifically, we discuss immune-related adverse events after immune checkpoint inhibitor therapy (including myocarditis and hemophagocytic lymphohistiocytosis), chimeric antigen receptor-T cell therapy, cytokine release syndrome, chimeric antigen receptor-T cell-related encephalopathy syndrome, differentiation syndrome, sinusoid occlusion syndrome, QT-interval prolongation, and tumor lysis syndrome. Rapid advances in hematology and oncology will bring many new challenges for emergency health care providers in the near future; thus, the urgency to raise awareness among this community.

Clinical care of chimeric antigen receptor T-cell patients and managing immune-related adverse effects in the ambulatory and hospitalized setting: a review

Chimeric antigen receptor (CAR) T-cell therapies are increasingly providing options for care of oncology patients with advanced hematologic malignancies, which has led to two US FDA approvals. However, they are often associated with significant immune related adverse events that require prompt management. These toxicities are mainly cytokine release syndrome and neurotoxicity, and can be managed in an appropriate setting when presenting to nononcologists or internists. This paper discusses patient management for these toxicities. A management approach can be determined by the severity of the toxicity. Tocilizumab, a humanized monoclonal antibody, was FDA approved for the treatment of cytokine release syndrome, and corticosteroids may be used. Neurotoxicity is generally managed with supportive care and steroidal therapy.

Engaging Cytotoxic T and NK Cells for Immunotherapy in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is characterized by an acquired immune dysfunction. CLL cells affect the phenotype and function of the entire spectrum of innate and adaptive immune cells, including monocytes, T cells, and natural killer (NK) cells, leading to a tumor-supportive environment and reduced immunosurveillance. Novel immunotherapies like immune checkpoint blockade, bi- and tri-specific antibodies, and chimeric antigen receptor (CAR) T cells use the patients' immune system to induce therapeutic responses. Although these novel immunotherapies showed impressive results in several B cell lymphomas, responses in CLL were often disappointing. The strong immunomodulatory effect of CLL is believed to play a pivotal role in the low response rates to these immunotherapeutic strategies. In this review, we summarize how CLL influences the function of non-malignant lymphocytes, with a special focus on T and NK cells, two important cellular mediators for immunotherapy. Secondly, we provide a short overview of the activity of several immunotherapeutics in CLL, and discuss how novel strategies may overcome the disappointing response rates in CLL.

LEGENDplex™: Bead-assisted multiplex cytokine profiling by flow cytometry

Over the past two decades there have been tremendous advances in our understanding of tumor immunology, which have in turn led to new and exciting immunology-based therapeutics. However, further research is needed into the dynamics and regulation of the immune response in the tumor microenvironment in order to achieve the full potential of these agents in treating all cancer patients. Defining the role of cytokines, chemokines, and other soluble mediators will be essential to this endeavor. This chapter describes, in detail, the technical protocol and applicability of LEGENDplex™ bead-based multiplex assays in quantifying these critical signaling molecules.