Successful reintroduction of blinatumomab in a patient with relapsed/refractory acute lymphoblastic leukemia following grade 4 cytokine release syndrome

The pharmacology of blinatumomab: state of the art on pharmacodynamics, pharmacokinetics, adverse drug reactions and evaluation in clinical trials

WHAT IS KNOWN AND OBJECTIVE

Bispecific drugs (BDs) belong to the family of immunotherapies along with checkpoint inhibitors and CAR-T cells. In the field of oncology, BDs are designed to simultaneously bind a tumour antigen on the one side and an antigen present on the surface of effector cells on the other. This review summarizes the information available to date on the first marketed BiTE-format bispecific antibody, blinatumomab BLINCYTO® in acute lymphoblastic leukaemia.

METHODS

A literature search was conducted in the PubMed database by including studies published in English using the term blinatumomab. Furthermore, bibliographies of selected references were also evaluated for relevant articles. Clinical trial (CT) data were retrieved from clinicaltrials.gov (ongoing trials, adverse events [AEs]) and global pharmacovigilance data were retrieved from VigiBase®.

RESULTS AND DISCUSSION

Blinatumomab is a fusion protein which consists of two single-chain variable fragments arranged in tandem: the first binds the CD19 surface antigen of all B cells and the second targets the CD3 antigen of T cells. Binding of blinatumomab to B and T cells induces apoptosis of B cells after secretion of granzymes and perforins by T cells. T-cell activation results in secretion of pro-inflammatory cytokines and upregulation of activation markers and adhesion molecules on the surface of T cells. The major CTs that led to an indication show increased overall survival with blinatumomab with better efficacy in patients in haematological remission with minimal residual disease ≥10^-3 . The major AEs are cytokine release syndrome, neurotoxicity and hypogammaglobulinemia. The three most frequent system organ classes in CTs are haematological, gastrointestinal and general disorders. These results are also found in VigiBase® but neurological disorders and infections appear more frequently in real life.

WHAT IS NEW AND CONCLUSION

This review summarizes the current knowledge of blinatumomab in the literature. The subject of many CTs is to improve the route of administration and expand the indications for treatment.

Neurotoxicity of Tumor Immunotherapy: The Emergence of Clinical Attention

Tumor immunotherapy brings substantial and long-term clinical benefits that can even cure tumors. However, the accumulation of evidence suggests that immunotherapy also induces severe and complex neurologic immune-related adverse events (ir-AEs) and even leads to immunotherapy-related death, which arouses the concern of clinicians. The timely and accurate identification of neurotoxicity helps clinicians detect and treat these complications early, thereby enhancing treatment efficiency and improving the prognosis of patients. At present, the mechanism of neurotoxicity caused by immunotherapy has not been completely elucidated. This paper mainly reviews the clinical features, pathogenesis, and therapeutic strategies of neurologic ir-AEs.

Cytokine release syndrome. Reviewing a new entity in the intensive care unit

Immunotherapy seeks to harness the power of the immune system to eradicate malignant tissues. Despite impressive therapeutic success, however, it can be accompanied by severe adverse effects such as cytokine release syndrome (CRS). These therapies cause the release of a great amount of cytokines, with IL-6 playing a central role, that can potentially lead to multiple organ dysfunction. The diagnosis is based on the presence of compatible clinical symptoms, elevated biomarkers and recent treatment with a biological agent. Mild cases can be managed through symptomatic treatment and fluids, while more severe episodes may need supportive therapy and specific care with the anti-IL-6 receptor monoclonal antibody tocilizumab. Although corticosteroids are also effective, they suppress T-cell activity, and so should only be considered as second line therapy or in cases of severe neurological involvement, since tocilizumab does not cross the blood-brain barrier. Cytokine release syndrome generally has a good prognosis, often being reversible and with a good response to specific treatment. Despite possible concerns about the admission of such patients (mainly with advanced oncological disease), we consider that the Intensive Care Unit should remain an option, since these individuals present a potentially reversible drug-related adverse event and are being treated with a new drug that could change the prognosis of the disorder. Intensive care medicine will become a key component in the management of the complications of modern cancer therapies, dealing with patients presenting an overactive immune system producing organ dysfunction while also trying to maintain treatment efficacy. This is the new paradigm.

Successful use of blinatumomab in a patient with acute lymphoblastic leukemia and severe hepatic dysfunction

Relapsed/refractory acute lymphoblastic leukemia poses a significant clinical challenge due to its poor prognosis, with survival rates of less than a year, even with novel therapies. Patients frequently experience toxicities from induction chemotherapy such as hepatotoxicity, which can limit therapeutic options upon relapse. Blinatumomab, a novel immunotherapy, has demonstrated excellent efficacy in relapsed/refractory acute lymphoblastic leukemia; however, there are limited data on use of this agent in patients with significant organ dysfunction. In this report, we describe the safe and effective use of blinatumomab in an adult patient with refractory Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia in the setting of severe hepatic dysfunction. Blinatumomab may represent a viable option to treat relapsed/refractory acute lymphoblastic leukemia in patients with significant hepatic dysfunction.

Cytokine release syndrome and neurotoxicity after CD19 chimeric antigen receptor-modified (CAR-) T cell therapy

Chimeric antigen receptor-modified (CAR)-T cells have demonstrated impressive results in the treatment of haematological malignancies. However, cytokine release syndrome (CRS) and neurotoxicity are common toxicities which are potentially life-threatening in severe cases. Risk factors for CRS and neurotoxicity identified so far include disease burden, lymphodepletion intensity and CAR-T cell dose administered. Risk-adapted dosing, with lower CAR-T cell doses administered to B-cell acute lymphoblastic leukaemia patients with high marrow blast counts, has been successful at decreasing severe CRS rates in this population. Intervention with therapies, such as tocilizumab and corticosteroids, have been effective at ameliorating toxicity, enabling CAR-T cells to be administered safely to many patients without significantly compromising efficacy. Deeper understanding of the pathophysiology of underlying CRS and neurotoxicity will enable the development of novel approaches to reduce toxicity and improve outcomes.

Cytokine release syndrome

During the last decade the field of cancer immunotherapy has witnessed impressive progress. Highly effective immunotherapies such as immune checkpoint inhibition, and T-cell engaging therapies like bispecific T-cell engaging (BiTE) single-chain antibody constructs and chimeric antigen receptor (CAR) T cells have shown remarkable efficacy in clinical trials and some of these agents have already received regulatory approval. However, along with growing experience in the clinical application of these potent immunotherapeutic agents comes the increasing awareness of their inherent and potentially fatal adverse effects, most notably the cytokine release syndrome (CRS). This review provides a comprehensive overview of the mechanisms underlying CRS pathophysiology, risk factors, clinical presentation, differential diagnoses, and prognostic factors. In addition, based on the current evidence we give practical guidance to the management of the cytokine release syndrome.

Genetically enhanced T lymphocytes and the intensive care unit

Chimeric antigen receptor-modified T cells (CAR-T cells) and donor lymphocyte infusion (DLI) are important protocols in lymphocyte engineering. CAR-T cells have emerged as a new modality for cancer immunotherapy due to their potential efficacy against hematological malignancies. These genetically modified receptors contain an antigen-binding moiety, a hinge region, a transmembrane domain, and an intracellular costimulatory domain resulting in lymphocyte T cell activation subsequent to antigen binding. In present-day medicine, four generations of CAR-T cells are described depending on the intracellular signaling domain number of T cell receptors. DLI represents a form of adoptive therapy used after hematopoietic stem cell transplant for its anti-tumor and anti-infectious properties. This article covers the current status of CAR-T cells and DLI research in the intensive care unit (ICU) patient, including the efficacy, toxicity, side effects and treatment.