Management of Toxicities Associated with BCMA, GPRC5D, and FcRH5-Targeting Bispecific Antibodies in Multiple Myeloma

Recent development in bispecific antibody immunotherapy for hematological malignancies

While monoclonal antibody (mAb)-based therapies have revolutionized cancer treatment, challenges such as resistance mechanisms and tumor progression via alternative pathways underscore the need for novel therapeutic strategies. Bispecific antibodies (BsAbs), which target two distinct antigens simultaneously, represent a promising next-generation solution, improving therapeutic precision, efficacy, and safety. BsAbs also redirect cytotoxic effector cells to tumor sites, providing additional therapeutic mechanisms. Recent advancements in BsAb design, such as enhancements in pharmacokinetics and modular multi-specific formats, are expanding their use in hematological malignancies. Combining BsAbs with immune checkpoint inhibitors and other therapies may overcome resistance and improve clinical outcomes. Leading BsAbs, including mosunetuzumab, glofitamab, and blinatumomab, have demonstrated promising efficacy in clinical trials for leukemia and lymphoma subtypes. Despite remaining challenges, particularly in acute myeloid leukemia (AML), ongoing research into new targets and combination therapies is expected to enhance the efficacy of BsAbs in relapsed or refractory (R/R) disease. This review explores the structural and functional innovations of BsAbs, the challenges in current therapies, and their transformative potential in hematological malignancy immunotherapy.

Comprehensive Review of Bispecific Antibody Constructs In Multiple Myeloma: Affinities, Dosing Strategies and Future Perspectives

Despite significant advancements, multiple myeloma (MM) remains incurable, and there is still a pressing need for new therapeutic strategies with highly selective mechanisms of action and balanced off-target toxicity. In recent years, the development of "off-the-shelf" bispecific antibodies (bsAbs) has significantly enhanced our ability to treat relapsed or refractory MM. Teclistamab, elranatamab (both BCMA × CD3), and talquetamab (GPRC5D × CD3) are approved for treating MM patients who have received at least 3 prior lines of therapy, including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 monoclonal antibody. Meanwhile, the range of available bsAbs is rapidly expanding, offering patients and healthcare providers a broad selection of options that vary in target antigens, binding domains, construct designs, dosing regimens, and side effects. As linvoseltamab, alnuctamab, and ABBV-383 (all BCMA × CD3), as well as forimtamig (GPRC5D × CD3) and cevostamab (FcRH5 × CD3) progress through late-stage clinical development, emerging trispecific antibodies are now available that target either 2 different MM-associated antigens or provide additional co-stimulatory signals to prevent T-cell exhaustion. Despite this plethora of therapeutic options, resistance to bsAbs is an inevitability, and the optimal positioning of these drugs within the current MM treatment landscape remains to be determined. In this review, we examine the available data on all clinically accessible bsAbs, evaluating their potential, current limitations, and implications for efficacy and safety, with the aim of achieving deeper responses and longer overall survival for MM patients.

Pathogenesis, Diagnosis, and Management of Cytokine Release Syndrome in Patients with Cancer: Focus on Infectious Disease Considerations

Background: Cytokine Release Syndrome (CRS) is a hyperinflammatory state triggered by immune therapies like CAR T-cell therapy and bispecific T-cell engagers (BiTEs). Characterized by excessive cytokine release, CRS often mimics infectious and inflammatory conditions, complicating diagnosis and treatment. Immunosuppressive therapies used for CRS further elevate the risk of secondary infections. Methods: A systematic search of PubMed and EMBASE was conducted using terms related to "cytokine release syndrome", "cytokine storm", "infections", and "management". Studies were included if they described infectious complications, diagnostic mimics, or therapeutic approaches related to CRS. Results: Of 19,634 studies, 2572 abstracts were reviewed. Infections occurred in up to 23% of patients post-CAR T therapy and 24% post-BiTE therapy. Pathogens included gram-positive and gram-negative bacteria, herpesviruses (e.g., CMV, HSV), fungi (e.g., Candida, Aspergillus), and parasites (e.g., Toxoplasma gondii). CRS mimics also included non-infectious inflammatory syndromes. Differentiation remains challenging, but cytokine profiling and biomarkers (e.g., ferritin, CRP, sIL-2Rα) may aid in diagnosis. Treatments included tocilizumab, corticosteroids, and empiric antimicrobials. Prophylactic strategies were inconsistently reported. Conclusions: Effective CRS management requires early recognition, differentiation from infectious mimics, and collaboration between oncology and infectious disease (ID) specialists. A multidisciplinary, collaborative, and structured approach, including dedicated ID input and pre-treatment evaluation, is essential for optimizing CRS management and patient outcomes.

Bispecific antibody and chimeric antigen receptor (CAR) modified T-cell in the treatment of multiple myeloma: Where do we stand today?

Although the prognosis of patients with multiple myeloma (MM) has been significantly improved by the introduction of proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies, MM is still considered an incurable disease in the vast majority of the patients. In recent years, T-cell based immunotherapy represents a novel treatment strategy for relapsed/refractory (RR) MM. So far, chimeric antigen receptor (CAR) modified T-cells and bispecific T-cell engaging antibodies (bsAb) have shown promising anti-MM efficacy and manageable safety profile within clinical trials, and B-cell maturation antigen (BCMA) is the most commonly used immune target for T-cell based immunotherapies in MM. To date, several CAR T-cell and bsAb products have already been approved for the treatment of RRMM, leading to a paradigm shift in the MM therapy and providing a potential curative option. In this review, we provide a summary of mechanisms of action, immune targets, selected clinical data, resistance mechanisms and therapy sequencing of CAR T-cell and bsAb in MM.

Practical insights into bispecific antibody therapy in multiple myeloma

INTRODUCTION

The rise of recent novel therapies teclistamab, elranatamab, and talquetamab for the treatment of relapsed/refractory multiple myeloma (RRMM) is a rapidly evolving area with significant clinical implications that require exploration and evaluation.

AREAS COVERED

The current review highlights the clinical trial data, safety endpoints, and practical administration considerations for the bispecific therapies currently used in multiple myeloma. This article reviewed the efficacy and safety results between the three different bispecifics, and the differences in dosing and monitoring requirements. Adverse event management for the bispecific antibodies will be explored including the need for antimicrobial prophylaxis, premedication, and IVIG replacement. Future considerations for widespread bispecific administration and ongoing clinical trials are discussed.

EXPERT OPINION

Practical considerations for bispecific administration such as hospitalization requirements, monitoring of adverse events, and medication considerations are emphasized. Future directions and clinical implications regarding the pivotal role of these agents will be discussed.