[Development and prospects of bispecific antibodies for multiple myeloma].

Patients with triple-class refractory multiple myeloma once had a poor prognosis, but recently developed bispecific antibodies (bsAbs) targeting B-cell maturation antigen (BCMA), G protein-coupled receptor 5D (GPRC5D), and Fc receptor-homolog 5 (FcRH5) have shown significant clinical activity in these patients. However, responses to bsAbs are not universal, and resistance often develops during therapy. Mechanisms that mediate resistance may be tumor-intrinsic or immune-dependent. Tumor-intrinsic factors include antigen loss (biallelic or functional) due to deletion or mutation of target genes, increased soluble BCMA (for BCMA targeting bsAbs), high tumor burden, and extramedullary disease. Immune-mediated resistance highly depends on T cell fitness and the resistant immune environment. This article describes bispecific antibodies against multiple myeloma that are currently being developed.

Targeting B-cell maturation antigen for treatment and monitoring of relapsed/refractory multiple myeloma patients: a comprehensive review.

Despite major therapeutic advancements in recent years, multiple myeloma (MM) remains an incurable disease with nearly all patients experiencing relapsed and refractory disease over the course of treatment. Extending the duration and durability of clinical responses will necessitate the development of therapeutics with novel targets that are capable of robustly and specifically eliminating myeloma cells. B-cell maturation antigen (BCMA) is a membrane-bound protein expressed predominantly on malignant plasma cells and has recently been the target of several novel therapeutics to treat MM patients. This review will focus on recently approved and currently in development agents that target this protein, including bispecific antibodies, antibody-drug conjugates, and chimeric antigen receptor T-cell therapies. In addition, this protein also serves as a novel serum biomarker to predict outcomes and monitor disease status for MM patients; the studies demonstrating this use of BCMA will be discussed in detail.

Discovery of a highly specific radiolabeled antibody targeting B-cell maturation antigen: Applications in PET imaging of multiple myeloma.

PURPOSE: Multiple myeloma (MM) is characterized by the uncontrolled proliferation of monoclonal plasma cells (PC) in the bone marrow (BM). B-cell maturation antigen (BCMA) is predominantly expressed in malignant plasma cells, and associated with the proliferation, survival, and progression of various myeloma cells. Given these important roles, BCMA emerges as an ideal target antigen for MM therapy. However, effective stratification of patients who may benefit from targeted BCMA therapy and real-time monitoring the therapeutic efficacy poses significant clinical challenge. This study aims to develop a BCMA targeted diagnostic modality, and preliminarily explore its potential value in the radio-immunotherapy of MM. EXPERIMENTAL DESIGN: Using zirconium-89 (89Zr, t1/2 = 78.4 h) for labeling the BCMA-specific antibody, the BCMA-targeting PET tracer [89Zr]Zr-DFO-BCMAh230430 was prepared. The EC50 values of BCMAh230430 and DFO-BCMAh230430 were determined by ELISA assay. BCMA expression was assessed in four different tumor cell lines (MM.1S, RPMI 8226, BxPC-3, and KYSE520) through Western blot and flow cytometry. In vitro binding affinity was determined by cell uptake studies of [89Zr]Zr-DFO-BCMAh230430 in these tumor cell lines. For in vivo evaluation, PET imaging and ex vivo biodistribution studies were conducted in tumor-bearing mice to evaluate imaging performance and systemic distribution of [89Zr]Zr-DFO-BCMAh230430. Immunochemistry analysis was performed to detect BCMA expression in tumor tissues, confirming the specificity of our probe. Furthermore, we explored the anti-tumor efficacy of Lutetium-177 labeled BCMA antibody, [177Lu]Lu-DTPA-BCMAh230430, in tumor bearing-mice to validate its radioimmunotherapy potential. RESULTS: The radiolabeling of [89Zr]Zr-DFO-BCMAh230430 and [177Lu]Lu-DTPA-BCMAh230430 showed satisfactory radiocharacteristics, with a radiochemical purity exceeding 99%. ELISA assay results revealed closely aligned EC50 values for BCMAh230430 and DFO-BCMAh230430, which are 57 pM and 67 pM, respectively. Western blot and flow cytometry analyses confirmed the highest BCMA expression level. Cell uptake data indicated that MM.1S cells had a total cellular uptake (the sum of internalization and surface binding) of 38.3% ± 1.53% for [89Zr]Zr-DFO-BCMAh230430 at 12 h. PET imaging of [89Zr]Zr-DFO-BCMAh230430 displayed radioactive uptake of 7.71 ± 0.67%ID/g in MM.1S tumors and 4.13 ± 1.21%ID/g in KYSE520 tumors at 168 h post-injection (n = 4) (P < 0.05), consistent with ex vivo biodistribution studies. Immunohistochemical analysis of tumor tissues confirmed higher BCMA expression in MM.1S tumors xenograft compared to KYSE520 tumors. Notably, [177Lu]Lu-DTPA-BCMAh230430 showed some anti-tumor efficacy, evidenced by slowed tumor growth. Furthermore, no significant difference in body weight was observed in MM.1S tumor-bearing mice over 14 days of administration with or without [177Lu]Lu-DTPA-BCMAh230430. CONCLUSIONS: Our study has successfully validated the essential role of [89Zr]Zr-DFO-BCMAh230430 in non-invasively monitoring BCMA status in MM tumors, showing favorable tumor uptake and specific binding affinity to MM tumors. Furthermore, our research revealed, as a proof-of-concept, the effectiveness of [177Lu]Lu-DTPA-BCMAh230430 in radioimmunotherapy for MM tumors. In conclusion, we present a novel BCMA antibody-based radiotheranostic modality that holds promise for achieving efficient and precise MM diagnostic and therapy.

The first case of multiple myeloma treated with ASCT followed by Anti-BCMA CAR-T cells using retrovirus vector: A case report.

Chimeric antigen receptor T (CAR-T)-cell therapy targeting B-cell maturation antigen (BCMA) is currently one of the promising treatment methods for relapsed/refractory multiple myeloma (MM). Herein, this study is a case report on a 41-year-old male patient with MM. Unfortunately, he still developed multidrug-resistant, refractory, and bone marrow suppression after receiving multiline high-intensity chemotherapy. After a detailed evaluation, the physician recommended autologous hematopoietic stem cell transplantation (ASCT) support, followed by sequential immunotherapy with autologous anti- BCMA CAR-T cells. The CAR-T product is a novel anti-BCMA CAR-T based on Retrovirus vectors (RV). It was worth noting that the patient achieved VGPR (very good partial remission) one month after infusion of anti-BCMA CAR-T cells. Recent tests have found that the M protein was no longer detectable and the patient has achieved CR (complete response). Although grade 3 cytokine release syndrome (CRS) appeared, the symptom was well controlled and immune effector cell-associated neurotoxicity syndrome (ICANS) did not occur. This was the first case report of RV prepared anti-BCMA CAR-T cells combined with ASCT for the treatment of MM patient in clinical practice, indicating that the RV-based anti-BCMA-CAR-T cells with ASCT have excellent therapeutic efficacy and high safety in triple-refractory MM patients.

Next-generation BCMA-targeted chimeric antigen receptor CARTemis-1: the impact of manufacturing procedure on CAR T-cell features.

PURPOSE: CAR therapy targeting BCMA is under investigation as treatment for multiple myeloma. However, given the lack of plateau in most studies, pursuing more effective alternatives is imperative. We present the preclinical and clinical validation of a new optimized anti-BCMA CAR (CARTemis-1). In addition, we explored how the manufacturing process could impact CAR-T cell product quality and fitness. METHODS: CARTemis-1 optimizations were evaluated at the preclinical level both, in vitro and in vivo. CARTemis-1 generation was validated under GMP conditions, studying the dynamics of the immunophenotype from leukapheresis to final product. Here, we studied the impact of the manufacturing process on CAR-T cells to define optimal cell culture protocol and expansion time to increase product fitness. RESULTS: Two different versions of CARTemis-1 with different spacers were compared. The longer version showed increased cytotoxicity. The incorporation of the safety-gene EGFRt into the CARTemis-1 structure can be used as a monitoring marker. CARTemis-1 showed no inhibition by soluble BCMA and presents potent antitumor effects both in vitro and in vivo. Expansion with IL-2 or IL-7/IL-15 was compared, revealing greater proliferation, less differentiation, and less exhaustion with IL-7/IL-15. Three consecutive batches of CARTemis-1 were produced under GMP guidelines meeting all the required specifications. CARTemis-1 cells manufactured under GMP conditions showed increased memory subpopulations, reduced exhaustion markers and selective antitumor efficacy against MM cell lines and primary myeloma cells. The optimal release time points for obtaining the best fit product were > 6 and < 10 days (days 8-10). CONCLUSIONS: CARTemis-1 has been rationally designed to increase antitumor efficacy, overcome sBCMA inhibition, and incorporate the expression of a safety-gene. The generation of CARTemis-1 was successfully validated under GMP standards. A phase I/II clinical trial for patients with multiple myeloma will be conducted (EuCT number 2022-503063-15-00).

What Technologies Based on Unique Patient Identifiers Are Used for Patient Identification in Healthcare?

Ensuring the correct identification of the patient is key to matching the correct patients with the proper care (e.g. correct administration of medications and treatments), but it is also applied, for example, to monitoring the patient's movement in the hospital environment. This scoping review aims to find out what technologies based on unique patient identifiers are used to identify patients in healthcare facilities to increase patient safety and to identify future research trends. PRISMA-ScR guidelines were used, and the search focused on Web of Science and Scopus citation databases from 2000 to February 2024. Thirty-two papers dealing with patient identification methods from the point of view of person identification were found. The solutions found were built on the technologies (linear or 2D) of barcodes, RFID and NFC tags. None of the patient identification solutions found offer complete accuracy due to the human factor, and each solution targets a different problem context associated with a particular type of health facility. Future research can focus on the combination of multiple technologies, including biometric methods, to improve identification and tools to support decisions about the use of technology in a particular context and health facility (e.g. hospitals, medical nursing homes).

T-cell redirecting bispecific antibody treatment in multiple myeloma: current knowledge and future strategies for sustained T-cell engagement.

INTRODUCTION: T-cell redirecting bispecific antibodies (BsAbs), targeting B-cell maturation antigen (BCMA) or G-protein - coupled receptor class C group 5 member D (GPRC5D), are efficacious new agents for the treatment of patients with relapsed or refractory MM. AREAS COVERED: This review discusses the pharmacokinetic properties, efficacy, and safety profile of T-cell redirecting BsAbs in MM, with a special focus on their optimal dosing schedule, resistance mechanisms and future strategies to enhance efficacy, reduce toxicity, and maximize duration of response. EXPERT OPINION: To further improve the efficacy of BsAbs, ongoing studies are investigating whether combination therapy can enhance depth and duration of response. An important open question is also to what extent response to BsAbs can be improved when these agents are used in earlier lines of therapy. In addition, more evidence is needed on rational de-intensification strategies of BsAb dosing upon achieving a sufficient response, and if (temporary) treatment cessation is possible in patients who have achieved a deep remission (e.g. complete response or minimal residual disease-negative status).

Case report: Dual-targeted BCMA and CS1 CAR-T-cell immunotherapy in recurrent and refractory extramedullary multiple myeloma.

Background: The development of CAR-T-cell immunotherapy has notably elevated the efficacy of treating multiple myeloma. Currently, a variety of targets, including BCMA, CS1, CD38, FcRH5, and GPRC5D, are being investigated. Despite these significant advancements, challenges such as antigen escape, limited persistence of CAR-T cells, and the intricate nature of the tumor microenvironment persist, leading to relapses following treatment. Case presentation: We report the case of a patient with recurrent and refractory multiple myeloma (RRMM) who developed a substantial extramedullary plasmacytoma in the muscles of the lower limb following multiple rounds of radiotherapy and chemotherapy. The patient underwent CAR-T-cell immunotherapy targeting BCMA and CS1; however, the tumor progressed despite treatment. Surgical resection of the extramedullary plasmacytoma was subsequently performed. Upon comparison of the tumor tissue with the adjacent tissue, increased expression of MYBL2 was noted in the tumor tissue, potentially contributing to the lack of improvement in extramedullary relapse after dual-targeted CAR-T cell therapy. Conclusions: In patients with recurrent and refractory multiple myeloma who underwent multiple cycles of chemotherapy and radiotherapy, dual-targeted CAR-T cell therapy aimed at BCMA and CS1 failed to effectively manage extramedullary relapse. Elevated expression of MYBL2 in multiple myeloma correlates with a poorer prognosis.

Chimeric antigen receptor T-cells: a review on current status and future directions for relapsed/refractory multiple myeloma.

Although multiple myeloma is an incurable disease, the past decade has witnessed significant improvement in patient outcomes. This was brought about by the development of T-cell redirection therapies such as chimeric antigen receptor (CAR) T-cells, which can leverage the natural ability of the immune system to fight myeloma cells. The approval of the B-cell maturation antigen (BCMA)-directed CAR T, idecabtagene vicleucel (ide-cel), and ciltacabtagene autoleucel (cilta-cel) has resulted in a paradigm shift in the treatment of relapsed/refractory multiple myeloma. Overall response rates ranging from 73 to 97% are currently achievable. However, the limitations of KarMMa-1 and CARTITUDE-1 studies spurred the generation of real-world data to provide some insights into the effectiveness of ide-cel and cilta-cel among patients who were excluded from clinical trials, particularly those who received prior BCMA-targeted or other T-cell redirection therapies. Despite their unprecedented clinical efficacy in heavily pretreated patients, responses to CAR T remain non-durable. Although the underlying mechanisms of resistance to these agents haven't been fully elucidated, studies have suggested that resistance patterns could be multifaceted, implicating T-cell exhaustion and tumor intrinsic mechanisms such as BCMA target loss, upregulation of gamma-secretase, and others. Herein, we provide a succinct overview of the development of CAR T-cells, manufacturing process, and associated toxicities/complications. In this review, we also recapitulate the existing literature pertaining MM CAR-T as well as emerging data from some of the ongoing clinical trials designed to mitigate the shortcomings of these agents, and improve the clinical efficacy of CAR T, especially in the relapsed/refractory setting.

Plain language summary of the CARTITUDE-4 study of ciltacabtagene autoleucel for the treatment of people with relapsed or refractory multiple myeloma.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of a phase 3 clinical trial called CARTITUDE-4. This trial compared the anti-cancer therapy ciltacabtagene autoleucel (or cilta-cel) with standard therapies in people who have multiple myeloma, a cancer that affects specific kinds of blood cells called plasma cells. The people in the study had been treated with 1 to 3 previous treatments for multiple myeloma, including a common anti-myeloma treatment called lenalidomide, but their multiple myeloma did not get better. HOW WAS THE STUDY IN THIS SUMMARY CONDUCTED?: About half of the 419 participants in this study received cilta-cel, while the other half received standard therapies, or therapies that are commonly used to treat multiple myeloma. Participants who received cilta-cel had a type of immune cell called T cells collected from their blood and genetically modified to recognize a specific protein found on myeloma cells. These modified T cells, which comprise cilta-cel, were then infused back into the bloodstream. WHAT WERE THE RESULTS OF THE STUDY?: After approximately 1 year in the study, more participants were alive without their cancer getting worse in the cilta-cel group (76%) than in the standard therapies group (49%). The most common side effects in both groups were infections and low blood cell counts. Cytokine release syndrome (a potentially serious side effect caused by overactivation of the immune system) was common but mostly mild. Neurotoxicities (including immune effector cell-associated neurotoxicity syndrome, which can cause symptoms such as headaches, changes in consciousness, and difficulty with memory, attention, speaking, or understanding others) were less common and were reported in 20.5% of participants treated with cilta-cel. WHAT WERE THE MAIN CONCLUSIONS REPORTED BY THE RESEARCHERS?: In CARTITUDE-4, more participants treated with cilta-cel showed improvements and were alive with control of their disease 12 months after receiving cilta-cel compared with participants who received standard therapies.Clinical Trial Registration: NCT04181827 (CARTITUDE-4) (ClinicalTrials.gov).

Safety outcomes of teclistamab accelerated dose escalation.

INTRODUCTION: Teclistamab, a bispecific T-cell engaging antibody targeting B-cell maturation antigen (BCMA), is indicated for the treatment of relapsed or refractory multiple myeloma after at least four lines of therapy. It has boxed warnings for life threatening cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). To mitigate these risks, teclistamab is initiated using step-up doses. This article examines safety event rates following the implementation of a 2-day separation between step-up doses at one institution to streamline patient care. METHODS: This was a retrospective, single-center study encompassing all patients who received teclistamab within a 1-year period. The primary endpoint was the overall incidence of CRS and ICANS. Secondary endpoints included hospital length of stay, hematological toxicities, infection rates, among other adverse events. RESULTS: A total of 27 patients were included in the analysis and stratified into accelerated (days 1,3,5) or standard (days 1,4,7) dosing groups. CRS occurred in 48% (11) of patients for the accelerated dosing and 50% (2) for the standard dosing group. ICANS was seen in 17% (4) of patients in the accelerated dosing group and none in the standard dosing group. Average length of stay in the accelerated dose was 7.6 days versus 9.2 days in the standard dose group. CONCLUSION: Accelerated dose escalation of teclistamab yielded safety event rates comparable to those in the literature. These findings may support outpatient administration for teclistamab. Accelerated dose escalation strategy allowed for the optimization of hospitalization and resources.

Fast and furious: Changing gears on the road to cure with chimeric antigen receptor T cells in multiple myeloma.

Based on the pivotal KarMMa-1 and CARTITUDE-1 studies, Idecabtagene vicleucel (Ide-cel) and Ciltacabtagene autoleucel (Cilta-cel) have been approved to treat multiple myeloma patients, who have been exposed to at least 1 proteasome inhibitor, immunomodulatory drug and anti-CD38 antibody after 4 or 3 lines of therapy, respectively. The unprecedented rates of deep and long-lasting remissions have been meanwhile confirmed in multiple real-world analyses and more recently, the KarMMa-3 and CARTITUDE-4 studies lead to the approval in earlier lines of therapy. It is currently believed that ultimately all patients with relapsed/refractory multiple myeloma experience relapse after anti-BCMA CAR T-cell therapies. There is a plethora of CAR T-cell therapies targeting novel antigens, with the aim to overcome current CAR T-cell resistance. In this review, we will summarize current evidence of novel antigens and their clinical potential. Together with current CAR T-cell therapy and T-cell engagers, these approaches might lead us to the next frontier in multiple myeloma: total immunotherapy and the road to chemotherapy-free cure.

Persistent cytopenias after anti-BCMA CAR T-cell therapy are associated with reduced hematopoietic activity in posttreatment bone marrows.

OBJECTIVES: We attempt to analyze bone marrow findings and correlation with cytopenia(s) after anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell infusion in this study. METHODS: Relevant clinicopathologic data, including complete blood counts, neutrophil counts, relevant therapy history, and pre- and posttherapy bone marrow evaluations, were studied in 12 patients who received anti-BCMA CAR T-cell therapy. RESULTS: Bone marrow findings after CAR T-cell therapy were available in 6 of 12 cases, 3 of which showed markedly hypocellular marrow with either markedly reduced or essentially absent hematopoiesis. One case showed a hypocellular marrow with trilineage hematopoiesis, while the remaining 2 cases showed persistent involvement by plasma cell myeloma. Reticulin stains did not reveal significant fibrosis. Ten patients had anemia, and 8 patients had leukopenia and thrombocytopenia at day 90 posttherapy. Long-term follow-up showed persistent disease in 10 of 12 cases. CONCLUSIONS: Prolonged cytopenias occur in most patients after BCMA CAR T-cell therapy with bone marrow evaluations demonstrating associated marked hypocellularity with minimal or no hematopoiesis without an increase in fibrosis.

Unique and redundant roles of mouse BCMA, TACI, BAFF, APRIL, and IL-6 in supporting antibody-producing cells in different tissues.

Antibody-producing plasma cells fuel humoral immune responses. They also contribute to autoimmune diseases such as systemic lupus erythematosus or IgA nephropathy. Interleukin-6 and the tumor necrosis factor (TNF) family ligands BAFF (B cell-activating factor) and APRIL (a proliferation-inducing ligand) participate in plasma cell survival. BAFF binds to three receptors, BAFFR (BAFF receptor), TACI (transmembrane activator and CAML interactor), and BCMA (B cell maturation antigen), while APRIL binds to TACI, BCMA, and proteoglycans. However, which ligand-receptor pair(s) are required to maintain plasma cells in different body locations remains unknown. Here, by combining mouse genetic and pharmacological approaches, we found that plasma cells required BCMA and/or TACI but not BAFFR. BCMA responded exclusively to APRIL, while TACI responded to both BAFF and APRIL, identifying three self-sufficient ligand-receptor pairs for plasma cell maintenance: BAFF-TACI, APRIL-TACI, and APRIL-BCMA. Together, these actors accounted for 90% of circulating antibodies. In BAFF-ko mice, the reduction of plasma cells upon APRIL inhibition indicated that APRIL could function in the absence of BAFF-APRIL heteromers. No evidence was found that in the absence of BCMA and TACI, binding of APRIL to proteoglycans would help maintain plasma cells. IL-6, alone or together with BAFF and APRIL, supported mainly splenic plasmablasts and plasma cells and contributed to circulating IgG but not IgA levels. In conclusion, survival factors for plasma cells can vary with body location and with the antibody isotype that plasma cells produce. To efficiently target plasma cells, in particular IgA-producing ones, dual inhibition of BAFF and APRIL is required.

Introduction of Mobile Technology to Improve Emergency Department BCMA Rates.

Barcode Medication Administration (BCMA) is a proven process for maintaining patient safety during medication administration. However, maintaining compliance with BCMA scanning in the Emergency Department has its challenges. To overcome these challenges handheld devices, enabled with scanning technology, were provided to each nurse. BCMA compliance rates increased by 20% over a 6-month period. Handheld devices work to improve BCMA compliance in the ED environment when using a 1:1 model.

CXCR4 has a dual role in improving the efficacy of BCMA-redirected CAR-NK cells in multiple myeloma.

Multiple myeloma (MM) is a plasma cell disease with a preferential bone marrow (BM) tropism. Enforced expression of tissue-specific chemokine receptors has been shown to successfully guide adoptively-transferred CAR NK cells towards the malignant milieu in solid cancers, but also to BM-resident AML and MM. For redirection towards BM-associated chemokine CXCL12, we armored BCMA CAR-NK-92 as well as primary NK cells with ectopic expression of either wildtype CXCR4 or a gain-of-function mutant CXCR4R334X. Our data showed that BCMA CAR-NK-92 and -primary NK cells equipped with CXCR4 gained an improved ability to migrate towards CXCL12 in vitro. Beyond its classical role coordinating chemotaxis, CXCR4 has been shown to participate in T cell co-stimulation, which prompted us to examine the functionality of CXCR4-cotransduced BCMA-CAR NK cells. Ectopic CXCR4 expression enhanced the cytotoxic capacity of BCMA CAR-NK cells, as evidenced by the ability to eliminate BCMA-expressing target cell lines and primary MM cells in vitro and through accelerated cytolytic granule release. We show that CXCR4 co-modification prolonged BCMA CAR surface deposition, augmented ZAP-70 recruitment following CAR-engagement, and accelerated distal signal transduction kinetics. BCMA CAR sensitivity towards antigen was enhanced by virtue of an enhanced ZAP-70 recruitment to the immunological synapse, revealing an increased propensity of CARs to become triggered upon CXCR4 overexpression. Unexpectedly, co-stimulation via CXCR4 occurred in the absence of CXCL12 ligand-stimulation. Collectively, our findings imply that co-modification of CAR-NK cells with tissue-relevant chemokine receptors affect adoptive NK cell therapy beyond improved trafficking and retention within tumor sites.

B-cell maturation antigen-based therapies post-talquetamab in relapsed or refractory multiple myeloma.

Talquetamab recently received approval for relapsed refractory multiple myeloma. However, there is currently no available data on how patients perform with BCMA based agents after progression on talquetamab. Herein, we present the outcome of 10 patients who received BCMA based therapies following talquetamab. The median follow-up was 9.5 months (range: 6-24 months). The median progression free survival was 5.5 months (range: 1-10 months). Patients had varying grades of cytokine release syndrome and Immune effector cell-associated neurotoxicity syndrome. Our results suggest that treatment with talquetamab followed by BCMA based therapies is feasible and can be considered as clinically indicated.

Toll-like receptor signaling in multiple myeloma cells promotes the expression of pro-survival genes B-cell lymphoma 2 and MYC and modulates the expression of B-cell maturation antigen.

Infections are common in plasma cell cancer multiple myeloma (MM) due to disease-related immune deficiencies and cancer treatment. Myeloma cells express Toll-like receptors (TLRs), and TLR activation has been shown to induce proliferative and pro-survival signals in cancer cells. MM is a complex and heterogeneous disease, and expression levels of TLRs as well as downstream signaling components are likely to differ between patients. Here, we show that in a large cohort of patients, TLR1, TLR4, TLR6, TLR9, and TLR10 are the most highly expressed in primary CD138+ cells. Using an MM cell line expressing TLR4 and TLR9 as a model, we demonstrate that TLR4 and TLR9 activation promoted the expression of well-established pro-survival and oncogenes in MM such as MYC, IRF4, NFKB, and BCL2. TLR4 and TLR9 activation inhibited the efficacy of proteasome inhibitors bortezomib and carfilzomib, drugs used in the treatment of MM. Inhibiting the autophagosome-lysosome protein degradation pathway by hydroxychloroquine (HCQ) diminished the protective effect of TLR activation on proteasome inhibitor-induced cytotoxicity. We also found that TLR signaling downregulated the expression of TNFRSF17, the gene encoding for B-cell maturation antigen (BCMA). MYC, BCL2, and BCL2L1 were upregulated in approximately 50% of primary cells, while the response to TLR signaling in terms of TNFRSF17 expression was dichotomous, as an equal fraction of patients showed upregulation and downregulation of the gene. While proteasome inhibitors are part of first-line MM treatment, several of the new anti-MM immune therapeutic drugs target BCMA. Thus, TLR activation may render MM cells less responsive to commonly used anti-myeloma drugs.

Multiple Myeloma: A Personal Account of My Journey With the Disease and Response to Teclistamab.

Multiple myeloma (MM) remains an incurable hematologic cancer leading to damage to the bone marrow that causes destructive bone lesions in addition to many other effects. I am a patient with MM who has undergone treatment to date since the diagnosis of this disease in December 2019. This paper reviews the treatments and observations made throughout this period. The salient results of such treatments are discussed in chronological order. During this period, my MM relapsed and then I was introduced to teclistamab treatment. The outcome of teclistamab treatment is quite promising, and I anticipate a longer life at a maintenance dose of this drug with a better quality of life. When writing this article, I am still receiving the teclistamab treatment cycles that maintain a constant normal level of my kappa-free light chain (FLC) and kappa/lambda ratio, with no significant side effects.