Extramedullary disease in multiple myeloma: a systematic literature review

Perinephric Extramedullary Disease in Multiple Myeloma

ABSTRACT

Extramedullary disease represents an aggressive form of multiple myeloma occurring outside the skeleton and is a poor prognostic indicator. Extramedullary disease most commonly involves the skin, muscle, pleura, lymph nodes, liver, and central nervous system. Infrequently, extramedullary disease can involve the kidneys or perirenal space. We present 3 cases of perirenal involvement of extramedullary disease on 18 F-FDG PET/CT confirmed with tissue sampling as plasma cell infiltration. Within the limitation of physiologic activity in the kidneys due to 18 F-FDG excretion, close consideration is essential when evaluating multiple myeloma patients for genitourinary involvement as it can resemble other malignancies, hemorrhage, or renal injury.

Superior outcomes and high-risk features with carfilzomib, lenalidomide, and dexamethasone combination therapy for patients with relapsed and refractory multiple myeloma: results of the multicenter KMMWP2201 study

Carfilzomib, lenalidomide, and dexamethasone (KRd) combination therapy improves the survival of patients with relapsed and/or refractory multiple myeloma (RRMM). Nonetheless, evidence on the use of KRd in Asian populations remains scarce. Accordingly, this study aimed to investigate this regimen's efficacy in a large group of patients. This retrospective study included patients with RRMM who were treated with KRd at 21 centers between February 2018 and October 2020. Overall, 364 patients were included (median age, 63 years). The overall response rate was 90% in response-evaluable patients, including 69% who achieved a very good partial response or deeper responses. With a median follow-up duration of 34.8 months, the median progression-free survival (PFS) was 23.4 months and overall survival (OS) was 59.5 months. Among adverse factors affecting PFS, high-risk cytogenetics, extramedullary disease, and doubling of monoclonal protein within 2-3 months prior to start of KRd treatment significantly decreased PFS and OS in multivariate analyses. Patients who underwent post-KRd stem cell transplantation (i.e., delayed transplant) showed prolonged PFS and OS. Grade 3 or higher adverse events (AE) were observed in 56% of the patients, and non-fatal or fatal AE that resulted in discontinuation of KRd were reported in 7% and 2% of patients, respectively. Cardiovascular toxicity was comparable to that reported in the ASPIRE study. In summary, KRd was effective in a large, real-world cohort of patients with RRMM with long-term follow-up. These findings may further inform treatment choices in the treatment of patients with RRMM.

miR-744-5p promotes T-cell differentiation via inhibiting STK11

T cells utilized in adoptive T cell immunotherapy are typically activated in vitro. Although these cells demonstrate proliferation and anti-tumor activity following activation, they often face difficulties in sustaining long-term survival post-reinfusion. This issue is attributed to the induction of T cells into a terminal differentiation state upon activation, whereas early-stage differentiated T cells exhibit enhanced proliferation potential and survival capabilities. In previous study, we delineated four T cell subsets at varying stages of differentiation: TN, TSCM, TCM, and TEM, and acquired their miRNA expression profiles via high-throughput sequencing. In the current study, we performed a differential analysis of miRNA across these subsets, identifying a distinct miRNA, hsa-miR-744-5p, characterized by progressively increasing expression levels upon T cell activation. This miRNA is not expressed in TSCM but is notably present in TEM. Target genes of miR-744-5p were predicted, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, revealing that these genes predominantly associate with pathways related to the 'Wnt signaling pathway'. We established that miR-744-5p directly targets STK11, influencing its expression. Further, we investigated the implications of miR-744-5p on T cell differentiation and functionality. Overexpression of miR-744-5p in T cells resulted in heightened apoptosis, reduced proliferation, an increased proportion of late-stage differentiated T cells, and elevated secretion of the cytokine TNF-α. Moreover, post-overexpression of miR-744-5p led to a marked decline in the expression of early-stage differentiation-associated genes in T cells (CCR7, CD62L, LEF1, BCL2) and a significant rise in late-stage differentiation-associated genes (KLRG1, PDCD1, GZMB). In conclusion, our findings affirm that miR-744-5p contributes to the progressive differentiation of T cells by downregulating the STK11 gene expression.

Preclinical Evaluation of STI-8811, a Novel Antibody-Drug Conjugate Targeting BCMA for the Treatment of Multiple Myeloma

Treatment for patients with multiple myeloma has experienced rapid development and improvement in recent years; however, patients continue to experience relapse, and multiple myeloma remains largely incurable. B-cell maturation antigen (BCMA) has been widely recognized as a promising target for treatment of multiple myeloma due to its exclusive expression in B-cell linage cells and its critical role in the growth and survival of malignant plasma cells. Here, we introduce STI-8811, a BCMA-targeting antibody-drug conjugate (ADC) linked to an auristatin-derived duostatin payload via an enzymatically cleavable peptide linker, using our proprietary C-lock technology. STI-8811 exhibits target-specific binding activity and rapid internalization, leading to G2/M cell-cycle arrest, caspase 3/7 activation, and apoptosis in BCMA-expressing tumor cells in vitro. Soluble BCMA (sBCMA) is shed by multiple myeloma cells into the blood and increases with disease progression, competing for ADC binding and reducing its efficacy. We report enhanced cytotoxic activity in the presence of high levels of sBCMA compared with a belantamab mafodotin biosimilar (J6M0-mcMMAF). STI-8811 demonstrated greater in vivo activity than J6M0-mcMMAF in solid and disseminated multiple myeloma models, including tumor models with low BCMA expression and/or in large solid tumors representing soft-tissue plasmacytomas. In cynomolgus monkeys, STI-8811 was well tolerated, with toxicities consistent with other BCMA-targeting ADCs with auristatin payloads in clinical studies. STI-8811 has the potential to outperform current clinical candidates with lower toxicity and higher activity under conditions found in patients with advanced disease. Significance: STI-8811 is a BCMA-targeting ADC carrying a potent auristatin derivative. We report unique binding properties which maintain potent cytotoxic activity under sBCMA-high conditions that hinder the clinical efficacy of current BCMA-targeting ADC candidates. Beyond disseminated models of multiple myeloma, we observed efficacy in solid tumor models of plasmacytomas with low and heterogenous BCMA expressions at a magnitude and duration of response exceeding that of clinical comparators.

Advanced imaging for earlier diagnosis and morbidity prevention in multiple myeloma: A British Society of Haematology and UK Myeloma Society Good Practice Paper

This Good Practice Paper provides recommendations for the use of advanced imaging for earlier diagnosis and morbidity prevention in multiple myeloma. It describes how advanced imaging contributes to optimal healthcare resource utilisation by in newly diagnosed and relapsed myeloma, and provides a perspective on future directions of myeloma imaging, including machine learning assisted reporting.

Visual impairment as the initial presentation in multiple myeloma: a case report and literature review

Background

Multiple myeloma (MM) is a type of blood cancer, which rarely infiltrates the central nervous system (CNS) and lacks specific neurological symptoms. The prognosis is often poor, as the disease progresses rapidly. Herein, we present a rare case of MM with CNS involvement.

Case Description

A 53-year-old man was admitted to the Neurosurgery Department, Jinhua Hospital Affiliated to Zhejiang University with initial symptoms of "blurred vision for 3 months accompanied by numbness on the right side of the face for 7 days". Enhanced cranial magnetic resonance imaging revealed a tumor deep in the right temporal bone. During exploratory surgery, the "fleshy" mass was completely removed. Postoperative pathology confirmed a diagnosis of "plasmacytoma with intermediate features". The patient received multiple systematic chemotherapy treatments after surgery in the department of hematology of Jinhua Hospital Affiliated to Zhejiang University. During a 10-month follow-up period, the patient's neurological symptoms improved, and his general condition was considered good.

Conclusions

This report summarizes the clinical features, diagnosis, treatment, and prognosis of a patient with MM involving the CNS and examines the relevant literature. This case may serve as a reference for future clinical treatment and diagnosis. Further research on the pathophysiology of such cases is warranted.

BCMA-BBZ-OX40 CAR-T Therapy Using an Instant Manufacturing Platform in Multiple Myeloma

BACKGROUND

Chimeric antigen receptor (CAR)-T cell has revolutionary efficacy against relapsed/refractory multiple myeloma (R/R MM). However, current CAR-T cell therapy has several limitations including long vein-to-vein time and limited viability.

METHODS

A 4-1BB-costimulated B-cell maturation antigen (BCMA) CAR-T integrating an independently-expressed OX40 (BCMA-BBZ-OX40) was designed and generated by a traditional manufacturing process (TraditionCART) or instant manufacturing platform (named InstanCART). The tumor-killing efficiency, differentiation, exhaustion, and expansion level were investigated in vitro and in tumor-bearing mice. An investigator-initiated clinical trial was performed in patients with R/R MM to evaluate the outcomes of both TraditionCART and InstanCART. The primary objective was safety within 1 month after CAR-T cell infusion. The secondary objective was the best overall response rate.

RESULTS

Preclinical studies revealed that integrated OX40 conferred BCMA CAR-T cells with superior cytotoxicity and reduced exhaustion levels. InstanCART process further enhanced the proliferation and T-cell stemness of BCMA-BBZ-OX40 CAR-T cells. BCMA-BBZ-OX40 CAR-T cells were successfully administered in 22 patients with R/R MM, including 15 patients with TraditionCART and 7 patients with InstanCART. Up to 50% (11/22) patients had a high-risk cytogenetic profile and 36% (8/22) had extramedullary disease. CAR-T therapy caused grade 1-2 cytokine release syndrome in 19/22 (80%) patients, grade 1 neurotoxicity in 2/22 (9%) patients and led to ≥grade 3 adverse events including neutropenia (20/22, 91%), thrombocytopenia (15/22, 68%), anemia (12/22, 55%), creatinine increased (1/22, 5%), hepatic enzymes increased (5/22, 23%), and sepsis (1/22, 5%). The best overall response rate was 100%, and 64% (14/22) of the patients had a complete response or better. The median manufacturing time was shorter for InstanCART therapy (3 days) than for TraditionCART therapy (10 days). Expansion and duration were dramatically higher for InstanCART cells than for TraditionCART cells.

CONCLUSIONS

BCMA-BBZ-OX40 CAR-T cells were well tolerated and exhibited potent responses in patients with R/R MM. InstanCART shortened the manufacturing period compared to TraditionCART, and improved the cellular kinetics. Our results demonstrated the potency and feasibility of OX40-modified BCMA CAR-T cells using InstanCART technology for R/R MM therapy.

TRIAL REGISTRATION NUMBER

This trial was registered at www.

CLINICALTRIALS

gov as #NCT04537442.

Association of ADAM family members with proliferation signaling and disease progression in multiple myeloma

Multiple myeloma (MM) is a hematological malignancy whose curability is greatly challenged by recurrent patient relapses and therapy resistance. We have previously proposed the high expression of ADAM8, ADAM9 and ADAM15 (A Disintegrin And Metalloproteinase 8/9/15) as adverse prognostic markers in MM. This study focused on the so far scarcely researched role of ADAM8/9/15 in MM using two patient cohorts and seven human MM cell lines (HMCL). High ADAM8/9/15 expression was associated with high-risk cytogenetic abnormalities and extramedullary disease. Furthermore, ADAM8/15 expression increased with MM progression and in relapsed/refractory MM compared to untreated patient samples. RNA sequencing and gene set enrichment analysis comparing ADAM8/9/15high/low patient samples revealed an upregulation of proliferation markers and proliferation-associated gene sets in ADAM8/9/15high patient samples. High ADAM8/9/15 expression correlated with high Ki67 and high ADAM8/15 expression with high MYC protein expression in immunohistochemical stainings of patient tissue. Conversely, siRNA-mediated knockdown of ADAM8/9/15 in HMCL downregulated proliferation-related gene sets. Western blotting revealed that ADAM8 knockdown regulated IGF1R/AKT signaling and ADAM9 knockdown decreased mTOR activation. Lastly, high ADAM8/9/15 expression levels were verified as prognostic markers independent of Ki67/MYC expression and/or high-risk abnormalities. Overall, these findings suggest that ADAM8/9/15 play a role in MM progression and proliferation signaling.

Orbital Myeloma and Plasmacytoma: An Australian Study

PURPOSE

The purpose of this study was to provide Australian data on the clinical and radiological features and outcomes in patients with orbital plasmacytomas.

METHODS

Multicentre retrospective review of orbital plasmacytoma and orbital involvement in multiple myeloma (MM) from 2005 to 2022 in Australia.

RESULTS

Twenty-one participants were identified. The median age was 62 years (range 34-88 years), and 11 (52%) were females. Eighteen (84%) had a known diagnosis of MM prior to their orbital presentation, with all patients eventually being diagnosed with systemic MM. Thirteen (72%) were receiving active treatment for systemic myeloma on presentation, while 3 (17%) were in remission. All but 1 had unilateral orbital involvement (n = 20, 95%). Common presenting symptoms and signs were decreased visual acuity (n = 13, 62%), proptosis (n = 11, 52%), limited motility (n = 15, 71%), and optic neuropathy (n = 5, 24%). Radiologically, 15 (71%) involved the superotemporal orbit, 7 (33%) inferotemporal orbit, and 16 (76%) involved ≥1 extraocular muscle. Sixteen (76%) were biopsied and confirmed orbital plasmacytoma on histopathology. Treatment modalities included intravenous and oral steroids (n = 7, 33%), chemotherapy (n = 9, 43%), radiotherapy (n = 13, 62%), stem cell transplant (n = 3, 14%), and surgical debulking and decompression (n = 3, 14%). Mortality was high, with 15 (71%) having MM-related mortality.

CONCLUSIONS

This is the largest cohort of Australian data on orbital plasmacytomas. Most patients have a diagnosis of systemic MM at presentation. It is crucial to recognize and treat these patients early due to a poor systemic prognosis.

Effects of Consolidation Therapy With Autologous Hematopoietic Stem Cell Transplantation After BCMA-CAR T-Cell Therapy on the Survival of Patients With Relapsed or Refractory Multiple Myeloma

Despite the success of chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory multiple myeloma (RRMM), failure after CAR T-cell therapy remains an unmet medical need. An effective consolidation therapy after CAR T-cell therapy may improve the prognosis of RRMM. To investigate the effects of consolidation therapy with autologous hematopoietic stem cell transplantation (AHCT) after B-cell maturation antigen (BCMA)-targeted CAR T-cell therapy on the prognosis of RRMM patients. This retrospective study included 39 RRMM patients who received BCMA-targeted CAR T-cell therapy. Basic clinical, therapy, and outcome data were collected, and factors associated with survival were analyzed. Among the 39 RRMM patients included in the study, 15 had high-risk cytogenetics and 11 had extramedullary disease (EMD). All 39 patients reached peak CAR T-cell expansion within 28 days after infusion. Twenty-six patients developed cytokine release syndrome, including 12 grade 1 and 14 grade 2 cases. Survival analysis revealed that high-risk cytogenetics, high tumor load (International Staging System [ISS] stage III), and EMD were negatively associated with progression-free survival (PFS) and overall survival (OS). Thirteen patients received consolidation AHCT therapy 50-276 days after CAR T-cell therapy, with a median interval of 92 days. No serious complications occurred after consolidation AHCT. Survival analysis showed that consolidation AHCT effectively improved OS and PFS over maintenance chemotherapy. Moreover, Cox regression analysis identified low tumor load (ISS stage I/II) and consolidation AHCT as independent predictors of superior PFS and OS and high-risk cytogenetics as an independent risk factor for poor PFS. Consolidation AHCT after CAR T-cell therapy in RRMM patients can improve patient survival.

Proteasome and PARP1 dual-target inhibitor for multiple myeloma: Fluzoparib

One of the current mainstream treatments for multiple myeloma (MM) is chemotherapy. However, due to the high clonal heterogeneity and genomic complexity of MM, single-target drugs have limited efficacy and are prone to drug resistance. Therefore, there is an urgent need to develop multi-target drugs against MM. We screened drugs that simultaneously inhibit poly(ADP-ribose) polymerase 1 (PARP1) and 20S proteasome through computer-aided drug discovery (CADD) techniques, and explored the binding mode and dynamic stability of selected inhibitor to proteasome through Molecular biology (MD) simulation method. Thus, the dual-target inhibition effect of fluzoparib was proposed for the first time, and the ability of dual-target inhibition and tumor killing was explored at the enzyme, cell and animal level, respectively. This provides a theoretical and experimental basis for exploring multi-target inhibitory drugs for cancers.

IgG-k/IgG-λ Para-Osseous Plasmacytoma Relapsed as Soft-Tissue Plasmacytoma with IgA-k Immunophenotype: A Case Report and Review of the Literature on Related Biochemical Aspects

Neoplastic plasma cells (PCs) proliferation at anatomic sites dislocated from the bone marrow (BM) or their contiguous growth from osseous lesions that disrupt the cortical bone is termed extramedullary multiple myeloma (EMD). EMD still remains challenging from a therapeutic and biological perspective. Pathogenesis has not been completely clarified, and it is generally associated with high-risk cytogenetics (HRCAs). In order to emphasize the clinical and biochemical complexity of this disease, we have decided to describe the case of a patient affected by relapsed-refractory (RR) EMD, which presented as para-osseous plasmacytoma with a bi-phenotypical immunoglobulin (Ig) component and lately relapsed as soft-tissue plasmacytoma with a total immunophenotype switch. We have also hypothesized a correlation between Ig patterns and prognosis and suggested the possible inclusion of these biochemical features in the general risk assessment.

Multiple myeloma: clinical characteristics, current therapies and emerging innovative treatments targeting ribosome biogenesis dynamics

Multiple myeloma (MM) is a clinical disorder characterized by aberrant plasma cell growth in the bone marrow microenvironment. Globally, the prevalence of MM has been steadily increasing at an alarming rate. In the United States, more than 30,000 cases will be diagnosed in 2024 and it accounts for about 2% of cancer diagnoses and more than 2% of cancer deaths, more than double the worldwide figure. Both symptomatic and active MM are distinguished by uncontrolled plasma cell growth, which results in severe renal impairment, anemia, hypercalcemia, and bone loss. Multiple drugs have been approved by the FDA and are now widely used in clinical practice for MM. Although triplet and quadruplet induction regimens, autologous stem cell transplantation (ASCT), and maintenance treatment are used, MM continues to be an incurable illness characterized by relapses that may occur at various phases of its progression. MM patients with frailty, extramedullary disease, plasma cell leukemia, central nervous system recurrence, functional high risk, and the elderly are among those with the greatest current unmet needs. The high cost of care is an additional challenge. MM cells are highly protein secretary cells and thus are dependent on the activation of certain translation pathways. MM also has a high chance of altering ribosomal protein-encoding genes like MYC mutation. In this article we discuss the importance of ribosome biogenesis in promoting MM and RNA polymerase I inhibition as an upcoming treatment with potential promise for MM patients.

Liquid biopsy of peripheral blood using mass spectrometry detects primary extramedullary disease in multiple myeloma patients

Multiple myeloma (MM) is the second most prevalent hematological malignancy, characterized by infiltration of the bone marrow by malignant plasma cells. Extramedullary disease (EMD) represents a more aggressive condition involving the migration of a subclone of plasma cells to paraskeletal or extraskeletal sites. Liquid biopsies could improve and speed diagnosis, as they can better capture the disease heterogeneity while lowering patients' discomfort due to minimal invasiveness. Recent studies have confirmed alterations in the proteome across various malignancies, suggesting specific changes in protein classes. In this study, we show that MALDI-TOF mass spectrometry fingerprinting of peripheral blood can differentiate between MM and primary EMD patients. We constructed a predictive model using a supervised learning method, partial least squares-discriminant analysis (PLS-DA) and evaluated its generalization performance on a test dataset. The outcome of this analysis is a method that predicts specifically primary EMD with high sensitivity (86.4%), accuracy (78.4%), and specificity (72.4%). Given the simplicity of this approach and its minimally invasive character, this method provides rapid identification of primary EMD and could prove helpful in clinical practice.

Recurrent Cutaneous Manifestation in Multiple Myeloma

Cutaneous involvement is an uncommonly encountered manifestation in multiple myeloma (MM), more commonly observed in patients with aggressive subtypes, and often resistant to conventional therapies. Due to its infrequency, reported clinical characteristics have been diverse and relatively non-specific. Particularly uncommon is lower extremity involvement. In this case report, we present a unique case of a patient with refractory immunoglobulin G lambda MM, who subsequently developed recurrence in the lower leg, while being on systemic therapy. Initially, the lesion resembled squamous cell carcinoma, posing a diagnostic challenge. Through meticulous histopathological and immunohistochemical evaluation, cutaneous involvement by MM was confirmed. This case highlights the importance of maintaining a high clinical suspicion for cutaneous involvement in patients with MM who present with new skin lesions, as early diagnosis is crucial for appropriate management.

First-Line Combination with Proteasome Inhibitor-Based Treatment and Zoledronic Acid Is Effective in Reducing Later Fractures in Multiple Myeloma Irrespective of Multiple Myeloma Bone Disease at Diagnosis

The present study provides real-world evidence on the treatment of multiple myeloma (MM) bone disease with various bisphosphonates combined for different myeloma-specific treatments as no validated data regarding the best combination treatment for bone disease associated with MM are available. We examined retrospectively 345 MM patients treated with autologous stem cell transplantation in Finland during 1996-2020. The median age of the patients was 60 years with a median follow-up time of 50 months (1-339). At diagnosis, 72.1% of the patients had myeloma-associated bone disease and 45.8% had fractures. Most patients (58.8%) received proteasome inhibitor (PI)-containing treatment at first line. MM bone disease was treated in 91.6% of the patients; 49.9% received zoledronic acid (ZA) and 29.9% pamidronate. Inferior overall survival was associated with MM bone disease at diagnosis (p = 0.005) or a fracture at diagnosis (p = 0.003). A later fracture was identified in 29% of the patients, and in those patients without MM bone disease at diagnosis later fractures were less common after ZA treatment (p = 0.049). PI-based treatment plus ZA (p = 0.019) seemed to be the best combination to prevent later fractures, even though the same patient subgroup was more likely to experience relapse (p = 0.018), and also when excluding patients with previous induction therapy without novel agents (p = 0.008). To conclude, this study suggests that the best therapy to prevent later fractures in MM might be PI-based treatment combined with ZA.

A comprehensive review of the PTEN/PI3K/Akt axis in multiple myeloma: From molecular interactions to potential therapeutic targets

Phosphatase and tensin homolog (PTEN), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) signaling pathways contribute to the development of several cancers, including multiple myeloma (MM). PTEN is a tumor suppressor that influences the PI3K/Akt/mTOR pathway, which in turn impacts vital cellular processes like growth, survival, and treatment resistance. The current study aims to present the role of PTEN and PI3K/Akt/mTOR signaling in the development of MM and its response to treatment. In addition, the molecular interactions in MM that underpin the PI3K/Akt/mTOR pathway and address potential implications for the development of successful treatment plans are also discussed in detail. We investigate their relationship to both upstream and downstream regulators, highlighting new developments in combined therapies that target the PTEN/PI3K/Akt axis to overcome drug resistance, including the use of PI3K and mitogen-activated protein kinase (MAPK) inhibitors. We also emphasize that PTEN/PI3K/Akt pathway elements may be used in MM diagnosis, prognosis, and therapeutic targets.

Review of whole-body magnetic resonance imaging in multiple myeloma

Multiple Myeloma (MM) is a hematological malignancy affecting bone marrow, most frequently in elderly men. Imaging has a crucial role in this disease. Recently, whole-body MRI has been introduced and it has gained growing interest due to is high sensitivity and specificity in evaluating bone marrow involvement in MM. Diffusion-weighted sequences (DWI) with apparent diffusion coefficient (ADC) maps have emerged as the most sensitive technique to evaluate patients with MM, both in the pre- and post-treatment setting. Aim of this review is to provide an overview of the role and main imaging findings of whole-body MRI in MM.

Update on kidney injury caused by multiple myeloma

Multiple myeloma (MM) is a form of clonal plasma cell malignancy that associates with clinical manifestations such as anemia, hypercalcemia, bone pain, and renal impairment. Approximately 20-50% of MM patients at initial diagnosis experience renal injury, a vital complication that significantly influences prognosis and quality of life. This review seeks to clarify the multifaceted mechanisms of renal injury in MM, scrutinizing the pathogenic role of monoclonal proteins, the impact of hypercalcemia, and direct renal infiltration by plasma cells. Furthermore, it evaluates current diagnostic approaches, reviews management strategies, and highlights potential avenues for future research. By incorporating the latest scientific evidence and insights, this article aims to provide a comprehensive understanding of MM-associated renal impairment, offering a valuable resource for researchers and clinicians in handling this complex complication.

Multiple myeloma

Multiple myeloma (MM) is a haematological lymphoid malignancy involving tumoural plasma cells and is usually characterized by the presence of a monoclonal immunoglobulin protein. MM is the second most common haematological malignancy, with an increasing global incidence. It remains incurable because most patients relapse or become refractory to treatments. MM is a genetically complex disease with high heterogeneity that develops as a multistep process, involving acquisition of genetic alterations in the tumour cells and changes in the bone marrow microenvironment. Symptomatic MM is diagnosed using the International Myeloma Working Group criteria as a bone marrow infiltration of ≥10% clonal plasma cells, and the presence of at least one myeloma-defining event, either standard CRAB features (hypercalcaemia, renal failure, anaemia and/or lytic bone lesions) or biomarkers of imminent organ damage. Younger and fit patients are considered eligible for transplant. They receive an induction, followed by consolidation with high-dose melphalan and autologous haematopoietic cell transplantation, and maintenance therapy. In older adults (ineligible for transplant), the combination of daratumumab, lenalidomide and dexamethasone is the preferred option. If relapse occurs and requires further therapy, the choice of therapy will be based on previous treatment and response and now includes immunotherapies, such as bi-specific monoclonal antibodies and chimeric antigen receptor T cell therapy.

Impact of extramedullary multiple myeloma on outcomes with idecabtagene vicleucel

Idecabtagene vicleucel (Ide-cel) has demonstrated excellent efficacy and durable responses in patients with relapsed/refractory multiple myeloma (RRMM). However, the outcomes with ide-cel in patients with extramedullary disease (EMD) remain incompletely characterized. We included patients with RRMM treated with ide-cel between May 2021 and April 2023 across 11 US academic institutions. Visceral or soft tissue lesions non-contiguous from bone was classified as EMD. Time-to-event analyses were performed from date of ide-cel infusion. Among 351 patients, 84 (24%) had EMD prior to infusion. The median follow-up from ide-cel infusion was 18.2 months (95% CI: 17-19.3). The day 90 overall response rates (ORR) were 52% vs. 82% for the EMD and non-EMD cohorts, respectively (p < 0.001). The median progression-free survival (PFS) was 5.3 months (95% CI: 4.1-6.9) for the EMD cohort vs. 11.1 months (95% CI: 9.2-12.6; p < 0.0001) for the non-EMD cohort. In a multivariable analysis, EMD was an independent predictor of inferior PFS [hazard ratio 1.5 (1.1-2.2), p = 0.02]. The median overall survival was 14.8 months [95% CI: 9-Not reached (NR)] vs. 26.9 months (26.3 vs. NR, p = 0.006) for the EMD and non-EMD cohorts, respectively. Extramedullary disease represents an independent predictor of inferior day 90 ORR and PFS among patients treated with ide-cel.

Beyond the marrow: insights from comprehensive next-generation sequencing of extramedullary multiple myeloma tumors

Extramedullary multiple myeloma (EMM) is an aggressive form of multiple myeloma (MM). This study represents the most comprehensive next-generation sequencing analysis of EMM tumors (N = 14) to date, uncovering key molecular features and describing the tumor microenvironment. We observed the co-occurrence of 1q21 gain/amplification and MAPK pathway mutations in 79% of EMM samples, suggesting that these are crucial mutational events in EMM development. We also demonstrated that patients with mutated KRAS and 1q21 gain/amplification at the time of diagnosis have a significantly higher risk of EMM development (HR = 2.4, p = 0.011) using data from a large CoMMpass dataset. We identified downregulation of CXCR4 and enhanced cell proliferation, along with reduced expression of therapeutic targets (CD38, SLAMF7, GPRC5D, FCRH5), potentially explaining diminished efficacy of immunotherapy. Conversely, we identified significantly upregulated EZH2 and CD70 as potential future therapeutic options. For the first time, we report on the tumor microenvironment of EMM, revealing CD8+ T cells and NK cells as predominant immune effector cells using single-cell sequencing. Finally, this is the first longitudinal study in EMM revealing the molecular changes from the time of diagnosis to EMM relapse.

Daratumumab‑resistant multiple myeloma with extramedullary disease successfully treated with combination elotuzumab, pomalidomide and dexamethasone: A case report

Despite the emergence of monoclonal antibodies, the prognosis of patients with multiple myeloma (MM) with extramedullary disease remains poor. The present report describes a rare case of daratumumab-refractory MM that was successfully treated with elotuzumab, pomalidomide and dexamethasone. A 66-year-old male patient diagnosed with MM was treated with bortezomib, lenalidomide and dexamethasone, followed by high-dose chemotherapy and autologous stem cell transplantation. Thereafter, the patient was treated with lenalidomide and dexamethasone as maintenance therapy. This was changed to daratumumab, bortezomib and dexamethasone when new paraskeletal lesions were identified, resulting in marked tumor shrinkage. After 15 months, an increase in serum monoclonal protein levels, development of a skeletal lesion in the right second rib and extramedullary disease of the right thoracic mediastinal lymph nodes were noted. Treatment with elotuzumab, pomalidomide and dexamethasone (EPd) resulted in expeditious symptomatic improvement and regression of the lesions. Notably, during daratumumab, bortezomib and dexamethasone treatment, lymphocyte counts gradually increased to a level at which elotuzumab was sufficiently effective. EPd might be a promising strategy for the treatment of patients with relapsed extramedullary MM while on daratumumab treatment.

miR-34a promotes the immunosuppressive function of multiple myeloma-associated macrophages by dampening the TLR-9 signaling

BACKGROUND

Promising outcomes have been observed in multiple myeloma (MM) with the use of immunotherapies, specifically chimeric antigen receptor T (CAR-T) cell therapy. However, a portion of MM patients do not respond to CAR-T therapy, and the reasons for this lack of response remain unclear. The objective of this study was to investigate the impact of miR-34a on the immunosuppressive polarization of macrophages obtained from MM patients.

METHODS

The levels of miR-34a and TLR9 (Toll-like receptor 9) were examined in macrophages obtained from both healthy individuals and patients with MM. ELISA was employed to investigate the cytokine profiles of the macrophage samples. Co-culture experiments were conducted to evaluate the immunomodulatory impact of MM-associated macrophages on CAR-T cells.

RESULTS

There was an observed suppressed activation of macrophages and CD4+ T lymphocytes in the blood samples of MM patients. Overexpression of miR-34a in MM-associated macrophages dampened the TLR9 expression and impaired the inflammatory polarization. In both the co-culture system and an animal model, MM-associated macrophages suppressed the activity and tumoricidal effect of CAR-T cells in a miR-34a-dependent manner.

CONCLUSION

The findings imply that targeting the macrophage miR-34a/TLR9 axis could potentially alleviate the immunosuppression associated with CAR-T therapy in MM patients.

Imaging finding of multiple myeloma presenting as soft-tissue disease mimicking extrapleural space tumors: A case report

Extramedullary involvement of multiple myeloma is an uncommon and aggressive condition characterized by proliferation of monoclonal plasma cells located outside the bone marrow. This report describes the imaging findings of a patient who presented with continuous soft-tissue disease on the ribs, suspected as extrapleural space tumors on chest CT. The patient was diagnosed with multiple myeloma through surgical biopsy of the tumor and bone marrow.

BATF promotes extramedullary infiltration through TGF-β1/Smad/MMPs axis in acute myeloid leukemia

Acute myeloid leukemia (AML) is one of the most prevalent types of leukemia and is challenging to cure for most patients. Basic Leucine Zipper ATF-Like Transcription Factor (BATF) has been reported to participate in the development and progression of numerous tumors. However, its role in AML is largely unknown. In this study, the expression and prognostic value of BATF were examined in AML. Our results demonstrated that BATF expression was upregulated in AML patients, which was significantly correlated with poor clinical characteristics and survival. Afterward, functional experiments were performed after knocking down or overexpressing BATF by transfecting small interfering RNAs and overexpression plasmids into AML cells. Our findings revealed that BATF promoted the migratory and invasive abilities of AML cells in vitro and in vivo. Moreover, the target genes of BATF were searched from databases to explore the binding of BATF to the target gene using ChIP and luciferase assays. Notably, our observations validated that BATF is bound to the promoter region of TGF-β1, which could transcriptionally enhance the expression of TGF-β1 and activate the TGF-β1/Smad/MMPs signaling pathway. In summary, our study established the aberrantly high expression of BATF and its pro-migratory function via the TGF-β1-Smad2/3-MMP2/9 axis in AML, which provides novel insights into extramedullary infiltration of AML.

Impact of Extraosseous Extramedullary Disease on Outcomes of Patients with Relapsed-Refractory Multiple Myeloma receiving Standard-of-Care Chimeric Antigen Receptor T-Cell Therapy

The presence of extramedullary disease (EMD) has been associated with poor outcomes in patients with relapsed-refractory multiple myeloma (RRMM). Herein, we report the outcomes of RRMM patients who were treated with standard-of-care (SOC) chimeric antigen receptor (CAR) T-cell therapy and had active extraosseous EMD before the infusion. Data were retrospectively collected from patients at three US institutions with the intent to receive SOC CAR T. Responses were assessed per the International Myeloma Working Group criteria. A total of 152 patients proceeded with infusion, of whom 47 (31%) had EMD (EMD group) and 105 (69%) did not (non-EMD group). Baseline patient characteristics were comparable between the two groups. The EMD group had a higher incidence of high-grade CRS, steroid and anakinra use, and thrombocytopenia on day +30 compared to the non-EMD group. In addition, the EMD group had an inferior overall response rate (58% vs 96%, p < 0.00001), median progression-free survival (PFS) (5.1 vs 12.4 months; p < 0.0001), and overall survival (OS) (12.2 vs 27.5 months; p = 0.00058) compared to the non-EMD group. We further subdivided the non-EMD patients into those with paramedullary disease (PMD-only group, n = 26 [17%]) and those with neither EMD nor PMD (bone marrow-contained group or BM-only group, n = 79 [52%]). Patients with PMD-only had similar median PFS (11.2 vs 13.6 months, p = 0.3798) and OS (not reached [NR] vs 27.5 months, p = 0.6446) compared to patients with BM-only disease. However, patients with EMD exhibited inferior median PFS (5.1 vs 13.6 months, p < 0.0001) and OS (12.2 vs 27.5, p = 0.0008) compared to patients in the BM-only group. Treatment with SOC CAR T yielded meaningful clinical outcomes in real-world RRMM patients with extraosseous EMD, though responses and survival outcomes were suboptimal compared to patients without EMD. The presence of only EMD but not PMD was associated with significantly worse survival outcomes following the CAR T infusion.

Factors associated with refractoriness or early progression after idecabtagene vicleucel in patients with relapsed/ refractory multiple myeloma: US Myeloma Immunotherapy Consortium real world experience

While response rates and survival outcomes have been very promising for idecabtagene vicleucel (ide-cel), a proportion of patients do not respond or relapse early after this B-cell maturation antigen (BCMA) targeted chimeric antigen receptor (CAR) T-cell therapy. Understanding the characteristics of these patients is important for patient selection and development of novel strategies to improve outcomes. We evaluated factors associated with early progression (progression or death due to myeloma ≤3 months after CAR T-cell infusion) in patients treated with standard of care ide-cel at 11 US academic centers. Among 211 patients that received ide-cel, 43 patients had a progressive event ≤3 months of infusion. Patients with a history of extramedullary disease, prior BCMA targeted therapy, elevated ferritin at lymphodepletion, use of bridging therapy, Hispanic ethnicity, plasma cell leukemia and t(4;14) were more likely to progress ≤3 months of infusion (P<0.05). Of these risk factors for early progression identified in univariate analyses, history of extramedullary disease, prior BCMA targeted therapy, elevated ferritin at lymphodepletion, plasma cell leukemia, and t(4;14) were associated with worse progression-free survival (PFS) in multivariable analysis. Presence of three or more of these factors had a significant negative impact on PFS (P<0.001; median PFS for ≥3 factors, 3.2 months vs. 0 factors, 14.1 months). This study helps identify patients at high risk of early progression after CAR T-cell therapy who may benefit from specific interventions pre and post CAR T-cell therpy to improve outcomes.

Unusual painful pelvic masses: Extramedullary hematopoiesis with extramedullary multiple myeloma

The coexistence of extramedullary hematopoiesis and extramedullary multiple myeloma can occur and present as painful pelvic masses. In such a case, normal hematopoietic cells may outnumber clonal plasma cells, posing a diagnostic challenge.

Multiple Myeloma

Multiple myeloma (MM) is a cancer that arises from plasma cells in bone marrow. Approximately 35,730 Americans received a new diagnosis and MM will claim the lives of an estimated 12,590 people in 2023. Complications of the disease process include anemia, leukopenia, thrombocytopenia, renal failure, severe pain, bone loss, and hypercalcemia. Patients with MM have a high risk for pathological fractures. For most forms of MM there are effective treatments that may result in long-term remission using multi-drug regimens. Although the medications approved in the United States to treat MM generally produce good outcomes, they have serious, and potentially life-threatening adverse effects. In addition, patients with specific genetic variations are at high risk for relapse. Communication with the oncology team and early intervention in the event of adverse effects of medications, complications of the disease process, or evidence of relapse are important to obtain the best possible outcome. Patients are easily overwhelmed with a three- to four-drug treatment regimen with some drugs given intravenously and/or subcutaneously at the clinic, and others taken orally at home on specific days of each 28-day cycle. Home care nursing is needed to assess for tolerance, adverse effects, and to address patient concerns. Medication management and teaching are very important in guiding patients to safely manage a schedule that changes daily. In addition, the high risk of pathological fractures and serious injury if the patient should fall supports the need for physical and occupational therapy fall prevention and safety education and exercise programs to help avert decline in functional status and combat cancer-related fatigue.

Modeling Myeloma Dissemination In Vitro with hMSC-interacting Subpopulations of INA-6 Cells and Their Aggregation/Detachment Dynamics

Multiple myeloma involves early dissemination of malignant plasma cells across the bone marrow; however, the initial steps of dissemination remain unclear. Human bone marrow-derived mesenchymal stromal cells (hMSC) stimulate myeloma cell expansion (e.g., IL6) and simultaneously retain myeloma cells via chemokines (e.g., CXCL12) and adhesion factors. Hence, we hypothesized that the imbalance between cell division and retention drives dissemination. We present an in vitro model using primary hMSCs cocultured with INA-6 myeloma cells. Time-lapse microscopy revealed proliferation and attachment/detachment dynamics. Separation techniques (V-well adhesion assay and well plate sandwich centrifugation) were established to isolate MSC-interacting myeloma subpopulations that were characterized by RNA sequencing, cell viability, and apoptosis. Results were correlated with gene expression data (n = 837) and survival of patients with myeloma (n = 536). On dispersed hMSCs, INA-6 saturate hMSC surface before proliferating into large homotypic aggregates, from which single cells detached completely. On confluent hMSCs, aggregates were replaced by strong heterotypic hMSC-INA-6 interactions, which modulated apoptosis time dependently. Only INA-6 daughter cells (nMA-INA6) detached from hMSCs by cell division but sustained adherence to hMSC-adhering mother cells (MA-INA6). Isolated nMA-INA6 indicated hMSC autonomy through superior viability after IL6 withdrawal and upregulation of proliferation-related genes. MA-INA6 upregulated adhesion and retention factors (CXCL12), that, intriguingly, were highly expressed in myeloma samples from patients with longer overall and progression-free survival, but their expression decreased in relapsed myeloma samples. Altogether, in vitro dissemination of INA-6 is driven by detaching daughter cells after a cycle of hMSC-(re)attachment and proliferation, involving adhesion factors that represent a bone marrow-retentive phenotype with potential clinical relevance.

SIGNIFICANCE

Novel methods describe in vitro dissemination of myeloma cells as detachment of daughter cells after cell division. Myeloma adhesion genes were identified that counteract in vitro detachment with potential clinical relevance.

CD38 expression by plasma cells in extramedullary multiple myeloma

Not available.

Safety and Efficacy of Teclistamab in Patients with Relapsed/Refractory Multiple Myeloma: A Real-World Experience

Teclistamab is a B cell maturation antigen (BCMA)-directed bispecific antibody approved for relapsed/refractory multiple myeloma (RRMM) on the basis of the phase I/II MajesTEC-1 trial. Here we report clinical outcomes with standard-of-care teclistamab in a real-world RRMM population. A total of 106 patients from 5 academic centers who received teclistamab from August 2022 to August 2023 were included in this retrospective analysis, 83% of whom would have been considered ineligible for the MajesTEC-1 trial. All patients were triple-class exposed, 64% were penta-class refractory, and 53% had received prior BCMA-directed therapy. Cytokine release syndrome was observed in 64% of patients, and only 1 event was grade ≥3, whereas immune effector cell-associated neurotoxicity syndrome was observed in 14% of patients (3 events were grade 3 or 4). One-third (31%) of patients experienced at least 1 infection, with nearly half of these infections graded as severe (grade ≥3). The overall response rate (ORR) was 66%, and the complete or better response rate was 29%. The ORR was 47% for patients with extramedullary disease (EMD), 59% for patients with prior BCMA-directed therapy exposure, and 68% for patients with penta-refractory disease. At a median follow-up of 3.8 months, the median progression-free survival (PFS) was 5.4 months (95% CI, 3.4 months to not reached), while median overall survival was not reached. Patients with Eastern Cooperative Oncology Group Performance Status ≥2, EMD, and age ≤70 years had inferior PFS on multivariable analysis. Our study demonstrates reasonable safety and good efficacy of teclistamab in patients with RRMM treated in a real-world setting.

Utilizing 3D Models to Unravel the Dynamics of Myeloma Plasma Cells' Escape from the Bone Marrow Microenvironment

Recent therapeutic advancements have markedly increased the survival rates of individuals with multiple myeloma (MM), doubling survival compared to pre-2000 estimates. This progress, driven by highly effective novel agents, suggests a growing population of MM survivors exceeding the 10-year mark post-diagnosis. However, contemporary clinical observations indicate potential trends toward more aggressive relapse phenotypes, characterized by extramedullary disease and dominant proliferative clones, despite these highly effective treatments. To build upon these advances, it is crucial to develop models of MM evolution, particularly focusing on understanding the biological mechanisms behind its development outside the bone marrow. This comprehensive understanding is essential to devising innovative treatment strategies. This review emphasizes the role of 3D models, specifically addressing the bone marrow microenvironment and development of extramedullary sites. It explores the current state-of-the-art in MM modelling, highlighting challenges in replicating the disease's complexity. Recognizing the unique demand for accurate models, the discussion underscores the potential impact of these advanced 3D models on understanding and combating this heterogeneous and still incurable disease.

Real world evidence of epidemiological trends, clinical presentation, and prognostic outcomes of multiple myeloma (2007-2021)

Background

Multiple myeloma (MM) is one of the most common hematological malignancies globally, and it is projected to increase in the coming years. It occurs more frequently in males and affects older individuals. Presenting symptoms can range from being asymptomatic to severely debilitating. The objective of this study was to determine the epidemiology, clinical features, and prognostic outcomes of patients with MM in the only tertiary cancer hospital in Qatar.

Methods

Patients with symptomatic myeloma diagnosed at the National Center for Cancer Care and Research in Qatar between 2007 and 2021 were included. Data on demographics, laboratory work, bone marrow analysis, radiology, and given treatment were collected. Descriptive statistics, survival curves, and multivariable cox regression were used to identify independent mortality risk factors.

Results

During the study period of 15 years, a total of 192 patients were diagnosed with MM. The incident rate of myeloma cases in 2021 was 8 patients per million. The median age of patients was 57 years [range 22-88], with 68% being above the age of 50 years at diagnosis. The majority of patients were male (71%) and (85%) were expats. At the time of diagnosis, most patients [n = 169 (88%)] had bone lesions, and 27% had extramedullary plasmacytoma. Anemia, hypercalcemia, and spinal cord compression were reported in 53%, 28%, and 7% of patients, respectively, at presentation. The monoclonal immunoglobulin subtypes were IgG, IgA, and free light chain in 52%, 16%, and 26% of patients, respectively. The overall median survival was 103 months (95% CI 71-135 months). In a multivariate cox-regression analysis for risk factors, only high serum calcium (≥ 2.7 mmol/L) was associated with increased mortality (HR: 2.54, 95% C.I.: 1.40-4.63, p = 0.002). Patients who received an autologous stem cell transplant (ASCT) had significantly better overall survival.

Conclusion

In this comprehensive study of patients with MM treated in a country with a small and young general population, centralized hematology care, and free cancer care, we found a low but increasing incidence of MM and a good overall survival. Hypercalcemia was confirmed as a negative risk factor. ASCT had a significant positive impact on survival and should be provided to all patients eligible for this treatment, even in the era of novel agents.

Real-world analysis of teclistamab in 123 RRMM patients from Germany

Teclistamab, a B-cell maturation antigen (BCMA) × CD3 directed bispecific antibody, has shown high response rates and durable remissions in the MAJESTEC-1 trial in patients with relapsed and refractory multiple myeloma (RRMM). We retrospectively assessed efficacy and tolerability in 123 patients treated at 18 different German centers to determine whether outcome is comparable in the real-world setting. Most patients had triple-class (93%) or penta-drug (60%) refractory disease, 37% of patients had received BCMA-directed pretreatment including idecabtagene vicleucel (ide-cel) CAR-T cell therapy (21/123, 17.1%). With a follow-up of 5.5 months, we observed an overall response rate (ORR) of 59.3% and a median progression-free survival (PFS) of 8.7 months. In subgroup analyses, we found significantly lower ORR and median PFS in patients with extramedullary disease (37%/2.1 months), and/or an ISS of 3 (37%/1.3 months), and ide-cel pretreated patients (33%/1.8 months). Nonetheless, the duration of response in ide-cel pretreated patients was comparable to that of anti-BCMA naive patients. Infections and grade ≥3 cytopenias were the most frequent adverse events. In summary, we found that teclistamab exhibited a comparable efficacy and safety profile in the real-world setting as in the pivotal trial.

[Consensus for the diagnosis and management of extramedullary plasmacytoma in China(2024)]

Extramedullary plasmacytoma (EMP) is a special type of malignant plasmacytosis, which is complex and heterogeneous. Most EMP patients have poor prognosis and lack a stratified prognostic system or ideal treatment strategy supported by evidence-based medical evidence, which cannot meet clinical needs. In order to improve the understanding of this disease entity, Plasma Cell Disease Group, Chinese Society of Hematology, Chinese Medical Association and Chinese Myeloma Committee-Chinese Hematology Association developed the "Chinese Expert Consensus on the diagnosis and treatment of extramedullary plasmacytoma", which aims to standardize the clinical diagnosis and treatment of EMP and ultimately improve the overall survival of patients with plasmacytoma.

Superior Oblique Muscle Extramedullary Plasmacytoma in a Patient with Multiple Myeloma and a Review of Literature

Introduction

Multiple myeloma (MM), a plasma cell malignancy, is a systemic disease affecting various body organs. Plasmacytoma of bone and extramedullary disease (EMD) are presentations of MM. EMD is usually the sign of a more aggressive form of the disease. Herein, we report a patient with refractory MM presenting with extramedullary plasmacytoma in the superior oblique (SO) muscle.

Case Presentation

A 51-year-old female presented complaining of gradual protrusion of the left eye and ocular pain from 20 days prior. She received bone marrow transplantation 1 year prior and was on a chemotherapy regimen for MM for the past 1 year. Ocular examination revealed proptosis of the left eye and mild limitations of adduction and elevation. Orbital magnetic resonance imaging demonstrated remarkable enlargement of the left SO muscle with focal contrast enhancement. The patient underwent a biopsy and mass debulking. The histopathologic exam revealed fibromuscular tissue containing a neoplasm composed of sheets of plasmacytoid cells in a varying degree of differentiation with intervening scantly vascularized stromal components. The plasmacytoid cells were diffusely positive for a cluster of differentiation 138 (CD138), leading to a diagnosis of EMD involving the EOM and soft tissue of the orbit. The patient underwent palliative radiotherapy and a systemic workup. The PET-CT scan revealed involvement of the pelvic bone and left calf. Accordingly, the chemotherapy regimen was upgraded to reflect the aggressive nature of the disease. In the last follow-up, there was no sign of tumor reactivation in the orbital soft tissues. Unfortunately, the patient succumbed to her illness 7 months following her most recent presentation.

Conclusion

Early recognition of disease recurrence is lifesaving in MM patients; ophthalmic manifestations should be seriously considered as a sign of MM activity.

Isolated Non-Secretory Extramedullary Relapse of Multiple Myeloma Responded Completely to Localized Radiotherapy

Introduction

Non-secretory multiple myeloma (NSMM) is a rare form of multiple myeloma (MM) that is often difficult to detect and has not yet been well characterized. This is due to the lack of production or the presence of monoclonal protein (MP) levels below levels detectable by testing such as serum/urine electrophoresis and immunofixation.

Case Presentation

Two patients of ours were being treated for MM with typical courses of systemic therapy. By the third-line therapy, both developed an extramedullary mass, one in the pelvis and the other in the neck. In both cases, blood work showed no measurable MP, normal free light chain levels, and unremarkable skeletal surveys. Secondary malignancies were suspected due to the clinical presentation in each case, and biopsies confirmed the presence of non-secretory plasmacytomas. Both patients were only treated with localized radiotherapy with a total dose of 2,000 cGy in 5 fractions over 1 week. Ultimately, this resolved the original masses with no residual tumors. No changes had to be made to their systemic therapies, and both patients remained stable.

Conclusion

NSMM relapse is not unusual and should be suspected in patients with relapsed refractory disease. Relapse should be confirmed by a tissue biopsy, and secondary malignancies should be ruled out. Radiotherapy is an excellent option to treat localized relapse and preserve the current line of systemic anti-myeloma therapy.

Design and synthesis of 1H-benzo[d]imidazole selective HDAC6 inhibitors with potential therapy for multiple myeloma

Pan-HDAC inhibitors exhibit significant inhibitory activity against multiple myeloma, however, their clinical applications have been hampered by substantial toxic side effects. In contrast, selective HDAC6 inhibitors have demonstrated effectiveness in treating multiple myeloma. Compounds belonging to the class of 1H-benzo[d]imidazole hydroxamic acids have been identified as novel HDAC6 inhibitors, with the benzimidazole group serving as a specific linker for these inhibitors. Notably, compound 30 has exhibited outstanding HDAC6 inhibitory activity (IC50 = 4.63 nM) and superior antiproliferative effects against human multiple myeloma cells, specifically RPMI-8226. Moreover, it has been shown to induce cell cycle arrest in the G2 phase and promote apoptosis through the mitochondrial pathway. In a myeloma RPMI-8226 xenograft model, compound 30 has demonstrated significant in vivo antitumor efficacy (T/C = 34.8%) when administered as a standalone drug, with no observable cytotoxicity. These findings underscore the immense potential of compound 30 as a promising therapeutic agent for the treatment of multiple myeloma.

Real-world clinical outcomes in patients with relapsed and refractory multiple myeloma receiving VTD-PACE treatment in the era of monoclonal antibodies

Bortezomib (Velcade), thalidomide, dexamethasone, platinum (cisplatin), adriamycin (doxorubicin), cyclophosphamide, and etoposide (VTD-PACE) are commonly used as salvage treatment for patients with relapsed/refractory multiple myeloma (RRMM). However, its outcomes in the era of monoclonal antibodies remain unclear. Therefore, this retrospective cohort study assessed the clinical outcomes of 60 patients with RRMM (median four prior treatment lines) administered VTD-PACE. The median follow-up period was 11.1 months, during which they received a median of two cycles of VTD-PACE. The overall response rate (ORR) was 66.7%; ORRs of 53.1 and 82.1% were noted in patients with ≥ 4 and ≤ 3 prior lines (P = 0.027), respectively. The median overall survival (OS) was 17 months, with a median progression-free survival (PFS) of 9.8 months. Using the 3-month time point after VTD-PACE treatment as a landmark, 54 patients were still alive. Landmark analysis was conducted for PFS and OS of patients who received or did not receive HSCT or CART after VTD-PACE treatment. Patients who underwent subsequent hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T-cell therapy (CART) following VTD-PACE showed a trend of longer PFS and OS than those who did not undergo subsequent HSCT or CART. The median OS in patients with and without renal dysfunction was 10.7 months and 21.5 months, respectively (P = 0.0091). Therefore, VTD-PACE is useful as a bridging therapy for HSCT or CART, as a response can be expected regardless of organ damage, disease risk, or history of anti-CD38 antibody use.

Affibody-based hBCMA x CD16 dual engagers for NK cell-mediated killing of multiple myeloma cells

We describe the development and characterization of the (to date) smallest Natural Killer (NK) cell re-directing human B Cell Maturation Antigen (hBCMA) x CD16 dual engagers for potential treatment of multiple myeloma, based on combinations of small 58 amino acid, non-immunoglobulin, affibody affinity proteins. Affibody molecules to human CD16a were selected from a combinatorial library by phage display resulting in the identification of three unique binders with affinities (KD) for CD16a in the range of 100 nM-3 µM. The affibody exhibiting the highest affinity demonstrated insensitivity towards the CD16a allotype (158F/V) and did not interfere with IgG (Fc) binding to CD16a. For the construction of hBCMA x CD16 dual engagers, different CD16a binding arms, including bi-paratopic affibody combinations, were genetically fused to a high-affinity hBCMA-specific affibody. Such 15-23 kDa dual engager constructs showed simultaneous hBCMA and CD16a binding ability and could efficiently activate resting primary NK cells and trigger specific lysis of a panel of hBCMA-positive multiple myeloma cell lines. Hence, we report a novel class of uniquely small NK cell engagers with specific binding properties and potent functional profiles.

A population-based study on incidence trends of myeloma in the United States over 2000-2020

Myeloma is one of the most common types of haematological malignancies. We aimed to investigate the incidence rates of myeloma by sex, race, age, and histological subgroups in the United States (US) over 2000-2020. Data were retrieved from the the Surveillance, Epidemiology, and End Results (SEER) 22 database. The International Classification of Diseases for Oncology version 3 morphological codes 9731, 9732, and 9734 were assigned for solitary plasmacytoma of bone, plasma cell myeloma, and extraosseous plasmacytoma, respectively. Average annual percent change (AAPC) and the pairwise comparison with the parallelism and coincidence were reported. All estimates were reported as counts and age-adjusted incidence rates per 100,000 individuals. Over 2000-2019, most of myeloma cases were among those aged at least 55 years (85.51%), men (54.82%), and non-Hispanic Whites (66.67%). Among different subtypes, plasma cell myeloma with 193,530 cases had the highest frequency over the same period. Also, there was a significant decrease in the age-standardized incidence rate of myeloma across all races/ethnicities in both sexes within all age groups (AAPC: - 8.02; 95% confidence interval (CI): - 10.43 to - 5.61) and those aged < 55 (AAPC: - 8.64; 95% CI - 11.02 to - 6.25) from 2019 to November 2020. The overall trends of myeloma incidence rates were not parallel, nor identical. There was an increase in myeloma incidence in both sexes, with a highly increasing rate, particularly among younger Hispanic and non-Hispanic Black women over 2000-2019. However, a remarkable decline was observed in the incidence rates following the COVID-19 pandemic in 2020.

Multiple Myeloma in 2023 Ways: From Trials to Real Life

Multiple myeloma is a chronic hematologic malignancy that obstinately tends to relapse. Basic research has made giant strides in better characterizing the molecular mechanisms of the disease. The results have led to the manufacturing of new, revolutionary drugs which have been widely tested in clinical trials. These drugs have been approved and are now part of the therapeutic armamentarium. As a consequence, it is essential to combine what we know from clinical trials with real-world data in order to improve therapeutic strategies. Starting with this premise, our review aims to describe the currently employed regimens in multiple myeloma and compare clinical trials with real-life experiences. We also intend to put a spotlight on promising therapies such as T-cell engagers and chimeric antigen receptor T-cells (CAR-T) which are proving to be effective in changing the course of advanced-stage disease.