A real world multicenter retrospective study on extramedullary disease from Balkan Myeloma Study Group and Barcelona University: analysis of parameters that improve outcome

Extramedullary Multiple Myeloma: Challenges and Opportunities

Extramedullary multiple myeloma (EMM), defined in this review as soft tissue plasmacytomas resulting from hematogenous spread, is characterized by the ability of MM cells to proliferate outside of the bone marrow microenvironment. It is aggressive, often associated with high-risk cytogenetics and early relapse, and independently portends significantly shorter progression-free and overall survival, even in the era of highly effective immunotherapies. The molecular and microenvironmental factors underlying extramedullary MM dissemination continue to be studied to inform the development of better treatments. In this review, we discuss our current understanding of the biology of EMM, focusing on its distinct molecular and microenvironmental characteristics vis-à-vis MM. We also review the current treatment strategies, acknowledging the paucity of large, randomized studies specific to this population.

Extramedullary disease in multiple myeloma at diagnosis and over the course of the disease

Extramedullary disease (EMD) is an aggressive manifestation of multiple myeloma (MM) and is categorized into two distinct types: extramedullary-bone-related (EM-B) and extramedullary-extraosseous (EM-E). We aimed to investigate differences in the characteristics of disease and outcomes between these two types. This single-center, retrospective study included 132 patients with EMD who were diagnosed with MM between January 2010 and January 2020. Patients were divided into EM-B (n = 93) and EM-E (n = 39), and clinicopathological features and survival outcomes were analyzed. EMD was observed in 98 (74.2%) patients at initial diagnosis and in 34 (25.8%) during a relapse. EM-E was significantly associated with ≥ 2 involved sites, high bone marrow plasma cell percentage, high LDH and beta-2 microglobulin levels, anemia, and high-risk fluorescence in situ hybridization abnormalities compared to EM-B. Patients with EM-E had significantly shorter progression-free survival and overall survival than those with EM-B. Anemia, hypercalcemia, high LDH, EMD at relapse, ≥ 2 involved sites, and not receiving autologous stem cell transplantation were independent poor risk factors for survival. In conclusion, EMD is a heterogeneous entity, and this study demonstrated that patients with EM-E presented with different clinicopathological characteristics and had worse survival compared to those with EM-B.

Spleen Involvement at Diagnosis of Multiple Myeloma: A Case Report and Literature Review

BACKGROUND

Multiple myeloma (MM) is more often characterized by clonal plasma cell proliferation restricted to the bone marrow. However, a small percentage of patients with MM develop extramedullary disease (EMD): this type of localization is found in 1.7%-4.5% of the newly diagnosed MM (ND/MM) and in 3.4%-10% of patients with relapsed or refractory disease (RR/MM) and seems to have a bad prognostic impact. In the present report, we describe a very rare case of splenic involvement in a patient with ND/MM.

CASE

A 72-year-old female was referred to Santa Rosa Hospital of Viterbo in June 2022 with asthenia and abdominal pain. At physical examination, spleen enlargement was detected, with anemia (Hb 10.5 g/dL) and thrombocytopenia (48 × 109/L). Abdominal echography confirmed spleen enlargement (20 cm of longitudinal diameter). Blood tests showed free light chain alteration with a λ/κ ratio of 800. Marrow aspiration showed 60% of λ-restricted immature plasma cells: p53 expression was present in 91% of elements. Positron emission tomography/computed tomography (PET/CT) scan revealed multiple focal areas of increased metabolic activity in the bones and a widespread positivity of the spleen with focal areas of higher uptake. A diagnosis of MM with splenic EMD was made, and the Dara-VMP regimen (daratumumab, bortezomib, melphalan, and prednisone) was started. After the first cycle of therapy, a marked reduction in spleen size was observed with an increase in both Hb level and platelet count. After the second cycle of therapy, however, there was evolution into plasma cell leukemia: the Vd-PACE regimen (bortezomib, dexamethasone, cisplatin, doxorubicin, cyclophosphamide, and etoposide) was thus started, but after the second cycle, she died in October 2022 from septic shock and multiorgan failure.

CONCLUSIONS

Our very rare case of ND/MM with spleen involvement confirms the aggressive behaviour of EMD, with negative prognostic factors (p53 mutation) and failure to frontline highly effective therapy. In the other few cases of spleen involvement reported, however, there were only scarce details about response: as a consequence, collection of similar cases is warranted to fully understand clinical features and possible alternative approaches for these extremely rare patients.

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

Multicenter 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.

Extramedullary myeloma in the era of CAR T-cell and bispecific antibody therapies

Despite the significant advancements in multiple myeloma therapy over the last decade, current unmet needs include populations of patients who continue to have inferior outcomes, such as those with high-risk cytogenetics, elderly and frail patients, plasma cell leukemia, central nervous system involvement, and extramedullary disease. Though T-cell redirecting therapies have shown excellent efficacy in advanced multiple myeloma, the ability of these therapies to overcome high-risk disease such as extramedullary involvement in myeloma is an area of critical attention. In this review, we seek to examine the specific impact of currently available data of T-cell redirecting therapies, including approved and investigational chimeric antigen receptor T-cell and bispecific antibody therapies, on outcomes in patients with extramedullary myeloma.

Talquetamab plus Teclistamab in Relapsed or Refractory Multiple Myeloma

BACKGROUND

Talquetamab (anti-G protein-coupled receptor family C group 5 member D) and teclistamab (anti-B-cell maturation antigen) are bispecific antibodies that activate T cells by targeting CD3 and that have been approved for the treatment of triple-class-exposed relapsed or refractory multiple myeloma.

METHODS

We conducted a phase 1b-2 study of talquetamab plus teclistamab in patients with relapsed or refractory multiple myeloma. In phase 1, we investigated five dose levels in a dose-escalation study. Talquetamab at a dose of 0.8 mg per kilogram of body weight plus teclistamab at a dose of 3.0 mg per kilogram every other week was selected as the recommended phase 2 regimen. The primary objective was to evaluate adverse events and dose-limiting toxic effects.

RESULTS

A total of 94 patients received treatment, with the recommended phase 2 regimen used in 44. The median follow-up was 20.3 months. Three patients had dose-limiting toxic effects (including grade 4 thrombocytopenia in 1 patient with the recommended phase 2 regimen). Across all dose levels, the most common adverse events were cytokine release syndrome, neutropenia, taste changes, and nonrash skin events. Grade 3 or 4 adverse events, most commonly hematologic events, occurred in 96% of the patients. Grade 3 or 4 infections occurred in 64% of the patients. With the recommended phase 2 regimen, a response occurred in 80% of the patients (including in 61% of those with extramedullary disease); across all dose levels, a response occurred in 78%. The likelihood of patients continuing in response at 18 months was 86% with the recommended phase 2 regimen (82% among those with extramedullary disease) and 77% across all dose levels.

CONCLUSIONS

The incidence of grade 3 or 4 infections with talquetamab plus teclistamab was higher than has been observed with either therapy alone. A response was observed in a high percentage of patients across all dose levels, with durable responses with the recommended phase 2 regimen. (Funded by Janssen Research and Development; RedirecTT-1 ClinicalTrials.gov number, NCT04586426.).

The impact of high-risk cytogenetic abnormalities in extramedullary multiple myeloma in the era of novel agents: insights from a multicenter study

PURPOSE

This study aimed to examine the impact of high-risk cytogenetic abnormalities (HRA) on the survival outcomes of multiple myeloma patients with extramedullary disease (EMD) in the era of novel agents, utilizing the largest dataset of extramedullary multiple myeloma patients in China.

METHODS

This study included a total of 371 patients with EMD, comprising 113 patients with de novo EME and 258 patients with EMB.

RESULTS

Patients with one HRA and those with ≥ 2 HRA demonstrated significantly worse overall survival (OS) (P < 0.01) and progression-free survival (PFS) (P < 0.01) compared to patients without HRA. Additionally, 1q21 gain/amplification (1q21 +) remained a predictor of poor prognosis in EMD. CD38 monoclonal antibody-based therapy and single transplantation were less effective in improving survival outcomes for EMD with ≥ 2 HRA. Multivariable analysis identified LDH levels > 250 U/L, creatinine levels > 177 μmol/L, extramedullary extraosseous (EME), 1 HRA, and ≥ 2 HRA as independent adverse prognostic factors in patients with EMD.

CONCLUSION

Patients with EMD who had ≥ 2 HRA experienced an extremely poor prognosis, which could not be improved by single transplantation or CD38 monoclonal antibody-based treatment. The number of HRA could serve as an important factor in guiding treatment choices and predicting prognosis in patients with EMD. Furthermore, 1q21 + remained a significant factor associated with worse survival outcomes in EMD.

Daratumumab-based regimens for patients with multiple myeloma plus extramedullary plasmacytomas or paraskeletal plasmacytomas: initial follow-up of an Italian multicenter observational clinical experience

Myeloma with extramedullary plasmacytomas not adjacent to bone (EMP) is associated with an extremely poor outcome compared with paraosseous plasmacytomas (PP) as current therapeutic approaches are unsatisfactory. The role of new molecules and in particular of monoclonal antibodies is under investigation. To determine whether daratumumab-based regimens are effective for myeloma with EMP, we report herein an initial multicenter observational analysis of 102 myeloma patients with EMP (n = 10) and PP (n = 25) at diagnosis and EMP (n = 28) and PP (n = 39) at relapse, treated with daratumumab-based regimens at 11 Haematological Centers in Italy.EMP and PP at diagnosis were associated with higher biochemical (90% vs. 96%, respectively) and instrumental ORR (86% vs. 83.3%, respectively), while at relapse, biochemical (74% vs. 73%) and instrumental (53% vs. 59%) ORR were lower. Median OS was inferior in EMP patients compared with patients with PP both at diagnosis (21.0 months vs. NR) (p = 0.005) and at relapse (32.0 vs. 40.0 months) (p = 0.428), although, during relapse, there was no statistically significant difference between the two groups. Surprisingly, at diagnosis, median TTP and median TTNT were not reached either in EMP patients or PP patients and during relapse there were no statistically significant differences in terms of median TTP (20 months for two groups), and median TTNT (24 months for PP patients vs. 22 months for EMP patients) between the two groups. Median TTR was 1 month in all populations.These promising results were documented even in the absence of local radiotherapy and in transplant-ineligible patients.

The characteristics of patients with multiple myeloma surviving over 10 years

Objective

To explore the characteristics of patients with multiple myeloma (MM) who have achieved long-term survival of over 10 years in the context where novel agents and autologous stem cell transplantation (ASCT) serve as the primary therapeutic modalities.

Methods

A retrospective analysis was conducted on 168 MM patients diagnosed and treated in our institution from January 2004 to January 2014. 44 patients with a survival period exceeding 10 years were categorized into the long-term survival group, while 124 patients with a survival period of less than 10 years were categorized into the non-long-term survival group.

Results

Being younger than 57 years old (OR 3.634, 95%CI 1.302-10.143), having a neutrophil count of at least 3.66 * 109/L (OR 3.122, 95% CI 1.093-8.918), absence of high-risk genetic abnormalities (OR 7.146, 95%CI 1.066-47.904), and receiving frontline ASCT (OR 4.225, 95%CI 1.000-17.841) were positively associated with a survival period exceeding 10 years in patients with MM. Achieving sustained minimal residual disease (MRD) negativity for at least 24 months is associated with long-term survival regardless of the presence of high-risk cytogenetic abnormalities.

Conclusion

Being younger, having a neutrophil count above 3.66 * 109/L, the absence of high-risk cytogenetic abnormalities, and receiving frontline ASCT are independent protective factors for transplant-eligible MM patients to survive more than 10 years. Achieving maintained MRD negativity status for over 24 months might be associated with long-term survival.

Challenges in the treatment of soft-tissue plasmacytoma: a retrospective analysis of 120 patients with extramedullary multiple myeloma

PURPOSE

Despite the development of novel drugs and the widespread use of hematopoietic cell transplantation, the prognosis of patients (pts) with multiple myeloma and extramedullary involvement (soft-tissue plasmacytoma, STP) is rather unfavorable.

METHODS

A retrospective analysis of 120 pts with STP treated between 2007 and 2022 was performed. The effects of demographic and clinical characteristics on treatment response, progression-free survival (PFS), and overall survival (OS) were evaluated.

RESULTS

The rate of serological response to first-line STP treatment (at least partial remission) was 67%, and the rate of imaging response was 59%. With a median follow-up of 84.2 months, the median PFS was 10.5 months (primary STP: 20.2 months; secondary STP: 5.8 months), and the median OS was 24.5 months (primary STP: 34.5 months; secondary STP: 12.4 months). Based on the multivariate regression analysis, secondary STP (HRPFS 2.75; HROS 2.63) and organ involvement (HRPFS 1.45; HROS 1.68) were found to be negative prognostic factors of both PFS and OS. In a prognostic model, pts with at least one of these factors had a significantly worse PFS (HRPFS 3.31) and OS (HROS 3.45) than those with none risk factor.

CONCLUSION

In pts with STP, risk-adapted treatment strategies including immunotherapies and cell therapies are urgently required.

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.

Prognostic Implications of Circulating Plasma Cell Percentage in Multiple Myeloma and Primary Plasma Cell Leukemia Defined by New Criteria

INTRODUCTION

The definition of primary plasma cell leukemia (pPCL) has been revised from ≥20% to ≥5% circulating plasma cells (CPC). However, the precise prognosis associated with CPC remains controversial. This study aimed to investigate prognostic biomarkers for myeloma patients based on CPC presence.

METHODS

A comprehensive analysis was conducted on 309 consecutive patients diagnosed with either multiple myeloma or pPCL, utilizing peripheral blood smears stained with Wright-Giemsa.

RESULTS

Patients were grouped by CPC percentage: 0% (221, 71.5%), 1-4% (49, 15.9%), 5-19% (16, 5.2%), ≥20% (23, 7.4%). CPC >5% correlated with unfavorable characteristics, including anemia, renal dysfunction, and advanced International Staging System. Common cytogenetic abnormalities such as 1q21 amplification, 17p deletion, and Myc rearrangement were prevalent among CPC-positive patients. Median progression-free survival (PFS) and overall survival (OS) were shorter in patients with CPC ≥5% (29.47 vs. 10.03 months; 64.10 vs. 12.30 months). Additionally, PFS and OS were shorter in CPC-positive patients without autologous hematopoietic stem cell transplantation (ASCT) and those with response < partial remission to the first-line regimen. Furthermore, an association emerged between soft tissue-related extramedullary disease and inferior PFS, while Myc rearrangement correlated with abbreviated OS.

CONCLUSION

Biological characteristics displayed greater aggressiveness in patients with positive CPC, leading to significantly shorter PFS and OS. The presence of CPC, ASCT, and overall response rate were independent prognostic factors. While no new threshold for pPCL with CPCs is proposed, Myc rearrangements and CPC positivity could serve as ultra-high-risk factors for multiple myeloma.

INTRODUCTION

The definition of primary plasma cell leukemia (pPCL) has been revised from ≥20% to ≥5% circulating plasma cells (CPC). However, the precise prognosis associated with CPC remains controversial. This study aimed to investigate prognostic biomarkers for myeloma patients based on CPC presence.

METHODS

A comprehensive analysis was conducted on 309 consecutive patients diagnosed with either multiple myeloma or pPCL, utilizing peripheral blood smears stained with Wright-Giemsa.

RESULTS

Patients were grouped by CPC percentage: 0% (221, 71.5%), 1-4% (49, 15.9%), 5-19% (16, 5.2%), ≥20% (23, 7.4%). CPC >5% correlated with unfavorable characteristics, including anemia, renal dysfunction, and advanced International Staging System. Common cytogenetic abnormalities such as 1q21 amplification, 17p deletion, and Myc rearrangement were prevalent among CPC-positive patients. Median progression-free survival (PFS) and overall survival (OS) were shorter in patients with CPC ≥5% (29.47 vs. 10.03 months; 64.10 vs. 12.30 months). Additionally, PFS and OS were shorter in CPC-positive patients without autologous hematopoietic stem cell transplantation (ASCT) and those with response < partial remission to the first-line regimen. Furthermore, an association emerged between soft tissue-related extramedullary disease and inferior PFS, while Myc rearrangement correlated with abbreviated OS.

CONCLUSION

Biological characteristics displayed greater aggressiveness in patients with positive CPC, leading to significantly shorter PFS and OS. The presence of CPC, ASCT, and overall response rate were independent prognostic factors. While no new threshold for pPCL with CPCs is proposed, Myc rearrangements and CPC positivity could serve as ultra-high-risk factors for multiple myeloma.

Elranatamab efficacy in MagnetisMM-3 compared with real-world control arms in triple-class refractory multiple myeloma

Elranatamab efficacy in the single-arm, registrational MagnetisMM-3 trial (NCT04649359) was compared with that of physician's choice of treatment (PCT) for triple-class refractory multiple myeloma. MagnestisMM-3 eligibility criteria were applied to two USA-based oncology electronic health record databases, COTA and Flatiron Health (FH), to identify cohorts for this study (NCT05932290). Applied statistical techniques accounted for cohort imbalances. MagnetisMM-3 (BCMA-naive; n = 123) outcomes were compared with those from COTA (n = 239) and FH (n = 152). Elranatamab was associated with a significantly higher objective response rate (risk ratios, 1.88-2.25), significantly longer progression-free survival (hazard ratios [HRs], 0.37-0.57), and, across most analyses, significantly longer overall survival (HRs, 0.46-0.66) versus PCT. BCMA-naive patients who were treated with elranatamab exhibited significantly better outcomes than patients treated in real-world clinical practice.

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.

Doxorubicin-loaded PEG-CdTe QDs conjugated with anti-CXCR4 mAbs: a novel delivery system for extramedullary multiple myeloma treatment

Extramedullary multiple myeloma (EMM) is defined as the presence of plasma cells outside the bone marrow of multiple myeloma patients, and its prognosis is poor. High-dose chemotherapy with autologous stem cell transplantation, as a good option on early lines of therapy, has retained the survival benefit of youny EMM patients, but is intolerant for the majority of old patients because of drug cytotoxicity. To essentially address the intolerance above, we designed a CXCR4-PEG-CdTe-DOX (where CXCR4: chemokine receptor 4; PEG-CdTe: polyethylene glycol-modified cadmium telluride; DOX:doxorubicin) nanoplatform. First, CXCR4 is highly expressed in extramedullary plasma cells. Second, PEG-CdTe a drug carrier that controls drug release, can reduce adverse reactions, prolong drug (e.g, DOX) circulation time in the body, and form a targeting carrier after connecting antibodies. In vitro experiments showed CXCR4-PEG-CdTe-DOX facilitated intracellular drug accumulation through active CXCR4 targeting and released DOX into the microenvironment in a pH-controlled manner, enhancing the therapeutic efficacy and apoptosis rate of myeloma cells (U266). Therefore, targeted chemotherapy mediated by CXCR4-PEG-CdTe-DOX is a promising option for EMM treatment.

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.

Identification of evolutionary mechanisms of myelomatous effusion by single-cell RNA sequencing

Myelomatous effusion (ME) is a rare manifestation of extramedullary multiple myeloma (MM) with limited therapeutic options and poor outcomes. The molecular mechanisms underlying ME are incompletely understood. We profiled transcriptomes of bone marrow, peripheral blood (PB), and pleural effusion/ascites from 3 patients with ME using single-cell RNA sequencing analysis. We found that ME contained a higher percentage of cytotoxic T cells, whereas PB contained a higher proportion of naive T cells. Malignant cells varied within and between sites and patients in their expression of signatures. We identified a gene module highly expressed in intramedullary and extramedullary plasma cell clusters and defined cell clusters expressing this gene set as extramedullary-initiating cells (EMICs). This gene set was associated with increased cellular proliferation, involved in p53 signaling, and related to poor prognosis in MM. The transcriptional regulators E2F1, YY1, and SMAD1 were activated in EMICs. Leukocyte immunoglobulin-like receptor subfamily B4 (LILRB4) was upregulated in extramedullary EMICs. We confirmed that LILRB4 promoted MM cell migration in vitro. This study provided insight into the evolutionary mechanisms of ME and defined EMICs and LILRB4 associated with extramedullary development.

Massive Myelomatous Pleural Effusion With Contralateral Mediastinal Shift: A Unique Presentation of Extramedullary Myeloma

Multiple myeloma (MM) is a relatively common malignancy that primarily affects the bone marrow, while extramedullary disease (EMD) occurs in the skin and muscle, lung pleura, lymph nodes, liver, and CNS. Myelomatous pleural effusion (MPE) is a rare extramedullary manifestation of MM in which pleural fluid is composed almost entirely of abnormal plasma cells. MPE and other types of EMD are associated with poor prognosis, and MPE can present emergently due to tension physiology. We report a case of a patient with massive MPE presenting with contralateral midline shift. There are exceedingly few such cases and this report highlights a unique presentation of this rare clinical entity. Epidemiology, radiographic features, diagnosis, treatment, and implications for the prognosis of the disease are discussed.

Paraskeletal plasmacytoma presenting as a chest wall mass

Extramedullary involvement in multiple myeloma is uncommon. It can present as a plasma cell mass in the soft tissue surrounding the bony structures through direct extension or in various other organs via hematogenous spread. Here, we report a case of paraskeletal plasmacytoma that manifested as a chest wall mass in a 60-year-old man.

Proteomic and Metabolomic Analysis of Bone Marrow and Plasma from Patients with Extramedullary Multiple Myeloma Identifies Distinct Protein and Metabolite Signatures

Multiple myeloma (MM) is an incurable haematological malignancy of plasma cells in the bone marrow. In rare cases, an aggressive form of MM called extramedullary multiple myeloma (EMM) develops, where myeloma cells enter the bloodstream and colonise distal organs or soft tissues. This variant is associated with refractoriness to conventional therapies and a short overall survival. The molecular mechanisms associated with EMM are not yet fully understood. Here, we analysed the proteome of bone marrow mononuclear cells and blood plasma from eight patients (one serial sample) with EMM and eight patients without extramedullary spread. The patients with EMM had a significantly reduced overall survival with a median survival of 19 months. Label-free mass spectrometry revealed 225 proteins with a significant differential abundance between bone marrow mononuclear cells (BMNCs) isolated from patients with MM and EMM. This plasma proteomics analysis identified 22 proteins with a significant differential abundance. Three proteins, namely vascular cell adhesion molecule 1 (VCAM1), pigment epithelium derived factor (PEDF), and hepatocyte growth factor activator (HGFA), were verified as the promising markers of EMM, with the combined protein panel showing excellent accuracy in distinguishing EMM patients from MM patients. Metabolomic analysis revealed a distinct metabolite signature in EMM patient plasma compared to MM patient plasma. The results provide much needed insight into the phenotypic profile of EMM and in identifying promising plasma-derived markers of EMM that may inform novel drug development strategies.

Clinical Value of FDG-PET/CT in Multiple Myeloma: An Update

FDG-PET/CT is a standardized imaging technique that has reached a great importance in the management of patients affected by Multiple Myeloma. It is proved, in fact, that it allows a deep evaluation of therapy efficacy and provides several prognostic indexes both at staging and after therapy. For this reason, it is now recognised as a gold standard for therapy assessment. Beside this, in reacent years FDG-PET/CT contribution to the understanding of Multiple Myeloma has progressively grown. Papers have been published analyzing the prognostic value of active disease volume measurement and standardization issues, the meaning of FDG positive paramedullary and extrameduallary disease, the prognostic impact of FDG positive minimal residual disease, the relation between focal lesions and clonal eterogenity of this disease and the comparison with whole body DWI-MR in terms of detection and therapy assessment. These newer aspects not of clinical impact yet, of FDG-PET/CT in Multiple Myeloma will be presented and discussed in this review.

Impact of newly diagnosed extramedullary myeloma on outcome after first autograft followed by maintenance: A CMWP-EBMT study

BACKGROUND

No adequate data exist on the impact of multiple myeloma (MM) with extramedullary disease (EMD) after autograft and maintenance therapy.

METHODS

We identified 808 patients with newly diagnosed MM who received first autograft, of whom 107 had EMD (83 paraskeletal and 24 organ involvement), and who had been reported to the EBMT registry December 2018. Distribution according to type of involvement was similar between the treatment groups (p = .69). For EMD, 46 (40%) received thalidomide, 59 (51%) lenalidomide, and 11 (10%) bortezomib.

RESULTS

The median follow-up from maintenance start was 44 months. Three-year progression-free survival (PFS) was 52% (48%-57%) for no EMD, 56% (44%-69%) for paraskeletal involvement, and 45% (22%-68%) for organ involvement (p = .146). Early PFS (within first year) appeared to be significantly worse for organ involvement (hazard ratio, 3.40), while no significant influence was found after first year from maintenance start. Three-year overall survival (OS) was 81% (77%-84%), 88% (80%-96%), and 68% (47%-89%; p = .064), respectively. With thalidomide as reference, lenalidomide was significantly associated with better PFS and OS, whereas bortezomib appeared to improve outcome specifically in EMD.

CONCLUSION

Lenalidomide maintenance is standard of care for MM without EMD, whereas extramedullary organ involvement remains a significant risk factor for worse outcome, especially for early events after maintenance start.

Experts' consensus on the definition and management of high risk multiple myeloma

High risk multiple myeloma (HRMM) at diagnosis is currently recognized according to the Revised International Staging System (R-ISS) which was set up in 2015. Since then, new clinical and biological prognostic factors have been developed, which could implement the definition of High Risk (HR) category. We conducted a survey in order to identify which additional parameters, both clinical and biological, are considered more useful for the clinical practice and to evaluate if the management of Multiple Myeloma (MM) should change on the basis of the risk category. A questionnaire, consisting of 8 statements, was submitted to 6 Italian experts, from the European Myeloma Network (EMN) Research Italy, using the Delphi method. The colleagues were asked to answer each question using a scale between 0 and 100. If a statement did not reach at least 75 out of 100 points from all the participants, it was rephrased on the basis of the proposal of the experts and resubmitted in a second or further round, until a consensus was reached among all. From the first round of the survey a strong consensus was reached regarding the opportunity to revise the R-ISS including chromosome 1 abnormality, TP53 mutation or deletion, circulating plasma cells by next generation flow and extramedullary plasmacytomas. No consensus was reached for the definition of "double hit" MM and for the application in clinical practice of treatment strategies based on the risk category. In the second round of the Delphi questionnaire, "double-hit" MM was recognized by the association of at least two high-risk cytogenetic or molecular abnormalities. Moreover, the experts agreed to reserve an intensified treatment only to specific conditions, such as plasma cell leukaemia or patients with multiple extramedullary plasmacytomas, while they admitted that there are not sufficient real word data in order to modify treatment on the basis of MRD assessment in clinical practice. This survey suggests that the definition of HRMM should be implemented by additional clinical and biological risk factors, that will be useful to guide treatment in the future.

[Effects of extramedullary disease on patients with newly diagnosed multiple myeloma]

Objective: To summarize the characteristics of patients with newly diagnosed multiple myeloma (NDMM) admitted at Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine. We compared the clinical characteristics and prognoses among patients with non-extramedullary disease (EMD), bone-related extramedullary (EM-B) disease, and extraosseous extramedullary (EM-E) disease and further explored the effects of autologous hematopoietic stem cell transplantation (ASCT) for EMD. Methods: From January 2015 to January 2022, data of 114 patients (22%) with EMD out of 515 patients with NDMM were retrospectively analyzed; 91 (18%) and 23 (4%) patients comprised the EM-B and EM-E groups, respectively. The clinical characteristics of patients in all groups were compared with the Chi-square test. Progression-free survival (PFS) and overall survival (OS) of patients were analyzed by the Kaplan-Meier method. Independent prognostic factors were determined using multivariate Cox proportional hazard model. Results: There were no significant differences in age, gender, ISS stage, light chain, creatinine clearance, cytogenetic risk, 17p deletion, ASCT, and induction regimens among the three groups. Overall, 13% of EM-E patients had IgD-type M protein, which was significantly higher than that in EM-B patients (P=0.021). The median PFS of patients in the non-EMD, EM-B, and EM-E groups was 27.4, 23.1, and 14.0 months; the median OS was not reached, 76.8 months, and 25.6 months, respectively. The PFS (vs non-EMD, P=0.004; vs EM-B, P=0.036) and OS (vs non-EMD, P<0.001; vs EM-B, P=0.002) were significantly worse in patients with EM-E, while those were not significantly different between patients with EM-B and those with non-EMD. In the multivariate analysis, EM-E was an independent prognostic factor for OS in patients with NDMM (HR=8.779, P<0.001) and negatively impacted PFS (HR=1.874, P=0.050). In those who did not undergo ASCT, patients with EM-B had significantly worse OS than those with non-EMD (median 76.8 months vs. not reached, P=0.029). However, no significant difference was observed in the PFS and OS of patients with EM-B and those with non-EMD who underwent ASCT. Conclusions: Compared to patients with either non-EMD or EM-B, those with EM-E had the worst prognosis. EM-E was an independent risk factor for OS in patients with NDMM. ASCT can overcome the poor prognosis of EM-B.

Clinical and radiological presentations of ovarian plasmacytoma

BACKGROUND

The occurrence of extramedullary plasmacytoma (EMP) in the ovaries is rare. Here, we describe the clinical, pathological and radiological presentations of ovarian plasmacytomas to improve the differential diagnosis of this disease. Also, the reasons for misdiagnosis, clinical manifestations and radiological features were discussed through a literature review.

CASE PRESENTATION

A 54-year-old woman was suspected to have EMP upon routine ultrasound examination and was subsequently diagnosed using pathological examination of the left ovarian mass. The radiological features of this case included (1) a solitary soft-tissue mass in the left ovary with clear boundaries; (2) a homogeneous mass with medium-density without necrosis, which was homogeneously enhanced after contrast medium injection; and (3) magnetic resonance imaging showing a homogeneous lesion with isointense signals on T1- and T2-weighted imaging, restricted diffusion on diffusion-weighted imaging, and a low apparent diffusion coefficient value of approximately 0.72×10^-3 mm²/s, which was significantly and homogeneously enhanced after contrast medium injection with a rapid rise-slow decay type, and with thickened vascular shadows around the lesion.

CONCLUSIONS

EMP in the ovary is rare and only a few cases have been reported. We reviewed EMP-related literature and the summarized the clinical manifestations, radiological features and treatment strategies of this disease to help the diagnosis and management. Application of second-line drugs might be a viable strategy to improve the survival rate of patients and to prevent the progression to a certain extent.

A prognostic model for patients with primary extramedullary multiple myeloma

Background: Extramedullary disease is a manifestation of multiple myeloma, the prognosis of which remains poor even in the era of novel drugs. Therefore, we aimed to develop a predictive model for patients with primary extramedullary multiple myeloma (EMM). Methods: Clinical and laboratory data of patients diagnosed with primary EMM between July 2007 and July 2021 were collected and analyzed. Univariate and least absolute shrinkage and selection operation Cox regression analyses (LASSO) were used to select prognostic factors for overall survival (OS) to establish a nomogram prognostic model. The performance of the model was evaluated using concordance index which was internally validated by bootstraps with 1,000 resample, area under the curve (AUCs), and calibration curves. Results: 217 patients were included in this retrospective study. Patients with EMM had a higher rate of belonging to the male sex, age >50 years, advanced Durie-Salmon stage III, hypercalcemia, and low hemoglobin level. Compared with patients with bone-related extramedullary disease, those with extraosseous-related extramedullary disease had a higher frequency of advanced Durie-Salmon stage III, lower rate of hypercalcemia, and elevated prothrombin time. The OS and progression-free survival (PFS) of patients with bone-related extramedullary disease were significantly higher than those of patients with extraosseous-related extramedullary disease. After the univariate and LASSO analyses, six prognostic factors, including performance status, number of extramedullary involved sites, β2-microglobulin, lactate dehydrogenase, monocyte-lymphocyte ratio, and prothrombin time, were integrated to establish a nomogram. The model showed robust discrimination with a concordance index (C-index) of 0.775 (95% confidence interval [CI], 0.713-0.836), internally validated with the corrected C-index of 0.756, and excellent performance in time-dependent AUCs compared with other staging systems. The AUCs for 1-, 3-, and 5-year OS were 0.814, 0.744, and 0.832, respectively. The calibration curves exhibited good consistency between the observed and nomogram-predicted OS. The 5-year OS of patients in the high-risk group (23.3%; 95% CI, 13.9%-39.3%) was much worse than that in the low-risk group (73.0%; 95% CI, 62.5%-85.4%; p < 0.001). Conclusion: The nomogram predictive model based on six clinical variables showed good prognostic performance and could better predict individual survival in patients with EMM.

Phase II trial of daratumumab with DCEP in relapsed/refractory multiple myeloma patients with extramedullary disease

Extramedullary multiple myeloma (EMD) is an aggressive subentity of multiple myeloma (MM) with poor prognosis. As more innovative therapeutic approaches are needed for the treatment of MM with EMD, we conducted this multicenter, non-randomized phase II trial of daratumumab in combination with dexamethasone, cyclophosphamide, etoposide and cisplatin (DARA-DCEP). A total of 32 patients (median age 59, range 35–73) were treated with DARA-DCEP. Based on the best response during the study, the complete remission (CR) rate was 35.5% and overall response rate (ORR) 67.7%. During the median follow-up of 11 months, the median progression-free survival (PFS) was 5 months and median overall survival (OS) 10 months. There were 7 long-term responders whose median PFS was not reached. The most common grade ≥ 3 hematologic AE was thrombocytopenia. The most common non-hematologic AE was nausea (22.6%), followed by dyspepsia, diarrhea and stomatitis (all 12.9%). Grade ≥ 3 daratumumab infusion-related reaction was noted in 9.7% of the patients. Except for the planned 30% dose adjustment in cycle 1, only 2 patients required DCEP dose reduction. This is one of the very few prospective trials focusing on EMD and we successfully laid grounds for implementing immunochemotherapy in MM treatment.

This is one of the very few prospective trials focusing on refractory multiple myeloma with extramdedullary disease (EMD).

We successfully laid grounds for implementing immunochemotherapy in EMD treatment.

Clinical Characteristics and Prognosis of Multiple Myeloma With Myelomatous Pleural Effusion: A Retrospective Single-Center Study

Objectives: Myelomatous pleural effusion is a rare presentation of extramedullary disease in multiple myeloma, which has been reported with dismal prognosis. We aimed to explore whether it has distinctive clinical characteristics and outcomes compared to other anatomic locations of extramedullary involvements. Methods: Multiple myeloma patients diagnosed at our institution from 2010 to 2020 were retrieved retrospectively. In total, 42 pairs of patients with and without extramedullary disease were enrolled, including 13 with myelomatous pleural effusion. The clinical and laboratory parameters were collected and compared between different groups. Prognostic effect of myelomatous pleural effusion was assessed in cox regression model and Kaplan-Meier curves. Results: Myelomatous pleural effusion patients presented a higher level of β2-microglobulin (P = .041), greater prevalence of multisites extramedullary lesions (69.2% vs 38.0%, P = .036) and International Staging System stage III (76.9% vs 44.8%, P = .016). Median overall survival was 60.6 months in patients without extramedullary disease versus 35.0 months in patients with extramedullary disease (P = .045). Notably, median overall survival was 13.0 months in myelomatous pleural effusion patients versus 37.0 months in other extramedullary disease patients with a significant difference (P = .029). Furtherly, multivariate analysis recognized myelomatous pleural effusion as an independent prognostic indicator (Hazard ratio: 2.669, 95% CI [1.132-6.293], P = .025). Conclusion: Myelomatous pleural effusion patients presented heavier tumor burden and worse outcomes than other extramedullary diseases.

Unexpected Heterogeneity of Newly Diagnosed Multiple Myeloma Patients with Plasmacytomas

In multiple myeloma (MM), malignant plasma cells infiltrate the bone marrow. In some cases, plasma cells migrate out of the bone marrow creating either para-skeletal plasmacytomas (PS) or infiltrating soft tissues as extramedullary plasmacytomas (EMD). The aim of this study was to define risk groups in newly diagnosed MM (NDMM) patients with PS and EMD plasmacytomas. In total, 523 NDMM patients with PS plasmacytomas and 196 NDMM patients with EMD plasmacytomas were diagnosed in the Czech Republic between 2004 and 2021 using modern imaging methods. Patients’ data were analyzed from the Registry of Monoclonal Gammopathies of the Czech Myeloma Group. In NDMM patients with PS plasmacytomas, we found a subgroup with <5% of bone-marrow plasma cells to have the best prognosis (mPFS: 58.3 months (95% CI: 33.0−NA); mOS: not reached). The subgroup with >5% of bone-marrow plasma cells and ≥3 plasmacytomas had the worst prognosis (mPFS: 19.3 months (95% CI: 13.4−28.8), p < 0.001; mOS: 27.9 months (95% CI: 19.3−67.8), p < 0.001). Our results show association between tumor burden and prognosis of NDMM patients with plasmacytomas. In the case of PS plasmacytomas, NDMM patients with low BM PC infiltration have an excellent prognosis.

Paraskeletal and extramedullary plasmacytomas in multiple myeloma at diagnosis and at first relapse: 50-years of experience from an academic institution

From January 1970 to December 2018, 1304 patients were diagnosed with multiple myeloma (MM) at our institution and 256 (19.6%) had plasmacytomas (Ps) (paraskeletal –PPs- 17.6%, extramedullary –EMPs-1.9%). Patients with Ps had lower serum M-protein and less advanced ISS stage than those without. At first relapse, 192 out of 967 patients (19.8%) developed Ps (PPs 14.6%, EMPs 5.1%). The only factor associated with Ps at relapse was the presence of Ps at diagnosis (46% vs 13%, p < 0.00001) with no impact with exposure to novel drugs or previous autologous stem-cell transplantation (ASCT). The median overall survival (OS) was 45, 44 and 20 months for patients without Ps, PPs and EMPs, respectively (p = 0.013). Patients with PPs who underwent ASCT had similar OS than those without Ps (98 vs. 113 months) and significantly longer than those with EMPs (98 vs 47 months, p = 0.006). In patients non-eligible for ASCT the presence of PPs or EMPs was associated with shorter OS compared with patients without Ps (32 vs. 24 vs. 6 months, p = 0.009). In the relapsed setting, a significant survival benefit was observed beyond the year 2000, but still with significant differences among patients without Ps, PPs and EMPs (37 vs 22 vs 16 months, p = 0.003). Importantly, rescue therapy with combinations of proteasome-inhibitors plus immunomodulatory drugs was associated with prolonged OS from first relapse (over 6 years), even in patients with EMPs.

Evaluation of isatuximab in patients with soft-tissue plasmacytomas: An analysis from ICARIA-MM and IKEMA

The Phase 3 ICARIA-MM (NCT02990338) and IKEMA (NCT03275285) studies demonstrated that isatuximab (Isa) plus pomalidomide (P) and dexamethasone (d; Isa-Pd) or carfilzomib (K) and d (Isa-Kd) improved progression-free survival (PFS) versus Pd or Kd in patients with relapsed and/or refractory multiple myeloma. In this post hoc analysis of patients with soft-tissue plasmacytomas, we evaluated Isa-Pd/Isa-Kd efficacy using central radiology and central laboratory assessments. Given the low incidence of soft-tissue plasmacytomas (7.8 %, ICARIA-MM; 6.3 %, IKEMA), efficacy data were pooled across the two studies. PFS (HR, 0.47; 95 % CI, 0.21-1.08), overall response rate (50.0 % vs 17.7 %), and very good partial response or better rate (26.9 % vs 11.8 %) were improved with Isa-Pd/Isa-Kd versus Pd/Kd, with consistent improvements within individual studies. Patients with soft-tissue plasmacytomas who received Isa-Pd/Isa-Kd had similar median PFS compared with those without soft-tissue plasmacytomas and received Pd/Kd. Safety is reported individually per study. Longer median treatment duration and more Grade ≥ 3 treatment-emergent adverse events occurred in the Isa versus control arms in ICARIA-MM (36.9 vs 8.4 weeks; 85.7 % vs 70.0 %) and IKEMA (41.9 vs 29.9 weeks; 100.0 % vs 57.1 %); however, Isa did not increase the percentage of patients with fatal events or drug discontinuation. Isa-Pd or Isa-Kd is a potential new treatment option and partially overcomes the poor prognosis associated with soft-tissue plasmacytomas in relapsed and/or refractory multiple myeloma.

Gastrointestinal, Hepatic and Pancreatobiliary Involvement by Plasma Cell Neoplasms: Clinicopathologic Correlations in a Retrospective Cohort of 116 Cases

AIMS

Plasma cell neoplasms (PCNs) may involve the gastrointestinal (GI) tract in two forms: plasmacytoma (PC), an isolated lesion which lacks marrow involvement, and extramedullary myeloma (EMM). However, previous literature on PCNs involving the GI tract, liver and pancreas is limited. We evaluated the clinicopathologic features of the largest series of GI PCNs to date.

METHODS AND RESULTS

Six institutional archives were searched for GI, liver and pancreas cases involved by PCNs. Medical records were reviewed for clinical and imaging features. Histopathologic features evaluated included involved organ, tumor grade and marrow involvement. Overall, 116 cases from 102 patients were identified. Tumors most presented as incidental findings (29%). The liver was most involved (47%), and masses/polyps (29%) or ulcers (21%) were most common findings. Most cases had high-grade morphology (55%). The majority (74%) of GI PCNs were classified as EMM due to the presence of marrow involvement at some point during the disease course, occurring within a year of marrow diagnosis in 46% of patients. PC was classified in 26% of patients due to the lack of marrow involvement. Most (70%) patients died from disease within 10 years (median 14.1) of diagnosis and more than half (58%) died within 6 months.

CONCLUSION

PC and EMM involving the GI tract, liver and pancreas have a wide range of clinicopathologic presentations. Tumors may occur virtually anywhere in the GI tract or abdomen and may precede the diagnosis of marrow involvement. Both GI PC and EMM are associated with a poor prognosis.

Real-World Evidence of Daratumumab Monotherapy in Relapsed/Refractory Multiple Myeloma Patients and Efficacy on Soft-Tissue Plasmacytomas

INTRODUCTION

Daratumumab is an anti-CD38 agent that was first investigated as single agent in GEN501 and SIRIUS trials in patients with advanced multiple myeloma (MM). Overall response rate (ORR) was 30% with positive impact on progression-free survival (PFS). However, there is a lack of information regarding plasmacytoma response.

MATERIALS AND METHODS

Here, we described a heavily pretreated group of 43 patients who received daratumumab monotherapy after EMA approval and focused on plasmacytoma response.

RESULTS

After a median follow-up of 26 months, median time to best response was 2.9 months (range 0.8-13.1), median PFS was 5.2 months (95% CI 2.5 - 8.8) and median OS was 11.2 months (95% CI 6.3 - 17.0). Patients who achieved at least partial response had longer median PFS and OS (12.8 and 20.2 months, respectively) than those who achieved minimal response or stable disease (5.3 and 11.2 months, respectively). Ten patients (23%) had plasmacytomas (70% paraskeletal, 30% extramedullary). The clinical benefit for patients with and without plasmacytomas was 20% versus 42%. A dissociation between serological and plasmacytoma response was observed in 40% of the patients. Thus, 50% of the patients with plasmacytomas achieved at least serological minimal response but only 20% had plasmacytoma response.

CONCLUSION

This is the first real-world study of daratumumab monotherapy that focuses on efficacy data regarding soft-tissue plasmacytomas in patients with relapsed/refractory mieloma, showing a limited benefit in this patient population.

Advances in the treatment of extramedullary disease in multiple myeloma

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Extramedullary multiple myeloma results in an adverse prognosis.

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Novel agents such as bortezomib, lenalidomide, pomalidomide, isatuximab and selinexor showed efficacy and were recommended to treat EMD.

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For EMD at special sites, marizomib has advantages in the treatment of CNS-MM; Daratumumab combining with intrapleural bortezomib administration is active in treating myelomatous pleural effusion.

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Based on treatment experience of EMD in our department, we summarized treatment approach for EMD.

Extramedullary disease (EMD) is characterized by plasma cells outside of bone marrow in multiple myeloma (MM) patients, which results in an adverse prognosis. The cornerstone of treatment consists of combination therapy including proteasome inhibitors, immunomodulatory agents, steroids, followed by consolidative autologous hematopoietic stem cell transplantation in eligible patients. This review summarized the recent advances in the treatment of EMD. Bortezomib based therapy showed efficacy and was recommended to treat EMD. Marizomib had advantages in the treatment of central nervous system-multiple myeloma (CNS-MM) because of its good central nervous system penetrability. Immunomodulatory drugs such as lenalidomide and pomalidomide have been reported to be effective. Isatuximab and selinexor were also active. Based on the treatment experience of EMD in our department, we summarized treatment approach for EMD. However, the benefits of patients with EMD from the new era of novel drugs were limited. Novel drugs combination, monoclonal antibody, molecular targeted therapy, cellular immunotherapy and autologous stem cell transplantation (ASCT) are under investigation. Therapeutic studies and clinical trials specifically target EMD should be conducted. Hopefully, these treatment options for EMD will be demonstrated efficacy in the future.

Bone-Related Extramedullary Disease in Newly Diagnosed Myeloma Patients is an Independent Poor Prognostic Predictor

Background

Bone-related extramedullary disease (EMD-B) is mass of clonal plasma cells derived from adjacent bone lesions and has obvious heterogeneities in clinical outcomes. This retrospective study aims to evaluate the treatment outcomes and long-term prognosis of newly diagnosed myeloma patients with EMD-B.

Methods

This was a retrospective study conducted in Beijing Chaoyang Hospital from January 1, 2010 to December 31, 2019. Seventy-seven newly diagnosed multiple myeloma patients with EMD-B were selected. Propensity score matching (1:2) was used to match patients with and without EMD-B. After matching, 132 patients without extramedullary disease (non-EMD) were included in the study. All patients received bortezomib-based regimens as induction therapy.

Results

After matching, baseline data of the 2 groups were comparable. The Cox regression analysis of patients with EMD-B showed that age, paravertebral lesions, and immunoglobulin D (IgD) type may have adverse effects on survival. Bone-related extramedullary disease at new diagnosis was a risk predictor of survival (hazard ration [HR] = 1.80, 95% confidence interval [CI]: 1.09-2.98, P = .022). The median survival time of the EMD-B group was significantly shorter than that of the non-EMD group (52 months vs 96 months, P = .043). Induction therapy did not show any significant differences in effectiveness between the 2 groups. Autologous stem cell transplantation (ASCT) significantly increased complete remission rate of patients with EMD-B (EMD-B vs non-EMD: no ASCT 15.7% vs 31.9%, P = .035; ASCT 42.3% vs 48.8%, P = .626) and improved their median overall survival rate (EMD-B vs non-EMD: no ASCT 49 months vs 75 months, P = .003; ASCT not reached vs 96 months, P = .505).

Conclusions

This study demonstrated that newly diagnosed myeloma patients with EMD-B had poor outcomes, which could be improved by ASCT.

Central Nervous System Myeloma and Unusual Extramedullary Localizations: Real Life Practical Guidance

Central nervous system localization of multiple myeloma (CNS-MM) accounts for about 1% of all MM during disease course or even rarer at diagnosis. A difference in the origin, i.e., osteodural or primary dural vs leptomeningeal/intraparenchymal, seems to define two distinct types of intracranial myeloma, with different clinical behavior. CNS-MM may occur also as a presentation of MM. Treatment is still unsatisfactory and many treatments have been reported: chemotherapy, intrathecal therapy, and radiotherapy, with dismal prognosis. Other sites of myeloma localization could be also of interest and deserve description. Because of the rarity and aggressiveness of the disease clinicians are often doubtful on how to treat it since there is no general agreement. Moreover, recent drugs such as the anti CD38 monoclonal antibody, immunomodulatory drugs, and proteasome inhibitors have changed the treatment of patients with MM with a significant improvement in overall response and survival. The role of novel agents in CNS MM management and unusual presentations will be discussed as well as the potential role of other new immunomodulatory drugs and proteasome inhibitors that seem to cross the blood-brain barrier. The purpose of this review is to increase awareness of the clinical unusual presentation and neuroradiological findings, give practical diagnostic advice and treatment options algorithm.

Relapse with plasmacytoma after upfront autologous stem cell transplantation in multiple myeloma

Please present P values consistently.Plasmacytoma has been reported to be associated with a poor prognosis in patients with multiple myeloma (MM). In this study, we evaluated the incidence of relapse with plasmacytoma and survival outcomes after upfront autologous stem cell transplantation (ASCT). This study retrospectively analyzed the data of 303 patients with MM who underwent upfront ASCT between April 2000 and April 2018 at eight institutes in the Republic of Korea. In total, 52 patients (17.1%) had plasmacytoma at MM relapse after upfront ASCT, of whom, 27 had paramedullary plasmacytoma (PMD) and 25 had extramedullary plasmacytoma (EMD). Patients with initial plasmacytoma were more likely to have plasmacytoma at MM relapse than those without initial plasmacytoma (37.1% vs. 11.2%). Over a median follow-up of 66.0 months, patients with plasmacytoma at relapse had significantly inferior overall survival (OS) than those without plasmacytoma (43.9 vs. 100.7 months, P < 0.001), but the OS did not significantly differ between patients with EMD and those with PMD (42.2 vs. 56.6 months, P=0.464). After MM relapse, all patients received salvage therapy, and progression-free survival after relapse was significantly shorter in patients with plasmacytoma than in those without (6.4 vs. 12.4 months, P = 0.007). This study showed that plasmacytoma frequently developed at MM relapse after upfront ASCT in patients with plasmacytoma at the time of diagnosis. Plasmacytoma at relapse was significantly associated with a poor prognosis.

Comparison of clinical features of multiple myeloma with paraosseous and extraosseous plasmacytoma in the era of novel drugs: a systemic review and meta-analysis

BACKGROUND

Extramedullary myeloma constitutes a small portion of multiple myeloma (MM) with a more aggressive clinical course and inferior prognosis. Two types of extramedullary myeloma, paraosseous (PO) and extraosseous (EO) plasmacytoma, differ significantly in pathogenesis, clinical features and outcomes but there have been limited studies comparing them based on large patient cohorts.

METHODS

Relevant studies published before June 2021 were searched in MEDLINE, Embase and Cochrane databases. Two reviewers independently assessed the quality of included studies and discrepancies were evaluated by a third reviewer. Extracted data was analyzed by Stata12.

RESULTS

997 MM patients with PO and 288 with EO plasmacytoma were analyzed. Patients with EO plasmacytoma tended to have larger tumor burden according to International Staging System though it did not reach statistical significance (P=0.1). Newly diagnosed MM (NDMM) patients with EO plasmacytoma had significantly inferior outcome than PO plasmacytoma (OS OR=2.32, 95% CI 1.80-2.98, P<0.001, I²=40.9%; PFS OR=1.66, 95% CI 1.39-1.99, P<0.001, I²=0.0%). No significant difference in OS was found in relapsed MM patients. Auto-HSCT seemed to attenuate the disadvantage in response rate of EO plasmacytoma.

CONCLUSIONS

NDMM patients with EO plasmacytoma had significantly inferior prognosis than PO plasmacytoma, while relapsed MM patients did not show such difference. More strategies are needed to improve its clinical outcome.

Recurrent extramedullary plasmacytomas without multiple myeloma: A case report with review of the literature

BACKGROUND

Extramedullary plasmacytoma (EMP) is an uncommon presentation and usually occurs in conjunction with multiple myeloma (MM). An EMP without developing MM at any point is an extremely rare presentation, and only seven such cases have been reported in the literature to date.

PRESENTATION OF CASE

We present a case of EMP, who presented with multiple recurrent lesions in rare sites like nasal cavity, testis and skin without the involvement of bone marrow at any point of disease course. He was treated with multiagent chemotherapy (DT-PACE) and continues to be in remission at 29 months post-chemotherapy, which is the longest amongst all the cases reported so far.

DISCUSSION AND CONCLUSIONS

There are no clearly defined guidelines to treat EMP. Our case had a clinical presentation at very unusual sites and was treated with DT-PACE regimen as against the previous seven reported cases and had the most prolonged period of remission.

Extramedullary disease in multiple myeloma: a systematic literature review

Extramedullary involvement (or extramedullary disease, EMD) represents an aggressive form of multiple myeloma (MM), characterized by the ability of a clone and/or subclone to thrive and grow independent of the bone marrow microenvironment. Several different definitions of EMD have been used in the published literature. We advocate that true EMD is restricted to soft-tissue plasmacytomas that arise due to hematogenous spread and have no contact with bony structures. Typical sites of EMD vary according to the phase of MM. At diagnosis, EMD is typically found in skin and soft tissues; at relapse, typical sites involved include liver, kidneys, lymph nodes, central nervous system (CNS), breast, pleura, and pericardium. The reported incidence of EMD varies considerably, and differences in diagnostic approach between studies are likely to contribute to this variability. In patients with newly diagnosed MM, the reported incidence ranges from 0.5% to 4.8%, while in relapsed/refractory MM the reported incidence is 3.4 to 14%. Available data demonstrate that the prognosis is poor, and considerably worse than for MM without soft-tissue plasmacytomas. Among patients with plasmacytomas, those with EMD have poorer outcomes than those with paraskeletal involvement. CNS involvement is rare, but prognosis is even more dismal than for EMD in other locations, particularly if there is leptomeningeal involvement. Available data on treatment outcomes for EMD are derived almost entirely from retrospective studies. Some agents and combinations have shown a degree of efficacy but, as would be expected, this is less than in MM patients with no extramedullary involvement. The paucity of prospective studies makes it difficult to justify strong recommendations for any treatment approach. Prospective data from patients with clearly defined EMD are important for the optimal evaluation of treatment outcomes.

Efficacy and follow-up of humanized anti-BCMA CAR-T cell therapy in relapsed/refractory multiple myeloma patients with extramedullary-extraosseous, extramedullary-bone related, and without extramedullary disease

The prognosis of patients with multiple myeloma (MM) with extramedullary disease (EMD) remains poor. A high overall response rate (ORR) has been reported following anti‐B‐cell maturation antigen (BCMA) chimeric antigen receptor (CAR)‐T cell therapy in relapsed/refractory (R/R) patients with MM; however, data on patients with EMD remain limited. Herein, we compared and analyzed the efficacy and long‐term follow‐up of anti‐BCMA CAR‐T cell therapy in R/R MM patients with extramedullary‐extraosseous (EM‐E), extramedullary‐bone related (EM‐B), and without extramedullary disease. No difference in the ORR was observed between the three groups. The long‐term efficacy of anti‐BCMA CAR‐T cell therapy in the EM‐E group was worse than that in patients without EMD and with EM‐B. In the EM‐E group, disease progression was the reappearance of extramedullary lesions without an increase in the MM cell percentage or M protein level. Although no difference in the proportion of CAR‐T cells was detected among the three groups, the EM‐E group might exhibit a relatively high grade of cytokine release syndrome following anti‐BCMA CAR‐T therapy. Interleukin‐6 levels in the without EMD group were lower than those in the EM‐E and EM‐B groups. However, given the small number of cases in the three groups, statistical analysis was not performed.(ChiCTR1800017051 and ChiCTR2000033925).

Research progress on treatment of extramedullary multiple myeloma

ABSTRACTObjectives: Extramedullary multiple myeloma (EMM) is a relatively less frequent subentity of multiple myeloma (MM) and is generally considered to be a poor prognostic factor. Novel agents and hematopoietic stem cell transplantation (HSCT) have led to a significant improvement in the progression-free survival and overall survival of patients with MM, but outcomes of EMM remain dismal. Little is known regarding the role of novel therapies in this setting. This review summarizes the current available data regarding the roles of proteasome inhibitors, immunomodulators, monoclonal antibodies, chimeric antigen receptor (CAR)-T cell therapy and HSCT in EMM.Methods: A systematic literature review through PubMed was conducted to summarize the published evidence on the therapeutic developments of novel agents and HSCT in EMM. Literature sources published in English were searched, using the terms multiple myeloma, extramedullary and treatment.Results: Long-term outcomes of EMM patients remain dismal despite the utilization of novel agents and HSCT. The standard therapy of EMM has not been established. EMM should be managed as high-risk disease and treated accordingly.Discussion and conclusion: This review will provide an insight on the current and emerging treatment strategies as well as their efficacy in EMM. Further subgroup analyses in large prospective trials focusing on EMM is needed to help optimize the therapy.

Identification of patients at high risk of secondary extramedullary multiple myeloma development

Multiple myeloma (MM) is characterized by malignant plasma cell infiltration of the bone marrow. In extramedullary multiple myeloma (EMD), a subclone of these cells migrates out of the bone marrow. Out of 4 985 MM patients diagnosed between 2005 and 2017 in the Czech Republic, we analyzed 234 secondary EMD patients to clarify risk factors of secondary EMD development. We found younger age [<65 years; odds ratio (OR) 4·38, 95% confidence interval (CI): 2·46–7·80, P < 0·0001], high lactate dehydrogenase (LDH) levels (>5 μkat/l; OR 2·07, 95% CI: 1·51–2·84, P < 0·0001), extensive osteolytic activity (OR 2·21, 95% CI: 1·54–3·15, P < 0·001), and immunoglobulin A (IgA; OR 1·53, 95% CI: 1·11–2·11, P = 0·009) or the non‐secretory type of MM (OR 2·83; 95% CI: 1·32–6·04, P = 0·007) at the time of MM diagnosis to be the main risk factors for secondary EMD development. Newly diagnosed MM (NDMM) patients with subsequent EMD had inferior median progression‐free (PFS) and overall (OS) survival when compared to NDMM patients without future EMD [mPFS: 13·8 months (95% CI: 11·4–16·3) vs 18·8 months (95% CI: 17·7–19·9), P = 0·006; mOS: 26·7 months (95% CI: 18·1–35·4) vs 58·7 months (95% CI: 54·8–62·6), P < 0·001]. We found that NDMM patients with specific risk factors associated with secondary EMD development have a more aggressive disease course before secondary EMD develops.

Extramedullary disease in multiple myeloma

When clonal plasma cells grow at anatomic sites distant from the bone marrow or grows contiguous from osseous lesions that break through the cortical bone, it is referred to as extramedullary multiple myeloma (EMD). EMD remains challenging from a therapeutic and biological perspective. The pathogenetic mechanisms are not completely understood and it is generally associated with high-risk cytogenetics which portends poor outcomes. There is a rising incidence of EMD in the era of novel agents, likely a reflection of longer OS, with no standard treatment approach. Patients benefit from aggressive chemotherapy-based approaches, but the OS and prognosis remains poor. RT has been used for palliative care. There is a need for large prospective trials for development of treatment approaches for treatment of EMD.

Efficacy of Humanized Anti-BCMA CAR T Cell Therapy in Relapsed/Refractory Multiple Myeloma Patients With and Without Extramedullary Disease

In recent years, many new treatments for relapsed/refractory (R/R) multiple myeloma (MM) have improved patient prognosis, but the prognosis of patients with extramedullary MM is still particularly poor. Therefore, more efficacious therapies and novel strategies are urgently needed for these patients. The aim of this study was to observe and compare the efficacy and safety of humanized anti-B cell maturation antigen (anti-BCMA) chimeric antigen receptor (CAR) T cell therapy in R/R MM patients with and without extramedullary disease. Seven R/R MM patients with extramedullary disease and 13 without extramedullary disease received humanized anti-BCMA CAR T cell therapy. The overall response rate was not different between patients with and without extramedullary disease. There was no difference in the progression-free survival (PFS) or overall survival (OS) rates between the two groups at 180 days, but the PFS and OS rates in patients with extramedullary disease were lower at 360 days than those in patients without extramedullary disease. Although some patients with extramedullary disease experienced further disease progression, their M protein level did not increase. We did not see this change trend of M protein in patients without extramedullary disease. However, this was not observed in patients without extramedullary disease. Among patients who responded to CAR T cell therapy, the grades of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxic syndrome (ICANS) were much higher among patients with extramedullary disease. In summary, R/R MM patients with extramedullary disease could benefit from humanized anti-BCMA CAR T cell therapy in the short term, although the CRS and ICANS grades were much higher in patients with extramedullary disease. Therefore, anti-BCMA CAR T cell therapy allows for a remission time for R/R MM patients with extramedullary disease, which could be maintained by bridging hematopoietic stem cell transplantation, radiotherapy, and other therapies.

Clinical Trial Registration

http://www.chictr.org.cn/index.aspx, identifiers ChiCTR1800017051 and ChiCTR2000033925.

Multiple Extramedullary-Bone Related and/or Extramedullary Extraosseous Are Independent Poor Prognostic Factors in Patients With Newly Diagnosed Multiple Myeloma

Background

Extramedullary (EM) lesions are common in multiple myeloma (MM) and are often related to the poor prognosis of MM but are scarcely understood.

Methods

In this retrospective study, the baseline characteristics of 357 newly diagnosed patients with extramedullary multiple myeloma (EMM) and their impact on the prognosis were analyzed. All patients received first-line treatment with bortezomib-based regimen.

Results

The overall incidence rate of EM was 22.4%, and the detection rate of PET/CT was significantly higher than other imaging methods (P = 0.015). The cohorts consisted of 10 cases of extramedullary extraosseous (EME) and 70 cases of extramedullary-bone related (EMB), including 53 cases with single site involvement (one case with EME) and 27 cases with multiple sites (>1 site) involvement (nine cases with EME). EMM patients had high levels of hemoglobin (Hgb, ≥10 g/dl) and serum lactate dehydrogenase (LDH, >245u/L) and are inclined to early-stage revised international staging system (R-ISS). Compared to patients without EM, those with EMM had worse progression-free survival (PFS) (P = 0.014) and overall survival (OS) (P = 0.032). In addition, patients without EM and those with a single site of EMB had similar PFS and OS, while patients with multiple sites of EMB or EME and multiple sites of EMB with EME had poor PFS and OS. Multivariate analysis confirmed that multiple sites of EMB and/or EME were independent prognostic predictors affecting PFS and OS in newly diagnosed MM patients.

Conclusions

This study suggested that among patients treated with bortezomib-based regimens, multiple sites of EMB and/or EME are independent poor prognostic factors for newly diagnosed MM patients, while a single site of EMB does not affect the survival of newly diagnosed MM patients. Thus, these findings could be used as a reference for the study of EMM patients in the new drug era, but prospective clinical studies are needed to provide evidence-based data for the diagnosis and treatment of EMM.

Successful Treatment of Relapsed/Refractory Extramedullary Multiple Myeloma With Anti-BCMA CAR-T Cell Therapy Followed by Haploidentical Hematopoietic Stem Cell Transplantation: A Case Report and a Review of the Contemporary Literature

Extramedullary multiple myeloma (EMM) is an aggressive sub-entity of multiple myeloma (MM). Despite an excellent improvement in survival for most patients with MM over recent decades, the overall survival (OS) of patients with EMM was usually not longer than 3 years. Standard treatment for patients with EMM has not been established, and their management is particularly challenging. We presented a heavily pretreated young patient with relapsed EMM and refractoriness to a proteasome inhibitor (PI; bortezomib), a next-generation PI (ixazomib), immunomodulatory drugs (IMiDs; lenalidomide), autologous hematopoietic stem cell transplantation (ASCT), and monoclonal antibody (directed against CD38: daratumumab) and indicated that myeloablative haploidentical hematopoietic stem cell transplantation (haploidentical-HSCT) as a salvage treatment of relapse after a chimeric antigen receptor (CAR)-T cell therapy that targeted B-cell maturation antigen (BCMA) (NCT04650724) is feasible. Taken together of the contemporary literature, the promising results on the effect of anti-BCMA CAR-T cell therapy and allogeneic HSCT might present a proof-of-principle for patients with EMM, and therefore, patients with the disease need to be included in future studies.