Smouldering multiple myeloma: To seek or not to seek? To treat or not to treat. That is the question.

In this issue, the British Society for Haematology presents guidelines for the diagnosis and management of patients with smouldering multiple myeloma (SMM). The authors provide a practical, evidence-based approach to managing these patients. Key questions remain yet unsolved. Commentary on: Hughes et al. Diagnosis and management of smouldering myeloma: A British Society for Haematology Good Practice Paper. Br J Haematol 2024;204:1193-1206.

How I approach smoldering multiple myeloma.

The current standard of care in smoldering multiple myeloma (SMM) is close surveillance, outside of clinical trials. Efforts are being made to understand the pathobiologic process that leads to the progression of SMM to active MM. This review provides a critical description of available data, including risk factors and risk models of progression, as well as clinical trials investigating interventions for this patient population. We describe 2 cases in which patients were seen before the concept of a myeloma-defining event was established. Today, based on the International Myeloma Working Group criteria, both patients would have been identified as experiencing myeloma-defining events, and therapy would have been initiated. These cases show that occasionally, patients can undergo observation only, even when they exceed criteria for high-risk SMM.

Historical Perspective of High-Dose Therapy Followed by Autologous Stem Cell Transplantation in Multiple Myeloma.

BACKGROUND: High-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) has become part of standard of care (SOC) in newly diagnosed multiple myeloma. In this review, we provide a historical perspective on ASCT since its introduction in the 1990s. SUMMARY: Overall survival (OS) benefit for HDT followed by ASCT was demonstrated in studies comparing HDT with ASCT to standard-dose therapy (SDT) before the era of novel agents. Conditioning is done with melphalan 200 mg/m2. Lower doses (MEL140, MEL150) for older patients with comorbidities are safe and have comparable results. The addition of busulfan to melphalan improves progression-free survival (PFS) but not OS. HDT with ASCT after induction with novel agents prolongs PFS but not OS compared to SDT alone. The benefit is more evident in patients with high-risk cytogenetics. Mobilization can be achieved with granulocyte colony-stimulating factor alone, but is improved with the addition of chemotherapy. Plerixafor reduces mobilization failure and enables sufficient stem cell collection after induction with novel agents. ASCT is safe with a low rate of mortality (1%), and selected patients can be managed as outpatients. KEY MESSAGES: HDT followed by ASCT remains part of SOC due to its PFS benefit and relatively low toxicity.

Microvascular cardiac amyloidosis-Cardiac involvement of amyloidosis presenting as typical chest pain.

Coronary microvascular angina from cardiac amyloidosis.

Clinical and pathological predictors for FDG-PET/CT avidity in patients with marginal zone lymphoma-a retrospective cohort study.

BACKGROUND: The clinical value of FDG-PET/CT for staging and monitoring treatment response in patients with aggressive lymphoma is well established. Conversely, its role in the assessment and management of marginal zone lymphoma (MZL) is less conclusive. We aimed to assess clinical, laboratory, and pathological predictors for FDG uptake in these patients, in an attempt to identify MZL patients whose management will benefit from this imaging modality. METHODS: In this single-center, retrospective cohort study, we included all adult patients diagnosed with MZL at the Rabin Medical Center between January 2006 and December 2020 who underwent FDG-PET/CT at the time of diagnosis. Primary outcomes were FDG avidity (defined as a visual assessment of at least moderate intensity), SUVmax, and SUVliver. Variables such as advanced clinical stage, primary disease site, hemoglobin level (Hb), platelet count (Plt), serum albumin, LDH level, ß-2 microglobulin, and Ki 67 index were evaluated univariate and multivariate analysis using logistic and linear regression models. Association between FDG avidity and progression-free and overall survival was evaluated using Kaplan-Meier curves and Cox regression analysis. RESULTS: A total of 207 MZL patients were included in this study, 76 of whom (36.7%) had FDG-avid disease. Baseline patients' characteristics such as age, gender, and comorbid conditions were similar between patients with and without significant FDG uptake. In a multivariate logistic regression model, non-gastric MALT (OR 4.2, 95% CI 1.78-10), Ki 67 index ≥ 15% (OR 3.64, 95% CI 1.36-9.76), and elevated LDH level (OR 8.6, 95% CI 3.2-22.8) were all associated with positive FDG avidity. In a multivariate linear regression model, a combination of advanced clinical stage, specific disease subtypes, LDH level, and Ki 67 index predicted the value of SUVmax (P value < 0.001; adjusted R2 = 33.8%) and SUVmax/SUVliver (P value < 0.001; adjusted R2 = 27%). Baseline FDG avidity was associated to PFS and OS only in univariate analyses. CONCLUSIONS: In this retrospective cohort study, we present prediction models for positive FDG uptake and SUVmax in MZL patients. These models aim to help clinicians choose patients suitable for incorporation of FDG-PET/CT for staging and monitoring disease and reduce the costs of redundant tests.

Prevalence and Clinical Characteristics of Paraproteinemia Associated with Chronic Myeloid Leukemia.

INTRODUCTION: Data regarding the prevalence of paraproteinemia in patients with chronic myeloid leukemia (CML) are lacking. METHODS: To evaluate for the prevalence of paraproteinemia, we undertook this cross-sectional study among consecutive chronic-phase CML patients. Complete blood count, chemistry, immunoglobulins, serum-free light chains, serum-protein electrophoresis and immunofixation were collected. Further analyses evaluated whether various patient-, disease-, and treatment-related variables are associated with paraproteinemia. RESULTS: One hundred patients, median age 63.5 (IQR 48.1-72) years were recruited. Median time from CML diagnosis to enrollment was 6.3 (IQR 2.3-11.3) years. Monoclonal protein was detected in 8 patients (8%), diagnosed with smoldering multiple myeloma (SMM, n = 2) and low-risk monoclonal gammopathy of undetermined significance (MGUS, n = 6). Six patients were on tyrosine kinase inhibitor treatment, 2 were in treatment-free remission. The only covariate associated with paraproteinemia was the presence of anemia, albeit with borderline statistical significance in univariate analysis (p = 0.053) and when adjusted for age (p = 0.056). CONCLUSIONS: In this largest study so far describing the prevalence of paraproteinemia among CML patients, we found MGUS prevalence to be higher than the 3.2% expected prevalence in the general population above 50 years and a non-negligible prevalence of SMM (2%). Screening for paraproteinemia in CML patients, especially in the presence of anemia, should be considered.

Daratumumab for relapsed AL amyloidosis-When cumulative real-world data precedes clinical trials: A multisite study and systematic literature review.

OBJECTIVES: Patients with relapsed/refractory AL amyloidosis (RRAL) have poor prognosis, but emerging data shows promising results with the use daratumumab. We evaluated daratumumab treatment in RRAL in real-world setting. METHODS: A retrospective multisite study of RRAL patients treated with daratumumab alone and in combinations. RESULTS: Forty-nine patients, diagnosed between 1.1.2008 and 1.2.2018 were included; 27% also had multiple myeloma (MM). Revised Mayo score was ≥ 3 in 67%. Hematologic overall response rate was 81%, 64% achieved very good partial response (VGPR) or better. Concurrent active MM was associated with lower rates of VGPR (OR 0.19, 95% CI 0.04-0.81; P = .03) in a multi-variate analysis. Cardiac and renal responses were 74% and 73%, respectively. Median progression-free survival (PFS) was 28.4 months and median overall survival (OS) was not reached; 2-year PFS and OS were 68.6 ± 7.5% and 90.4 ± 4.6%, respectively. Hematologic response correlated with prolonged PFS and OS. Daratumumab was safe and well tolerated, no patients discontinued therapy due to toxicity. Our data was aligned with outcomes from a systematic literature review, which identified 10 case series (n = 517) and 2 clinical trials (n = 62) meeting prespecified criteria. CONCLUSIONS: Our data support favorable safety tolerability and efficacy of daratumumab among non-selective RRAL patients in a real-world setting.

The Role of Autologous Stem Cell Transplantation in Amyloidosis.

Autologous stem cell transplantation (ASCT) has been an essential part of the treatment armamentarium in light chain (AL) amyloidosis for several decades. Patients who achieve a complete hematologic response following ASCT have a long overall survival. However, only 1 randomized controlled trial compared ASCT with the standard of care used at the time, which was melphalan and dexamethasone, and the results did not support the use of ASCT in AL amyloidosis. These results are of limited significance due to the unexpected high transplant-related mortality (TRM) (24%). TRM is a major concern in AL amyloidosis, but its incidence can be lessened by better patient selection and by patients receiving ASCT in specialized centers. ASCT in AL amyloidosis is performed only in selected patients; approximately 20% of patients with AL amyloidosis are transplant eligible up front or after bortezomib (Velcade) based conditioning. The introduction of newer agents such as bortezomib and daratumumab (Darzalex), which lead to deep responses and have good safety profiles, encourage revisiting the benefit and timing of ASCT in the modern era. This review provides a comprehensive assessment of eligibility criteria for ASCT in AL amyloidosis, conditioning dosing, efficacy in terms of hematologic and organ response, and future areas of research.

Prior Carpal Tunnel Syndrome and Early Concomitant Echocardiographic Findings Among Patients With Cardiac Amyloidosis.

BACKGROUND: We aimed to characterize patients with systemic amyloidosis stratified by a prior diagnosis of carpal tunnel syndrome (CTS) and to describe early echocardiographic parameters concomitant with CTS. METHODS AND RESULTS: Patients with suspected amyloidosis during CTS diagnosis were excluded. Our cohort included 108 patients with systemic amyloidosis of which 36% had a prior CTS at a median of 4 years (interquartile range [IQR] 2.8-6.7 years) before disease diagnosis. Patients with prior CTS were more likely to present subsequently with cardiac amyloidosis (78% vs 53%, P = .013), yet overall survival was comparable between groups (53% vs 61%, P = .825). Prior CTS was more commonly diagnosed in subsequent patients with transthyretin (62%) than in patients with immunoglobulin light chain (24%, P < .001). Furthermore, in a subanalysis of patients subsequently diagnosed with cardiac amyloidosis, findings at CTS diagnosis (n = 17) demonstrated a mild increase in septal thickness 1.3 cm (IQR 1.2-1.5 cm), increased relative wall thickness 0.46 cm (IQR 0.45-0.58 cm), and increased left ventricular mass index 155 g/m2(IQR 92-177 g/m2) compared with age-adjusted normal range echocardiographic values. Doppler mitral flow data was supportive of left ventricular diastolic dysfunction. CONCLUSIONS: Early echocardiographic findings at CTS diagnosis, preceding the diagnosis of cardiac amyloidosis by several years, are suggestive of increased wall thickness and diastolic dysfunction.

When to Suspect a Diagnosis of Amyloidosis.

Amyloidosis is a group of complex diseases caused by extracellular deposition of pathological insoluble fibrillary protein in organs and tissues and may result in severe organ dysfunction. Despite the etiological heterogeneity of systemic amyloidosis, the clinical manifestations of the different forms of amyloidosis largely overlap and depend upon the effected organ. The signs and symptoms that should raise suspicion for the potential diagnosis of amyloidosis are usually nonspecific; therefore, establishing the diagnosis is difficult, and early diagnosis requires clinical suspicion. Light chain (AL) amyloidosis may present with highly specific signs such as macroglossia and periorbital purpura, but these signs are insensitive. Amyloidosis is still underdiagnosed, even though treatments are now available and are effective in improving patient's survival and quality of life. Cardiac amyloidosis is the major determinant of survival, and the earlier it is detected the better the survival. All MGUS patients should be routinely screened for AL amyloidosis by a focused history and physical examination and routine assessment of urine albumin. The aim of this review is to provide clinicians with knowledge about the signs and symptoms that raise the suspicion of amyloidosis, bearing in mind the importance of early diagnosis of this disease.

FDG PET/CT as a diagnostic and prognostic tool for the evaluation of marginal zone lymphoma.

We evaluated the role of 18-fluoro-2-deoxy-d-glucose positron emission tomography ([18F] FDG-PET) with computed tomography (CT) (PET/CT) as a diagnostic and prognostic tool in newly diagnosed marginal zone lymphoma (MZL) patients. This is a retrospective cohort study of patients with newly diagnosed MZL, treated with immunotherapy, chemotherapy regimens, surgery, or Helicobacter pylori eradication between 2008 and 2016 in a single tertiary center. Only patients who had a pretreatment PET/CT (P-PET/CT) were included. P-PET/CT, interim (I-PET/CT), and end-of-treatment PET/CT (E-PET/CT) studies were reviewed. P-PET/CT results were reported using two methods of evaluation, qualitative and semi quantitative: visual assessment (VAS) and maximal standardized uptake value (SUVmax), and I-PET and E-PET results were reported by Deauville 5-point score (DS) evaluation as well. Avidity of PET/CT was defined as abnormal uptake in any of these methods. The primary outcome was the prognostic role of P-PET/CT, I-PET/CT, and E-PET/CT on progression-free survival (PFS) and overall survival (OS). Data of 196 patients with MZL were identified, 110 of which had P-PET/CT and were included in this analysis. Median age was 67 years (range 18-93). The median follow-up period was 63 months (range 3-278). The median OS and PFS for the whole cohort were 63 (interquartile range 39-85) and 60 (interquartile range 37-76) months, respectively. The avidity of PET at baseline for the whole cohort was 70% (77/110 patients), for MALT lymphoma, 62.5% (40/64 patients), for NMZL, 76.4% (13/17 patients), and for SMZL, 82.7% (24/29 patients). When adjusted for IPI, sex, and comorbidities, positive E-PET/CT was associated with reduced PFS with a hazard ratio (HR) of 3.4 (95% CI, 1.27-9.14, P = 0.02). Positive E-PET/CT did not correlate with OS. However, there were only three events. P-PET/CT was not predictive of PFS or OS. Our study demonstrates that above 70% of MZL are FDG avid. Positive E-PET/CT is a strong prognostic factor for PFS.

Recent Advances in the Diagnosis, Risk Stratification, and Management of Systemic Light-Chain Amyloidosis.

The term amyloidosis refers to a group of disorders in which protein fibrils accumulate in certain organs, disrupt their tissue architecture, and impair the function of the effected organ. The clinical manifestations and prognosis vary widely depending on the specific type of the affected protein. Immunoglobulin light-chain (AL) amyloidosis is the most common form of systemic amyloidosis, characterized by deposition of a misfolded monoclonal light-chain that is secreted from a plasma cell clone. Demonstrating amyloid deposits in a tissue biopsy stained with Congo red is mandatory for the diagnosis. Novel agents (proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, venetoclax) and autologous stem cell transplantation, used for eliminating the underlying plasma cell clone, have improved the outcome for low- and intermediate-risk patients, but the prognosis for high-risk patients is still grave. Randomized studies evaluating antibodies that target the amyloid deposits (PRONTO, VITAL) were recently stopped due to futility and currently there is an intensive search for novel treatment approaches to AL amyloidosis. Early diagnosis is of paramount importance for effective treatment and prognosis, due to the progressive nature of this disease.

Agranulocytosis Associated with Waldenström Macroglobulinemia.

Currently, there are only 2 case reports of Waldenström macroglobulinemia (WM) associated with severe neutropenia. This is a case report of a woman with a past medical history of WM who presented with neutropenic fever. The patient's febrile neutropenia resolved after RCD chemotherapy (cyclophosphamide 750 mg/m2, dexamethasone 20 mg, and rituximab 375 mg/m2). Fourteen days after administration, the neutrophil level had started to rise and normalized after 6 days. To the best of our knowledge, this is the 3rd reported case of agranulocytosis due to WM.

Immune Therapies in AL Amyloidosis-A Glimpse to the Future.

Light-chain (AL) amyloidosis is a rare plasma cell disorder characterized by the deposition of misfolded immunoglobulin light chains in target organs, leading to multi-organ dysfunction. Treatment approaches have historically mirrored but lagged behind those of multiple myeloma (MM). Recent advancements in MM immunotherapy are gradually being evaluated and adopted in AL amyloidosis. This review explores the current state of immunotherapeutic strategies in AL amyloidosis, including monoclonal antibodies, antibody-drug conjugates, bispecific antibodies, and chimeric antigen receptor T-cell therapy. We discuss the unique challenges and prospects of these therapies in AL amyloidosis, including the exposure of frail AL amyloidosis patients to immune-mediated toxicities such as cytokine release syndrome (CRS) and immune effector-cell-associated neurotoxicity syndrome (ICANS), as well as their efficacy in promoting rapid and deep hematologic responses. Furthermore, we highlight the need for international initiatives and compassionate programs to provide access to these promising therapies and address critical unmet needs in AL amyloidosis management. Finally, we discuss future directions, including optimizing treatment sequencing and mitigating toxicities, to improve outcomes for AL amyloidosis patients.

Lymphoplasmacytic lymphoma and multiple myeloma coexisting in the same patient: a case series and literature review.

The simultaneous occurrence of Waldenström macroglobulinemia and multiple myeloma in the same patient has been published as case reports. Patients with Waldenström macroglobulinemia often have a small clone of plasma cells. However, the concurrent occurrence of symptomatic myeloma with lytic bone lesions is rare. The diagnosis of this 'hybrid' entity is challenging, and there are no standard therapies. We present six patients from five centers (three in Israel and two in the United States). We describe these patients' unique clinical course and treatment approaches.

The short and long-term characteristics and outcomes of patients with grade 1 myocardial uptake on cardiac scintigraphy.

AIMS: This study aimed to characterize the final diagnosis and prognosis of patients with grade 1 myocardial scintigraphy uptake, which is an unequivocal result for the diagnosis of transthyretin cardiac amyloidosis (ATTR-CA) requiring further invasive investigation with tissue biopsy. METHODS AND RESULTS: We retrospectively compared the clinical and imaging parameters of patients suspected for ATTR-CA (based on clinical and echocardiographic parameters) with grade 1 vs. grades 2/3 technetium pyrophosphate uptake on cardiac scintigraphy. Prospectively, grade 1 patients underwent re-evaluation for ATTR-CA at long term. Of the 132 ATTR-CA suspected patients, 89 (67%) were diagnosed as grade 1 and 43 (33%) as grades 2/3 uptake. Grade 1 vs. grades 2/3 patients were younger and female predominant with lower biomarker levels and left ventricular mass. Based on available imaging and pathology findings, only 6 out of the 89 patients with grade 1 uptake (7%) were finally diagnosed with light-chain cardiac amyloidosis, whereas no patient was diagnosed with ATTR-CA. At 2 [interquartile range (IQR) 0.75, 3.25] years of follow-up, the survival of patients with grade 1 vs. grades 2/3 uptake was significantly better [hazard ratio 0.271 (95% confidence interval 0.130 to 0.563, P = 0.0005)]. Prospectively, 30 patients with grade 1 uptake were re-evaluated at a median follow-up of 3.2 (IQR 2.2, 3.9) years. Their New York Heart Association class, biomarker levels, and echocardiography findings remained stable. No patient (0/25) demonstrated grades 2/3 uptake at repeated long-term scintigraphy. CONCLUSIONS: Patients with suspected ATTR-CA and a grade 1 scintigraphy uptake demonstrate a stable clinical, laboratory, imaging, and scintigraphy phenotype along with a benign survival profile at long-term follow-up. Larger studies should define the optimal evaluation strategy in this population.

Venetoclax in Relapse/Refractory AL Amyloidosis-A Multicenter International Retrospective Real-World Study.

Therapeutic options in relapsed refractory (R/R) light-chain (AL) amyloidosis patients are limited. Given the encouraging results in t(11;14) multiple myeloma and the high prevalence of t(11;14) in AL amyloidosis, venetoclax is an attractive treatment option in this setting. We report here the results of a multi-center retrospective study on 26 R/R AL amyloidosis patients treated off-label with venetoclax. The median lines of therapy prior to venetoclax was 3.5 (range 1-7), and 88% of our cohort had t (11;14). Twenty-two patients (85%) were previously treated with daratumumab. The overall hematologic response rate was 88%, 35% achieved a CR, and 35% achieved VGPR. The median event-free survival was 25 months (m) (95% CI 9.7 m-not reached), and the median overall survival was 33 m (95% CI 25.9-39.2 m). Most of the patients in this cohort are in ongoing deep responses and continuing venetoclax therapy. The treatment was relatively safe. One patient died due to infection, and there were two grade 3 infections in our cohort. Tumor lysis syndrome (TLS) was not seen in any patient. Dose reductions were frequent but did not affect the efficacy. These promising results require confirmation in a randomized controlled trial.

Delivery of Therapeutic RNA to the Bone Marrow in Multiple Myeloma Using CD38-Targeted Lipid Nanoparticles.

Multiple myeloma (MM) is a cancer of differentiated plasma cells that occurs in the bone marrow (BM). Despite the recent advancements in drug development, most patients with MM eventually relapse and the disease remains incurable. RNA therapy delivered via lipid nanoparticles (LNPs) has the potential to be a promising cancer treatment, however, its clinical implementation is limited due to inefficient delivery to non-hepatic tissues. Here, targeted (t)LNPs designed for delivery of RNA payload to MM cells are presented. The tLNPs consist of a novel ionizable lipid and are coated with an anti-CD38 antibody (αCD38-tLNPs). To explore their therapeutic potential, it is demonstrated that LNPs encapsulating small interference RNA (siRNA) against cytoskeleton-associated protein 5 (CKAP5) lead to a ≈90% decrease in cell viability of MM cells in vitro. Next, a new xenograft MM mouse model is employed, which clinically resembles the human disease and demonstrates efficient homing of MM cells to the BM. Specific delivery of αCD38-tLNPs to BM-residing and disseminated MM cells and the improvement in therapeutic outcome of MM-bearing mice treated with αCD38-tLNPs-siRNA-CKAP5 are shown. These results underscore the potential of RNA therapeutics for treatment of MM and the importance of developing effective targeted delivery systems and reliable preclinical models.