Understanding high-risk smoldering multiple myeloma

Smoldering multiple myeloma (SMM) is an asymptomatic condition with heterogeneous biology and various risks of progression to symptomatic disease. The best-known risk stratification models are Mayo-2018, and IWWG based on tumor burden. Recently, the personalized risk assessment tool PANGEA was introduced. New markers of SMM progression, including genomic and immune characteristics of plasma cells (PCs) and tumor microenvironment, are under investigation, and some have been incorporated into traditional scoring systems. Only one phase 3 clinical trial demonstrated an overall survival benefit of lenalidomide for high-risk SMM patients. The study has limitations, and most guidelines recommend observation or participation in clinical trials for high-risk SMM. High-intensity time-limited treatment strategies for high-risk SMM demonstrated deep responses in single-arm studies. But these treatments can cause adverse effects in asymptomatic patients.This review aims to understand better the risk of SMM progression from a clinical and biological point of view.

Prevalence, mutational spectrum and clinical implications of clonal hematopoiesis of indeterminate potential in plasma cell dyscrasias

Clonal hematopoiesis of indeterminate potential (CHIP) is common both in healthy individuals and patients with hematological cancers. Recent studies have showed worse prognosis for patients with multiple myeloma (MM) and non-Hodgkin lymphoma undergoing stem cell transplant, that have concomitant presence of CHIP. Data regarding the clinical and biological role of CHIP in plasma cell dyscrasias (PCDs) is rapidly increasing. However, the prevalence and prognostic implication of CHIP in patients with MM outside of the transplant setting, and in those with other more indolent PCDs remains elusive. Here we explored the prevalence and clinical implications of CHIP detected through next-generation sequencing in 209 patients with PCDs including MM, light chain (AL) amyloidosis (ALA), monoclonal gammopathy of undetermined significance (MGUS), and smoldering multiple myeloma (SMM). To avoid attributing the mutations to the plasma cell clone, CHIP was defined as the presence of DNMT3A, TET2, or ASXL1 mutations in the peripheral blood or bone marrow (DTA-CH). The prevalence of DTA-CH was 19% in patients with PCDs, with no difference between each PCD. TET2 (23%) and DNMT3A (22%), were the most frequently mutated genes. DTA-CH correlated with older age in MM (P = .001) and MGUS/SMM (P = 0.0007), as well as with coronary artery disease or congestive heart failure in MM (P = .03). DTA-CH did not predict worse OS or PFS in either MM or ALA, nor it predict higher risk of progression to MM in patients with MGUS/SMM. Our results overall further elucidate the prevalence and mutational spectrum of CHIP in PCDs, providing more information regarding the clinical relevance of CHIP in this patient population.

Lenalidomide-dexamethasone versus observation in high-risk smoldering myeloma after 12 years of median follow-up time: A randomized, open-label study

BACKGROUND

Smoldering multiple myeloma (SMM) is a heterogeneous disease in terms of progression to myeloma (MM), but its standard of care continues to be observation.

METHODS

The QuiRedex phase 3 trial initiated in 2007 included 119 high-risk patients with SMM randomized to treatment or observation. Treatment consisted of nine 4-week induction cycles (lenalidomide [Rd], 25 mg on days 1-21 plus dexamethasone, 20 mg on days 1-4 and 12-15), followed by maintenance (R, 10 mg on days 1-21) for up to 2 years. The primary end-point was time to progression (TTP) to myeloma based on per protocol population. Secondary end-points were overall survival (OS), response rate, and safety. An update of the trial after a long-term follow-up is presented here. This trial was registered with ClinicalTrials.gov (NCT00480363).

FINDINGS

After a median follow-up time of 12.5 years (range: 10.4-13.6), the median TTP to MM was 2.1 years in the observation arm and 9.5 years in the Rd arm (HR: 0.28, 95% CI: 0.18-0.44, p < 0.0001). The median OS was 8.5 years in the abstention arm and not reached in the Rd group (HR: 0.57, 95% CI: 0.34-0.95, p = 0.032). Patients who progressed received optimized treatments according to the standards of care, and the OS from progression was comparable in both arms (p = 0.96).

INTERPRETATION

This analysis confirms that early treatment with Rd for high-risk SMM translates into a sustained benefit in both TTP and OS.

FUNDING

Pethema (Spanish Program for the Treatment of Hematologic Diseases), Spain.

Gastrointestinal amyloidosis in a patient with smoldering multiple myeloma: A case report

BACKGROUND

Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell proliferative disorder that can progress to multiple myeloma (MM). Amyloidosis (light chain) (AL) is the most common form of systemic amyloidosis. There are few reports of SMM coexisting with AL involving the digestive tract.

CASE SUMMARY

A 63-year-old woman presented with lower limb edema, abdominal distension, abdominal pain, and hematochezia. Gastroscopy showed gastric retention, gastric angler mucosal coarseness, hyperemia, and mild oozing of blood. Colonoscopy showed hyperemic and edematous mucosa of the distal ascending colon and sigmoid colon with the presence of multiple round and irregular ulcers, submucosal ecchymosis, and hematoma. Gastric and colonic tissue biopsy confirmed the diagnosis of AL by positive Congo red staining. MM was confirmed by bone marrow biopsy and immunohistochemistry. The patient had no hypercalcemia, renal dysfunction, anemia, bone lesions or biomarkers of malignancy defined as plasma cells > 60% in bone marrow. Additionally, no elevated serum free light chain ratio, or presence of bone marrow lesions by magnetic resonance imaging (SLiM criteria) were detected. The patient was finally diagnosed with SMM coexisting with AL. She received chemotherapy and was discharged when the symptoms were relieved. She is doing well at nearly five years of follow up.

CONCLUSION

This case highlights that high index of suspicion is required to diagnose gastrointestinal AL. It should be suspected in elderly patients with endoscopic findings of granular-appearing mucosa, ecchymosis, and submucosal hematoma. Timely diagnosis and appropriate therapy can help to improve the prognosis of these patients.

The benefits of early intervention using lenalidomide for high-risk smoldering multiple myeloma: emerging data and its promising clinical impact

INTRODUCTION

Multiple myeloma is preceded by the early stages: monoclonal gammopathy of unknown significance (M.G.U.S.) and smoldering myeloma (S.M.M.), which are less genomically complex and where patients are overall healthier with preserved quality of life.

AREAS COVERED

This review focuses on the current evidence in risk stratification and initial therapy for these patients with the goal to delay progression to and/or cure multiple myeloma.

EXPERT OPINION

Advances in the understanding of the factors that contribute to myeloma evolution coupled with new therapeutics that have high efficacy and limited toxicity have revolutionized our approach to early myeloma. Although our current recommendation continues to be to observe S.M.M. outside of clinical trials, the clinical benefit of lenalidomide sets the stage for combinations with immunotherapy, which, in our opinion, will likely lead to regulatory approvals and more widespread treatment of early myeloma.

Smoldering multiple myeloma - Past, present, and future

Smoldering multiple myeloma (SMM) routinely precedes the development of multiple myeloma. While some patients experience aggressive disease, others have more indolent courses akin to those with monoclonal gammopathy of undetermined significance. Much effort has been made to understand the pathobiological basis of this heterogeneity. Scientific advancements have led to the emergence of various clinical and genomic markers of relevance, translating into evolution of disease definitions over time. More recently, the interest in manipulation of biological pathways has intensified in a bid to stall or halt disease progression. Studies with lenalidomide have exemplified the promise of early intervention, whereas numerous therapeutic approaches remain the subject of ongoing clinical investigation. This review summarizes the historic progress made in defining SMM as a distinct clinicopathologic entity, provides a critical appraisal of the evidence guiding risk assessment, and suggests a pragmatic approach to its modern-day management. Finally, an overview of developments on the horizon is also provided.

Evaluation of Cardiac Repolarization in the Randomized Phase 2 Study of Intermediate- or High-Risk Smoldering Multiple Myeloma Patients Treated with Daratumumab Monotherapy

Introduction

Daratumumab is a CD38-targeting monoclonal antibody that has demonstrated clinical benefit for multiple myeloma. Daratumumab inhibition of CD38, which is expressed on immune cell populations and cardiomyocytes, could potentially affect cardiac function. This QTc substudy of the phase 2 CENTAURUS study investigated the potential effect of intravenous daratumumab monotherapy on QTc prolongation and other electrocardiogram (ECG) parameters, including concentration-QTc effect modeling.

Methods

Patients had intermediate- or high-risk smoldering multiple myeloma. Patients with QT interval corrected by Fridericia’s formula (QTcF) > 470 ms, QRS interval ≥ 110 ms, or PR interval ≥ 200 ms were excluded. Triplicate ECGs were collected at screening, Dose 1, and Dose 8. Analyses of on-treatment ECGs were conducted with a time-matched baseline (primary analysis). By time-point, pharmacokinetic-pharmacodynamic (PK/PD), and outlier analyses were conducted.

Results

Of 123 patients in CENTAURUS, 31 were enrolled in the QTc substudy. Daratumumab produced a small increase in heart rate (5–12 beats per minute) of unclear significance. There was a small but clinically insignificant effect on QTc, as measured by both time-matched time-point and PK/PD analyses. The primary analysis demonstrated a maximum mean increase in QTcF of 9.1 ms (90% 2-sided upper confidence interval [CI], 14.1 ms). The primary PK/PD analysis predicted a maximum QTcF increase of 8.5 ms (90% 2-sided upper CI, 13.5 ms). No patient had an abnormal U wave, a new QTcF > 500 ms, or > 60 ms change from baseline for QTcF.

Conclusion

Analysis of ECG intervals and concentration-QTc relationships showed a small but clinically insignificant effect of daratumumab.

Trial Registration

ClinicalTrials.gov Identifier: NCT02316106.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-020-01601-w.

Symptom burden and health-related quality of life impacts of smoldering multiple myeloma: the patient perspective

Background

Smoldering multiple myeloma (SMM) is an early form of multiple myeloma (MM). SMM is typically considered asymptomatic, and research on how it affects health-related quality of life (HRQoL) is limited. This study assessed the symptoms and HRQoL of patients with SMM and those who progressed from SMM to MM and evaluated the content validity of two patient-reported outcome instruments (EORTC QLQ-C30 and nine items from the EORTC QLQ-MY20) for use in SMM clinical trials. To address these objectives, concept elicitation and cognitive interviews were conducted with SMM patients and recently diagnosed MM patients.

Results

Fifteen adult SMM and six adult MM participants with a prior SMM diagnosis were interviewed. On average, SMM study participants were 61 years old (46.0–78.0), 11 (73%) were female, and diagnosed 2.6 (±2.0) years ago. Each participant had experienced at least one symptom, most commonly tiredness/fatigue, weakness, and pain. The most common HRQoL impacts were emotional and physical. SMM study participants demonstrated good understanding of both the EORTC QLQ-C30 and EORTC QLQ-MY20 subscales and found them relevant to their SMM health state. The average age of MM participants was 53 years old (39.0–62.0); 5 (83%) were female and diagnosed 1.9 years ago (±2.1). MM participants most commonly reported tiredness, weakness, constipation, shortness of breath, and dry mouth as occurring when they progressed from SMM to MM.

Conclusions

Although previously described as asymptomatic, these SMM participants reported experiencing symptoms that affected their lives. Additionally, the EORTC subscales measured symptoms SMM patients experienced. The participants with MM reported that the symptom burden and HRQoL impacts increased when diagnosed with MM. These findings suggest the need for increased surveillance of symptoms within the SMM population and further suggest that the EORTC subscales can be used to assess symptoms and impacts in both the SMM and MM populations.

A tertiary center experience of multiple myeloma patients with COVID-19: lessons learned and the path forward

BACKGROUND

The COVID-19 pandemic, caused by SARS-CoV-2 virus, has resulted in over 100,000 deaths in the USA. Our institution has treated over 2000 COVID-19 patients during the pandemic in New York City. The pandemic directly impacted cancer patients and the organization of cancer care. Mount Sinai Hospital has a large and diverse multiple myeloma (MM) population. Herein, we report the characteristics of COVID-19 infection and serological response in MM patients in a large tertiary care institution in New York.

METHODS

We performed a retrospective study on a cohort of 58 patients with a plasma-cell disorder (54 MM, 4 smoldering MM) who developed COVID-19 between March 1, 2020, and April 30, 2020. We report epidemiological, clinical, and laboratory characteristics including the persistence of viral detection by polymerase chain reaction (PCR) and anti-SARS-CoV-2 antibody testing, treatments initiated, and outcomes.

RESULTS

Of the 58 patients diagnosed with COVID-19, 36 were hospitalized and 22 were managed at home. The median age was 67 years; 52% of patients were male and 63% were non-White. Hypertension (64%), hyperlipidemia (62%), obesity (37%), diabetes mellitus (28%), chronic kidney disease (24%), and lung disease (21%) were the most common comorbidities. In the total cohort, 14 patients (24%) died. Older age (> 70 years), male sex, cardiovascular risk, and patients not in complete remission (CR) or stringent CR were significantly (p < 0.05) associated with hospitalization. Among hospitalized patients, laboratory findings demonstrated elevation of traditional inflammatory markers (CRP, ferritin, D-dimer) and a significant (p < 0.05) association between elevated inflammatory markers, severe hypogammaglobulinemia, non-White race, and mortality. Ninety-six percent (22/23) of patients developed antibodies to SARS-CoV-2 at a median of 32 days after initial diagnosis. The median time to PCR negativity was 43 (range 19-68) days from initial positive PCR.

CONCLUSIONS

Drug exposure and MM disease status at the time of contracting COVID-19 had no bearing on mortality. Mounting a severe inflammatory response to SARS-CoV-2 and severe hypogammaglobulinemia was associated with higher mortality. The majority of patients mounted an antibody response to SARS-CoV-2. These findings pave a path to the identification of vulnerable MM patients who need early intervention to improve outcomes in future outbreaks of COVID-19.

Components of metabolic syndrome in patients with multiple myeloma and smoldering multiple myeloma

BACKGROUND

The prevalences of diabetes mellitus and hypertension, both of which are components of metabolic syndrome, are known to be increased among patients with multiple myeloma (MM), but remain undetermined among patients with smoldering MM (SMM).

METHODS

Changes in various components of metabolic syndrome were investigated during the follow-up of patients with either MM or SMM compared to healthy controls. The data of 153 patients (105 with MM and 48 with SMM) and 138 controls were accessed from our medical center's records between 2008 and 2015. We analyzed the patients' data at diagnosis (baseline) and after 1, 3, and 5 years of follow-up.

RESULTS

Patients with SMM had a significantly higher prevalence of diabetes, hypertension, and dyslipidemia at baseline compared to controls. A multivariate Cox regression analysis revealed a higher risk to develop dyslipidemia after 1, 3, and 5 years of follow-up among the SMM patients. The MM patients had a higher risk to develop diabetes after 1 year, hypertension after 5 years, and dyslipidemia after 1, 3, and 5 years of follow-up.

CONCLUSIONS

These data demonstrate that patients with SMM and those with MM are more prone to develop various components of metabolic syndrome, and they stress the importance of following-up metabolic syndrome components in both groups of patients.

Recent Advances in the Management of Smoldering Multiple Myeloma

There is remarkable progress in the treatment of multiple myeloma (MM) with significant improvement in survival in the past 10 years. Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) can evolve into symptomatic multiple myeloma (sy-MM) with organ involvement. SMM has associated with a much higher progression to MM compared to MGUS. In 2014, International Myeloma Working Group (IMWG) reclassified ultra-high-risk smoldering myeloma patients with bone marrow plasma cells > 60% or serum-free light chain ratio (FLCr) > 100 or > 1 focal bone lesion on the magnetic resonance imaging as MM. SMM is a heterogeneous disorder with probability for progression to myeloma up to 50% in the first 5 years. Several risk models and clinical features have been identified to stratify the risk of progression to MM. Thanks to advances in our understanding of the genomic profile of MM, there are several ongoing clinical trials, and genomic studies are being done to assess the risk of progression to MM and early intervention. There is still no standard criterion regarding when to start therapy. This review discusses identifying SMM patients who are at high risk of progression to sy-MM and recent development of new and early treatment strategies and ongoing clinical trials for these high-risk SMM patients.

State of the science in smoldering myeloma: Should we be treating in the clinic?

Currently the standard of care for smoldering multiple myeloma (SMM) is "watch and wait." However, in recent years the treatment for multiple myeloma (MM) has shifted from cytotoxic chemotherapy with poor efficacy to less toxic, more effective treatments. Therefore, the standard for SMM is coming into question, especially for patients at the highest risk of developing MM. There are currently multiple active clinical trials investigating earlier intervention in patients with SMM. This article will review the history of SMM and how the current standard of care came to be. We will define prognostic factors of SMM and how to identify patients at highest risk of developing MM. Next we will review previous clinical trials examining treatment of SMM and finally discuss active clinical trials. While there are clear guidelines outlining management of high-risk SMM patients, they are mostly based on expert opinion and therefore it is an active area of research. Accordingly, patients should be encouraged to participate in clinical trials to better understand the benefit versus risk of early treatment.

[Recurrent invasive pneumococcal disease in a patient with IgG-κ smoldering multiple myeloma]

A 68-year-old female with smoldering multiple myeloma (IgG-κ type) was admitted to the hospital owing to general fatigue, fever, and pain in the right leg. On the day following admission, she developed shock, and a blood culture revealed Streptococcus pneumoniae. She was diagnosed with septic shock and invasive pneumococcal disease (IPD). She received antibiotics and intravenous immunoglobulin and improved after several days. She had a history of recurrent IPD and had received the pneumococcal polysaccharide vaccine 23 (PPSV23) 2 years earlier. Therefore, we inquired with the National Institute of Infectious Diseases if the pneumococcal serotype isolated from her present IPD contained PPSV23. The results showed that her serotype was 19F, a serotype present in PPSV23. We administered pneumococcal conjugate vaccine 13 (PCV13) ; however, she was unable to mount high enough opsonophagocytic assay titers against some serotypes, including 19F. We think she was unable to mount effective humoral immune responses to PPSV23 or PCV13 owing to her underlying disease, smoldering myeloma. It should be considered how IPD can be effectively prevented in patients with multiple myeloma.

Smoldering Multiple Myeloma: Who and When to Treat

Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell disorder characterized by the presence of ≥ 3 g/dL serum M-protein and/or 10% to 60% bone marrow plasma cell infiltration with no myeloma-defining event. The risk of progression to active multiple myeloma (MM) is not uniform, and several markers are useful for identifying patients at high risk of progression. The definition of the disease has recently been revisited and asymptomatic MMs at 80% to 90% of progression risk at 2 years are now considered to be active MM candidates for treatment. In the future, more precise biomarkers are necessary for accurate risk stratification to plan an optimized follow-up according to the risk of progression, as well as to expand the group of patients that can obtain a benefit if they receive early treatment. A phase 3, randomized trial in high-risk patients with SMM comparing early treatment versus observation has shown a significant benefit in terms of time to progression and overall survival for early intervention and confirmatory clinical trials will definitively contribute to establish the early treatment as standard of care in high-risk SMM.

Treatment of high-risk smoldering myeloma

Multiple myeloma (MM) is a hematologic malignancy of the plasma cell that causes symptoms of bone pain, renal failure, and anemia. It is usually preceded by a precursor disease state, such as smoldering multiple myeloma (SMM) or monoclonal gammopathy of undetermined significance (MGUS), and traditional dogma dictates that treatment should be initiated on frank MM symptom development. Emerging evidence suggests that a defined group of "high-risk SMM" may benefit from early treatment, before organ damage and symptoms actually occur. The following article frames the evidence for treatment of high-risk SMM by defining risk categories, reviewing existing therapeutic trial data, and exploring the long-term biologic implications of early treatment.

The Changing Landscape of Smoldering Multiple Myeloma: A European Perspective

Smoldering multiple myeloma (SMM) is an asymptomatic clonal plasma cell disorder and bridges monoclonal gammopathy of undetermined significance to multiple myeloma (MM), based on higher levels of circulating monoclonal immunoglobulin and bone marrow plasmocytosis without end-organ damage. Until a Spanish study reported fewer MM-related events and better overall survival among patients with high-risk SMM treated with lenalidomide and dexamethasone, prior studies had failed to show improved survival with earlier intervention, although a reduction in skeletal-related events (without any impact on disease progression) has been described with bisphosphonate use. Risk factors have now been defined, and a subset of ultra-high-risk patients have been reclassified by the International Myeloma Working Group as MM, and thus will require optimal MM treatment, based on biomarkers that identify patients with a >80% risk of progression. The number of these redefined patients is small (∼10%), but important to unravel, because their risk of progression to overt MM is substantial (≥80% within 2 years). Patients with a high-risk cytogenetic profile are not yet considered for early treatment, because groups are heterogeneous and risk factors other than cytogenetics are deemed to weight higher. Because patients with ultra-high-risk SMM are now considered as MM and may be treated as such, concerns exist that earlier therapy may increase the risk of selecting resistant clones and induce side effects and costs. Therefore, an even more accurate identification of patients who would benefit from interventions needs to be performed, and clinical judgment and careful discussion of pros and cons of treatment initiation need to be undertaken. For the majority of SMM patients, the standard of care remains observation until development of symptomatic MM occurs, encouraging participation in ongoing and upcoming SMM/early MM clinical trials, as well as consideration of bisphosphonate use in patients with early bone loss.

Flow cytometric differentiation of abnormal and normal plasma cells in the bone marrow in patients with multiple myeloma and its precursor diseases

Flow cytometric (FC) enumeration of abnormal plasma cells (APCs) for diagnosis and prognostication of plasma cell dyscrasias (PCD) is challenging. We studied antigen expression in normal plasma cells (NPC) (N = 34) and APC in a series of unselected PCD (N = 59). NPC subpopulations often demonstrated CD19(-), CD20(+), CD45(-) or dim and CD56(+), an immunophenotype observed in PCD. However abnormal CD81 was only observed in APCs (APC detection sensitivity 95%; specificity 100%). We evaluated differences in antigen expression patterns among MGUS (N = 14), SMM (N = 35) and MM (N = 10), finding the combination of CD45 and CD56 helpful in differentiating MGUS from SMM and MM (p = 0.0002).

[Smoldering multiple myeloma]

Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell neoplasia, characterized by monoclonal plasma cell proliferation in the absence of end-organ damage, but with a high risk of progression to multiple myeloma. It has therefore to be distinguished from monoclonal gammapathy of undetermined significance (MGUS), which has a much lower risk of progression, but also from multiple myeloma, which remains an incurable disease and requires a specific treatment. The critical question in the management of SMM is whether an early therapeutic strategy could help delaying the progression to multiple myeloma, in order to lower the risk of serious complications related to this progression, or even to cure the disease. This early treatment could not be proposed to all SMM patients, who are indeed asymptomatic, and in whom the risk of toxicity could make it difficult to justify the potential benefit obtained. The challenge is to target early at diagnosis SMM patients with a high risk of progression, using available routine tests sufficiently reliable to warrant the therapeutic sanction which relies on it. Today however, apart from randomized studies, recommendations are to maintain therapeutic abstention in SMM patients.