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

Round Table Discussion on Optimal Clinical Trial Design in Precursor Multiple Myeloma

SUMMARY

While the current approach to precursor hematologic conditions is to "watch and wait," this may change with the development of therapies that are safe and extend survival or delay the onset of symptomatic disease. The goal of future therapies in precursor hematologic conditions is to improve survival and prevent or delay the development of symptomatic disease while maximizing safety. Clinical trial considerations in this field include identifying an appropriate at-risk population, safety assessments, dose selection, primary and secondary trial endpoints including surrogate endpoints, control arms, and quality-of-life metrics, all of which may enable more precise benefit-risk assessment.

Development of a Multivariable Model to Predict the Need for Bone Marrow Sampling in Persons With Monoclonal Gammopathy of Undetermined Significance : A Cohort Study Nested in a Clinical Trial

BACKGROUND

Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic precursor conditions to multiple myeloma and related disorders. Smoldering multiple myeloma is distinguished from MGUS by 10% or greater bone marrow plasma cells (BMPC) on sampling, has a higher risk for progression, and requires specialist management.

OBJECTIVE

To develop a multivariable prediction model that predicts the probability that a person with presumed MGUS has 10% or greater BMPC (SMM or worse by bone marrow criteria) to inform the decision to obtain a bone marrow sample and compare its performance to the Mayo Clinic risk stratification model.

DESIGN

iStopMM (Iceland Screens, Treats or Prevents Multiple Myeloma), a prospective population-based screening study of MGUS. (ClinicalTrials.gov: NCT03327597).

SETTING

Icelandic population of adults aged 40 years or older.

PATIENTS

1043 persons with IgG, IgA, light-chain, and biclonal MGUS detected by screening and an interpretable bone marrow sample.

MEASUREMENTS

Monoclonal gammopathy of undetermined significance isotype; monoclonal protein concentration; free light-chain ratio; and total IgG, IgM, and IgA concentrations were used as predictors. Bone marrow plasma cells were categorized as 0% to 4%, 5% to 9%, 10% to 14%, or 15% or greater.

RESULTS

The c-statistic for SMM or worse was 0.85 (95% CI, 0.82 to 0.88), and calibration was excellent (intercept, -0.07; slope, 0.95). At a threshold of 10% predicted risk for SMM or worse, sensitivity was 86%, specificity was 67%, positive predictive value was 32%, and negative predictive value was 96%. Compared with the Mayo Clinic model, the net benefit for the decision to refer for sampling was between 0.13 and 0.30 higher over a range of plausible low-risk thresholds.

LIMITATION

The prediction model will require external validation.

CONCLUSION

This accurate prediction model for SMM or worse was developed in a population-based cohort of persons with presumed MGUS and may be used to defer bone marrow sampling and referral to hematology.

PRIMARY FUNDING SOURCE

International Myeloma Foundation and the European Research Council.

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.

Diagnosis and management of smouldering myeloma: A British Society for Haematology Good Practice Paper

Multiple myeloma is a bone marrow-based plasma cell tumour that develops from asymptomatic pre-cursor conditions smouldering myeloma and monoclonal gammopathy of uncertain significance and all are characterised by the presence of a monoclonal protein in the blood. Diagnosis and distinction between these conditions is based on blood tests, the bone marrow biopsy and cross sectional imaging. There are various risk stratification models that group patients with smouldering myeloma into risk groups based on risk of progression to symptomatic disease. Management is mainly observational for patients with smouldering myeloma although clinical trials for high-risk disease may be available. Restaging is required if evidence for progression.

Novel Insights into the Initiation, Evolution, and Progression of Multiple Myeloma by Multi-Omics Investigation

The evolutionary history of multiple myeloma (MM) includes malignant transformation, followed by progression to pre-malignant stages and overt malignancy, ultimately leading to more aggressive and resistant forms. Over the past decade, large effort has been made to identify the potential therapeutic targets in MM. However, MM remains largely incurable. Most patients experience multiple relapses and inevitably become refractory to treatment. Tumor-initiating cell populations are the postulated population, leading to the recurrent relapses in many hematological malignancies. Clonal evolution of tumor cells in MM has been identified along with the disease progression. As a consequence of different responses to the treatment of heterogeneous MM cell clones, the more aggressive populations survive and evolve. In addition, the tumor microenvironment is a complex ecosystem which plays multifaceted roles in supporting tumor cell evolution. Emerging multi-omics research at single-cell resolution permits an integrative and comprehensive profiling of the tumor cells and microenvironment, deepening the understanding of biological features of MM. In this review, we intend to discuss the novel insights into tumor cell initiation, clonal evolution, drug resistance, and tumor microenvironment in MM, as revealed by emerging multi-omics investigations. These data suggest a promising strategy to unravel the pivotal mechanisms of MM progression and enable the improvement in treatment, both holistically and precisely.

Mode of progression in smoldering multiple myeloma: a study of 406 patients

The approach to patients with high-risk smoldering multiple myeloma (SMM) varies among clinicians; while some advocate early intervention, others reserve treatment at progression to multiple myeloma (MM). We aimed to describe the myeloma-defining events (MDEs) and clinical presentations leading to MM diagnosis among SMM patients seen at our institution. We included 406 patients diagnosed with SMM between 2013-2022, seen at Mayo Clinic, Rochester, MN. The 2018 Mayo 20/2/20 criteria were used for risk stratification. Median follow-up was 3.9 years. Among high-risk patients who did not receive treatment in the SMM phase (n = 71), 51 progressed by last follow-up; the MDEs included: bone lesions (37%), anemia (35%), hypercalcemia (8%), and renal failure (6%); 24% met MM criteria based on marrow plasmacytosis (≥60%) and/or free light chain ratio (>100); 45% had clinically significant MDEs (hypercalcemia, renal insufficiency, and/or bone lesions). MM diagnosis was made based on surveillance labs/imaging(45%), testing obtained due to provider suspicion for progression (14%), bone pain (20%), and hospitalization/ED presentations due to MM complications/symptoms (4%). The presentation was undocumented in 14%. A high proportion (45%) of patients with high-risk SMM on active surveillance develop end-organ damage at progression. About a quarter of patients who progress to MM are not diagnosed based on routine interval surveillance testing.

Screening in Multiple Myeloma and Its Precursors: Are We There Yet?

BACKGROUND

Multiple myeloma (MM) is a hematological malignancy that develops over years from the asymptomatic precursors, monoclonal gammopathy of undetermined significance, and smoldering multiple myeloma. Recent evidence shows that by initiating treatment at an asymptomatic stage, outcomes in MM can be significantly improved. However, a vast majority of MM patients are diagnosed after the development of symptomatic end-organ damage and cannot reap the benefits of early treatment. The precursors of MM are easily detected by serum protein electrophoresis and free light chain assay of the serum, raising the question of whether population-based screening could detect MM at an asymptomatic stage and significantly expand the availability of early treatment in MM. Screening is a hallmark of care in many malignancies, and there are accepted criteria for when screening is appropriate.

CONTENT

Here we review the available relevant evidence for the introduction of screening and discuss whether screening for MM and its precursors fulfills these criteria. We also highlight gaps in our current knowledge, most notably a lack of data on the benefits and harms of screening and the lack of a defined target population. There are ongoing studies that may fill these critical gaps in the literature, but their results are still pending.

SUMMARY

Screening could lead to a paradigm shift in the care of patients with MM, but critical scientific questions need to be answered before screening of healthy individuals can be recommended. In short, we should not screen for MM and its precursors-yet.

Clinician preferences on treatment of smoldering myeloma: a cross-sectional survey

Background

Smoldering myeloma (SMM) is an asymptomatic precursor condition to multiple myeloma (MM) with a variable risk of progression. The management of high-risk SMM (HR-SMM) remains controversial, particularly with changes in diagnostic criteria that led to reclassifying of some patients with SMM to MM. This study aimed to assess clinician preferences for whether to treat patients with HR-SMM and/or patients with MM diagnosed solely by SLiM criteria (free light chain ratio >100, bone marrow plasma cell percentage >60, greater than two focal marrow lesions on MRI) through an electronic survey.

Methods

This was a cross-sectional survey of clinicians, conducted via an anonymous online REDCap survey from May 16th to July 5th, 2023. The survey included questions on demographics, SMM surveillance practices, and management preferences for two clinical scenarios (HR-SMM and MM based solely on the free light chain ratio >100 criterion). Data was analysed descriptively via Microsoft Excel.

Findings

A total of 146 clinicians completed the full survey, with 92% recommending against routine treatment for a patient with HR-SMM based on a single time point assessment, instead preferring active surveillance. For patients with MM diagnosed solely on the basis of a free light chain ratio >100, 61% recommended active treatment, while 37% recommended active surveillance. The most common reasons recommending against treatment of HR-SMM were toxicity, lack of demonstrated overall survival benefit, and low MM-defining event rates in clinical trials.

Interpretation

The survey indicates that most clinicians recommend against routine treatment for HR-SMM. Active surveillance is the prevailing standard of care and it is therefore an appropriate control arm in future SMM trials. More randomised trials are needed to determine if early treatment of modern-era SMM offers a net benefit to patients.

Funding

None.

Mode of Progression in Smoldering Multiple Myeloma: A study of 406 patients

The approach to patients with high-risk smoldering multiple myeloma (SMM) varies among clinicians; while some advocate early intervention, others reserve treatment at progression to multiple myeloma (MM). We aimed to describe the myeloma-defining events (MDEs) and clinical presentations leading to MM diagnosis among SMM patients seen at our institution. We included 406 patients diagnosed with SMM between 2013-2022, seen at Mayo Clinic, Rochester, MN. The 2018 Mayo 20/2/20 criteria were used for risk stratification. Median follow-up was 3.9 years. Among high-risk patients who did not receive treatment in the SMM phase (n=71), 51 progressed by last follow-up; the MDEs included: bone lesions(37%), anemia(35%), hypercalcemia(8%), and renal failure(6%); 24% met MM criteria based on marrow plasmacytosis (≥60%) and/or free light chain ratio (>100); 45% had clinically significant MDEs (hypercalcemia, renal insufficiency, and/or bone lesions). MM diagnosis was made based on surveillance labs/imaging(45%), testing obtained due to provider suspicion for progression(14%), bone pain(20%), and hospitalization/ED presentations due to MM complications/symptoms(4%). The presentation was undocumented in 14%. A high proportion (45%) of patients with high-risk SMM on active surveillance develop end-organ damage at progression. About a quarter of patients who progress to MM are not diagnosed based on routine interval surveillance testing.

Clinical characteristics and outcomes in risk-stratified patients with smoldering multiple myeloma: data from the Czech Republic Registry of Monoclonal Gammopathies

Smoldering multiple myeloma (SMM) is an asymptomatic precursor to active multiple myeloma (MM). The aim of this study was to report clinical characteristics and outcomes of patients with SMM stratified based on their risk of progression to MM using the Mayo 20/2/20 criteria. Data were leveraged from the Czech Myeloma Group Registry of Monoclonal Gammopathies (RMG). Key outcomes included progression-free survival from SMM diagnosis to active MM diagnosis or death (PFS), progression-free survival from SMM diagnosis to progression on first line (1 L) MM treatment or death (PFS2), and overall survival (OS). Of 498 patients, 174 (34.9%) were classified as high risk and 324 (65.1%) as non-high risk. Median follow-up was approximately 65 months. During follow-up, more patients in the high-risk vs non-high-risk group received 1 L MM treatment (76.4% vs 46.6%, p < 0.001). PFS, PFS2, and OS were significantly shorter in high-risk vs non-high-risk patients (13.2 vs 56.6 months, p < 0.001; 49.9 vs 84.9 months, p < 0.001; 93.2 vs 131.1 months, p = 0.012, respectively). The results of this study add to the growing body of evidence that patients with high-risk vs non-high-risk SMM have significantly worse outcomes, including OS.

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.

Presenting Symptoms in Newly Diagnosed Myeloma, Relation to Organ Damage, and Implications for Symptom-Directed Screening: A Secondary Analysis from the Tackling Early Morbidity and Mortality in Myeloma (TEAMM) Trial

Multiple myeloma (MM) patients risk diagnostic delays and irreversible organ damage. In those with newly diagnosed myeloma, we explored the presenting symptoms to identify early signals of MM and their relationships to organ damage. The symptoms were recorded in patients' own words at diagnosis and included diagnostic time intervals. Those seen by a haematologist >6 months prior to MM diagnosis were classified as precursor disease (PD). Most (962/977) patients provided data. Back pain (38%), other pain (31%) and systemic symptoms (28%) predominated. Patients rarely complain of 'bone pain', simply 'pain'. Vertebral fractures are under-recognised as pathological and are the predominant irreversible organ damage (27% of patients), impacting the performance status (PS) and associated with back pain (odds ratio (OR) 6.14 [CI 4.47-8.44]), bone disease (OR 3.71 [CI 1.88-7.32]) and age >65 years (OR 1.58 [CI 1.15-2.17]). Renal failure is less frequent and associated with gastrointestinal symptoms (OR 2.23 [CI1.28-3.91]), age >65 years (OR 2.14 [CI1.28-3.91]) and absence of back pain (OR 0.44 [CI 0.29-0.67]). Patients with known PD (n = 149) had fewer vertebral fractures (p = 0.001), fewer adverse features (p = 0.001), less decline in PS (p = 0.001) and a lower stage (p = 0.04) than 813 with de novo MM. Our data suggest subgroups suitable for trials of 'symptom-directed' screening: those with back pain, unexplained pain, a general decline in health or low-impact vertebral compression fractures.

Immune biomarkers of response to immunotherapy in patients with high-risk smoldering myeloma

Patients with smoldering multiple myeloma (SMM) are observed until progression, but early treatment may improve outcomes. We conducted a phase II trial of elotuzumab, lenalidomide, and dexamethasone (EloLenDex) in patients with high-risk SMM and performed single-cell RNA and T cell receptor (TCR) sequencing on 149 bone marrow (BM) and peripheral blood (PB) samples from patients and healthy donors (HDs). We find that early treatment with EloLenDex is safe and effective and provide a comprehensive characterization of alterations in immune cell composition and TCR repertoire diversity in patients. We show that the similarity of a patient's immune cell composition to that of HDs may have prognostic relevance at diagnosis and after treatment and that the abundance of granzyme K (GZMK)+ CD8+ effector memory T (TEM) cells may be associated with treatment response. Last, we uncover similarities between immune alterations observed in the BM and PB, suggesting that PB-based immune profiling may have diagnostic and prognostic utility.