A prognostic index for multiple myeloma

Multiple myeloma: 2024 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

DIAGNOSIS

The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) attributable to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L and urine monoclonal protein is ≥200 mg/24 h), or >1 focal lesion on magnetic resonance imaging.

RISK STRATIFICATION

The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, del 1p, or p53 mutation is considered high-risk multiple myeloma. Presence of any two high risk factors is considered double-hit myeloma; three or more high risk factors is triple-hit myeloma.

RISK-ADAPTED INITIAL THERAPY

In patients who are candidates for autologous stem cell transplantation, induction therapy consists of anti-CD38 monoclonal antibody plus bortezomib, lenalidomide, dexamethasone (VRd) followed by autologous stem cell transplantation (ASCT). Selected standard risk patients can delay transplant until first relapse. Frail patients who not candidates for transplant are treated with VRd for approximately 8-12 cycles followed by maintenance or alternatively with daratumumab, lenalidomide, dexamethasone (DRd) until progression.

MAINTENANCE THERAPY

Standard risk patients need lenalidomide maintenance, while bortezomib plus lenalidomide maintenance is needed for high-risk myeloma.

MANAGEMENT OF RELAPSED DISEASE

A triplet regimen is usually needed at relapse, with the choice of regimen varying with each successive relapse. Chimeric antigen receptor T (CAR-T) cell therapy and bispecific antibodies are additional options.

Monoclonal Antibodies in Smoldering Multiple Myeloma and Monoclonal Gammopathy of Undetermined Significance: Current Status and Future Directions

Monoclonal antibodies (MoAbs) targeting several cellular receptors have significantly improved the prognosis of multiple myeloma (MM). Their high effectiveness and safety raise the question of whether earlier therapeutic intervention in monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) influences the natural course of the disease. MM is preceded by clinically recognized conditions such as MGUS and SMM. Numerous studies are investigating the disease biology and immune profile of SMM and MGUS to unravel the intricate relationship between immunosurveillance and disease progression. The standard approach to MGUS and SMM remains close observation. Early studies indicate benefits in terms of progression or even survival for promptly treating high-risk SMM patients. Ongoing debates are focused on which patients with SMM and MGUS to treat, as well as on determining the optimal therapeutic approach. The first approach aims to cure by attempting to eliminate the pathological clone, while the second approach is preventive, aiming to manage disease progression to active MM and restore the immune system. In this review, we focus on the available and emerging data on early treatment, particularly with MoAbs alone or in combination with other therapies, in SMM and MGUS patients.

Smoldering multiple myeloma current treatment algorithms

Smoldering multiple myeloma (SMM) is an asymptomatic condition that occupies a space between monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) along the spectrum of clonal plasma cell proliferative disorders. It is not a biologic intermediate stage between MGUS and MM, but rather represents a heterogeneous clinically defined condition in which some patients (approximately two-thirds) have MGUS (pre-malignancy), and some (approximately one-third) have MM (biologic malignancy). Unfortunately, no single pathologic or molecular feature can reliably distinguish these two groups of patients. For purposes of practice and clinical trials, specific risk factors are used to identify patients with SMM in whom malignant transformation has already likely occurred (high risk SMM). Patients with newly diagnosed high risk SMM should be offered therapy with lenalidomide or lenalidomide plus dexamethasone (Rd) for 2 years, or enrollment in clinical trials. Patients with low risk SMM should be observed without therapy every 3-4 months.

Multiple myeloma: 2022 update on diagnosis, risk stratification, and management

DISEASE OVERVIEW

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

DIAGNOSIS

The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy-proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) attributable to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥ 100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging.

RISK STRATIFICATION

The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, or p53 mutation is considered high-risk multiple myeloma. The presence of any two high risk factors is considered double-hit myeloma, and three or more high risk factors is triple-hit myeloma.

RISK-ADAPTED INITIAL THERAPY

In patients who are candidates for autologous stem cell transplantation, induction therapy consists of bortezomib, lenalidomide, dexamethasone (VRd) given for approximately 3-4 cycles followed by autologous stem cell transplantation (ASCT). In high-risk patients, daratumumab, bortezomib, lenalidomide, dexamethasone (Dara-VRd) is an alternative to VRd. Selected standard-risk patients can collect stem cells, get additional cycles of induction therapy, and delay transplant until first relapse. Patients who are not candidates for transplant are treated with VRd for approximately 8-12 cycles followed by maintenance or alternatively with daratumumab, lenalidomide, dexamethasone (DRd) until progression.

MAINTENANCE THERAPY

Standard-risk patients need lenalidomide maintenance, while bortezomib plus lenalidomide maintenance is needed for high-risk myeloma.

MANAGEMENT OF RELAPSED DISEASE

A triplet regimen is usually needed at relapse, with the choice of regimen varying with each successive relapse.

Multiple myeloma: 2020 update on diagnosis, risk-stratification and management

DISEASE OVERVIEW

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

DIAGNOSIS

The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE) namely CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) features felt related to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging (MRI).

RISK STRATIFICATION

The presence of del(17p), t(4;14), t(14;16), t(14;20), gain 1q, or p53 mutation is considered high-risk multiple myeloma. Presence of any two high risk factors is considered double-hit myeloma; three or more high risk factors is triple-hit myeloma.

RISK-ADAPTED INITIAL THERAPY

In transplant eligible patients, induction therapy consists of bortezomib, lenalidomide, dexamethasone (VRd) given for approximately 3-4 cycles followed by autologous stem cell transplantation (ASCT). In high-risk patients, daratumumab, bortezomib, lenalidomide, dexamethasone (Dara-VRd) is an alternative to VRd. Selected standard risk patients can get additional cycles of induction, and delay transplant until first relapse. Patients not candidates for transplant are typically treated with VRd for approximately 8-12 cycles followed by lenalidomide; alternatively these patients can be treated with daratumumab, lenalidomide, dexamethasone (DRd).

MAINTENANCE THERAPY

After ASCT, standard risk patients need lenalidomide maintenance, while bortezomib-based maintenance is needed for patients with high-risk myeloma.

MANAGEMENT OF REFRACTORY DISEASE

Most patients require a triplet regimen at relapse, with the choice of regimen varying with each successive relapse.

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.

Randomized Trial of Lenalidomide Versus Observation in Smoldering Multiple Myeloma

PURPOSE

Observation is the current standard of care for smoldering multiple myeloma. We hypothesized that early intervention with lenalidomide could delay progression to symptomatic multiple myeloma.

METHODS

We conducted a randomized trial that assessed the efficacy of single-agent lenalidomide compared with observation in patients with intermediate- or high-risk smoldering multiple myeloma. Lenalidomide was administered orally at a dose of 25 mg on days 1 to 21 of a 28-day cycle. The primary end point was progression-free survival, with disease progression requiring the development of end-organ damage attributable to multiple myeloma and biochemical progression.

RESULTS

One hundred eighty-two patients were randomly assigned-92 patients to the lenalidomide arm and 90 to the observation arm. Median follow-up is 35 months. Response to therapy was observed in 50% (95% CI, 39% to 61%) of patients in the lenalidomide arm, with no responses in the observation arm. Progression-free survival was significantly longer with lenalidomide compared with observation (hazard ratio, 0.28; 95% CI, 0.12 to 0.62; P = .002). One-, 2-, and 3-year progression-free survival was 98%, 93%, and 91% for the lenalidomide arm versus 89%, 76%, and 66% for the observation arm, respectively. Only six deaths have been reported, two in the lenalidomide arm versus four in the observation arm (hazard ratio for death, 0.46; 95% CI, 0.08 to 2.53). Grade 3 or 4 nonhematologic adverse events occurred in 25 patients (28%) on lenalidomide.

CONCLUSION

Early intervention with lenalidomide in smoldering multiple myeloma significantly delays progression to symptomatic multiple myeloma and the development of end-organ damage.

Smoldering Multiple Myeloma: To Treat or Not to Treat

Smoldering multiple myeloma (SMM) is an asymptomatic, intermediate stage positioned between the plasma cell disorders of monoclonal gammopathy of undermined significance and overt multiple myeloma (MM). Although the patients with SMM have a higher risk of progression to MM in comparison to their counterparts with monoclonal gammopathy of undermined significance, their clinical course can be highly variable. The standard of care for SMM, irrespective of the risk status, continues to be observation due to paucity of high-level evidence demonstrating survival or quality-of-life benefit with early intervention. With the expanded 2014 criteria for MM utilizing biomarkers, the subset of SMM patients with 70% to 80% risk of progression at 2 years (ultra-high risk SMM) is now categorized as active MM and treated prior to the development of end-organ damage. After exclusion of this group, patients with approximately 50% risk of progression in 2 years are now considered high-risk SMM, and the value of early treatment in this subset can be established only through clinical trials. Despite its limitations, a recent phase III trial (QuiRedex) has shown survival advantage to using lenalidomide and dexamethasone doublet over observation in high-risk SMM. In this article, we review the evolving concepts in the diagnosis, risk stratification, and management of SMM.

Multiple myeloma: 2018 update on diagnosis, risk‐stratification, and management

Disease overview

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

Diagnosis

The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hyperc alcemia, r enal failure, a nemia, or lytic b one lesions) features felt related to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging.

Risk stratification

Patients with del(17p), t(14;16), and t(14;20) have high-risk multiple myeloma. Patients with t(4;14) translocation and gain(1q) have intermediate-risk. All others are considered standard-risk.

Risk-adapted initial therapy

Initial treatment consists of bortezomib, lenalidomide, dexamethasone (VRd). In high-risk patients, carfilzomib, lenalidomide, dexamethasone (KRd) is an alternative to VRd. In eligible patients, initial therapy is given for approximately 3–4 cycles followed by autologous stem cell transplantation (ASCT). Standard risk patients can opt for delayed ASCT at first relapse. Patients not candidates for transplant are treated with VRd for approximately 8–12 cycles followed by lenalidomide or lenalidomide plus dexamethasone.

Maintenance therapy

After ASCT, lenalidomide maintenance is recommended for standard risk patients, while maintenance with a bortezomib-based regimen is needed for patients with intermediate or high-risk disease.

Management of refractory disease

Most patients require a triplet regimen at relapse, with the choice of regimen varying with each successive relapse. Aggressive relapse with extramedullary plasmacytomas or plasma cell leukemia may require anthracycline containing combination chemotherapy regimens.

Diagnosis and management of smoldering multiple myeloma: the razor's edge between clonality and cancer

Smoldering multiple myeloma (SMM) is a rare plasma cell disorder, and as the disease is asymptomatic, diagnosis is often incidental. SMM is characterized by increased marrow infiltration by clonal plasma cells and/or elevated serum M-protein in the absence of a myeloma-defining event (MDE). In recent years, SMM has gained increased attention owing to a broadening of the criteria for MDE, which include apart from the CRAB criteria, three additional parameters. Survival advantage may be offered by early treatment in the high-risk subset, based on a single trial. In this review, we assess the risk factors and models for progression to multiple myeloma. A review of our diagnostic and management approaches to SMM is presented.

Blockade of Deubiquitylating Enzyme USP1 Inhibits DNA Repair and Triggers Apoptosis in Multiple Myeloma Cells

Purpose: The ubiquitin proteasome pathway is a validated therapeutic target in multiple myeloma. Deubiquitylating enzyme USP1 participates in DNA damage response and cellular differentiation pathways. To date, the role of USP1 in multiple myeloma biology is not defined. In the present study, we investigated the functional significance of USP1 in multiple myeloma using genetic and biochemical approaches.Experimental Design: To investigate the role of USP1 in myeloma, we utilized USP1 inhibitor SJB3-019A (SJB) for studies in myeloma cell lines and patient multiple myeloma cells.Results: USP1-siRNA knockdown decreases multiple myeloma cell viability. USP1 inhibitor SJB selectively blocks USP1 enzymatic activity without blocking other DUBs. SJB also decreases the viability of multiple myeloma cell lines and patient tumor cells, inhibits bone marrow plasmacytoid dendritic cell-induced multiple myeloma cell growth, and overcomes bortezomib resistance. SJB triggers apoptosis in multiple myeloma cells via activation of caspase-3, caspase-8, and caspase-9. Moreover, SJB degrades USP1 and downstream inhibitor of DNA-binding proteins as well as inhibits DNA repair via blockade of Fanconi anemia pathway and homologous recombination. SJB also downregulates multiple myeloma stem cell renewal/survival-associated proteins Notch-1, Notch-2, SOX-4, and SOX-2. Moreover, SJB induced generation of more mature and differentiated plasma cells. Combination of SJB and HDACi ACY-1215, bortezomib, lenalidomide, or pomalidomide triggers synergistic cytotoxicity.Conclusions: Our preclinical studies provide the framework for clinical evaluation of USP1 inhibitors, alone or in combination, as a potential novel multiple myeloma therapy. Clin Cancer Res; 23(15); 4280-9. ©2017 AACR.

Multiple myeloma: 2016 update on diagnosis, risk-stratification, and management

Multiple myeloma accounts for approximately 10% of hematologic malignancies.The diagnosis requires ≥10% clonal bone marrow plasma cells or a biopsy proven plasmacytoma plus evidence of one or more multiple myeloma defining events (MDE): CRAB (hypercalcemia, renal failure, anemia, or lytic bone lesions) features felt related to the plasma cell disorder, bone marrow clonal plasmacytosis ≥60%, serum involved/uninvolved free light chain (FLC) ratio ≥100 (provided involved FLC is ≥100 mg/L), or >1 focal lesion on magnetic resonance imaging. Patients with del(17p), t(14;16), and t(14;20) have high-risk multiple myeloma. Patients with t(4;14) translocation and gain(1q) have intermediate-risk. All others are considered standard-risk. Initial treatment consists of bortezomib, lenalidomide, dexamethasone (VRD). In high-risk patients, carfilzomib, lenalidomide, dexamethasone (KRD) is an alternative to VRD. In eligible patients, initial therapy is given for approximately 3-4 months followed by autologous stem cell transplantation (ASCT). Standard risk patients can opt for delayed ASCT at first relapse. Patients not candidates for transplant are treated with Rd until progression, or alternatively, a triplet regimen such as VRD for approximately 12-18 months. After ASCT, lenalidomide maintenance is considered for standard risk patients especially in those who are not in very good partial response or better, while maintenance with a bortezomib-based regimen is needed for patients with intermediate or high-risk disease. Patients with indolent relapse can be treated with 2-drug or 3-drug combinations. Patients with more aggressive relapse require a triplet regimen or a combination of multiple active agents. Am. J. Hematol. 91:720-734, 2016. © 2016 Wiley Periodicals, Inc.

State-of-the-Art Imaging and Staging of Plasma Cell Dyscrasias

Monoclonal gammopathy of unknown significance (MGUS) is a clinically asymptomatic premalignant clonal plasma cell or lymphoplasmacytic proliferative disorder. Smoldering multiple myeloma, also called asymptomatic multiple myeloma, is an intermediate stage between MGUS and symptomatic multiple myeloma. As the name implies, extraosseous or extramedullary myeloma refers to the presence of myeloma deposits outside the skeletal system. Waldenström macroglobulinemia is a distinct subtype of plasma cell dyscrasia characterized by lymphoplasmacytic lymphoma in the bone marrow with an associated IgM monoclonal gammopathy. Amyloidosis is a condition characterized by extracellular deposition of fibrils composed of a variety of normal serum proteins.

Multiple Myeloma: Diagnosis and Treatment

The diagnosis and treatment of multiple myeloma has changed dramatically in the past decade. The disease definition has been updated to include highly specific biomarkers in addition to established markers of end-organ damage. The staging system has been revised to combine both measures of tumor burden and disease biology. Advances in therapy have resulted in a marked improvement in overall survival. New drugs introduced in the past few years include carfilzomib, pomalidomide, panobinostat, ixazomib, elotuzumab, and daratumumab. In this review, we outline the current approach to the diagnosis, prognosis, and management of multiple myeloma.

Asymptomatic monoclonal gammopathies

Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) represent the earlier phases of plasma cell dyscrasias. Their definition is based on absence of end-organ damage with presence of a malignant clone that grows in the bone marrow. They share, as a common feature, the risk of progression to a symptomatic disease. MGUS progression risk is approximately 1% per year, and SMM has a risk of progression of 10% for the first 5 years which tapers off over time. The main purpose of identification of these earlier phases of the plasma cell dyscrasia was to identify patients who do not warrant treatment with chemotherapy, in whom the risk of treatment outweighs the benefit. Over the years, the definitions have not been modified to incorporate developments in imaging (magnetic resonance or positron emission and computed tomography), or genomics to identify patients at highest risk of progression within 2 years, where wait and watch might not be an appropriate option. In the absence of such definition, patients who have only a 50% chance of progression within 2 years are being offered therapy, which might also not be an optimal approach. In this review, we provide an overview of the definition, current prognostic factors, and risk stratifications in asymptomatic gammopathies, and discuss clinical trial outcomes in high-risk SMM.

Advances in the management of asymptomatic myeloma

PURPOSE OF REVIEW

Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell disorder characterized by the presence of one or both features of serum M-protein at least 30 g/l and bone marrow plasma cell infiltration at least 10%. The standard of care is no treatment until symptomatic progression occurs. However, the risk of progression to active multiple myeloma is not uniform, and several markers are useful for identifying SMM patients at high risk of progression to active multiple myeloma. Overall, the presence of these factors is useful to stratify SMM patients according to their risk but the forthcoming challenge is to identify high and ultra-high-risk SMM patients because they can benefit from early treatment.

RECENT FINDINGS

A randomized trial that focused on high-risk SMM patients allocated to receive early treatment with lenalidomide plus dexamethasone vs. observation did report a significant benefit with respect to time to progression and overall survival.

SUMMARY

High-risk SMM patients should be targeted for early treatment, and more such efforts should be made to identify the ultra-high-risk subgroup within the high-risk SMM patient population which may be considered as early multiple myeloma and thereby candidates for receiving therapy before they develop myeloma-related symptomatology.

Smoldering multiple myeloma

Smoldering multiple myeloma (SMM) is an asymptomatic clonal plasma cell disorder. SMM is distinguished from monoclonal gammopathy of undetermined significance by a much higher risk of progression to multiple myeloma (MM). There have been major advances in the diagnosis, prognosis, and management of SMM in the last few years. These include a revised disease definition, identification of several new prognostic factors, a classification based on underlying cytogenetic changes, and new treatment options. Importantly, a subset of patients previously considered SMM is now reclassified as MM on the basis of biomarkers identifying patients with an ≥80% risk of progression within 2 years. SMM has assumed greater significance on the basis of recent trials showing that early therapy can be potentially beneficial to patients. As a result, there is a need to accurately diagnose and risk-stratify patients with SMM, including routine incorporation of modern imaging and laboratory techniques. In this review, we outline current concepts in diagnosis and risk stratification of SMM, and provide specific recommendations on the management of SMM.

Smoldering multiple myeloma: when to observe and when to treat?

Smoldering multiple myeloma (SMM) is an asymptomatic disorder characterized by the presence of at least 3 g/dL of 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 patients with asymptomatic MM at 80% to 90% of progression risk at 2 years are now considered to have MM. Although the current standard of care is not to treat, a randomized trial in patients with high-risk SMM that compared early treatment versus observation demonstrated that early intervention resulted in substantial benefits in terms of time to progression and overall survival (OS). These findings highlight the need to follow a correct diagnosis by an accurate risk stratification to plan an optimized follow-up according to the risk of disease progression.

Evolving diagnostic criteria for multiple myeloma

Multiple myeloma (MM) is a plasma cell malignancy historically defined by the presence of end-organ damage, specifically, hypercalcemia, renal failure, anemia, and bone lesions (CRAB features) that can be attributed to the neoplastic process. In 2014, the International Myeloma Working Group (IMWG) updated the diagnostic criteria for MM to add specific biomarkers that can be used to make the diagnosis of the disease in patients who did not have CRAB features. In addition, the update allows modern imaging methods including computed tomography (CT) and positron emission tomography-CT to diagnose MM bone disease. These changes enable early diagnosis, and allow the initiation of effective therapy to prevent the development of end-organ damage in patients who are at the highest risk. This article reviews these and several other clarifications and revisions that were made to the diagnostic criteria for MM and related disorders. The updated disease definition for MM also automatically resulted in a revision to the diagnostic criteria for the asymptomatic phase of the disease termed smoldering MM (SMM). Thus the current diagnosis and risk-stratification of SMM is also reviewed in this article. Using specific prognostic factors, it is possible to identify a subset of patients with SMM who have a risk of progression to MM of 25% per year (high-risk SMM). An approach to the management of patients with low- and high-risk SMM is discussed.

Management of asymptomatic myeloma patients

Smoldering multiple myeloma is an asymptomatic disorder characterized by the presence of ≥30 g/l serum M-protein and/or ≥10% bone marrow plasma cell infiltration. The risk of progression to active multiple myeloma is not uniform, and several markers are useful for identifying patients at high risk of this. Although the current standard of care is not to treat, a randomized trial in high-risk smoldering multiple myeloma patients comparing those allocated to receive early treatment with lenalidomide plus dexamethasone with those under observation reported a significant benefit with respect to time to progression and overall survival. We conclude that efforts should be made to identify high-risk patients who are candidates for receiving early treatment before they develop myeloma-related symptomatology.

How long can we let the myeloma smolder?

Smoldering or asymptomatic multiple myeloma may be best described as a state of limbo where the patient has not developed any symptoms of disease and is being observed expectantly. With the advent of novel agents in myeloma therapy, several clinical investigations are underway to determine whether early intervention will help improve survival outcomes in this patient population. Mateos MV et al. report on the first Phase III trial in smoldering multiple myeloma that has shown overall survival benefit. The commentary discusses the study design, key results and potential implications of the study.

Asymptomatic (smoldering) myeloma: treatment strategy

SUMMARY Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell disorder that requires no treatment until progression occurs. Several trials have been conducted in SMM patients to delay the time to progression to symptomatic disease but these yielded no clear benefit. However, the risk of progression to symptomatic disease is not uniform. Several markers have been identified and, overall, these factors identify patients who have a 50% probability of progression after 2 years. The aforementioned trials were conducted in SMM patients without stratification according to risk. A randomized trial including only high-risk SMM patients has recently been carried out, showing a significant benefit of early treatment with lenalidomide plus dexamethasone.

Lenalidomide plus dexamethasone for high-risk smoldering multiple myeloma

BACKGROUND

For patients with smoldering multiple myeloma, the standard of care is observation until symptoms develop. However, this approach does not identify high-risk patients who may benefit from early intervention.

METHODS

In this randomized, open-label, phase 3 trial, we randomly assigned 119 patients with high-risk smoldering myeloma to treatment or observation. Patients in the treatment group received an induction regimen (lenalidomide at a dose of 25 mg per day on days 1 to 21, plus dexamethasone at a dose of 20 mg per day on days 1 to 4 and days 12 to 15, at 4-week intervals for nine cycles), followed by a maintenance regimen (lenalidomide at a dose of 10 mg per day on days 1 to 21 of each 28-day cycle for 2 years). The primary end point was time to progression to symptomatic disease. Secondary end points were response rate, overall survival, and safety.

RESULTS

After a median follow-up of 40 months, the median time to progression was significantly longer in the treatment group than in the observation group (median not reached vs. 21 months; hazard ratio for progression, 0.18; 95% confidence interval [CI], 0.09 to 0.32; P<0.001). The 3-year survival rate was also higher in the treatment group (94% vs. 80%; hazard ratio for death, 0.31; 95% CI, 0.10 to 0.91; P=0.03). A partial response or better was achieved in 79% of patients in the treatment group after the induction phase and in 90% during the maintenance phase. Toxic effects were mainly grade 2 or lower.

CONCLUSIONS

Early treatment for patients with high-risk smoldering myeloma delays progression to active disease and increases overall survival. (Funded by Celgene; ClinicalTrials.gov number, NCT00480363.).

Monoclonal gammopathy and smoldering multiple myeloma: diagnosis, staging, prognosis, management

Monoclonal gammopathy of unknown significance (MGUS) as one of the most common premalignant disorders and smoldering multiple myeloma (sMM) are both caused by a proliferation of monoclonal plasma cells leading to a detectable serum monoclonal protein and/or excess of plasma cells in the bone marrow. Prerequisite for the diagnosis is that plasma cell disease does not cause clinical symptoms. Cytogenetic aberrations are detectable in the majority of patient in the clonally expanded plasma cells. MGUS consistently proceeds symptomatic MM. The lifetime risk of progression into symptomatic multiple myeloma lies between 15% and 59% for patients with MGUS or sMM. Prognostic parameters for development of symptomatic multiple myeloma from MGUS or sMM are concentration of monoclonal protein, bone marrow plasmocytosis, a non- IgG subtype and an abnormal free-light chain ratio. Detection of more than 1 focal lesion in whole body MRI, 95% or more of bone marrow plasma cells displaying an aberrant phenotype in flow cytometry and an evolving clinical course in two consecutive follow-up visits are additional prognostic parameters for sMM. Currently there is no accepted secondary prevention strategy available for sMM and MGUS progression. Future studies are required to combine increasing knowledge on risk factors and molecular pathogenesis with targeted agents to prevent progression.

The Belgian 2010 consensus recommendations for the treatment of multiple myeloma

Since the introduction of novel therapeutic agents including thalidomide, lenalidomide and bortezomib, the prognosis of multiple myeloma (MM) has significantly improved. These agents have been incorporated into numerous treatment schedules for newly diagnosed as well as more advanced MM patients. Hence, the therapeutic options for MM have become more complex and subject to rapid changes. The multiple myeloma study group (MMSG) of the Belgian Hematological Society has established recommendations for the treatment of MM as based on an extensive review of the literature which is also summarized in this paper. The recommendations are the result of a consensus opinion between haematologists with experience in the field and representing most haematology centres in Belgium. Where applicable, reimbursement criteria are also taken into account. The consensus recommendations should be a reference for use by clinical haematologists in daily practice.

Lenalidomide in multiple myeloma: an evidence-based review of its role in therapy

INTRODUCTION

Multiple myeloma (MM) is a relatively common and incurable hematological malignancy. Currently, there is no single standard therapy, with choice of treatment dependent on individual patient factors. Lenalidomide is an immunomodulatory drug with potent antitumor, antiangiogenic, immunomodulatory, and proapoptotic activity in MM.

AIMS

To evaluate the evidence for the use of lenalidomide in its current indication in relapsed or refractory MM, and additionally its investigational use for the treatment of newly diagnosed MM.

EVIDENCE REVIEW

In patients with relapsed and refractory MM, adding lenalidomide to high-dose dexamethasone significantly improves response rates and time-to-progression, relative to high-dose dexamethasone alone. This translates into a significant extension of overall survival (with a median extension of 9.1 months in a pivotal phase III study). Outcome is independent of patient age, number of previous therapies, type of previous therapy (including thalidomide or autologous stem cell transplantation), renal impairment, and beta(2)-microglobulin level. Evidence suggests that combining lenalidomide with low-dose dexamethasone improves outcomes in patients with newly diagnosed disease and is superior to lenalidomide combined with high-dose dexamethasone. Myelosuppression is the predominant toxicity observed, although some studies have shown high incidences of venous thromboembolism in the absence of prophylactic antithrombotic anticoagulation therapy. There is currently only limited evidence regarding the health economics of lenalidomide. ROLE IN THERAPY: The encouraging results obtained with lenalidomide alone and in combination with dexamethasone in patients with relapsed or refractory MM have led to its adoption as a recommended therapy in patients who have received at least one prior treatment. Emerging evidence supports the ongoing investigation of lenalidomide in combination with low-dose dexamethasone, and in other combinations including bortezomib, for use both in relapsed, refractory, and newly diagnosed MM.

Smoldering (asymptomatic) multiple myeloma: current diagnostic criteria, new predictors of outcome, and follow-up recommendations

PURPOSE

To provide an overview on smoldering (asymptomatic) multiple myeloma (SMM) including current diagnostic criteria, predictors of progression, pattern of progression, and outcome.

DESIGN

A comprehensive review of the literature on risk factors for progression, treatment attempts to delay progression and outcome in patients with SMM.

RESULTS

The risk factors for progression of SMM include: plasma cell mass including M-protein size and percentage of bone marrow clonal plasma cells (BMPC), abnormal free light chain ratio, proportion of phenotypically abnormal BMPC, immunoparesis, evolution pattern (evolving v nonevolving), and pattern of magnetic resonance imaging abnormalities. Most patients with SMM progress with anemia and/or skeletal involvement. Immediate therapy with cytotoxic agents, such as melphalan/prednisone has not resulted in improved outcome. Patients should not be treated until progressive disease with end-organ damage occurs. Increasing anemia is the most reliable indicator of progression.

CONCLUSION

These recently recognized predictors of outcome may be helpful for better disease monitoring and for investigation of new treatment approaches. Thus, recommendations for follow-up every to 3 to 6 months depending on the risk of progression are suggested, and clinical trials with new noncytotoxic biologically derived agents to delay progression, particularly in high-risk patients, are ongoing.

Clinically relevant end points and new drug approvals for myeloma

This manuscript summarizes the recommendations of the American Society of Hematology/US Food and Drug Administration Workshop on Clinical Endpoints in Multiple Myeloma, which brought together clinical investigators in multiple myeloma, the United States Food and Drug Administration, pharmaceutical companies, patient advocates and other concerned scientists and physicians to provide guidance, consensus and consistency in the definition of clinically relevant end points to expedite new drug approvals for multiple myeloma in the appropriate trial design settings. This manuscript will therefore be a most valuable resource to provide the framework for the design of appropriate clinical trial strategies for more rapid new drug approval in myeloma.

Monoclonal gammopathy of undetermined significance and smoldering multiple myeloma

Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic disorders characterized by monoclonal plasma cell proliferation in the bone marrow in the absence of end-organ damage. Updated diagnostic criteria for these disorders, risk-stratification models to determine prognosis, and the current management of these two entities are discussed in this review.

Targeted therapeutics for multiple myeloma: The arrival of a risk-stratified approach

Multiple myeloma (MM) remains an incurable hematologic malignancy characterized by frequent early responses, inevitably followed by treatment relapse. Until recently, few effective therapies existed. Indeed, the use of alkylating agents and corticosteroids had remained the treatment of choice for almost four decades. Several novel agents for MM have now become available, including the immunomodulatory drugs thalidomide and lenalidomide, as well as the proteasome inhibitor bortezomib. Each of these agents is undergoing extensive clinical evaluation in combination with other therapies to produce unprecedented response rates in newly diagnosed and relapsed MM. Nevertheless, relapse remains universal and further therapeutics with broad activity are required. Importantly, it has become clear that pivotal genetic events are the primary harbingers of clinical outcome and novel targeted therapy approaches using existing approved drugs or novel agents, which address that disrupted signaling pathways are now in various stages of clinical testing. It seems increasingly likely that novel drug combinations, which together turn off these critical Achilles heels, will become the standard of care and that treatment will become increasingly personalized and guided by genetic testing and prognostic factors.

Smoldering multiple myeloma and monoclonal gammopathy of undetermined significance

Smoldering multiple myeloma (SMM) consists of the presence of a serum M protein of 30 g/L or more and/or 10% or more bone marrow plasma cells (BMPCs), with no clinical manifestations or symptoms of myeloma. It accounts for approximately 10% of all myelomas, and the median time to progression to a symptomatic multiple myeloma ranges from 2 to 3 years. The main factors for progression are the plasma cell mass (M-protein size and percent of BMPCs), the spinal MRI pattern, the plasma cell proliferative index, and the variant of SMM ("evolving" vs "nonevolving"). Although treatment with thalidomide is promising (based on the results of two phase II trials), outside the context of a clinical trial, a watch-and-wait approach with clinical evaluation every 4 months is recommended until evident symptomatic disease progression occurs. Patients with monoclonal gammopathy of undetermined significance (MGUS) have a serum M protein lower than 30 g/L and a proportion of BMPCs of less than 10%, with no clinical findings or symptoms attributable to the monoclonal gammopathy. MGUS has a high prevalence, and its annual rate of malignant transformation is 1%, such that the actuarial probability of progression to a symptomatic monoclonal gammopathy at 25 years of follow-up is as high as 40%. The factors associated with a higher probability of malignant transformation are a relatively high plasma cell mass, immunoglobulin A M-protein type, and the "evolving" variant. It is recommended that patients with MGUS are monitored annually. Importantly, patients with asymptomatic monoclonal gammopathies must not be treated before the development of overt multiple myeloma.

Monoclonal gammopathy of undetermined significance, Waldenström macroglobulinemia, AL amyloidosis, and related plasma cell disorders: diagnosis and treatment

The spectrum of plasma cell disorders is broad. Monoclonal gammopathy of undetermined significance and smoldering multiple myeloma are asymptomatic disorders characterized by monoclonal plasma cell proliferation in the bone marrow in the absence of end-organ damage. Waldenström macroglobulinemia typically involves an ontogenically less mature lymphoplasmacytic bone marrow cell and is characterized by secretion of a monoclonal IgM protein. Solitary plasmacytoma is the only known potentially curable plasma cell disorder. Finally, AL (immunoglobulin light chain) amyloidosis and POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome are disorders characterized by low tumor burden but profound multisystemic disease. Updated diagnostic criteria for these disorders, risk stratification models to determine prognosis, and the current management of these diverse entitles are discussed in this review.

Monoclonal gammopathies of undetermined significance

The monoclonal gammopathies include multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS), primary systemic amyloidosis (AL), and Waldenström's macroglobulinemia (WM). At Mayo Clinic, almost 60% of patients with a monoclonal gammopathy have MGUS. MGUS is characterized by the presence of a serum monoclonal protein value <3 g/dL, fewer than 10% plasma cells in the bone marrow, no or a small amount of monoclonal protein in the urine, and absence of lytic bone lesions, anemia, hypercalcemia, or renal insufficiency related to the plasma-cell proliferative process. During long-term follow-up of 241 patients with MGUS seen at Mayo Clinic from 1956 to 1970, MM, WM, AL, or a related disorder developed in 64. To confirm the findings, we conducted a population-based study on MGUS in the 11 counties of southeastern Minnesota from 1960 to 1994. The risk of progression to a malignant plasma-cell disorder was 1% per year.

Multiple myeloma: diagnosis and treatment

Major advances have occurred in our understanding of the biology of multiple myeloma (MM) and in its treatment in the past decade. New diagnostic criteria have been developed, and an international Staging System has replaced the Durle-Salmon Staging System. It is now possible to classify MM as standard risk or high risk on the basis of specific Independent prognostic factors. The role of single and double autologous stem cell transplantation has been clarified by randomized trials. Most importantly, thalidomide, bortezomib, and lenalidomide have emerged as new active agents and are being incorporated rapidly into the treatment of both newly diagnosed and relapsed MM. The current approach to the diagnosis, prognosis, and management of MM is reviewed.

Prognostic factors for survival after autologous transplantation: a single centre experience in 133 multiple myeloma patients

Autologous stem cell transplantation (ASCT) has an established role in the treatment of symptomatic multiple myeloma (MM). Our aim was to analyse the impact of selected prognostic parameters on the survival of patients with MM after ASCT. The new International Staging System (ISS) was also evaluated. A total of 133 MM patients were transplanted in our centre between 1995 and 2002. Following ASCT, 35% of patients were in complete remission (CR) and 60% were in partial remission (PR). The median progression-free (PFS) and overall (OS) survival from transplantation were 29.5 and 68.8 months, respectively. Transplant-related mortality (TRM) was 3%. On multivariate analysis, factors associated with significantly shorter OS were lack of CR after transplant (P = 0.002, hazard ratio (HR): 3.1), stage 3 according to ISS (P = 0.001, HR: 3.0) and age at transplant over 60 years (P = 0.035, HR: 2.0). The status of disease before ASCT did not significantly affect PFS and OS after transplantation. We conclude that ASCT is a safe and effective procedure in MM patients, associated with low TRM. The survival after ASCT was dependent on response after ASCT, stage according to ISS and age.

Thalidomide in newly diagnosed multiple myeloma and overview of experience in smoldering/indolent disease

Based on the activity of single-agent thalidomide demonstrated in relapsed or refractory multiple myeloma, investigators have evaluated the role of this agent in the treatment of earlier stage disease. Two key phase II trials of thalidomide plus dexamethasone in patients with previously untreated symptomatic multiple myeloma have yielded overall response rates of 64% to 73%. Comparable response rates, reduced toxicity, and increased patient convenience with oral administration suggest it may offer an alternative to standard infusional chemotherapies, such as vincristine/doxorubicin/dexamethasone (VAD), before stem cell mobilization and high-dose chemotherapy in patients with active disease; further study is warranted. Two key phase II trials of single-agent thalidomide in patients with smoldering/indolent (asymptomatic) disease have yielded overall response rates of approximately 35%, and further study of thalidomide in this setting is also indicated. The primary toxicities of thalidomide-based therapy are neuropathy, sedation/fatigue, constipation, and rash. Studies of thalidomide in combination with dexamethasone suggest toxicities of both agents may be increased due to the synergy of these agents. Phase III trials of thalidomide in newly diagnosed symptomatic multiple myeloma or smoldering/indolent disease are ongoing.

Monoclonal gammopathies of undetermined significance: a review

Monoclonal gammopathy of undetermined significance (MGUS) denotes the presence of a monoclonal protein (M-protein) in patients without evidence of multiple myeloma (MM), macroglobulinemia, amyloidosis (AL), or a related plasma cell proliferative disorder. MGUS is found in approximately 3% of persons older than 70 years and in about 1% of those older than 50 years. In a series of 1384 patients from south-eastern Minnesota in whom MGUS was diagnosed at Mayo Clinic from 1960 through 1994, the risk of progression was 1% per year. Patients were at risk of progression even after 25 years or more of a stable monoclonal gammopathy. The risk of development of MM was increased by 25-fold, the risk of macroglobulinemia was 46-fold, and the risk of primary AL was 8.4-fold when compared with a similar population (Surveillance, Epidemiology and End Results). The concentration of the serum M-protein was the major independent predictor of progression. Patients with an immunoglobulin M (IgM) or an IgA monoclonal gammopathy had a higher risk of progression than those with an IgG monoclonal gammopathy. The presence of a urine M-protein or the reduction of one or more uninvolved Igs was not a risk factor for progression. MGUS may be associated with many different disorders, including lymphoproliferative diseases, leukemia, connective tissue disorders, dermatologic diseases, and neurologic disorders.

Thalidomide as initial therapy for early-stage myeloma

Patients with early-stage myeloma are typically observed without therapy until symptomatic disease occurs. However, they are at high risk of progression to symptomatic myeloma, with a median time to progression of approximately 1-2 years. We report the final results of a phase II trial of thalidomide as initial therapy for early-stage multiple myeloma in an attempt to delay progression to symptomatic disease. In total, 31 patients with smoldering or indolent multiple myeloma were studied at the Mayo Clinic. Two patients were deemed ineligible because they were found to have received prior therapy for myeloma, and were excluded from analyses except for toxicity. Thalidomide was initiated at a starting dose of 200 mg/day. Patients were followed-up monthly for the first 6 months and every 3 months thereafter. Of the 29 eligible patients, 10 (34%) had a partial response to therapy with at least 50% or greater reduction in serum and urine monoclonal (M) protein. When minor responses (25-49% decrease in M protein) were included, the response rate was 66%. Three patients had progressive disease while on therapy. Kaplan-Meier estimates of progression-free survival are 80% at 1 year and 63% at 2 years. Major grade 3-4 toxicities included two patients with somnolence and one patient each with neuropathy, deep-vein thrombosis, hearing loss, weakness, sinus bradycardia, and edema. Thalidomide has significant activity in early-stage myeloma and has the potential to delay progression to symptomatic disease. This approach must be further tested in randomized trials.

Monoclonal gammopathies of undetermined significance

The term 'monoclonal gammopathy of undetermined significance' denotes the presence of a monoclonal protein in patients without evidence of multiple myeloma, macroglobulinemia, amyloidosis or related plasma cell proliferative disorders. The disorder has been found in approximately 3% of persons older than 70 years and in approximately 1% of persons older than 50 years. A population-based study included 1384 patients from south-eastern Minnesota who had the disorder diagnosed at the Mayo Clinic from 1960 through 1994. Risk of progression was about 1% per year, but patients were at risk of progression even after 25 years or more of stable monoclonal gammopathy of undetermined significance. The risk for development of multiple myeloma was increased 25-fold; the risk of macroglobulinemia, 46-fold; and the risk of primary amyloidosis, 8.4-fold. Concentration and type of monoclonal protein were the only independent predictors of progression. The presence of a urine monoclonal protein and the reduction of one or more uninvolved immunoglobulins were not risk factors for progression. Monoclonal gammopathy of undetermined significance may be associated with various disorders, including lymphoproliferative diseases, leukemia, von Willebrand disease, connective tissue diseases and neurologic disorders.

Current therapy for multiple myeloma

Multiple myeloma is an incurable plasma cell malignancy that accounts for 10% of all hematologic cancers. For decades the mainstay of therapy has been the use of melphalan and prednisone; with this regimen, the median survival is approximately 3 years. Recently, important advances were made that have substantially altered the manner in which patients with myeloma are treated. Newly diagnosed patients with good performance status are now treated with autologous stem cell transplantation, resulting in improved survival. Because of the increasing use of transplantation as initial therapy, several therapeutic issues have emerged: the role of tandem transplantation, early vs delayed transplantation, and the role of allogeneic transplantation. The pronounced activity of thalidomide in patients with refractory myeloma represents another important advance. This has prompted the study of several novel agents in the treatment of myeloma, at least 2 of which appear promising. Supportive care measures also have improved, including the use of bisphosphonates to prevent osteolytic lesions. The purpose of this review is to summarize recent advances and provide an evidence-based approach to the treatment of multiple myeloma.

Solitary plasmacytoma of bone and asymptomatic multiple myeloma

Most patients with multiple myeloma (MM) present with symptoms, have evidence of generalized disease, and require chemotherapy promptly to reduce the malignant clone. Some patients present with a local symptom from a single plasmacytoma but no myeloma elsewhere. Such patients usually become free of symptoms after local radiotherapy. In patients with MM without symptoms, the diagnosis is made on the basis of screening laboratory tests. In patients with either solitary plasmacytoma of bone or asymptomatic MM, systemic treatment should be deferred until there is evidence of disease progression.

Solitary plasmacytoma of bone and asymptomatic multiple myeloma

Most patients with multiple myeloma (MM) present with symptoms, have evidence of generalized disease, and require chemotherapy promptly to reduce the malignant clone. Some patients present with a local symptom from a single plasmacytoma but no myeloma elsewhere. Such patients usually become free of symptoms after local radiotherapy. In patients with MM without symptoms, the diagnosis is made on the basis of screening laboratory tests. In patients with either solitary plasmacytoma of bone or asymptomatic MM, systemic treatment should be deferred until there is evidence of disease progression.