Complete response in myeloma extends survival without, but not with history of prior monoclonal gammopathy of undetermined significance or smouldering disease

Minimal residual disease in multiple myeloma: why, when, where

Improvements in multiple myeloma therapy have led to deeper responses that are beyond the limit of detection by historical immunohistochemistry and conventional flow cytometry in bone marrow samples. In parallel, more sensitive techniques for assessing minimal residual disease (MRD) through next-generation flow cytometry and sequencing have been developed and are now routinely available. Deep responses when measured by these assays correspond with improved outcomes and survival. We review the data supporting MRD testing as well as its limitations and how it may fit in with current and future clinical practice.

Bortezomib therapy in a real-world setting in patients with relapsed or refractory multiple myeloma

Bortezomib is a proteasome inhibitor, approved for treating newly diagnosed and relapsed multiple myeloma (MM). This realworld, multicenter, observational, non-interventional study of bortezomib was designed to collect and analyze prospective data in Taiwanese patients with relapsed or refractory MM. The primary endpoints included clinical effectiveness outcomes (disease response, disease progression [PD], time-to-response, time-toprogression, response duration, and overall survival [OS]). Secondary endpoints were safety and healthcare resource utilization.

Total 100 patients (median [range] age 64.9 [37.0-85.5] years) were enrolled; 47 patients completed the study. Of the withdrawn patients (n=53), there were 48 deaths (PD-related death: n=35, adverse events [AEs]-related: n=12, other reason: n=1), and 5 due to loss to follow-up. Four patients in Cycle 1, 6 patients each in Cycle 2 and 5, 7 in Cycle 3, 10 patients in Cycle 4, 5 patients in Cycle 6, and 3 patients each in Cycle 7 and 8 achieved overall response during the study. Time-to-response was 4.68 months (95%CI: 3.2, NE) and response duration was 10.08 months (95%CI: 2.3, 28.6). Median OS was 9.8 months (95%CI: 3.8, 13.7), and median time-to-progression was 11.3 months (95%CI: 6.2, 20.2). Most common non-hematological AEs were diarrhea (n=32) and hypoesthesia (n=25); most common hematological AE was thrombocytopenia (n=18).

Efficacy and safety profile of bortezomib in Taiwanese patients with MM was similar to global and other Asian population. Study provides a critical insight on use of bortezomib in realworld clinical practice, which can be helpful for Taiwanese healthcare providers’ decision-making processes.

Analysis of long-term survival in multiple myeloma after first-line autologous stem cell transplantation: impact of clinical risk factors and sustained response

The widespread use of high-dose therapy and autologous stem cell transplantation (ASCT) as well as the introduction of novel agents have significantly improved outcomes in multiple myeloma (MM) enabling long-term survival. We here analyze factors influencing survival in 865 newly diagnosed MM patients who underwent first-line ASCT at our center between 1993 and 2014. Relative survival and conditional survival were assessed to further characterize long-term survivors. Achievement of complete response (CR) post-ASCT was associated with prolonged progression-free survival (PFS) in the whole cohort and with significantly superior overall survival (OS) in the subgroup of patients receiving novel agent-based induction therapy. Landmark analyses performed at 1, 3, and 5 years post-ASCT revealed that sustainment of any response had a highly significant influence on survival with no significant differences between sustained CR and sustained inferior responses. Furthermore, outcome was independently improved by administration of maintenance therapy. A subset of patients did experience long-term survival >15 years. However, conditional survival demonstrated a persistent risk of myeloma-associated death and cumulative relative survival curves did not show development of a clear plateau, even in prognostically advantageous groups. In conclusion, in this large retrospective study, sustained response after first-line ASCT was found to be a major prognostic factor for OS independent of depth of sustained response. Administration of maintenance therapy further improved outcome, supporting the hypothesis that interventions to prolong responses achieved post-ASCT may be essential to reach long-term survival, especially in the setting of persisting residual disease.

Advances in understanding prognosis in myeloma

In the last two decades outcomes in multiple myeloma (myeloma) have greatly improved, due to the introduction of newer, more effective therapies. This improvement is not uniform. Response to treatment and survival remains heterogeneous, with some patients living for 1-2 years whilst others are alive and progression-free at 10 years. This variation in outcome is due to patient characteristics plus features intrinsic to the myeloma tumour. Alongside the introduction of novel therapies there has been a greater understanding of disease biology and mechanisms of resistance. This has led to an increase in the number of prognostic markers that can be used in myeloma. This is important not only for more accurate counselling of patients in terms of disease outcome, but also in paving the way for risk-adapted therapy. Both newer and traditional prognostic markers need to be used in the context of planned therapy. Indeed, the prognostic value of certain markers varies according to which therapy the patient receives. As such, these prognostic factors will require constant re-evaluation as agents with new mechanisms of action are added into the myeloma treatment algorithm. This article summarises current concepts of prognostic markers in myeloma.

Is it possible to cure myeloma without allogeneic transplantation?

During the last decades, a better understanding of the biology of multiple myeloma (MM) has led to the application of novel treatment strategies for MM patients. The new anti-myeloma regimens produce higher incidence of durable and of better quality responses and they improve overall survival, challenging the dogma of incurable disease, outside the context of allogeneic transplantation. This review presents all these strategies that aim to cure MM, including continuous treatment i.e. induction, consolidation and maintenance, treatment of asymptomatic MM and monitoring minimal residual disease using modern techniques, such as multi-parameter flow cytometry, molecular assays and advanced imaging.

Consolidation and maintenance in de novo first-line multiple myeloma with modern agents

SUMMARY 

Inclusion of new active drugs, such as IMiDs, proteasome inhibitors and soon the monoclonal antibodies, in first-line therapy has and will significantly enhance the response rate and depth of response, with the consequence of prolongation of the progression free and overall survivals. One of the greatest challenges faced in myeloma in recent years was to demonstrate the impact of prolonged therapy in the form of consolidation and/or maintenance. To date, this concept has almost always improved duration of response and progression free survival, but infrequently overall survival. Furthermore, this concept is associated to a certain cost, with not always predictable mid- and long-term adverse events along with the economic cost accompanying these events. As patients with myeloma live significantly longer, physicians need to discuss the risk/benefit of this approach at the individual level, and remain aware of the potential consequences as more knowledge becomes available.

Expression of L-type amino acid transporter 1 (LAT1) as a prognostic and therapeutic indicator in multiple myeloma

L-type amino-acid transporter 1 (LAT1) plays a key role in cell growth and survival. To determine the prognostic significance of LAT1 in multiple myeloma (MM), we investigated the expression of LAT1 and its functional subunit, 4Fc heavy chain (CD98), on myeloma cells by immunohistochemistry in 100 newly diagnosed MM patients. High expression (moderate or strong staining intensity) of LAT1 and CD98 was detected in 56% and 45% of patients, respectively. The LAT1 expression score was positively correlated with Ki-67 index (r = 0.631, P < 0.001), and there was a statistically significant difference in Durie-Salmon stage between patients with high and low LAT1 expression (P = 0.03). In 43 patients treated with melphalan and prednisolone, the overall response rate was significantly higher in the high LAT1 expression group (60.0%) than in the low LAT1 expression group (17.6%) (P = 0.03). Multivariate analysis confirmed that high expression of LAT1 was a significant prognostic factor for predicting poor overall survival independently from the International Staging System (both P = 0.01). Here, we show that the overexpression of LAT1 is significantly associated with high proliferation and poor prognosis in newly diagnosed MM patients. Thus, LAT1 may be a promising pathological marker for identifying high-risk MM.

Curing myeloma at last: defining criteria and providing the evidence

Does the dogma that multiple myeloma is incurable still hold?. The genomic chaos and resulting resistance to apoptosis of myeloma, long considered an obstacle to cure, formed the basis of Total Therapy (TT) program. The TT approach uses all myeloma-active drugs upfront to target drug-resistant subclones during initial treatment to prevent later relapse. Long-term follow-up of 1202 patients (TT1: n = 231, median follow-up: 21 years; TT2: 668, median follow-up: 12 years; TT3a: n = 303, median follow-up: 9 years) permitted investigation of whether progression-free survival (PFS) and complete response (CR) duration were consistent with curability, ie observation of plateaus in Kaplan-Meier plots for PFS and CR duration. In the subset of 627 patients with plasma cell gene expression profiling data, cure plateaus were apparent at 5 years in the 14% with high-risk myeloma compared with 10 years in the remainder with low-risk disease. A parametric model based on PFS and CR duration supported an increase in curability: 10-year PFS and CR estimates increased from 8.8%/17.9% in TT1 to 15.5%/28.2% in TT2's control arm to 25.1%/35.6% in TT2's thalidomide arm and to 32.9%/48.8% in TT3a. Toward developing novel therapies, we recommend a concerted focus on patients with high-risk myeloma whose outcome has not been advanced.

Determining the clinical significance of monoclonal gammopathy of undetermined significance: a SEER-Medicare population analysis

BACKGROUND

Clinical guidelines have recommended annual follow-up examinations of most patients with monoclonal gammopathy of undetermined significance (MGUS); however, evidence supporting this practice is lacking. We performed a population-based study to examine the patterns of disease presentation and outcomes of patients with multiple myeloma, Waldenström macroglobulinemia, and lymphoplasmacytic lymphoma (monoclonal gammopathy-associated malignancies) comparing those with or without a previous MGUS follow-up examination.

MATERIALS AND METHODS

Patients with monoclonal gammopathy-associated malignancy from 1994 through 2007 were identified using the Surveillance, Epidemiology, and End Results-Medicare linked database and divided into 2 cohorts: those with follow-up (MGUS follow-up examination preceding the diagnosis) and those with no follow-up (no such follow-up examination). We compared the outcomes, including the rates of major complications at cancer diagnosis (acute kidney injury, cord compression, dialysis use, fracture, and hypercalcemia) and survival using propensity score adjustment and Cox proportional hazard models. All statistical tests were 2-sided.

RESULTS

Of the 17,457 study patients, 6% had undergone MGUS follow-up. After multivariable modeling, the follow-up group had significantly fewer major complications at diagnosis (odds ratio 0.68; 95% confidence interval [CI], 0.57-0.80) and better disease-specific (median, 38 vs. 29 months, P < .001; hazard ratio [HR] 0.85; 95% CI, 0.76-0.94) and overall (median, 23 vs. 19 months, P < .001; HR 0.87; 95% CI, 0.80-0.95) survival.

CONCLUSION

Patients with MGUS follow-up preceding the diagnosis of a monoclonal gammopathy-associated malignancy can experience fewer major complications and have longer survival than those without such follow-up examinations. Future studies replicating our findings in the non-Medicare population and determining the optimal schedule and cost-effectiveness of MGUS follow-up are warranted.

[Use of whole-body diffusion-weighted magnetic resonance imaging for the diagnosis of and therapeutic response in multiple myeloma]

INTRODUCTION

Multiple myeloma is an incurable neoplastic disorder of B cells characterized by diffuse bone marrow infiltration, circumscribed bone lesions, and soft-tissue spreading. The role of novel functional imaging techniques in multiple myeloma includes initial staging of the disease, detection and characterization of complications, and evaluation of the response to treatment.

AIM

The authors present their 2 and a half-year experience with diffusion-weighted magnetic resonance imaging in staging and follow up of patients with multiple myeloma.

METHOD

Conventional T1 weighted, T2 weighted fat suppressed and 2 b-values diffusion-weighted sequences were performed from skull base to symphysis in 27 patients suspected to have multiple myeloma. Apparent diffusion coefficient calculation was carried out in 3 cases. The final diagnosis of multiple myeloma was verified by bone-marrow biopsy.

RESULTS

In 13 cases magnetic resonance imaging revealed the suspected disease. In one patient magnetic resonance imaging failed to detect the disease because of metallic artifacts. In 6 cases diffusion-weighted sequences showed additional information about bone-marrow infiltration.

CONCLUSIONS

Diffusion-weighted magnetic resonance imaging with conventional sequences is a useful and promising functional imaging modality in the early diagnosis of myeloma multiple.

The future of autologous stem cell transplantation in myeloma

Autologous stem cell transplantation (ASCT) has long been considered frontline therapy for newly diagnosed myeloma patients. This Spotlight examines the role of ASCT in the era of novel drugs and argues that ASCT should continue to be considered for eligible patients. A combination of novel drugs with ASCT in a sequential treatment approach can attain long-term survival and perhaps cure a subset of patients. ASCT will likely remain an important platform to develop curative strategies in the foreseeable future.

Association of response endpoints with survival outcomes in multiple myeloma

Since the introduction of the proteasome inhibitor bortezomib and the immunomodulatory drugs (IMiDs) thalidomide and lenalidomide, more patients with multiple myeloma are achieving deep, durable responses and disease control, and are living longer. These improvements have afforded more robust analyses of the relationship between response and survival. Generally, these studies have demonstrated that improvements in the quality of response across all stages of treatment are associated with better disease control and longer survival. Thus, achievement of maximal response should be strongly considered, particularly in the frontline setting, but must also be balanced with tolerability, quality of life and patient preferences. In select patients, achievement of a lesser response may be adequate to prolong survival, and attempts to treat these patients to a deeper response may place them at unnecessary risk without significant benefit. Maintenance therapy has been shown to improve the quality of response and disease control and, in some studies, survival. Studies support maintenance therapy for high-risk patients as a standard of care, and there are emerging data supporting maintenance therapy in standard-risk patients to improve progression-free and possibly overall survival. Multidrug regimens combining a proteasome inhibitor and an IMiD have shown exceptional response outcomes with acceptable increases in toxicity in both the frontline and salvage settings, and are becoming a standard treatment approach. Moving forward, the use of immunophenotypic and molecular response criteria will be essential in better understanding the impact of highly active and continuous treatment regimens across myeloma patient populations. Future translational studies will help to develop antimyeloma agents to their fullest potential. The introduction of novel targeted therapies, including the IMiD pomalidomide and the proteasome inhibitors carfilzomib and ixazomib (MLN9708), will provide greater options to individualize treatment and help patients achieve a clinically meaningful response.

Autologous stem cell transplantation for multiple myeloma: identification of prognostic factors

INTRODUCTION

The purpose of this study was to evaluate the effect of prognostic factors on the outcome of patients with MM after ASCT.

PATIENTS AND METHODS

We analyzed results of 170 consecutive patients (121 male and 49 female) of MM who underwent ASCT. Patients' median age was 52 years (range, 26-68 years). High dose melphalan (200 mg/m(2)) was used for conditioning. One hundred thirty-two patients (77.6%) had evidence of chemosensitive disease before transplant. Response was assessed using European Group for Blood and Bone Marrow Transplantation criteria.

RESULTS

Post ASCT 44.7% of patients achieved CR, 24.7% had very good partial response (VGPR), and 21.2% had partial response (PR). Presence of pretransplant chemosensitive disease (CR, VGPR, and PR) and transplant within 12 months of diagnosis for years before 2006 were associated with higher response rates on multivariate analysis. At a median follow-up of 84 months, median overall (OS) and event-free survival (EFS) is 85.5 and 41 months, respectively. Estimated OS and EFS at 60 months is 62 ± 0.04% and 41 ± 0.04%, respectively. Patients who responded to transplant (CR, VGPR, and PR) had a longer OS (P < .001) and EFS (P < .001). Additionally, patients who achieved CR post transplant had a longer OS (P < .001) and EFS (P < .001). Patients who received novel agents for induction pretransplant had a longer OS (P < .001) and EFS (P < .002).

CONCLUSION

Outcome after ASCT is better for myeloma patients with pretransplant chemosensitive disease and those who achieve CR after transplant.

Analysis of the immune system of multiple myeloma patients achieving long-term disease control by multidimensional flow cytometry

Multiple myeloma remains largely incurable. However, a few patients experience more than 10 years of relapse-free survival and can be considered as operationally cured. Interestingly, long-term disease control in multiple myeloma is not restricted to patients with a complete response, since some patients revert to having a profile of monoclonal gammopathy of undetermined significance. We compared the distribution of multiple compartments of lymphocytes and dendritic cells in the bone marrow and peripheral blood of multiple myeloma patients with long-term disease control (n=28), patients with newly diagnosed monoclonal gammopathy of undetermined significance (n=23), patients with symptomatic multiple myeloma (n=23), and age-matched healthy adults (n=10). Similarly to the patients with monoclonal gammopathy of undetermined significance and symptomatic multiple myeloma, patients with long-term disease control showed an expansion of cytotoxic CD8(+) T cells and natural killer cells. However, the numbers of bone marrow T-regulatory cells were lower in patients with long-term disease control than in those with symptomatic multiple myeloma. It is noteworthy that B cells were depleted in patients with monoclonal gammopathy of undetermined significance and in those with symptomatic multiple myeloma, but recovered in both the bone marrow and peripheral blood of patients with long-term disease control, due to an increase in normal bone marrow B-cell precursors and plasma cells, as well as pre-germinal center peripheral blood B cells. The number of bone marrow dendritic cells and tissue macrophages differed significantly between patients with long-term disease control and those with symptomatic multiple myeloma, with a trend to cell count recovering in the former group of patients towards levels similar to those found in healthy adults. In summary, our results indicate that multiple myeloma patients with long-term disease control have a constellation of unique immune changes favoring both immune cytotoxicity and recovery of B-cell production and homing, suggesting improved immune surveillance.

Response-adjusted ISS (RaISS) is a simple and reliable prognostic scoring system for predicting progression-free survival in transplanted patients with multiple myeloma

Complete response (CR) is associated with better outcome in patients with multiple myeloma (MM) treated with autologous transplant even though the progression-free survival (PFS) can be very variable among patients with good response. No simple and reliable prognostic scoring system, able to predict the duration of response, are so far available. Aim of this study was to identify any correlation between baseline clinical findings, response after transplant and the length of PFS, and thus develop a prognostic model. The new prognostic model was developed in a learning cohort of 549 patients with MM transplanted in five Italian hospitals. The prognostic value of this new score was confirmed in a validation cohort of 276 distinct patients with MM transplanted in two different Italian hospital. Univariate and multivariate analyses were performed using Cox models. The most important independent baseline predictor of transplant outcome, together with response after transplant, was International Staging System (ISS). We thus incorporated response to transplant and baseline ISS in a new scoring system, named response-adjusted international scoring system (RaISS), that was able to classify patients in three risk groups (low, intermediate, high) with different probabilities of progression after transplant (median PFS 35.9-15.4 months). The prognostic value of this new score was confirmed in the validation cohort. In conclusion, RaISS is a new simple and easily available scoring system that, accurately defining the risk of progression, can allow to identify patients who could deserve further treatment after transplant (consolidation, maintenance).

High-risk cytogenetics and persistent minimal residual disease by multiparameter flow cytometry predict unsustained complete response after autologous stem cell transplantation in multiple myeloma

The achievement of complete response (CR) after high-dose therapy/autologous stem cell transplantation (HDT/ASCT) is a surrogate for prolonged survival in multiple myeloma; however, patients who lose their CR status within 1 year of HDT/ASCT (unsustained CR) have poor prognosis. Thus, the identification of these patients is highly relevant. Here, we investigate which prognostic markers can predict unsustained CR in a series of 241 patients in CR at day +100 after HDT/ASCT who were enrolled in the Spanish GEM2000 (n = 140) and GEM2005 < 65y (n = 101) trials. Twenty-nine (12%) of the 241 patients showed unsustained CR and a dismal outcome (median overall survival 39 months). The presence of baseline high-risk cytogenetics by FISH (hazard ratio 17.3; P = .002) and persistent minimal residual disease by multiparameter flow cytometry at day +100 after HDT/ASCT (hazard ratio 8.0; P = .005) were the only independent factors that predicted unsustained CR. Thus, these 2 parameters may help to identify patients in CR at risk of early progression after HDT/ASCT in whom novel treatments should be investigated.

International Myeloma Working Group consensus approach to the treatment of multiple myeloma patients who are candidates for autologous stem cell transplantation

The role of high-dose therapy followed by autologous stem cell transplantation (ASCT) in the treatment of multiple myeloma (MM) continues to evolve in the novel agent era. The choice of induction therapy has moved from conventional chemotherapy to newer regimens incorporating the immunomodulatory derivatives thalidomide or lenalidomide and the proteasome inhibitor bortezomib. These drugs combine well with traditional therapies and with one another to form various doublet, triplet, and quadruplet regimens. Up-front use of these induction treatments, in particular 3-drug combinations, has affected unprecedented rates of complete response that rival those previously seen with conventional chemotherapy and subsequent ASCT. Autotransplantation applied after novel-agent-based induction regimens provides further improvement in the depth of response, a gain that translates into extended progression-free survival and, potentially, overall survival. High activity shown by immunomodulatory derivatives and bortezomib before ASCT has recently led to their use as consolidation and maintenance therapies after autotransplantation. Novel agents and ASCT are complementary treatment strategies for MM. This article reviews the current literature and provides important perspectives and guidance on the major issues surrounding the optimal current management of younger, transplantation-eligible MM patients.

Advances in understanding monoclonal gammopathy of undetermined significance as a precursor of multiple myeloma

Monoclonal gammopathy of undetermined significance (MGUS) affects at least 3% of the population above the age of 50 and is the precursor to multiple myeloma (MM), an incurable malignancy of plasma cells. Recent advances in MGUS include: an improved understanding of the pathogenesis of MGUS and its progression to MM, involving molecular events intrinsic to the malignant plasma cell as well as the microenvironment; novel techniques to assess risk for progression to MM using serum-free light-chain analysis and immunophenotyping; and a renewed interest in chemoprevention of MM. In the future, continued improvement in our understanding of MGUS will lead to the development of better biomarkers for prognosis and therapies for chemoprevention of MM.

High-dose therapy and autologous peripheral blood stem cell transplantation in patients with multiple myeloma

Since its introduction in 1983, high-dose therapy followed by autologous peripheral blood stem cell transplantation is a pillar of the treatment of patients with multiple myeloma. In the last decades, a multitude of clinical trials helped to improve strategies based on high-dose therapy and autologous stem cell transplantation resulting in a continuously prolongation of overall survival of patients. In this chapter we will review the progress, which has been made in order to enhance the mobilisation of autologous stem cells and increase the effectiveness of this treatment.

Survival of cancer patients with prior monoclonal gammopathy of undetermined significance

INTRODUCTION

It is unknown whether a prior diagnosis of monoclonal gammopathy of undetermined significance (MGUS) affects cancer survival.

DESIGN AND METHODS

We linked data on 1652 cases of MGUS diagnosed during 1978-2006 in North Jutland County, Denmark with the Danish Cancer Registry and the National Patient Registry to obtain information on survival of cancer patients with a previous MGUS compared with that of cancer patients without MGUS, matched on cancer type, age, sex and year of diagnosis. Stratified Cox regression analysis was used to compute mortality rate ratios controlling for the matching factors and comorbidity.

RESULTS

We included 323 cancer patients with previously detected MGUS and 3154 comparison cancer patients without MGUS. The 5-year survival probability was 26.2% (95% CI, 21.2%-31.5%) in cancer patients with MGUS and 30.5% (28.8%-32.1%) in cancer patients without MGUS. The adjusted mortality rate ratio (MRR) was=0.94 (95% CI, 0.82-1.09). Survival following a diagnosis of multiple myeloma, the cancer site of main interest, did not differ according to a preceding MGUS diagnosis. Among patients with immune-related cancers (liver, cervix, malignant melanoma and non-melanoma skin cancers), a preceding MGUS diagnosis was associated with reduced survival (adjusted MRR=1.49 (95% CI: 0.96-2.31)). In contrast, for other non-haematological cancers a prior MGUS diagnosis was associated with a lower MRR (0.78 (95% CI, 0.63-0.96)).

CONCLUSION

Our study does not indicate that previously detected MGUS is a prognostic factor for cancer survival in general.

Bortezomib and dexamethasone for Japanese patients with relapsed and refractory multiple myeloma: a single center experience

Bortezomib is a novel proteasome inhibitor, which has shown high antimyeloma activity. APEX trial, phase III randomized study for relapsed or refractory myeloma established efficacy and feasibility of bortezomib. In our study, we retrospectively investigated 60 Japanese patients with relapsed or refractory multiple myeloma (MM) who underwent bortezomib and dexamethasone (BD) therapy in our institution. Overall response rate was 75%, including 7 cases (11.7%) of complete response and 13 cases (21.7%) of very good partial response. Stable disease and progressive disease were observed in 15 patients (25%). Major ≥ grade 3 adverse events were hematological toxicities and grade 3 non-hematological toxicities included appetite loss, diarrhea and peripheral neuropathy. BD therapy was well tolerated, and produced significant response in relapsed or refractory MM patients. Recently, many worldwide trials including bortezomib or other new agents are ongoing to evaluate its efficacy not only as a therapy for relapsed or refractory disease but also as a frontline therapy. Further investigations are required to define how to use new antimyeloma agents for Japanese MM patients.

Importance of achieving a complete response in multiple myeloma, and the impact of novel agents

The goal of treatment for multiple myeloma (MM) is to improve patients' long-term outcomes. One important factor that has been associated with prolonged progression-free and overall survival is the quality of response to treatment, particularly achievement of a complete response (CR). There is extensive evidence from clinical studies in the transplant setting in first-line MM demonstrating that CR or maximal response post-transplant is significantly associated with prolonged progression-free and overall survival, with some studies demonstrating a similar association with postinduction response. Supportive evidence is also available from studies in the nontransplant and relapsed settings. With the introduction of bortezomib, thalidomide, and lenalidomide, higher rates of CR are being achieved in both first-line and relapsed MM compared with previous chemotherapeutic approaches, thereby potentially improving long-term outcomes. While standard CR by established response criteria has been shown to have differential prognostic impact compared with lesser responses, increasingly sensitive analytic techniques are now being explored to define more stringent degrees of CR or elimination of minimal residual disease (MRD), including multiparameter flow cytometry and polymerase chain reaction. Demonstrating eradication of MRD by these techniques has already been shown to predict for improved outcomes. Here, we review the prognostic significance of achieving CR in MM and highlight the importance of CR as an increasingly realizable goal at all stages of treatment. We discuss clinical management issues and provide recommendations relevant to practicing oncologists, such as the routine use of sensitive techniques for assessment of disease status to inform evidence-based decisions on optimal patient management.

Current multiple myeloma treatment strategies with novel agents: a European perspective

The treatment of multiple myeloma (MM) has undergone significant developments in recent years. The availability of the novel agents thalidomide, bortezomib, and lenalidomide has expanded treatment options and has improved the outcome of patients with MM. Following the introduction of these agents in the relapsed/refractory setting, they are also undergoing investigation in the initial treatment of MM. A number of phase III trials have demonstrated the efficacy of novel agent combinations in the transplant and nontransplant settings, and based on these results standard induction regimens are being challenged and replaced. In the transplant setting, a number of newer induction regimens are now available that have been shown to be superior to the vincristine, doxorubicin, and dexamethasone regimen. Similarly, in the front-line treatment of patients not eligible for transplantation, regimens incorporating novel agents have been found to be superior to the traditional melphalan plus prednisone regimen. Importantly, some of the novel agents appear to be active in patients with high-risk disease, such as adverse cytogenetic features, and certain comorbidities, such as renal impairment. This review presents an overview of the most recent data with these novel agents and summarizes European treatment practices incorporating the novel agents.

How I treat multiple myeloma in younger patients

Therapeutic options for multiple myeloma (MM) patients have changed quickly in recent years and uncertainty has arisen about optimal approaches to therapy. A reasonable goal of MM treatment in younger “transplant eligible” patients is to initiate therapy with a target goal of durable complete remission, and the anticipated consequence of long-term disease control. To achieve this goal we recommend induction therapy with multi-agent combination chemotherapies (usually selected from bortezomib, lenalidomide, thalidomide, cyclophosphamide, and corticosteriods) which when employed together elicit frequent, rapid, and deep responses. We recommend consolidation with high-dose melphalan and autologous stem cell transplantation in the majority of patients willing and able to undergo this procedure and subsequent maintenance therapy, especially in those failing to achieve a complete response or at high risk for early relapse based on prognostic, genetically defined risk factors. Defining genetic risk for early relapse is therefore an important aspect of early diagnostic testing and attention to minimizing expected toxicities once therapy begins is critical in ensuring the efficacy of modern combination therapy approaches. When access to newer drugs is restricted participation in clinical trials should be pursued.

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.

Management of newly diagnosed symptomatic multiple myeloma: updated Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) consensus guidelines

Multiple myeloma is a malignant plasma cell neoplasm that affects more than 20,000 people each year and is the second most common hematologic malignancy. It is part of a spectrum of monoclonal plasma cell disorders, many of which do not require active therapy. During the past decade, considerable progress has been made in our understanding of the disease process and factors that influence outcome, along with development of new drugs that are highly effective in controlling the disease and prolonging survival without compromising quality of life. Identification of well-defined and reproducible prognostic factors and introduction of new therapies with unique modes of action and impact on disease outcome have for the first time opened up the opportunity to develop risk-adapted strategies for managing this disease. Although these risk-adapted strategies have not been prospectively validated, enough evidence can be gathered from existing randomized trials, subgroup analyses, and retrospective studies to develop a working framework. This set of recommendations represents such an effort-the development of a set of consensus guidelines by a group of experts to manage patients with newly diagnosed disease based on an interpretation of the best available evidence.

Achievement of at least very good partial response is a simple and robust prognostic factor in patients with multiple myeloma treated with high-dose therapy: long-term analysis of the IFM 99-02 and 99-04 Trials

PURPOSE

The prognostic impact of complete response (CR) achievement in multiple myeloma (MM) has been shown mostly in the context of autologous stem-cell transplantation. Other levels of response have been defined because, even with high-dose therapy, CR is a relatively rare event. The purpose of this study was to analyze the prognostic impact of very good partial response (VGPR) in patients treated with high-dose therapy.

PATIENTS AND METHODS

All patients were included in the Intergroupe Francophone du Myelome 99-02 and 99-04 trials and treated with vincristine, doxorubicin, and dexamethasone (VAD) induction therapy followed by double autologous stem-cell transplantation (ASCT). Best post-ASCT response assessment was available for 802 patients.

RESULTS

With a median follow-up of 67 months, median event-free survival (EFS) and 5-year EFS were 42 months and 34%, respectively, for 405 patients who achieved at least VGPR after ASCT versus 32 months and 26% in 288 patients who achieved only partial remission (P = .005). Five-year overall survival (OS) was significantly superior in patients achieving at least VGPR (74% v 61% P = .0017). In multivariate analysis, achievement of less than VGPR was an independent factor predicting shorter EFS and OS. Response to VAD had no impact on EFS and OS. The impact of VGPR achievement on EFS and OS was significant in patients with International Staging System stages 2 to 3 and for patients with poor-risk cytogenetics t(4;14) or del(17p).

CONCLUSION

In the context of ASCT, achievement of at least VGPR is a simple prognostic factor that has importance in intermediate and high-risk MM and can be informative in more patients than CR.

The role of complete response in multiple myeloma

In multiple myeloma (MM), the impact of complete response (CR) could be shown only after introduction of high-dose therapy plus autologous stem cell transplantation (ASCT). In the context of ASCT, achieving CR (negative immunofixation and normal bone marrow) or at least very good partial response is associated with longer progression-free survival and in most studies longer survival. With novel agents, high CR rates are achieved and this prognostic impact of CR is being shown as well, both in relapsed and in newly diagnosed MM. However the benefit of CR achievement depends on the type of treatment and is not identical for all patients. In elderly patients, treatments inducing more CR may be more toxic. Although CR achievement is necessary in patients with poor-risk disease, it might not be as critical for long survival in more indolent MM. CR achievement is not the only objective of treatment because it is possible to further improve the depth of response and the outcome by continuing treatment after CR achievement. Finally, there are several levels of CR and in the future it will be necessary to confirm the prognostic impact of immunophenotypic or molecular CR or of CR defined by imaging procedures.

Complete remission in multiple myeloma examined as time-dependent variable in terms of both onset and duration in Total Therapy protocols

Landmark analyses are used to investigate the importance for survival of achieving complete response (CR), an important initial goal of myeloma therapy. With median times to CR in Total Therapy (TT) trials of approximately 1 year, this approach excludes a sizeable fraction of patients dying before such a landmark. To permit inclusion of all trial participants, we investigated the prognostic implications of both onset and duration of CR as time-dependent variables. Superseding the adverse effects of cytogenetic abnormalities and other standard prognostic parameters, both failure to achieve CR (non-CR) and, especially, loss of CR (los-CR) were independently associated with inferior survival in TT1, TT2, and TT3 protocols. In the context of gene array-defined risk, available in TT2 and TT3 subsets, both los-CR and non-CR terms were retained in the survival model as dominant adverse variables, stressing the prognostic importance of sustaining CR status, especially in high-risk disease.

A monoclonal gammopathy precedes multiple myeloma in most patients

Preexisting plasma cell disorders, monoclonal gammopathy of undetermined significance, or smoldering myeloma are present in at least one-third of multiple myeloma patients. However, the proportion of patients with a preexisting plasma cell disorder has never been determined by laboratory testing on prediagnostic sera. We cross-referenced our autologous stem cell transplantation database with the Department of Defense Serum Repository. Serum protein electrophoresis, immunofixation electrophoresis, and serum free light-chain analysis were performed on all sera collected 2 or more years before diagnosis to detect a monoclonal gammopathy (M-Ig). In 30 of 90 patients, 110 prediagnostic samples were available from 2.2 to 15.3 years before diagnosis. An M-Ig was detected initially in 27 of 30 patients (90%, 95% confidence interval, 74%-97%); by serum protein electrophoresis and/or immunofixation electrophoresis in 21 patients (77.8%), and only by serum free light-chain analysis in 6 patients (22.2%). Four patients had only one positive sample within 4 years before diagnosis, with all preceding sera negative. All 4 patients with light-chain/nonsecretory myeloma evolved from a light-chain M-Ig. A preexisting M-Ig is present in most multiple myeloma patients before diagnosis. Some patients progress rapidly through a premalignant phase. Light-chain detected M-Ig is a new entity that requires further study.

Complete remission sustained 3 years from treatment initiation is a powerful surrogate for extended survival in multiple myeloma

BACKGROUND

Complete response (CR) has been considered a necessary although not sufficient early clinical endpoint for extended survival in multiple myeloma.

METHODS

By using Total Therapy 2 (TT2) clinical outcome data in 668 patients, whether sustained CR (SUS-CR) was potentially a superior surrogate for survival than attaining CR status per se was evaluated.

RESULTS

Compared with not achieving CR (NON-CR) and especially achieving and subsequently losing CR status (LOS-CR) within a 3-year landmark from treatment initiation, SUS-CR was associated with highly superior postlandmark survival (P < .0001). These results were validated in 231 untreated patients enrolled in the predecessor trial, TT1 (hazard ratio [HR] = 0.54, P = .013) and in 1103 previously treated patients on other transplant protocols (HR = 0.49; P < .001).

CONCLUSIONS

In all 3 trial settings the survival benefit of SUS-CR was independent of metaphase abnormalities as a dominant adverse parameter. Given its bleak prognosis despite high CR rates, SUS-CR should be evaluated as a primary trial endpoint in high-risk myeloma.

Completion of premaintenance phases in total therapies 2 and 3 improves clinical outcomes in multiple myeloma: an important variable to be considered in clinical trial designs

BACKGROUND

Total Therapy (TT) programs are complex and their execution over the course of several years is fraught with patient attrition due to failure and toxicity of therapy and patient/physician acceptance.

METHODS

The impact of completion versus noncompletion of intended treatment steps was examined in protocols TT2 (n=668) and TT3 (n=303) on overall survival (OS) and event-free survival (EFS).

RESULTS

By using appropriate landmarks of 36 months with TT2 and 18 months with TT3, representing the maxima to completion of premaintenance phases, postconsolidation OS was superior for 211 patients completing versus 311 patients not completing premaintenance steps on TT2 (P=.001), which also pertained to the 161 patients completing versus 47 not completing intended treatment steps on TT3 (P=.01). On multivariate analysis that included all patients, completion of therapy independently favored longer OS and EFS in the context of both standard prognostic factors and gene expression profiling-defined risk; in addition, TT3 prolonged EFS over results obtained with TT2.

CONCLUSIONS

1) Completion of intended therapy was a significant independent variable conferring superior OS and EFS in TT programs; and 2) after adjusting for completion of therapy, EFS was still superior with TT3 versus TT2, supporting the beneficial role of bortezomib included in TT3. Collectively, these data point to the importance of designing clinical trials that balance the treatment requirements for disease control with host acceptance and tolerance.

Thalidomide arm of Total Therapy 2 improves complete remission duration and survival in myeloma patients with metaphase cytogenetic abnormalities

Total Therapy 2 examined the clinical benefit of adding thalidomide up-front to a tandem transplant regimen for newly diagnosed patients with multiple myeloma. When initially reported with a median follow-up of 42 months, complete response rate and event-free survival were superior among the 323 patients randomized to thalidomide, whereas overall survival was indistinguishable from that of the 345 patients treated on the control arm. With further follow-up currently at a median of 72 months, survival plots segregated 5 years after initiation of therapy in favor of thalidomide (P = .09), reaching statistical significance for the one third of patients exhibiting cytogenetic abnormalities (CAs; P = .02), a well-recognized adverse prognostic feature. The duration of complete remission was also superior in the cohort presenting with CAs such that, at 7 years from onset of complete remission, 45% remained relapse-free as opposed to 20% on the control arm (P = .05). These observations were confirmed when examined by multivariate analysis demonstrating that thalidomide reduced the hazard of death by 41% among patients with CA-positive disease (P = .008). Because two thirds of patients without CAs have remained alive at 7 years, the presently emerging separation in favor of thalidomide may eventually reach statistical significance as well.

Benefit of complete response in multiple myeloma limited to high-risk subgroup identified by gene expression profiling

EXPERIMENTAL DESIGN

To determine whether the clinical benefit of complete remission (CR) may depend on prognostic subgroups of patients with multiple myeloma.

PATIENTS AND METHODS

Newly diagnosed patients with myeloma received a tandem autotransplant regimen. Using multivariate regression analyses, we examined the prognostic implications of time-dependent onset of CR on overall survival and event-free survival in the context of standard prognostic factors (SPF) and gene expression profiling-derived data available for 326 patients.

RESULTS

CR benefited patients regardless of risk status when only SPFs were examined. With knowledge of gene array data, a survival (and event-free survival) benefit of CR only pertained to the small high-risk subgroup of 13% of patients (hazard ratio, 0.23; P = 0.001), whereas the majority of patients with low-risk disease had similar survival expectations whether or not CR was achieved (hazard ratio, 0.68; P = 0.128).

CONCLUSIONS

Access to gene expression information permitted the recognition of a small very high-risk subgroup of 13% of patients, in whom prolonged survival critically depended on achieving CR. Absence of such benefit in the remainder should lead to a reassessment of clinical trial designs that rely on this end point as a surrogate for long-term prognosis.

The impact of race on outcomes of autologous transplantation in patients with multiple myeloma

Multiple myeloma is the most common hematologic malignancy in African-Americans, with twice the mortality of Caucasians according to population based data. In the pretransplantation era, comparable conventional therapy has resulted in similar outcomes between African-Americans and Caucasians. However, there has been limited data on outcomes after high dose chemotherapy with autologous stem cell transplantation (ASCT). A retrospective analysis of Caucasian (n = 55) and African-American (n = 36) myeloma patients who underwent ASCT in an equal access health care system in the Department of Defense was performed. Presenting demographic variables, pre/post ASCT characteristics, overall mortality and relapse rates after ASCT were obtained. Progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan-Meier, and compared via log-rank testing. The median age at diagnosis for African-Americans = 52 years, Caucasians = 56 years (P = 0.009). There were no differences in presenting ISS stage, hemoglobin, calcium, or creatinine. African-Americans presented with higher CRP levels (P = 0.005), and a trend for less skeletal involvement (P = 0.10). Response to induction and ASCT was similar. Median PFS was 60.5 months (95% CI: 31.3-89.8 months) for African-Americans, 43.7 months (95% CI: 33.9-53.5 months) for Caucasians, HR of 1.3 (95% CI: 0.7-2.4), P = 0.46. Median OS was 95.2 months (95% CI: N/A) for African-Americans, 68.5 months (95% CI: 14.2-122.9 months) for Caucasians, HR of 1.4 (95% CI: 0.7-2.9), P = 0.41. In a cohort of myeloma patients who received autologous transplantation in an equal access health care system, there was comparable survival between African-Americans and Caucasians, suggesting that the historical increased mortality for African-Americans may be due to inequalities in access to care.

Outcome after autologous stem cell transplantation for multiple myeloma in patients with preceding plasma cell disorders

A third of patients with multiple myeloma (MM) have a preceding diagnosis of plasma cell proliferative disorder (PCPD), mostly monoclonal gammopathy of undetermined significance (MGUS), smoldering MM (SMM) or plasmacytoma. While autologous stem cell transplantation (SCT) improves survival in MM, it is not clear if patients with preceding PCPD have a different outcome. We identified 151 patients with preceding PCPD from among 804 patients undergoing SCT, and their outcomes were compared. The response rates, including complete responses, were similar between the groups. Patients with a preceding diagnosis of MGUS had longer time to progression (TTP; 27.5 months vs. 17.2 months, P = 0.01), and longer overall survival (OS) from transplant (80.2 months vs. 48.3 months, P = 0.03) compared to those with de novo myeloma. However no differences were seen among those with a preceding diagnosis of SMM or plasmacytoma in terms of TTP or OS from transplant when compared to those with de novo myeloma. Multivariate analysis indicated that the presence of MGUS prior to myeloma was prognostic for post-transplant relapse independent of other known risk factors. Patients with pre-existing MGUS prior to myeloma diagnosis have a better outcome following HDT, reflecting more indolent disease and a favourable biology than those presenting with de novo myeloma.

Induction Therapy in Multiple Myeloma

In most hematologic malignancies the role of induction treatment is to achieve complete remission (CR). In multiple myeloma this has been possible only with the introduction of high-dose therapy plus autologous stem-cell transplantation (ASCT). In the context of ASCT there is a statistical relationship between CR or very good partial remission (VGPR) achievement and progression-free survival or overall survival. High-dose therapy consists of 3 to 6 courses of a dexamethasone alone or combined with vincristine-adriamycin (VAD) to reduce the tumor burden and the plasma cell infiltration followed by 1 or 2 courses of high-dose melphalan plus ASCT. This treatment induces 20% to 40% CR and 40% to 55% CR/VGPR. The introduction of novel agents in the induction treatment is changing this scenario. The combinations of dexamethasone with thalidomide, bortezomib or lenalidomide increase the CR/VGPR rates compared to dexamethasone or VAD. Triple combinations are currently being evaluated, but preliminary results with not more than 3 or 4 cycles show post-ASCT CR/VGPR rates of 60% to 75%

In elderly patients who are not candidates for ASCT, combinations of melphalan-prednisone with a novel agent (thalidomide, bortezomib or lenalidomide) yield CR/VGPR rates that are quite comparable to those achieved in younger patients with ASCT. Prolonged treatment with the combination of lenalidomide plus dexamethasone can be administered safely and appears to induce very high (up to 70%) CR/VGPR rates as well.

The Arkansas approach to therapy of patients with multiple myeloma

This chapter gives an account of the experience of the Arkansas myeloma program since 1989 with transplant-supported high-dose melphalan, novel agents, and prognostic factors as they relate to standard laboratory features, gene expression profiling, and magnetic resonance imaging (MRI). Incorporation of novel agents and new concepts, such as post-tandem transplant consolidation therapy, has improved the rate and duration of complete response and prolonged event-free and overall survival rates. With Total Therapy 2, median survival exceeds 8 years, while Total Therapy 3 with added bortezomib has sustained complete remissions in more than 90% of patients at 2 years which, when used as a survival surrogate in Total Therapy 2, assured a high 6-year survival rate of 75%. Gene expression profiling identified 15% of patients with very short survival. MRI-defined focal lesions are associated with poor outcome, while their resolution - although slower than the time course of attaining clinical complete remission - conferred superior survival. Representing a frequent source of recurrence, with genetic profiles (in both plasma and stromal cells) distinct from those in random bone-marrow samples, therapeutic efforts are directed at hastening onset and increasing frequency of focal lesion resolution.