The molecular characterization and clinical management of multiple myeloma in the post-genome era

Breaking through Multiple Myeloma: A Paradigm for a Comprehensive Tumor Ecosystem Targeting

Multiple myeloma (MM) is a cancerous condition characterized by the proliferation of plasma cells within the hematopoietic marrow, resulting in multiple osteolytic lesions. MM patients typically experience bone pain, kidney damage, fatigue due to anemia, and infections. Historically, MM was an incurable disease with a life expectancy of around three years after diagnosis. However, over the past two decades, the development of novel therapeutics has significantly improved patient outcomes, including response to treatment, remission duration, quality of life, and overall survival. These advancements include thalidomide and its derivatives, lenalidomide and pomalidomide, which exhibit diverse mechanisms of action against the plasma cell clone. Additionally, proteasome inhibitors such as bortezomib, ixazomib, and carfilzomib disrupt protein degradation, proving specifically toxic to cancerous plasma cells. Recent advancements also involve monoclonal antibodies targeting surface antigens, such as elotuzumab (anti-CS1) and daratumumab (anti-CD38), bispecific t-cell engagers such as teclistamab (anti-BCMA/CD3) and Chimeric antigen receptor T (CAR-T)-based strategies, with a growing focus on drugs that exhibit increasingly targeted action against neoplastic plasma cells and relevant effects on the tumor microenvironment.

Molecular characterization of multiple myeloma

Multiple myeloma (MM) is a hematologic malignancy that occurs when plasma cells, a type of white blood cell, grow out of control and start to overproduce antibodies that accumulates in blood and bone marrow. Despite the recent advance the survival rate for MM has not been increased significantly, which opens the need for identifying new molecular targets. This review article presents the most frequently observed gene mutations (KRAS (22.0%), NRAS (18.0%), DIS3 (9.3%), TTN (8.3%), ZNF717 (8.3%), TENT5C (7.3%), TP53 (7.3%) %), BRAF (6.3%), MUC16 (6.3%), RYR2 (5.4%), LRP1B (5.4%)) in MM patients and its rates, correlations, clinical significance, importance in the framework of MM disease and potential novel targets which are collected from the literature. The genes that are mutated in MM patients (211) taken from cBioportal data set. In conclusion, in the study conducted in MM patients, the 3 genes with the most frequent mutations were recorded as KRAS, NRAS and DIS3, respectively. In addition, in the context of our literature reviews and the data obtained, it appears that the TZNF717, TTN, MUC16, RYR2 genes need further study within the framework of MM.

The genetic heterogeneity and drug resistance mechanisms of relapsed refractory multiple myeloma

Multiple myeloma is the second most common hematological malignancy. Despite significant advances in treatment, relapse is common and carries a poor prognosis. Thus, it is critical to elucidate the genetic factors contributing to disease progression and drug resistance. Here, we carry out integrative clinical sequencing of 511 relapsed, refractory multiple myeloma (RRMM) patients to define the disease’s molecular alterations landscape. The NF-κB and RAS/MAPK pathways are more commonly altered than previously reported, with a prevalence of 45–65% each. In the RAS/MAPK pathway, there is a long tail of variants associated with the RASopathies. By comparing our RRMM cases with untreated patients, we identify a diverse set of alterations conferring resistance to three main classes of targeted therapy in 22% of our cohort. Activating mutations in IL6ST are also enriched in RRMM. Taken together, our study serves as a resource for future investigations of RRMM biology and potentially informs clinical management.

The genetic factors involved in disease progression and drug resistance in multiple myeloma (MM) are varied and complex. Here, genomic and transcriptomic profiling of 511 relapsed and refractory MM patients reveals genetic alterations in several oncogenic pathways contributing to progression and resistance to MM therapies.

Autophagy and the Bone Marrow Microenvironment: A Review of Protective Factors in the Development and Maintenance of Multiple Myeloma

The role of the unfolded protein response (UPR) in plasma cells (PC) and their malignant multiple myeloma (MM) counterparts is a well described area of research. The importance of autophagy in these cells, as well as the interplay between autophagy and the UPR system, has also been well studied. In this review, we will discuss the relationship between these two cellular responses and how they can be utilized in MM to account for the high levels of monoclonal immunoglobulin (Ig) protein synthesis that is characteristic of this disease. Interactions between MM cells and the bone marrow (BM) microenvironment and how MM cells utilize the UPR/autophagy pathway for their survival. These interacting pathways form the foundation for the mechanism of action for bortezomib, a proteasome inhibitor used to modify the progression of MM, and the eventual drug resistance that MM cells develop. One important resistance pathway implicated in MM progression is caspase 10 which attenuates autophagy to maintain its prosurvival function and avoid cell death. We lay a groundwork for future research including 3D in vitro models for better disease monitoring and personalized treatment. We also highlight pathways involved in MM cell survival and drug resistance that could be used as new targets for effective treatment.

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.

Deciphering spatial genomic heterogeneity at a single cell resolution in multiple myeloma

Osteolytic lesions (OL) characterize symptomatic multiple myeloma. The mechanisms of how malignant plasma cells (PC) cause OL in one region while others show no signs of bone destruction despite subtotal infiltration remain unknown. We report on a single-cell RNA sequencing (scRNA-seq) study of PC obtained prospectively from random bone marrow aspirates (BM) and paired imaging-guided biopsies of OL. We analyze 148,630 PC from 24 different locations in 10 patients and observe vast inter- and intra-patient heterogeneity based on scRNA-seq analyses. Beyond the limited evidence for spatial heterogeneity from whole-exome sequencing, we find an additional layer of complexity by integrated analysis of anchored scRNA-seq datasets from the BM and OL. PC from OL are characterized by differentially expressed genes compared to PC from BM, including upregulation of genes associated with myeloma bone disease like DKK1, HGF and TIMP-1 as well as recurrent downregulation of JUN/FOS, DUSP1 and HBB. Assessment of PC from longitudinally collected samples reveals transcriptional changes after induction therapy. Our study contributes to the understanding of destructive myeloma bone disease.

Multiple Extramedullary-Bone Related and/or Extramedullary Extraosseous Are Independent Poor Prognostic Factors in Patients With Newly Diagnosed Multiple Myeloma

Background

Extramedullary (EM) lesions are common in multiple myeloma (MM) and are often related to the poor prognosis of MM but are scarcely understood.

Methods

In this retrospective study, the baseline characteristics of 357 newly diagnosed patients with extramedullary multiple myeloma (EMM) and their impact on the prognosis were analyzed. All patients received first-line treatment with bortezomib-based regimen.

Results

The overall incidence rate of EM was 22.4%, and the detection rate of PET/CT was significantly higher than other imaging methods (P = 0.015). The cohorts consisted of 10 cases of extramedullary extraosseous (EME) and 70 cases of extramedullary-bone related (EMB), including 53 cases with single site involvement (one case with EME) and 27 cases with multiple sites (>1 site) involvement (nine cases with EME). EMM patients had high levels of hemoglobin (Hgb, ≥10 g/dl) and serum lactate dehydrogenase (LDH, >245u/L) and are inclined to early-stage revised international staging system (R-ISS). Compared to patients without EM, those with EMM had worse progression-free survival (PFS) (P = 0.014) and overall survival (OS) (P = 0.032). In addition, patients without EM and those with a single site of EMB had similar PFS and OS, while patients with multiple sites of EMB or EME and multiple sites of EMB with EME had poor PFS and OS. Multivariate analysis confirmed that multiple sites of EMB and/or EME were independent prognostic predictors affecting PFS and OS in newly diagnosed MM patients.

Conclusions

This study suggested that among patients treated with bortezomib-based regimens, multiple sites of EMB and/or EME are independent poor prognostic factors for newly diagnosed MM patients, while a single site of EMB does not affect the survival of newly diagnosed MM patients. Thus, these findings could be used as a reference for the study of EMM patients in the new drug era, but prospective clinical studies are needed to provide evidence-based data for the diagnosis and treatment of EMM.

Prognostic and predictive performance of R-ISS with SKY92 in older patients with multiple myeloma: the HOVON-87/NMSG-18 trial

The standard prognostic marker for multiple myeloma (MM) patients is the revised International Staging System (R-ISS). However, there is room for improvement in guiding treatment. This applies particularly to older patients, in whom the benefit/risk ratio is reduced because of comorbidities and subsequent side effects. We hypothesized that adding gene-expression data to R-ISS would generate a stronger marker. This was tested by combining R-ISS with the SKY92 classifier (SKY-RISS). The HOVON-87/NMSG-18 trial (EudraCT: 2007-004007-34) compared melphalan-prednisone-thalidomide followed by thalidomide maintenance (MPT-T) with melphalan-prednisone-lenalidomide followed by lenalidomide maintenance (MPR-R). From this trial, 168 patients with available R-ISS status and gene-expression profiles were analyzed. R-ISS stages I, II, and III were assigned to 8%, 75%, and 7% of patients, respectively (3-year overall survival [OS] rates: 80%, 65%, 33%, P = 8 × 10-3). Using the SKY92 classifier, 13% of patients were high risk (HR) (3-year OS rates: standard risk [SR], 70%; HR, 28%; P < .001). Combining SKY92 with R-ISS resulted in 3 risk groups: SKY-RISS I (SKY-SR + R-ISS-I; 15%), SKY-RISS III (SKY-HR + R-ISS-II/III; 11%), and SKY-RISS II (all other patients; 74%). The 3-year OS rates for SKY-RISS I, II, and III are 88%, 66%, and 26%, respectively (P = 6 × 10-7). The SKY-RISS model was validated in older patients from the CoMMpass dataset. Moreover, SKY-RISS demonstrated predictive potential: HR patients appeared to benefit from MPR-R over MPT-T (median OS, 55 and 14 months, respectively). Combined, SKY92 and R-ISS classify patients more accurately. Additionally, benefit was observed for MPR-R over MPT-T in SKY92-RISS HR patients only.

Bone marrow microenvironments that contribute to patient outcomes in newly diagnosed multiple myeloma: A cohort study of patients in the Total Therapy clinical trials

BACKGROUND

The tumor microenvironment (TME) is increasingly appreciated as an important determinant of cancer outcome, including in multiple myeloma (MM). However, most myeloma microenvironment studies have been based on bone marrow (BM) aspirates, which often do not fully reflect the cellular content of BM tissue itself. To address this limitation in myeloma research, we systematically characterized the whole bone marrow (WBM) microenvironment during premalignant, baseline, on treatment, and post-treatment phases.

METHODS AND FINDINGS

Between 2004 and 2019, 998 BM samples were taken from 436 patients with newly diagnosed MM (NDMM) at the University of Arkansas for Medical Sciences in Little Rock, Arkansas, United States of America. These patients were 61% male and 39% female, 89% White, 8% Black, and 3% other/refused, with a mean age of 58 years. Using WBM and matched cluster of differentiation (CD)138-selected tumor gene expression to control for tumor burden, we identified a subgroup of patients with an adverse TME associated with 17 fewer months of progression-free survival (PFS) (95% confidence interval [CI] 5-29, 49-69 versus 70-82 months, χ2 p = 0.001) and 15 fewer months of overall survival (OS; 95% CI -1 to 31, 92-120 versus 113-129 months, χ2 p = 0.036). Using immunohistochemistry-validated computational tools that identify distinct cell types from bulk gene expression, we showed that the adverse outcome was correlated with elevated CD8+ T cell and reduced granulocytic cell proportions. This microenvironment develops during the progression of premalignant to malignant disease and becomes less prevalent after therapy, in which it is associated with improved outcomes. In patients with quantified International Staging System (ISS) stage and 70-gene Prognostic Risk Score (GEP-70) scores, taking the microenvironment into consideration would have identified an additional 40 out of 290 patients (14%, premutation p = 0.001) with significantly worse outcomes (PFS, 95% CI 6-36, 49-73 versus 74-90 months) who were not identified by existing clinical (ISS stage III) and tumor (GEP-70) criteria as high risk. The main limitations of this study are that it relies on computationally identified cell types and that patients were treated with thalidomide rather than current therapies.

CONCLUSIONS

In this study, we observe that granulocyte signatures in the MM TME contribute to a more accurate prognosis. This implies that future researchers and clinicians treating patients should quantify TME components, in particular monocytes and granulocytes, which are often ignored in microenvironment studies.

Risk adapted post-transplant maintenance in multiple myeloma

INTRODUCTION

The survival of multiple myeloma patients is increasing due to new medications, the widespread implementation of autologous stem cell transplantation and better supportive treatments. The controversy surrounding post-transplant treatment is debated due to a lack of large randomized trials comparing the different treatment modalities. The questions for each proposed treatment are whether it improves outcomes, has low cumulative toxicities and is easy to administer. Areas covered: In this review, we have summarized the current data on maintenance therapy in newly diagnosed MM patients undergoing ASCT, focusing on bortezomib, thalidomide and lenalidomide as well as newer agents Expert opinion: Maintenance treatment has been shown to deepen and prolong responses and increase PFS and OS. Lenalidomide is approved for maintenance and guidelines recommend its use post ASCT. Ixazomib has recently been reported to improve PFS.

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.

Robust Sampling of Defective Pathways in Multiple Myeloma

We present the analysis of defective pathways in multiple myeloma (MM) using two recently developed sampling algorithms of the biological pathways: The Fisher's ratio sampler, and the holdout sampler. We performed the retrospective analyses of different gene expression datasets concerning different aspects of the disease, such as the existing difference between bone marrow stromal cells in MM and healthy controls (HC), the gene expression profiling of CD34+ cells in MM and HC, the difference between hyperdiploid and non-hyperdiploid myelomas, and the prediction of the chromosome 13 deletion, to provide a deeper insight into the molecular mechanisms involved in the disease. Our analysis has shown the importance of different altered pathways related to glycosylation, infectious disease, immune system response, different aspects of metabolism, DNA repair, protein recycling and regulation of the transcription of genes involved in the differentiation of myeloid cells. The main difference in genetic pathways between hyperdiploid and non-hyperdiploid myelomas are related to infectious disease, immune system response and protein recycling. Our work provides new insights on the genetic pathways involved in this complex disease and proposes novel targets for future therapies.

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.

Calorimetric markers for monitoring of multiple myeloma and Waldenström's macroglobulinemia patients

The blood proteome has been studied extensively for identification of novel reliable disease biomarkers. In recent years, differential scanning calorimetry has emerged as a new tool for characterization of the thermodynamic properties of the major serum/plasma proteins and for the establishment of calorimetric markers for a variety of diseases. Here we applied calorimetry to monitor the effect of treatment of patients diagnosed with multiple myeloma and Waldenström's macroglobulinemia on the calorimetric profiles of patients' blood sera. The parameters derived from the calorimetric profiles were compared with the primary serum biomarkers, monoclonal immunoglobulin (M protein) concentration, and κ/λ free light chain ratio. For the secretory cases, the calorimetric parameters thermogram's shape similarity and weighted average center strongly depended on the M protein level but had lower sensitivity and specificity. By contrast, for non-secretory cases, the calorimetric parameters did not depend on the κ/λ free light chains ratio and exhibited significantly higher sensitivity and specificity than M protein levels. A combination of the immunological and calorimetric tests was found to greatly improve the sensitivity and specificity of the clinical status evaluation. The pronounced differences in blood sera thermograms before and during monitoring reflected the individual patients' response to treatment received and showed maintenance of heterogeneity during the disease course.

Cutting edge genomics reveal new insights into tumour development, disease progression and therapeutic impacts in multiple myeloma

Multiple Myeloma (MM) is a haematological malignancy characterised by the clonal expansion of plasma cells (PCs) within the bone marrow. Despite advances in therapy, MM remains a largely incurable disease with a median survival of 6 years. In almost all cases, the development of MM is preceded by the benign PC condition Monoclonal Gammopathy of Undetermined Significance (MGUS). Recent studies show that the transformation of MGUS to MM is associated with complex genetic changes. Understanding how these changes contribute to evolution will present targets for clinical intervention. We discuss three models of MM evolution; the linear, the expansionist and the intraclonal heterogeneity models. Of particular interest is the intraclonal heterogeneity model. Here, distinct populations of MM PCs carry differing combinations of genetic mutations. Acquisition of additional mutations can contribute to subclonal lineages where "driver" mutations may influence selective pressure and dominance, and "passenger" mutations are neutral in their effects. Furthermore, studies show that clinical intervention introduces additional selective pressure on tumour cells and can influence subclone survival, leading to therapy resistance. This review discusses how Next Generation Sequencing approaches are revealing critical insights into the genetics of MM development, disease progression and treatment. MM disease progression will illuminate possible mechanisms underlying the tumour.

The varied distribution and impact of RAS codon and other key DNA alterations across the translocation cyclin D subgroups in multiple myeloma

We examined a set of 805 cases that underwent DNA sequencing using the FoundationOne Heme (F1H) targeted sequencing panel and gene expression profiling. Known and likely variant calls from the mutational data were analyzed for significant associations with gene expression defined translocation cyclin D (TC) molecular subgroups. The spectrum of KRAS, NRAS, and BRAF codon mutations varied across subgroups with NRAS mutations at Q61 codon being common in hyperdiploid (HRD) and t(11;14) myeloma while being rare in MMSET and MAF. In addition, the presence of RAS-RAF mutations was inversely associated with NFκB pathway activation in all subgroups excluding MAF. In the MMSET subgroup, cases with low FGFR3 expression frequently had RAS-RAF mutations. Conditional inference tree analysis determined that mutation and homozygous deletion of TP53, CDKN2C, and RB1 were key prognostic factors associated with adverse outcome in a non-relapse clinical setting. In conclusion, this study highlights the heterogeneity in the distribution and clinical outcomes of RAS codon and other mutations in multiple myeloma dependent upon primary molecular subgroup.

Endothelin-1 (ET-1) induces resistance to bortezomib in human multiple myeloma cells via a pathway involving the ETB receptor and upregulation of proteasomal activity

PURPOSE

Bortezomib (BTZ) is used for the treatment of multiple myeloma (MM). However, a significant proportion of patients may be refractory to the drug. This study aimed to investigate whether the endothelin (ET-1) axis may act as an escape mechanism to treatment with bortezomib in MM cells.

METHODS

NCI-H929 and RPMI-8226 (human MM cell lines) were cultured with or without ET-1, BTZ, and inhibitors of the endothelin receptors. ET-1 levels were determined by ELISA, while the protein levels of its receptors and of the PI3K and MAPK pathways' components by western blot. Effects of ET-1 on cell proliferation were studied by MTT and on the ubiquitin proteasome pathway by assessing the chymotryptic activity of the 20S proteasome in cell lysates.

RESULTS

Endothelin receptors A and B (ETAR and ETBR, respectively) were found to be expressed in both cell lines, with the RPMI-8226 cells that are considered resistant to BTZ, expressing higher levels of ETBR and in addition secreting ET-1. Treatment of the NCI-H929 cells with ET-1 increased proliferation, while co-incubation of these cells with ET-1 and BTZ decreased BTZ efficacy with concomitant upregulation of 20S proteasomal activity. Si-RNA silencing or chemical blockade of ETBR abrogated the protective effects of ET-1. Finally, data suggest that the predominant signaling pathway involved in ET-1/ETBR-induced BTZ resistance in MM cells may be the MAPK pathway.

CONCLUSION

Our data suggest a possible role of the ET-1/ETBR axis in regulating the sensitivity of MM cells to BTZ. Thus, combining bortezomib with strategies to target the ET-1 axis could prove to be a novel promising therapeutic approach in MM.

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.

Myeloma Is Not a Single Disease

Treatment of plasma cell disorders has dramatically improved during the past decade as a result of the availability of new biology-based drugs, such as proteasome inhibitors and immunomodulatory agents. With increased attention to disease biology, however, it has become clear that there are many different subsets of patients with myeloma with different biologic drivers as well as different patient-based characteristics that can influence treatment. Obtaining initial genetics or genomics information can provide some of the information needed to define therapy after initial induction, and careful performance status assessment can help to define patient-specific characteristics that are important when determining the intensity of therapy. Careful assessment of both can help to optimize therapy type and duration for all patients and to improve long-term outcomes.

Multiple Myeloma, Version 2.2016: Clinical Practice Guidelines in Oncology

Multiple myeloma (MM) is a malignant neoplasm of plasma cells that accumulate in bone marrow, leading to bone destruction and marrow failure. Recent statistics from the American Cancer Society indicate that the incidence of MM is increasing. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) included in this issue address management of patients with solitary plasmacytoma and newly diagnosed MM.

Upregulation of CD200 is associated with regulatory T cell expansion and disease progression in multiple myeloma

Immune dysfunction is an important feature of multiple myeloma (MM) leading to infections, enhancement of tumour growth and resistance to chemotherapy. The overexpression of CD200, expansion of T regulatory (Treg) cell and increased levels of immune modulatory cytokines like IL10, IL6 and transforming growth factor beta (TGFβ) were suggested to have a role in this context. The aim of this study was to assess CD200 expression, Treg percentage by flow cytometry and immune modulatory cytokines (IL10, IL6, TGFβ) by enzyme-linked immunosorbent assay in MM patients at diagnosis. This study included 50 MM patients at diagnosis and 20 healthy controls. The positive CD200 expression was detected in 72% of MM patients. Among the CD200 positive group, 4/13 patients (30.8%) were classified as stage I, 18/23 (78.3%) were in stage II and 14/14 (100%) were in stage III; according to International scoring system. Treg percentage was significantly higher in stage III, followed by stage II then stage I (p < 0.01). Serum IL6, IL10 and TGFβ were significantly higher in MM patients as compared with controls (p < 0.01, p < 0.01, p < 0.05, respectively). The increased expression of CD200 and Treg percentages was associated with increased severity biomarkers (serum LDH and β2 microglobulin). The degree of CD200 expression was significantly positively correlated to Treg percentage (r = 0.565, p < 0.01). Analysis of the CD200 negative patients had a better progression free survival (p = 0.032) and overall survival (p = 0.04) as compared with those positive for CD200 expression. These findings illustrate a clear correlation between myeloma cell CD200 expression level and the frequency of immunosuppressive Treg cells. In conclusion, increased expression of CD200, expansion of suppressive Treg cells and elevation of cytokines might have a role in MM progression in this cohort of patients. Copyright © 2015 John Wiley & Sons, Ltd.

Four genes predict high risk of progression from smoldering to symptomatic multiple myeloma (SWOG S0120)

Multiple myeloma is preceded by an asymptomatic phase, comprising monoclonal gammopathy of uncertain significance and smoldering myeloma. Compared to the former, smoldering myeloma has a higher and non-uniform rate of progression to clinical myeloma, reflecting a subset of patients with higher risk. We evaluated the gene expression profile of smoldering myeloma plasma cells among 105 patients enrolled in a prospective observational trial at our institution, with a view to identifying a high-risk signature. Baseline clinical, bone marrow, cytogenetic and radiologic data were evaluated for their potential to predict time to therapy for symptomatic myeloma. A gene signature derived from four genes, at an optimal binary cut-point of 9.28, identified 14 patients (13%) with a 2-year therapy risk of 85.7%. Conversely, a low four-gene score (< 9.28) combined with baseline monoclonal protein < 3 g/dL and albumin ≥ 3.5 g/dL identified 61 patients with low-risk smoldering myeloma with a 5.0% chance of progression at 2 years. The top 40 probe sets showed concordance with indices of chromosome instability. These data demonstrate high discriminatory power of a gene-based assay and suggest a role for dysregulation of mitotic checkpoints in the context of genomic instability as a hallmark of high-risk smoldering myeloma.

Multiple myeloma: 2014 Update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

DIAGNOSIS

The diagnosis requires 10% or more clonal plasma cells on bone marrow examination or a biopsy proven plasmacytoma plus evidence of associated end-organ damage. If end-organ damage is not present, the presence of 60% or more clonal plasma cells in the marrow is also considered as myeloma.

RISK STRATIFICATION

In the absence of concurrent trisomies, patients with 17p deletion, t(14;16), and t(14;20) are considered to have high-risk myeloma. Patients with t(4;14) translocation are considered intermediate-risk. All others are considered as standard-risk. Risk-adapted initial therapy: Standard-risk patients can be treated with lenalidomide plus low-dose dexamethasone (Rd), or a bortezomib-containing triplet such as bortezomib, cyclophosphamide, dexamethasone (VCD). Intermediate-risk and high-risk patients require a bortezomib-based triplet regimen. In eligible patients, initial therapy is given for approximately 4 months followed by autologous stem cell transplantation (ASCT). Standard risk patients can opt for delayed ASCT if stem cells can be cryopreserved. In patients who are not candidates for transplant, initial therapy is given for approximately 12 to 18 months. Maintenance therapy: After initial therapy, lenalidomide maintenance is considered for standard risk patients who are not in very good partial response or better, while maintenance with a bortezomib-based regimen should be considered in patients with intermediate or high risk myeloma. Management of refractory disease: Patients with indolent relapse can be treated first with 2-drug or 3-drug combinations. Patients with more aggressive relapse often require therapy with a combination of multiple active agents.

Limited value of the international staging system for predicting long-term outcome of transplant-ineligible, newly diagnosed, symptomatic multiple myeloma in the era of novel agents

We retrospectively investigated clinical outcomes and prognostic factors of 131 patients with transplant-ineligible newly diagnosed multiple myeloma (NDMM) who received melphalan and prednisolone (MP) as first-line therapy from 2006 to 2013. Eighty-one patients received salvage therapies incorporating bortezomib, lenalidomide, and/or thalidomide. The overall response rate to MP was 54.2 %, including 9.2 % of better than very good partial response. With a median follow-up period of 30.2 months, median overall survival (OS) and median time to next treatment (TNT) were 54.4 and 19.0 months, respectively. Univariate analysis revealed that performance status and serum calcium level significantly associated with both OS and TNT, and multivariate analysis revealed that the higher serum calcium level had a significantly unfavorable impact on OS and TNT. Importantly, staging informed by the international staging system (ISS) was not predictive for OS or TNT in the analyzed cohort. Our study revealed that, in the context of first-line MP therapy for NDMM, the salvage therapy incorporating novel agents produced a survival period of >30 months after the initiation of second-line therapy, suggesting that the predictive value of ISS for OS and TNT may be limited in the era of novel agents.

Neurologic aspects of lymphoma and leukemias

The lymphomas and leukemias are a heterogenous group of hematologic malignancies with protean manifestations. Neurologic sequelae of the diseases have been recognized since the time the conditions were first described in the mid-1800s. Although our understanding of the various presentations of these blood disorders evolved along with our knowledge of malignancies, accurate diagnosis can still be difficult. It is critical for neurologists to have a high index of clinical suspicion to appropriately recognize their heralding features. This review's focus is the relevant clinical neurologic features and diagnostic studies that identify leukemias and lymphomas affecting the nervous system.

Proof of the concept to use a malignant B cell line drug screen strategy for identification and weight of melphalan resistance genes in multiple myeloma

In a conceptual study of drug resistance we have used a preclinical model of malignant B-cell lines by combining drug induced growth inhibition and gene expression profiling. In the current report a melphalan resistance profile of 19 genes were weighted by microarray data from the MRC Myeloma IX trial and time to progression following high dose melphalan, to generate an individual melphalan resistance index. The resistance index was subsequently validated in the HOVON65/GMMG-HD4 trial data set to prove the concept. Biologically, the assigned resistance indices were differentially distributed among translocations and cyclin D expression classes. Clinically, the 25% most melphalan resistant, the intermediate 50% and the 25% most sensitive patients had a median progression free survival of 18, 32 and 28 months, respectively (log-rank P-value  = 0.05). Furthermore, the median overall survival was 45 months for the resistant group and not reached for the intermediate and sensitive groups (log-rank P-value  = 0.003) following 38 months median observation. In a multivariate analysis, correcting for age, sex and ISS-staging, we found a high resistance index to be an independent variable associated with inferior progression free survival and overall survival. This study provides clinical proof of concept to use in vitro drug screen for identification of melphalan resistance gene signatures for future functional analysis.

Strategies for induction, autologous hematopoietic stem cell transplantation, consolidation, and maintenance for transplantation-eligible multiple myeloma patients

There have been major advances in the past decade in the continuum of therapy for transplantation-eligible multiple myeloma patients. For patients requiring therapy, recommended induction treatment consists of triple drug regimens followed by the collection of hematopoietic stem cells. The question of early versus delayed transplantation is under investigation and may identify patients for whom early transplantation is optimal therapy and those for whom it may be delayed. For transplantation-eligible patients, high-dose melphalan remains the standard regimen. After transplantation, consolidation can be considered for patients with less than a complete remission. Maintenance therapy with bortezomib or lenalidomide (or both in very-high-risk patients) is a reasonable option for long-term disease control and improvement in overall survival. Incorporation of new agents into the continuum of multiple myeloma care should result in improved outcomes and long-term disease control.

Oncolytic vesicular stomatitis virus and bortezomib are antagonistic against myeloma cells in vitro but have additive anti-myeloma activity in vivo

Multiple myeloma cells are highly sensitive to the oncolytic effects of vesicular stomatitis virus (VSV), which specifically targets and kills cancer cells. Myeloma cells are also exquisitely sensitive to the cytotoxic effects of the clinically approved proteasome inhibitor bortezomib. Therefore, we sought to determine whether the combination of VSV and bortezomib would enhance tumor cell killing. However, as shown here, combining these two agents in vitro results in antagonism. We show that bortezomib inhibits VSV replication and spread. We found that bortezomib inhibits VSV-induced NF-κB activation and, using the NF-κB-specific inhibitor BMS-345541, that VSV requires NF-κB activity to spread efficiently in myeloma cells. In contrast to other cancer cell lines, viral titer is not recovered by BMS-345541 when myeloma cells are pretreated with interferon β. Thus, inhibiting NF-κB activity, either with bortezomib or BMS-345541, results in reduced VSV titers in myeloma cells in vitro. However, when VSV and bortezomib are combined in vivo in two syngeneic, immunocompetent myeloma models, the combination reduces tumor burden to a greater degree than VSV does as a single agent. Intratumoral VSV viral load is unchanged when mice are treated concomitantly with bortezomib compared to VSV treatment alone. To our knowledge, this report is the first to analyze the combination of VSV and bortezomib in vivo. Although antagonism between VSV and bortezomib is seen in vitro, analyzing these cells in the context of their host environment shows that bortezomib enhances VSV response, suggesting that this combination will also enhance response in myeloma patients.

Multiple myeloma international staging system: "staging" or simply "aging" system?

Because of the wide variation in multiple myeloma (MM) survival, numerous studies have focused over the past 40 years on the biological and cytogenetic prognostic values in MM patients. Since 2005, the MM International Staging System (ISS) has recognized the combination of beta-2 microglobulin (β2M) with serum albumin (SA) concentrations as the most simple and potent combination to determine the prognosis in MM patients. Curiously, the reasons for the efficiency of the combination of β2M with SA remain not clear-cut. In 2007, Fonseca and San Miguel (Prognostic factors and staging in multiple myeloma. Hematol Oncol Clin North Am 2007; 21:1115-40) underlined that cytogenetic assessment might also be useful for evaluating MM prognosis. Furthermore, new perspectives recently appeared with the genomic approach. Here, we (1) question the specific rationale for β2M and SA as prognostic markers in MM, (2) emphasize the well-documented prognostic implications of β2M and SA as potent biomarkers of comorbidity in older adults, and (3) conclude that the current MM-ISS is rather a staging system for age-related comorbidity burden (ie, aging system) than a specific MM staging system, and should not be used alone. Thus, we suggest that: (1) cytogenetics with the superscript MM-ISS could be the standard method; (2) some factors discovered using genomics could reflect the comorbidity burden and the intrinsic malignancy of MM clone, and thus needs more investigation; and (3) while waiting for standard genomic classification.

The translocation t(4;14) can be present only in minor subclones in multiple myeloma

PURPOSE

Although the translocation t(4;14) is supposed to be a primary event in multiple myeloma, we have been surprised to observe that in large relapse series of patients, the t(4;14) can be observed only in subpopulations of plasma cells, in contrast to what is seen at diagnosis. This observation raised the question of possible subclones harboring the translocation that would be observable only at the time of relapse.

EXPERIMENTAL DESIGN

To address this issue, we analyzed by FISH a cohort of 306 patients for whom we had at least two samples obtained at different disease phases.

RESULTS

We observed a "gain" of the t(4;14) in 14 patients, and conversely, a "loss" of the translocation in 11 patients. Two hypotheses were raised: either an acquisition of the translocation during evolution or the existence of small t(4;14)-positive subclones at the time of diagnosis. To address this question, we had the opportunity to analyze two patients at the time of diagnosis by RT-PCR (reverse transcription-polymerase chain reaction) to look for the chimeric Eμ-MMSET transcript, and one patient positive at diagnosis, but negative at relapse. The samples were positive, supporting the second hypothesis. Furthermore, the IGH sequences of two patients who "lose" the t(4;14) were identical at diagnosis and relapse, confirming the existence of a common ancestral clone.

CONCLUSION

Thus, the conclusion of this study is that the t(4;14) is not a primary event in multiple myeloma and that it can be present in silent subclones at diagnosis, but also at relapse.

Multiple myeloma: 2013 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

DIAGNOSIS

The diagnosis requires 10% or more clonal plasma cells on bone marrow examination or a biopsy proven plasmacytoma plus evidence of associated end-organ damage. In addition, the presence of 60% or more clonal plasma cells in the marrow is also considered as myeloma regardless of the presence or absence of end-organ damage.

RISK STRATIFICATION

In the absence of concurrent trisomies, patients with 17p deletion, t(14;16), and t(14;20) are considered to have high-risk myeloma. Patients with t(4;14) translocation are considered intermediate-risk. All others are considered as standard-risk. RISK-ADAPTED INITIAL THERAPY: Standard-risk patients can be treated with lenalidomide plus low-dose dexamethasone (Rd), or a bortezomib-containing triplet such as bortezomib, cyclophosphamide, dexamethasone (VCD). Intermediate-risk and high-risk patients require a bortezomib-based triplet regimen. In eligible patients, initial therapy is given for approximately 4 months followed by autologous stem cell transplantation (ASCT). Standard-risk patients can opt for delayed ASCT if stem cells can be cryopreserved. In patients are not candidates for transplant, initial therapy is given for approximately 12-18 months.

MAINTENANCE THERAPY

After initial therapy, lenalidomide maintenance is considered for standard-risk patients who are not in very good partial response or better, while maintenance with a bortezomib-based regimen should be considered in pateints with intermediate or high-risk myeloma.

MANAGEMENT OF REFRACTORY DISEASE

Patients with indolent relapse can be treated first with two-drug or three-drug combinations. Patients with more aggressive relapse often require therapy with a combination of multiple active agents.

Multiple myeloma is affected by multiple and heterogeneous somatic mutations in adhesion- and receptor tyrosine kinase signaling molecules

Multiple myeloma (MM) is a largely incurable plasma cell malignancy with a poorly understood and heterogeneous clinical course. To identify potential, functionally relevant somatic mutations in MM, we performed whole-exome sequencing of five primary MM, corresponding germline DNA and six MM cell lines, and developed a bioinformatics strategy that also integrated published mutational data of 38 MM patients. Our analysis confirms that identical, recurrent mutations of single genes are infrequent in MM, but highlights that mutations cluster in important cellular pathways. Specifically, we show enrichment of mutations in adhesion molecules of MM cells, emphasizing the important role for the interaction of the MM cells with their microenvironment. We describe an increased rate of mutations in receptor tyrosine kinases (RTKs) and associated signaling effectors, for example, in EGFR, ERBB3, KRAS and MAP2K2, pointing to a role of aberrant RTK signaling in the development or progression of MM. The diversity of mutations affecting different nodes of a particular signaling network appears to be an intrinsic feature of individual MM samples, and the elucidation of intra- as well as interindividual redundancy in mutations that affect survival pathways will help to better tailor targeted therapeutic strategies to the specific needs of the MM patient.

Current approaches to the initial treatment of symptomatic multiple myeloma

The treatment of newly diagnosed multiple myeloma has dramatically changed since the emergence of proteasome inhibitors and immunomodulatory drugs. Front-line combination regimens incorporating novel drugs such as thalidomide, bortezomib and lenalidomide, have significantly improved response rates and are the standard of care for induction regimens. Although the timing and role of autologous stem cell transplant are now being questioned, it remains an important part of the treatment paradigm in eligible patients. In addition, the concept of extended sequential therapy has recently emerged, including consolidation and/or maintenance in both the post-transplant setting and in nontransplant candidates. In this article we focus on management strategies in newly diagnosed multiple myeloma, including choice of induction regimens in transplant-eligible and -ineligible patients, as well as the role of autologous stem cell transplant, consolidation therapy and maintenance therapy.

Anti-Notch treatment prevents multiple myeloma cells localization to the bone marrow via the chemokine system CXCR4/SDF-1

Multiple myeloma (MM) is a deadly hematopoietic malignancy characterized by proliferation of malignant plasma cells in the bone marrow (BM) and bone disease. Interactions between myeloma and BM cells facilitate tumor progression and resistance to therapies. CXCR4 and its ligand Stromal cell-derived factor-1 (SDF-1) have a primary role in this process and are associated with poor prognosis. The Notch pathway is active in myeloma cells, resulting in increased proliferation, resistance to apoptosis and osteolytic activity. We hypothesized that the CXCR4/SDF-1 axis mediates the effects of Notch signals in myeloma cells. Here we show that Notch positively controls CXCR4/SDF-1 expression and functions in myeloma cell lines, and that forced CXCR4 activation partially rescues tumor cells from the outcomes of Notch inhibition. Additionally, we provide evidences that Notch blocking in vivo significantly reduces BM infiltration by human myeloma cells in mouse xenografts. This is the first evidence that a Notch-targeted approach effectively prevents MM cell migration, proliferation and resistance to apoptosis by reducing CXCR4 and SDF-1 levels.

Gain(1)(q21) is an unfavorable genetic prognostic factor for patients with relapsed multiple myeloma treated with thalidomide but not for those treated with bortezomib

Chromosomal aberrations are important prognostic factors in multiple myeloma diagnosis. We evaluated the effect common high-risk chromosomal aberrations in a cohort of 102 patients with relapsed disease treated with bortezomib or thalidomide. Our results showed that patients treated with thalidomide with a gain(1)(q21) had inferior survival compared with the bortezomib group. Therefore, bortezomib-based regiments are more effective for patients with relapsed multiple myeloma with an incidence of gain in the gain(1)(q21).

BACKGROUND

Prognostic impact of specific chromosomal aberrations in patients with relapsed multiple myeloma (MM) treated with the novel agents is briefly described.

PATIENTS AND METHODS

We analyzed the prognostic value of an extended panel of chromosomal aberrations [del(13)(q14), del(17)(p13), t(4;14)(p16;q32), gain(1)(q21), and hyperdiploidy] by using the technique of interphase fluorescence in situ hybridization in a cohort of 102 patients with relapsed MM treated with thalidomide- or bortezomib-based protocols.

RESULTS

The gain(1)(q21) had a negative impact on overall survival for patients with MM treated with thalidomide (15.7 vs. 41.3 months; P = .004). Moreover, we confirmed the negative impact of the cumulative effect of 2 or more cytogenetic changes that occur simultaneously on the overall survival in the thalidomide group (20.3 months vs. not yet reached; P = .039). We did not find any significant impact of the aberrations studied on overall survival in the bortezomib cohort of patients.

CONCLUSION

We conclude that bortezomib-based protocols are able to partially overcome the negative prognostic impact of the tested chromosomal abnormalities in patients with relapsed MM.

Strategies for induction, autologous hematopoietic stem cell transplantation, consolidation, and maintenance for transplantation-eligible multiple myeloma patients

There have been major advances in the past decade in the continuum of therapy for transplantation-eligible multiple myeloma patients. For patients requiring therapy, recommended induction treatment consists of triple drug regimens followed by the collection of hematopoietic stem cells. The question of early versus delayed transplantation is under investigation and may identify patients for whom early transplantation is optimal therapy and those for whom it may be delayed. For transplantation-eligible patients, high-dose melphalan remains the standard regimen. After transplantation, consolidation can be considered for patients with less than a complete remission. Maintenance therapy with bortezomib or lenalidomide (or both in very-high-risk patients) is a reasonable option for long-term disease control and improvement in overall survival. Incorporation of new agents into the continuum of multiple myeloma care should result in improved outcomes and long-term disease control.

Downregulation of specific miRNAs in hyperdiploid multiple myeloma mimics the oncogenic effect of IgH translocations occurring in the non-hyperdiploid subtype

Currently, multiple myeloma (MM) patients are broadly grouped into a non-hyperdiploid (nh-MM) group, highly enriched for IgH translocations, or into a hyperdiploid (h-MM) group, which is typically characterized by trisomies of some odd-numbered chromosomes. We compared the micro RNA (miRNA) expression profiles of these two groups and we identified 16 miRNAs that were downregulated in the h-MM group, relative to the nh-MM group. We found that target genes of the most differentially expressed miRNAs are directly involved in the pathogenesis of MM; specifically, the inhibition of hsa-miR-425, hsa-miR-152 and hsa-miR-24, which are all downregulated in h-MM, leads to the overexpression of CCND1, TACC3, MAFB, FGFR3 and MYC, which are the also the oncogenes upregulated by the most frequent IgH chromosomal translocations occurring in nh-MM. Importantly, we showed that the downregulation of these specific miRNAs and the upregulation of their targets also occur simultaneously in primary cases of h-MM. These data provide further evidence on the unifying role of cyclin D pathways deregulation as the key mechanism involved in the development of both groups of MM. Finally, they establish the importance of miRNA deregulation in the context of MM, thereby opening up the potential for future therapeutic approaches based on this molecular mechanism.

Development of gene expression-based score to predict sensitivity of multiple myeloma cells to DNA methylation inhibitors

Multiple myeloma is a plasma cell cancer with poor survival, characterized by the clonal expansion of multiple myeloma cells (MMC), primarily in the bone marrow. Novel compounds are currently tested in this disease, but partial or minor patients' responses are observed for most compounds used as a single agent. The design of predictors for drug efficacy could be most useful to better understand basic mechanisms targeted by these drugs and design clinical trials. In the current study, we report the building of a DNA methylation score (DM score) predicting the efficacy of decitabine, an inhibitor of DNA methyltransferase (DNMT), targeting methylation-regulated gene expression. DM score was built by identifying 47 genes regulated by decitabine in human myeloma cell lines and the expression of which in primary MMCs of previously untreated patients is predictive for overall survival. A high DM score predicts patients' poor survival, and, of major interest, high sensitivity of primary MMCs or human myeloma cell lines to decitabine in vitro. Thus, DM score could be useful to design novel treatments with DMNT inhibitor in multiple myeloma and has highlighted 47 genes, the gene products of which could be important for multiple myeloma disease development.

Array-based karyotyping in plasma cell neoplasia after plasma cell enrichment increases detection of genomic aberrations

The discovery of genomic abnormalities present in monoclonal plasma cells has diagnostic, prognostic, and disease-monitoring implications in plasma cell neoplasms (PCNs). However, technical and disease-related limitations hamper the detection of these abnormalities using cytogenetic analysis or fluorescence in situ hybridization (FISH). In this study, 28 bone marrow specimens with known PCNs were examined for the presence of genomic abnormalities using microarray analysis after plasma cell enrichment. Cytogenetic analysis was performed on 15 of 28 samples, revealing disease-related genomic aberrations in only 3 (20%) of 15 cases. FISH analysis was performed on enriched plasma cells and detected aberrations in 84.6% of specimens while array comparative genomic hybridization (aCGH) detected abnormalities in 89.3% of cases. Furthermore, aCGH revealed additional abnormalities in 24 cases compared with FISH alone. We conclude that aCGH after plasma cell enrichment, in combination with FISH, is a valuable approach for routine clinical use in achieving a more complete genetic characterization of patients with PCN.

Impediments to curing myeloma in 2012

SUMMARY Our understanding of multiple myeloma biology over the last two decades has led to a marked improvement in progression-free and overall survival for the majority of patients. The introduction of novel agents, improvement in administration of high-dose therapy with autologous stem cell support, along with supportive care measures have enabled the myeloma researchers to once again debate the curability of this disease. The present article is a succinct review of the progress that has been made and the impediments to curability of this disease.

Improvement in long-term outcomes with successive Total Therapy trials for multiple myeloma: are patients now being cured?

The concept of applying all active therapeutic agents in Total Therapy (TT) clinical trials for newly diagnosed multiple myeloma was pursued with the intent of developing curative treatment. The results of TT1 (n=231), TT2 (n=668) without or with thalidomide and TT3 with added bortezomib (n=303) have been reported. An update with median follow-up times of 17.1, 8.7 and 5.5 years, respectively, is provided. Conditional overall survival (OS) analysis from a 4-year landmark was applied to account for earlier protocol failure owing to disease aggressiveness and toxicities. Cumulative relative survival was computed in the context of age- and gender-matched US population, and interval-specific relative survival ratios were estimated to determine times to normal survival expectation. Based on Cox model-adjusted statistics, OS, progression-free survival and complete-response duration all improved with the transitions from TT1 to TT2 to TT3; improvement was also evident from time-to-progression estimates, 4-year conditional survival data and cumulative relative survival. Interval-specific relative survival normalized progressively sooner, reaching near-normal levels with TT3 in patients who attained complete response. Thus, a strategy using all myeloma-effective agents up-front seems effective at preventing, in progressively larger patient cohorts over time, the outgrowth of resistant tumor cells that account for ongoing relapses.

Extramedullary disease portends poor prognosis in multiple myeloma and is over-represented in high-risk disease even in the era of novel agents

BACKGROUND

Extramedullary disease is an uncommon manifestation in multiple myeloma and can either accompany newly diagnosed disease or develop with disease progression or relapse. We evaluated the impact of this disease feature on patients' outcome in the context of novel agents.

DESIGN AND METHODS

We analyzed clinical and biological features of extramedullary disease in 936 patients with multiple myeloma enrolled in Total Therapy protocols, 240 patients in non-Total Therapy protocols, and 789 non-protocol patients, all of whom had baseline positron emission tomography scans to document extramedullary disease at diagnosis and its subsequent development at the time of disease progression or relapse.

RESULTS

The most common sites for extramedullary disease at diagnosis were skin and soft tissue whereas liver involvement was the striking feature in extramedullary disease at disease relapse or progression. Regardless of therapy, extramedullary disease was associated with shorter progression-free and overall survival, as well as the presence of anemia, thrombocytopenia, elevated serum lactate dehydrogenase, cytogenetic abnormalities, and high-risk features in 70-and 80-gene risk models in univariate analysis. Multivariate analysis with logistic regression revealed that this disease feature was more prevalent in patients with an elevated centrosome index, as determined by gene expression profiling, as well as in myeloma molecular subtypes that are more prone to relapse. These include the MF subtype (also called the "MAF" subtype, associated with over-expression of the MAF gene seen with chromosome translocation 14;16 or 14;20) and the PR subtype (also called the "Proliferation" subtype, associated with overexpression of pro-proliferative genes).

CONCLUSIONS

These data show that extramedullary disease is more prevalent in genomically defined high-risk multiple myeloma and is associated with shorter progression-free survival and overall survival, even in the era of novel agents. All clinical trials included in the analyses were registered with www.clinicaltrials.gov (NCT00083551, NCT00083876, NCT00081939, NCT00572169, NCT00644228,NCT00002548,NCT00734877).