Management and outcome of patients with chronic myeloid leukemia in blast phase in the tyrosine kinase inhibitor era - analysis of the European LeukemiaNet Blast Phase Registry

Blast phase (BP) of chronic myeloid leukemia (CML) still represents an unmet clinical need with a dismal prognosis. Due to the rarity of the condition and the heterogeneity of the biology and clinical presentation, prospective trials and concise treatment recommendations are lacking. Here we present the analysis of the European LeukemiaNet Blast Phase Registry, an international collection of the clinical presentation, treatment and outcome of blast phases which had been diagnosed in CML patients after 2015. Data reveal the expected heterogeneity of the entity, lacking a clear treatment standard. Outcomes remain dismal, with a median overall survival of 23.8 months (median follow up 27.8 months). Allogeneic stem cell transplantation (alloSCT) increases the rate of deep molecular responses. De novo BP and BP evolving from a previous CML do show slightly different features, suggesting a different biology between the two entities. Data show that outside clinical trials and in a real-world setting treatment of blast phase is individualized according to disease- and patient-related characteristics, with the aim of blast clearance prior to allogeneic stem cell transplantation. AlloSCT should be offered to all patients eligible for this procedure.

A digital twin model for evidence-based clinical decision support in multiple myeloma treatment

The treatment landscape for multiple myeloma (MM) has experienced substantial progress over the last decade. Despite the efficacy of new substances, patient responses tend to still be highly unpredictable. With increasing cognitive burden that is introduced through a complex and evolving treatment landscape, data-driven assistance tools are becoming more and more popular. Model-based approaches, such as digital twins (DT), enable simulation of probable responses to a set of input parameters based on retrospective observations. In the context of treatment decision-support, those mechanisms serve the goal to predict therapeutic outcomes to distinguish a favorable option from a potential failure. In the present work, we propose a similarity-based multiple myeloma digital twin (MMDT) that emphasizes explainability and interpretability in treatment outcome evaluation. We've conducted a requirement specification process using scientific literature from the medical and methodological domains to derive an architectural blueprint for the design and implementation of the MMDT. In a subsequent stage, we've implemented a four-layer concept where for each layer, we describe the utilized implementation procedure and interfaces to the surrounding DT environment. We further specify our solutions regarding the adoption of multi-line treatment strategies, the integration of external evidence and knowledge, as well as mechanisms to enable transparency in the data processing logic. Furthermore, we define an initial evaluation scenario in the context of patient characterization and treatment outcome simulation as an exemplary use case for our MMDT. Our derived MMDT instance is defined by 475 unique entities connected through 438 edges to form a MM knowledge graph. Using the MMRF CoMMpass real-world evidence database and a sample MM case, we processed a complete outcome assessment. The output shows a valid selection of potential treatment strategies for the integrated medical case and highlights the potential of the MMDT to be used for such applications. DT models face significant challenges in development, including availability of clinical data to algorithmically derive clinical decision support, as well as trustworthiness of the evaluated treatment options. We propose a collaborative approach that mitigates the regulatory and ethical concerns that are broadly discussed when automated decision-making tools are to be included into clinical routine.

Maintenance lenalidomide in newly diagnosed transplant eligible and non-eligible myeloma patients; profiling second primary malignancies in 4358 patients treated in the Myeloma XI Trial

Background

Early trials of long-term lenalidomide use reported an increased incidence of second primary malignancy (SPM), including acute myeloid leukaemia and myelodysplastic syndrome. Later, meta-analysis suggested the link to be secondary to lenalidomide in combination with melphalan.

Methods

Myeloma XI is a large, phase III randomised trial in-which lenalidomide was used at induction and maintenance, in transplant eligible (TE) and non-eligible (TNE) newly diagnosed patients (NCT01554852). Here we present an analysis of SPM incidence and profile the SPM type to determine the impact of autologous stem cell transplantation (ASCT) and lenalidomide exposure in 4358 patients treated on study. Data collection took place from the start of the trial in May 2010, to May 2019, as per the protocol timeline. The Median follow-up following maintenance randomisation was 54.5 and 46.1 months for TE and TNE patients, respectively.

Findings

In the TE pathway, the overall SPM incidence was 7.7% in lenalidomide maintenance patients compared to 3.2% in those being observed (p = 0.006). Although the TNE lenalidomide maintenance patients had the greatest SPM incidence (15.4%), this was not statistically significant when compared to the observed patients (10%, p = 0.10).The SPM incidence was higher in patients who received lenalidomide at induction and maintenance (double exposure), when compared to those treated with lenalidomide at one time point (single exposure). Again, this was most marked in TNE patients where the overall SPM incidence was 16.9% in double exposed patients, compared to 11.7% in single exposed patients, and 11.2% in patients who did not receive lenalidomide (p = 0.04). This is likely an effect of treatment duration, with the median number of cycles being 27 in the TNE double exposed patients, vs 6 in the single exposure patients.Haematological SPMs were uncommon, diagnosed in 50 patients (incidence 1.1%). The majority of cases were diagnosed in TE patients treated with lenalidomide maintenance (n = 25, incidence 2.8%), suggesting a possible link with melphalan. Non-melanoma skin cancer incidence was highest in patients receiving lenalidomide maintenance, particularly in TNE patients, where squamous cell carcinoma and basal cell carcinoma were diagnosed in 5.5% and 2.6% of patients, respectively. The incidence of most solid tumour types was higher in lenalidomide maintenance patients.Mortality due to progressive myeloma was reduced in patients receiving lenalidomide maintenance, noted to be 16.6% compared 22.6% in those observed in TE patients and 32.7% compared to 41.5% in TNE patients. SPM related mortality was low, 1.8% and 6.1% in TE and TNE lenalidomide maintenance patients, respectively, compared to 0.4% and 2.8% in those being observed.

Interpretation

This provides reassurance that long-term lenalidomide treatment is safe and associated with improved outcomes in TE and TNE populations, although monitoring for SPM development should be incorporated into clinic review processes.

Funding

Primary financial support was from Cancer Research UK [C1298/A10410].

Pomalidomide combinations are a safe and effective option after daratumumab failure

PURPOSE

Outcomes of multiple myeloma (MM) patients who are refractory to daratumumab are dismal and no standard of treatment exists for this patients' population. Here, we investigate the role of pomalidomide combinations in daratumumab-refractory MM patients.

METHODS

We performed a retrospective analysis of myeloma patients treated at four referral centers (three in Germany and one in Italy). Review chart identified 30 patients with relapsed and refractory myeloma, who progressed during treatment with daratumumab and were treated with pomalidomide-based combinations in the subsequent lines of therapy.

RESULTS

Responses improved from 37% with daratumumab to 53% with pomalidomide. Of seven patients with extramedullary MM (EMM), four achieved a clinical stabilization with pomalidomide, including one patient with a long-lasting complete response. Median progression-free survival and overall survival were 6 and 12 months, respectively. Pomalidomide combinations were well tolerated, no patient discontinued treatment due to adverse events.

CONCLUSION

These data show that pomalidomide-based combinations can be an effective and safe salvage regimen for daratumumab-refractory patients, including those with EMM.

[Differences due to socio-economic status, genetic background and sex in cancer and precision medicine - An intersectional approach to close the care gap for marginalized groups]

Malignant tumor diseases constitute the 2^nd most common cause of death and due to our extended life expectancy cancer per se has substantially increased, being highly prevalent after cardiovascular diseases. Evidence also generated from the COVID-19 pandemic, that defined gender differences exist in symptom and disease courses, and have advocated the need to assess gender, ethnic/racial and minority differences in cancer care and treatment more meticulously. It is becoming increasingly evident that in novel cancer care/precision oncology, representation of minorities, elderly and frail patients in clinical trials remains largely unbalanced, thus distribution of cancer success is iniquitous. This article focusses on these aspects and suggests solutions, how this can be improved.

Immunogenic cell death triggered by impaired deubiquitination in multiple myeloma relies on dysregulated type I interferon signaling

Introduction

Proteasome inhibition is first line therapy in multiple myeloma (MM). The immunological potential of cell death triggered by defects of the ubiquitin-proteasome system (UPS) and subsequent perturbations of protein homeostasis is, however, less well defined.

Methods

In this paper, we applied the protein homeostasis disruptors bortezomib (BTZ), ONX0914, RA190 and PR619 to various MM cell lines and primary patient samples to investigate their ability to induce immunogenic cell death (ICD).

Results

Our data show that while BTZ treatment triggers sterile type I interferon (IFN) responses, exposure of the cells to ONX0914 or RA190 was mostly immunologically silent. Interestingly, inhibition of protein de-ubiquitination by PR619 was associated with the acquisition of a strong type I IFN gene signature which relied on key components of the unfolded protein and integrated stress responses including inositol-requiring enzyme 1 (IRE1), protein kinase R (PKR) and general control nonderepressible 2 (GCN2). The immunological relevance of blocking de-ubiquitination in MM was further reflected by the ability of PR619-induced apoptotic cells to facilitate dendritic cell (DC) maturation via type I IFN-dependent mechanisms.

Conclusion

Altogether, our findings identify de-ubiquitination inhibition as a promising strategy for inducing ICD of MM to expand current available treatments.

Sex-disaggregated analysis of biology, treatment tolerability and outcome of Multiple Myeloma in a German cohort

INTRODUCTION

Multiple Myeloma (MM) is a plasma cell disease that affects more men than women. Although there is an obvious imbalance in incidence, knowledge on differences in biology and outcome between the sexes is surprisingly rare.

METHODS

We performed a unicentric retrospective analysis of patients with MM treated at a tertiary cancer center between 2003 and 2018.

RESULTS

We present sex-disaggregated analysis of the characteristics and outcome of MM in a cohort of 655 patients (median age at diagnosis 62 years; 363 men with a median age at diagnosis 62 years and 292 women with a median age at diagnosis 63 years, p=0.086). Most patients (n=561, 86%) received myeloma-specific treatment. Median overall survival was 76 months (95% CI 63 - 89) (72 months in men [95% CI 54 - 90] and 83 months in women [95% CI 66 - 100], p=ns). Apart from a higher incidence of moderate and severe anaemia in women (p<0.001) there were no statistically significant differences in the biology of the underlying MM. Similarly, in the group of patients who received high-dose therapy with autologous stem cell transplantation (ASCT, n=313), no statistically significant differences apart from more frequent anaemia in women were detected regarding the biology of the disease. However, there was a trend towards a higher plasma cell infiltration of the bone marrow and towards more frequent high-risk features in women. In contrast, relevant comorbidities were significantly more common in men (for example coronary heart disease in 13% of men vs. 2% of women, p<0.001). Toxicities after ASCT were not significantly different between the sexes with the exception of severe mucositis, which occurred in 22% of men vs. 40% of women (p=0.001).

CONCLUSION

In conclusion, this first sex-disaggregated analysis of MM patients in Germany supports previous findings that survival is comparable amongst sexes, but women experience more toxicity of high-dose therapy. The higher incidence of clinically relevant anaemia in women warrants further investigation to exclude underlying treatable causes.

Suppression of MYC by PI3K/AKT/mTOR pathway inhibition in combination with all-trans retinoic acid treatment for therapeutic gain in acute myeloid leukaemia

Aberrant activity of the phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR [PAM]) pathway, as well as suppressed retinoic acid signalling, contribute to enhanced proliferation and the differentiation blockade of immature myeloid cells in acute myeloid leukaemia (AML). Inhibition of the PAM pathway was shown to affect especially mixed-lineage leukaemia-rearranged AML. Here, we sought to test a combined strategy using small molecule inhibitors against members of the PAM signalling pathway in conjunction with all-trans retinoic acid (ATRA) to target a larger group of different AML subtypes. We find that ATRA treatment in combination with inhibition of PI3K (ZSTK474), mTOR (WYE132) or PI3K/mTOR (BEZ235, dactolisib) drastically reduces protein levels of the proto-oncogene MYC. In combination with BEZ235, ATRA treatment led to almost complete eradication of cellular MYC, G1 arrest, loss of clonal capacity and terminal granulocytic differentiation. We demonstrate that PAM inhibitor/ATRA treatment targets MYC via independent mechanisms. While inhibition of the PAM pathway causes MYC phosphorylation at threonine 58 via glycogen synthase kinase 3 beta and subsequent degradation, ATRA reduces its expression. Here, we present an approach using a combination of known drugs to synergistically reduce aberrant MYC levels, thereby effectively blocking proliferation and enabling differentiation in various AML subtypes.

Investigating the Interplay between Myeloma Cells and Bone Marrow Stromal Cells in the Development of Drug Resistance: Dissecting the Role of Epigenetic Modifications

Simple Summary

Despite advances made in the last two decades, multiple myeloma (MM) is still an incurable disease. The genetic complexity of MM and the presence of intra-clonal heterogeneity are major contributors to disease relapse and the development of treatment resistance. Additionally, the bone marrow microenvironment is known to play a pivotal role in MM disease progression. Together with genetic modifications, epigenetic changes have been shown to influence MM development and progression. However, epigenetic treatments for MM are still lacking. This is mainly due to the high rate of adverse events of epigenetic drugs in clinical practice. In this review, we will focus on the role of epigenetic modifications in MM disease progression and the development of drug resistance, as well as their role in shaping the interplay between bone marrow stromal cells and MM cells. The current and future treatment strategies involving epigenetic drugs will also be addressed.

Abstract

Multiple Myeloma (MM) is a malignancy of plasma cells infiltrating the bone marrow (BM). Many studies have demonstrated the crucial involvement of bone marrow stromal cells in MM progression and drug resistance. Together with the BM microenvironment (BMME), epigenetics also plays a crucial role in MM development. A variety of epigenetic regulators, including histone acetyltransferases (HATs), histone methyltransferases (HMTs) and lysine demethylases (KDMs), are altered in MM, contributing to the disease progression and prognosis. In addition to histone modifications, DNA methylation also plays a crucial role. Among others, aberrant epigenetics involves processes associated with the BMME, like bone homeostasis, ECM remodeling or the development of treatment resistance. In this review, we will highlight the importance of the interplay of MM cells with the BMME in the development of treatment resistance. Additionally, we will focus on the epigenetic aberrations in MM and their role in disease evolution, interaction with the BMME, disease progression and development of drug resistance. We will also briefly touch on the epigenetic treatments currently available or currently under investigation to overcome BMME-driven treatment resistance.

Melphalan 200 mg/m2 does not increase toxicity and improves survival in comparison to reduced doses of melphalan in multiple myeloma patients

Autologous stem cell transplantation (ASCT) conditioned with melphalan 200 mg/m² (Mel200) is standard of care for young multiple myeloma (MM) patients. Lower doses of melphalan (MelRed) have been used to reduce toxicity, although data regarding their efficacy are not concordant. We retrospectively evaluated 313 MM patients receiving ASCT at Jena University Hospital between 2003 and 2017. Patients receiving MelRed were on average older (p < 0.001), had a worse renal function (p < 0.001) and more comorbidities (p < 0.001). No differences were seen in treatment response before ASCT between the two groups, whilst after ASCT the rate of at least very good partial responses (VGPR) was significantly higher for patients receiving Mel200 (93% vs. 76%, p < 0.001). PFS (39 vs. 20 months, p < 0.001) and OS (103 vs. 59 months, p = 0.001) were longer with Mel200. Toxicities were comparable in the two groups. After adjusting for age and clinical characteristics using the propensity score, for VGPR before and after ASCT and for double ASCT strategy in a Cox regression analysis, Mel200 was still associated with a lower risk of disease progression (HR = 0.40, 95% CI = 0.40-0.96) and of death (HR = 0.61, 95% CI = 0.35-1.07). Our results confirm that Mel200 is still the standard of care for ASCT eligible myeloma patients.

Safety issues and management of toxicities associated with new treatments for multiple myeloma

INTRODUCTION

In the last decade, the availability of new drugs for the treatment of Multiple Myeloma (MM) significantly improved patients' outcomes, but also raised attention towards a new spectrum of adverse events. Recently, four novel agents with different mechanisms of action (carfilzomib, elotuzumab, daratumumab and panobinostat) have been approved for the treatment of MM. This review aims at providing physicians with the tools to recognize and handle toxicity issues related with these new treatments. Areas covered: This review focuses on the management of drug related adverse events of the latest approved drug combinations. New drug combinations under development and still in the phase of approval will be briefly discussed. PubMed was searched using the terms 'toxicity', 'carfilzomib', 'elotuzumab' 'daratumumab' and 'panobinostat'. Phase II and III clinical trials and previously published analyses on toxicities were reviewed. For new drug combination abstracts presented at the latest ASH, ASCO and EHA meetings as well as clinicaltrial.gov website was searched and reviewed. Expert commentary: With the development of newer drugs and the availability of different treatment options for MM patients, an accurate evaluation of treatment side effects, their prompt recognition and management is mandatory for all clinical hematologists.

The genetic and genomic background of multiple myeloma patients achieving complete response after induction therapy with bortezomib, thalidomide and dexamethasone (VTD)

The prime focus of the current therapeutic strategy for Multiple Myeloma (MM) is to obtain an early and deep tumour burden reduction, up to the level of complete response (CR). To date, no description of the characteristics of the plasma cells (PC) prone to achieve CR has been reported. This study aimed at the molecular characterization of PC obtained at baseline from MM patients in CR after bortezomib-thalidomide-dexamethasone (VTD) first line therapy.

One hundred and eighteen MM primary tumours obtained from homogeneously treated patients were profiled both for gene expression and for single nucleotide polymorphism genotype. Genomic results were used to obtain a predictor of sensitivity to VTD induction therapy, as well as to describe both the transcription and the genomic profile of PC derived from MM with subsequent optimal response to primary induction therapy.

By analysing the gene profiles of CR patients, we identified a 5-gene signature predicting CR with an overall median accuracy of 75% (range: 72%–85%). In addition, we highlighted the differential expression of a series of genes, whose deregulation might explain patients' sensitivity to VTD therapy. We also showed that a small copy number loss, covering 606Kb on chromosome 1p22.1 was the most significantly associated with CR patients.

First line vs delayed transplantation in myeloma: Certainties and controversies

Since the middle of 1990s autologous stem cell transplantation has been the cornerstone for the treatment of young patients with multiple myeloma (MM). In the last decade the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PI), has dramatically changed the therapeutic scenario of this yet incurable disease. Due to the impressive results achieved with IMiDs and PI both in terms of response rates and in terms of progression free and overall survival, and to the toxicity linked to high dose therapy and autologous stem cell transplantation (ASCT), a burning question nowadays is whether all young patients should be offered autotransplantation up front or if this should be reserved for the time of relapse. This article provides a review of the data available regarding ASCT in MM and of the current opinion of the scientific community regarding its optimal timing.

Prognostic impact of serial measurements of serum-free light chain assay throughout the course of newly diagnosed multiple myeloma treated with bortezomib-based regimens

We retrospectively investigated the role of serial serum-free light chain (sFLC) evaluations in 150 multiple myeloma (MM) patients treated with first-line bortezomib-based regimens. Baseline sFLC ratio (sFLCR) identified three groups of patients - normal, lightly abnormal (<100), and highly abnormal (≥100) - with different progression-free survival (PFS: 3-year estimate 72% versus 61% versus 44%, respectively, p = 0.03). Moreover, the achievement of a normal sFLCR correlated with extended PFS (49 versus 17 months, p < 0.0001) and overall survival (75 versus 43 months, p < 0.0001) as compared with abnormal sFLCR, a gain maintained in a multivariate analysis for PFS. At relapse, a high sFLCR was associated with earlier start of salvage therapy compared with sFLCR <100 (3-month probability: 89% versus 64%, p = 0.0426). In 20% of patients, sFLC escape preceded the conventional relapse by a median of 3.8 months. Our results highlight the role of sFLC assay in the prognosis and follow-up of MM.

Current and emerging triplet combination therapies for relapsed and refractory multiple myeloma

Despite significant improvement in outcomes have been observed for multiple myeloma (MM) patients over the past 10-15 years, mainly due to the introduction of novel agents targeting the tumor clone and the bone marrow microenvironment, treatment of refractory and/or relapsed (RR) disease remains a challenge, particularly for patients who have failed prior bortezomib- and lenalidomide-based therapies. More recently, new drugs with different mechanisms of action, including second generation proteasome inhibitors, third generation immunomodulatory drugs, histone deacetylase inhibitors and monoclonal antibodies, have been developed and are under investigation, further increasing treatment options for RRMM patients. Overall, novel agent-based triplet combinations demonstrated superior response rates and prolonged disease control when compared with two-drug regimens in several randomized clinical trials, without adding any relevant additional toxicity. Salvage triplet therapies are likely to play a key role in overcoming drug-resistance and hold promise to further improve long-term outcomes of RRMM patients.

Mutational Spectrum, Copy Number Changes, and Outcome: Results of a Sequencing Study of Patients With Newly Diagnosed Myeloma

PURPOSE

At the molecular level, myeloma is characterized by copy number abnormalities and recurrent translocations into the immunoglobulin heavy chain locus. Novel methods, such as massively parallel sequencing, have begun to describe the pattern of tumor-acquired mutations, but their clinical relevance has yet to be established.

METHODS

We performed whole-exome sequencing for 463 patients who presented with myeloma and were enrolled onto the National Cancer Research Institute Myeloma XI trial, for whom complete molecular cytogenetic and clinical outcome data were available.

RESULTS

We identified 15 significantly mutated genes: IRF4, KRAS, NRAS, MAX, HIST1H1E, RB1, EGR1, TP53, TRAF3, FAM46C, DIS3, BRAF, LTB, CYLD, and FGFR3. The mutational spectrum is dominated by mutations in the RAS (43%) and nuclear factor-κB (17%) pathways, but although they are prognostically neutral, they could be targeted therapeutically. Mutations in CCND1 and DNA repair pathway alterations (TP53, ATM, ATR, and ZNFHX4 mutations) are associated with a negative impact on survival. In contrast, those in IRF4 and EGR1 are associated with a favorable overall survival. We combined these novel mutation risk factors with the recurrent molecular adverse features and international staging system to generate an international staging system mutation score that can identify a high-risk population of patients who experience relapse and die prematurely.

CONCLUSION

We have refined our understanding of genetic events in myeloma and identified clinically relevant mutations that may be used to better stratify patients at presentation.

Biology and treatment of myeloma

In recent years significant progress has been made in the understanding of multiple myeloma (MM) biology and its treatment. Current strategies for the treatment of MM involve the concept of sequential blocks of therapy given as an induction followed by consolidation and maintenance. In an age characterized by emerging and more powerful laboratory techniques, it is of primary importance to understand the biology of MM and how this biology can guide the development of new treatment strategies. This review focuses on the genetic basis of myeloma, including the most common genetic abnormalities and pathways affected and the effects that these have on MM treatment strategies. MM biology is discussed also in the light of more recent theory of intraclonal heterogeneity.

Bortezomib-based therapy combined with high cut-off hemodialysis is highly effective in newly diagnosed multiple myeloma patients with severe renal impairment

Multiple myeloma (MM) is often associated with renal insufficiency (RI) which adversely influences the prognosis. Several studies demonstrated that bortezomib can improve both renal function and outcome. We prospectively evaluated 21 newly diagnosed MM patients with severe renal impairment secondary to tubular-interstitial damage, most of them due to myeloma kidney, who were primarily treated with bortezomib-based therapy combined with high cut-off hemodialysis (HCOD). The median serum creatinine level at baseline was 6.44 mg dL(-1) and calculated median estimated glomerular filtration rate (eGFR), according to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation, was 8 mL/min/1.73 m(2) . Serum free light chain (sFLC) median concentration was 6,040 mg L(-1) . Post induction and best stringent complete response rates were 19 and 38%, respectively. Responses were fast, occurring within a median of 1.4 months. The combination of bortezomib and HCOD led to a prompt and remarkable (>90%) decrease in sFLC levels. Sixteen patients (76%) became dialysis independent within a median of 32 days. With a median follow up of 17.2 months, the 3-year PFS and OS were 76 and 67%, respectively. No early deaths were observed. This study demonstrates that incorporation of bortezomib into induction therapy combined with HCOD is a highly effective strategy in rescuing renal function and improving outcomes in patients with MM and RI.

Therapeutic targeting of hypoxia and hypoxia-inducible factor 1 alpha in multiple myeloma

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by accumulation of malignant plasma cells (PCs) within the bone marrow (BM). The PCs are in close contact with stromal cells, which secrete growth factors and cytokines, promoting tumor cell growth and survival. Despite the availability of new drugs with immunomodulatory properties targeting the neoplastic clone and its microenvironment, MM is still an incurable disease, with patients experiencing subsequent phases of remission and relapse, eventually leading to disease resistance and patient death. It is now well established that the MM BM microenvironment is hypoxic, a condition required for the activation of the hypoxia-inducible factor 1 alpha (HIF-1α). It has been shown that HIF-1α is constitutively expressed in MM even in normoxic conditions, suggesting that HIF-1α suppression might be part of a therapeutic strategy. Constitutively activated HIF-1α enhances neovascularization, increases glucose metabolism, and induces the expression of antiapoptotic proteins. HIF-1α is thought to be one of the most important molecular targets in the treatment of cancer, and a variety of chemical inhibitors for HIF-1α have been developed to date. This review examines the role of HIF-1α in MM and recent developments in harnessing the therapeutic potential of HIF-1α inhibition in MM.

Abstract 3884: Gene expression profiling and copy number alterations of circulating clonotypic B cells of multiple myeloma newly diagnosed patients reveals pathways potentially involved in the development and in the disease persistence

Background Although the advances in Multiple Myeloma (MM) therapy, the disease remains incurable. The existence of Myeloma Propagating Cells (MPCs) is supposed to be one of the major causes of MM drug-resistance, leading to relapse. However, very little is known about the molecular characteristics of MPCs, even if some studies suggested that these cells have phenotypic characteristics resembling the memory B cells.

Aim and methods In order to molecularly characterize the 138+ neoplastic clone and the memory B cells located both in bone marrow (BM) and in peripheral blood (PBL), we collected the 138+ 138- cell fractions of 50 newly diagnosed MM patients (pts). We isolated the B cell population and, when possible, the memory B cell clone. For each cell fraction we performed a VDJ rearrangement analysis. The complete set of genomic aberrations was evaluated by SNP Array 6.0 (Affymetrix). Gene expression profile HG-U133 Plus 2.0 microarray analyses (Affymetrix) were performed according to a standardized protocol.

Results The VDJ rearrangement analyses confirmed the clonal relationship between the 138+ clone and the memory B cells clone.

Both BM and PBL 138+ cell fractions showed exactly the same genomic macro-alterations. In the BM and PBL 138-19+27+ cell fractions any macro-alteration was detected, whereas several micro-alterations (range: 1-350 Kb) unique of the memory B cells clone, were highlighted. These micro-alterations were located out of any genomic variants region and are presumably associated to the MM pathogenesis, as confirmed by the presence of KRAS, WWOX and XIAP genes among the amplified regions. Moreover, the memory B cells were characterized by the presence of several LOH regions, including possibly involved tumor suppressor (TS) genes.

To get insight into the biology of the clonotypic B cell population, we compared the gene expression profile of 7 MM B cells vs 5 donor B cells samples, thus showing a differential expression of 11480 probes (Fold Change: 2;-2; FDR: 0,05; p-value: &lt;0,05) by unsupervised analysis of hierarchical clustering. Among the self-renewal mechanisms, we observed the down-regulation of Hedgehog pathway and the iperactivation of Notch and Wnt signaling. Moreover, these immature cells showed a particular phenotype correlated to resistance to proteasome inhibitors, due to the attenuation of the unfolded protein response (IRE1α-XBP1: -18.0; -19.96. P&lt;0,05).

Conclusions Data suggested that the MM 138+ clone might resume the end of the complex process of myelomagenesis, whereas the memory B cells have some intriguing micro-alterations and a specific transcriptional program, supporting the idea that these post germinal center cells might be involved in the transforming event that originate and sustain the neoplastic clone.

Citation Format: Marina Martello, Carolina Terragna, Giovanni Martinelli, Flores Dico, Enrica Borsi, Elena Zamagni, Lucia Pantani, Paola Tacchetti, Beatrice Zannetti, Katia Mancuso, Serena Rocchi, Annamaria Brioli, Viviana Guadagnuolo, Michele Cavo. Gene expression profiling and copy number alterations of circulating clonotypic B cells of multiple myeloma newly diagnosed patients reveals pathways potentially involved in the development and in the disease persistence. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3884. doi:10.1158/1538-7445.AM2014-3884

Abstract 3608: HIF-1α inhibition blocks the cross talk between multiple myeloma plasmacells and tumour microenvironment

Multiple Myeloma (MM) is a clonal B-cell malignancy characterized by accumulation of malignant plasma cells (PCs) within the bone marrow (BM) in close contact with stromal cells (SCs) which secrete growth factors and cytokines, promoting tumor cell growth and survival. The rapid progression of MM is dependent upon cellular interactions within the BM microenvironment, and novel agents targeting this interaction appear to be promising therapeutic strategies for the treatment of MM tumor expansion.

Unlike most other organs, the BM microenvironment is physiologically hypoxic, a pre-requisite for normal BM hematopoiesis. It is well established that hypoxia is an important selective force in the evolution of tumor cells and a stabilization of HIF-1α protein has been documented in several human cancers. While the role of hypoxia in the pathogenesis of hematologic malignancies has yet to be elucidated, recent animal studies have shown that changes in oxygen levels within the BM microenvironment support the survival and expansion of MM cells. Furthermore, some drugs active in MM, such as Bortezomib and Lenalidomide, are believed to exert their effects in part by interfering with hypoxia-induced signaling cascades.

Given the importance of the BM microenvironment in MM pathogenesis, we investigated the possible involvement of HIF-1α in the PCs-BMSCs interplay. To test this hypothesis, we used EZN-2968, a small 3rd generation antisense oligonucleotide against HIF-1α, to inhibit HIF-1α functions. We have already shown that EZN-2968 is highly specific for HIF-1α mRNA and it results in a long lasting and time dependent inhibition of HIF-1α protein level. Herein, we provide evidence that the interaction between MM cells and BMSCs is drastically reduced upon HIF-1α down-modulation. Notably, we showed that upon exposure to HIF-1α inhibitor, neither the incubation with IL-6 nor the co-culture with BMSCs were able to revert the anti-proliferative effect induced by EZN-2968. Moreover, we observed that EZN-2968 down-modulates cytokine-induced signaling cascades after a short incubation, and seems to induce a negative modulation of those transcripts previously shown to reflect the activation state of specific tumor cell pathways (cell proliferation and survival). This observation was also supported by gene expression profile experiments.

One of the key finding of our study is that PC attachment to the extracellular matrix protein was markedly reduced in the presence of EZN-2968. The effects of HIF inhibition on MM cell adhesion are quite intriguing, since MM pathogenesis is dependent upon the interaction of MM cells with the SCs. Taken together, these results strongly support the concept that HIF-1α plays a critical role in the interactions between BMSCs and PCs in MM. We conclude that HIF inhibition may be an attractive therapeutic target for MM.

Citation Format: Enrica Borsi, Giulia Perrone, Carolina Terragna, Marina Martello, Angela Flores Dico, Lucia Pantani, Annamaria Brioli, Giovanni Martinelli, Michele Cavo. HIF-1α inhibition blocks the cross talk between multiple myeloma plasmacells and tumour microenvironment. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3608. doi:10.1158/1538-7445.AM2014-3608

Abstract 5595: Impact of p53 impaired function on outcomes of multiple myeloma patients carrying deleted TP53 and/or amplified MDM4

Background. The TP53 tumor-suppressor gene is mutated or functionally inactivated in most human cancers. In MM, TP53 del on chr 17p13 defines a pts group with a particularly poor prognosis, even if its prevalence at diagnosis is quite low. One of the most potent inhibitor of p53 is MDM4, whose locus is on chr1q32.1, a region frequently amplified in MM.

Aim. To investigate the possibility that both TP53 del and MDM4 amp might affect similar pathways, thus finally leading to a poor prognosis MM pts carrying at diagnosis at least one of them.

Pts and methods. 89 pts treated with bortezomib-thalidomide-dexamethasone (VTD) as induction therapy prior to, and as consolidation after, double ASCT were analyzed at diagnosis by unpaired analysis CNA (Affymetrix 6.0 SNP array) and GEP (Affymetrix U133 Plus2.0 array); in 21 pts carrying MDM4 amp the p53 activity was explored both by deep sequencing of TP53 (Roche GS Junior 454 platform) and by immunoblotting assays of MDM4, p-p53 and p53. Genomic results were evaluated in the clinical context.

Results. CNA analysis showed a 482 Kb minimal del region on chr17p13, including TP53, in 8/89 pts (8,9%) and a 1.1 Mb minimal amp region on chr1q32.1 including MDM4 in 27/89 pts (30,3%).

GEP analysis performed in TP53 del and MDM4 amp pts generated two lists, including genes differentially expressed among pts carrying or not either amp MDM4 (4211 probes sets, p&lt;0.05), or del TP53 (2725 genes, p&lt;0.05). In both cases, an overall deregulation of pathways related to the cell cycle, the DNA damage repair and the cell adhesion and cytoskeleton remodeling was shown.

In 21 pts carrying MDM4 amp the p53 activity was evaluated by p-p53 immunoblotting assays: the absence of p-p53 protein was shown in 60% of them.

The TP53 mutational rate, as detected by deep sequencing of exons 4-11, was analyzed in 21 pts carrying MDM4 amp: point mutations were shown in 15 pts, with mutated reads frequencies ranging from 1.03% to 16.9% (median coverage for each amplicon = 1000 reads).

The prognostic relevance of p53 pathway impaired function was evaluated by stratifying pts into two subgroups according to the presence or absence of MDM4 amp and/or TP53 del (group A: 34 pts, 38%, group B; 55 pts, 62%). Baseline clinical characteristics were homogeneous, whereas groups A and B resulted clearly imbalanced with respect to the genomic background: the t(4,14) frequency (38% vs. 14% positive, p=0.0002) and the average number of CNAs (165 vs 103, p = 0.03) were overall higher in group A. Despite the initially slightly higher response rate after VTD (38% vs 20% ≥near complete response), group A pts showed a shorter PFS (40.13 months vs not reached, p=0.001) and OS (66.6 vs not reached, p=0.0006). The poorer impact associated with MDM4 amp was retained also in the absence of TP53 del (PFS: 50.5 months vs not reached, p=0.01).

Conclusions. The involvement of the p53 pathway alteration in MM might be wider than expected, possibly due to the activation of negative regulators of p53.

Citation Format: Carolina Terragna, Marina Martello, Enrica Borsi, Lucia Pantani, Elena Zamagni, Paola Tacchetti, Annamaria Brioli, Beatrice Anna Zannetti, Flores Dico, Nicoletta Testoni, Giulia Marzocchi, Katia Mancuso, Serena Rocchi, Giovanni Martinelli, Michele Cavo. Impact of p53 impaired function on outcomes of multiple myeloma patients carrying deleted TP53 and/or amplified MDM4. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5595. doi:10.1158/1538-7445.AM2014-5595

HIF-1α inhibition blocks the cross talk between multiple myeloma plasma cells and tumor microenvironment

Multiple myeloma (MM) is a malignant disorder of post-germinal center B cells, characterized by the clonal proliferation of malignant plasma cells (PCs) within the bone marrow (BM). The reciprocal and complex interactions that take place between the different compartments of BM and the MM cells result in tumor growth, angiogenesis, bone disease, and drug resistance. Given the importance of the BM microenvironment in MM pathogenesis, we investigated the possible involvement of Hypoxia-Inducible transcription Factor-1 alpha (HIF-1α) in the PCs-bone marrow stromal cells interplay. To test this hypothesis, we used EZN-2968, a 3rd generation antisense oligonucleotide against HIF-1α, to inhibit HIF-1α functions. Herein, we provide evidence that the interaction between MM cells and BM stromal cells is drastically reduced upon HIF-1α down-modulation. Notably, we showed that upon exposure to HIF-1α inhibitor, neither the incubation with IL-6 nor the co-culture with BM stromal cells were able to revert the anti-proliferative effect induced by EZN-2968. Moreover, we observed a down-modulation of cytokine-induced signaling cascades and a reduction of MM cells adhesion capability to the extracellular matrix proteins in EZN-2968-treated samples. Taken together, these results strongly support the concept that HIF-1α plays a critical role in the interactions between bone BM cells and PCs in Multiple Myeloma.

Translocations at 8q24 juxtapose MYC with genes that harbor superenhancers resulting in overexpression and poor prognosis in myeloma patients

Secondary MYC translocations in myeloma have been shown to be important in the pathogenesis and progression of disease. Here, we have used a DNA capture and massively parallel sequencing approach to identify the partner chromosomes in 104 presentation myeloma samples. 8q24 breakpoints were identified in 21 (20%) samples with partner loci including IGH, IGK and IGL, which juxtapose the immunoglobulin (Ig) enhancers next to MYC in 8/23 samples. The remaining samples had partner loci including XBP1, FAM46C, CCND1 and KRAS, which are important in B-cell maturation or myeloma pathogenesis. Analysis of the region surrounding the breakpoints indicated the presence of superenhancers on the partner chromosomes and gene expression analysis showed increased expression of MYC in these samples. Patients with MYC translocations had a decreased progression-free and overall survival. We postulate that translocation breakpoints near MYC result in colocalization of the gene with superenhancers from loci, which are important in the development of the cell type in which they occur. In the case of myeloma these are the Ig loci and those important for plasma cell development and myeloma pathogenesis, resulting in increased expression of MYC and an aggressive disease phenotype.

Maintenance therapy in newly diagnosed multiple myeloma: current recommendations

The recent availability of novel agents has substantially improved the outcomes of patients with Multiple Myeloma (MM). Achieving the deepest level of complete response and maintaining a sustained remission are important steps towards MM cure. To achieve this goal, consolidation and maintenance therapies are currently incorporated into the modern therapeutic paradigm. The excellent activity shown by new drugs has led to their investigational use as maintenance therapy. However, despite promising results of continuous treatment with the novel agents, consensus regarding maintenance therapy still lacks. This review will focus on maintenance therapy, offering an overview of the different strategies available in MM. The issue of continuous treatment in the light of new biological discoveries, including intra-clonal heterogeneity, will also be addressed.

The impact of intra-clonal heterogeneity on the treatment of multiple myeloma

It is clear that cancers comprise a mixture of clones, a feature termed intra-clonal heterogeneity, that compete for spatial and nutritional resources in a fashion that leads to disease progression and therapy resistance. This process of competition resembles the schema proposed by Darwin to explain the origin of the species, and applying these evolutionary biology concepts to cancer has the potential to improve our treatment strategies. Multiple myeloma (MM) has a unique set of characteristics that makes it a perfect model in which to study the presence of intra-clonal heterogeneity and its impact on therapy. Novel therapies have improved the outcome of MM patients, increasing both progression-free and overall survival. Current therapy comprises an induction, consolidation and maintenance phases and it is important to consider how these components of MM therapy are affected by the presence of intra-clonal heterogeneity. In this evolutionary context therapy can be considered as a selective pressure differentially acting on the myeloma clones and impacting on their chances of survival. In this review current knowledge of intra-clonal heterogeneity, as well as its impact on the different components of MM treatment is discussed.

The utility of newer imaging techniques as predictors of clinical outcomes in multiple myeloma

The 14th International Myeloma Workshop Kyoto, Japan, 3-7 April 2013 The International Myeloma Workshop (IMW) is a biannual meeting that gathers experts in multiple myeloma (MM) from all over the world and scientists interested in clinical and biological aspects of myeloma. The 2013 IMW was held in Kyoto, Japan and presented an interesting program with an appealing section on newer imaging techniques as predictor of outcome in asymptomatic and symptomatic MM. During the meeting, the importance of newer functional imaging techniques as new ways of assessing bone disease and the extent of marrow infiltration by myeloma cells was highlighted. This short meeting report will provide a review of new and/or functional imaging techniques, such as magnetic resonance imaging (MRI), both axial and whole body (WB-MRI), dynamic contrast enhanced (DCE) MRI, diffusion weighted imaging (DWI) and PET integrated with computed tomography.

Role of consolidation therapy in transplant eligible multiple myeloma patients

The role of high-dose therapy and autologous stem-cell transplantation (ASCT) in the treatment of multiple myeloma (MM) has continued to evolve in recent years. The novel agents thalidomide, bortezomib, and lenalidomide have been successfully incorporated into induction therapy in preparation for ASCT and are currently being investigated also as post-ASCT consolidation and maintenance therapy. Consolidation treatment is generally short term and aims to increase the frequency and depth of response obtained with the previous treatment phases, including novel agent-based induction therapy and ASCT. This review will focus on recent trials of novel agents as post-ASCT consolidation therapy, offering an overview of pros and cons of this new treatment strategy in the ASCT sequence for MM patients.

Abstract 3415: SIRT regulates the molecular interaction between c-MYC and HIF-1α in multiple myeloma

Multiple Myeloma (MM) is an incurable hematologic malignancy characterized by the accumulation of malignant plasma cells. Dysregulation of MYC by rearrangement or translocation are common somatic events described either in early or late stage of the disease, and transcriptional profiling of MYC pathway activation is observed in more than 60% of MM cell lines. Hypoxia Inducible Factor-1α (HIF-1α) overexpression has been described in several MM cell lines and in about 30% of MM patients samples. In solid tumours, deregulation of c-MYC has been associated with HIF-1α up-regulation.

In the present study we explored the interaction between c-MYC and HIF-1α in a panel of MM cell lines. We had previously shown that treatment with EZN2968, an antisense oligonucleotide against HIF-1α, resulted in a significantly reduction of HIF-1α protein level as soon as 24h and lasted over 96h. To confirm the inhibition of HIF-1α activity, MM1S cells were treated with EZN2968 for 24h, lysed, co-precipitated with p300, and incubated with anti-HIF-1α antibody. We showed that HIF-1α was no longer associated p300 in EZN-treated compared to untreated samples, suggesting an inhibitory effect of HIF-1α activity. We next observed that treatment with EZN2968 induced a progressive accumulation of cells in S-phase with concomitant reduction of G2/M phase. By western blot analysis, we observed that p21, cell cycle check point negatively regulated by c-MYC, was up-regulated in treated samples. We further verified the effect of HIF-1α inhibition on c-MYC protein level by western blotting. After treatment with EZN2968, c-MYC protein expression was reduced in a time dependent manner, suggesting that c-MYC protein level is associated with inhibition of HIF-1α. To examine whether HIF-1α and c-MYC regulate each other promoter activity, we performed Chromatin Immunoprecipitation (ChIP) assays with HIF-1α or c-MYC antibodies. HIF-1A and MYC promoter amplification signals, were present in the controls samples, and decreased after EZN2968 exposure.

Recently, it has been shown that SIRT1, a transcription factor involved in a development and cellular stress responses, can modulate HIF-1α and c-MYC activity. By Immunoblotting assay, we observed that SIRT1 physically interacts with both proteins and that, after 24h of exposure to EZN2968, c-MYC and HIF-1α were strongly associated to SIRT1. These results were also confirmed at the transcriptional level, by ChIP assay using an anti-SIRT1 antibody. After 24h of treatment with EZN2968, we observed a significant increase of HIF-1A and MYC promoter amplification signals in treated compared to untreated samples, suggesting that SIRT1 recruitment at both promoters is dependent on HIF inhibition.

We showed that in MM cells the expression of HIF-1α and c-MYC are linked and mediated by SIRT1 deacetylase protein. The data suggests a new regulatory mechanism for controlling c-MYC and HIF-1α activity by SIRT1.

Supported by PRIN.

Citation Format: Enrica Borsi, Giulia Perrone, Carolina Terragna, Marina Martello, Manuela Mancini, Elisa Leo, Elena Zamagni, Paola Tacchetti, Annamaria Brioli, Lucia Pantani, Beatrice Zannetti, Giovanni Martinelli, Michele Cavo. SIRT regulates the molecular interaction between c-MYC and HIF-1α in multiple myeloma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3415. doi:10.1158/1538-7445.AM2013-3415

Biologically defined risk groups can be used to define the impact of thalidomide maintenance therapy in newly diagnosed multiple myeloma

Maintenance therapy is an attractive strategy for patients with multiple myeloma. However, the impact of maintenance thalidomide according to the underlying biology of the disease is still a matter of debate, with some studies suggesting that thalidomide is more beneficial in high risk disease, whilst others show the opposite. Biological risk groups defined by interphase fluorescence in situ hybridization (FISH) are powerful predictors of outcome. In this report we investigated the effect of maintenance thalidomide in different biological risk groups defined by different FISH categories. Our data show that maintenance thalidomide improves outcome in patients with biologically low risk disease, defined by the absence of adverse cytogenetic lesion or by the presence of hyperdiploidy alone. Conversely, thalidomide maintenance is detrimental for the overall survival of patients with biological high risk. We conclude that it is important to identify biologically low risk patients who will benefit from a maintenance strategy with thalidomide.

Abstract 1873: Gene expression analysis of newly diagnosed Multiple Myeloma (MM) patients carrying amplified MDM4 and/or deleted p53

The p53 tumor suppressor pathway is tightly kept in check or completely silenced in cancer cells. A potent inhibitor of p53 is MDM4, which is located on chr.1q: it is critical for the control of p53 activity during the response to stress and is often amplified in several types of cancer. Since both del(17p) and amp(1q) identify a subgroup of high-risk MM pts, even when the novel agents are part of up-front treatment strategy, we molecularly analyzed a subgroup of MM patients treated with bortezomib-thalidomide-dexamethasone (VTD) and autologous stem cell transplantation (ASCT) in order to investigate mechanisms which might be activated in myeloma plasma cells to direct and/or indirect limit the p53 function. CD138+ plasma cells obtained at diagnosis from 61 pts, subsequently treated with VTD and ASCT were analysed by means of GEP and unpaired analysis of CNA (Affymetrix U133 Plus2.0 and 6.0 SNP arrays). Nineteen out of 61 pts (31%) carried a minimal amplification region on chr.1q, harboring MDM4. Eight out of 61 pts (13%) carried a 482 Kb minimal deletion region on chr.17 harboring TP53. To explore the involvement of the p53 pathway in MM, pts were stratified according to the presence of amplified MDM4 and/or deleted p53 (group A, 24 pts) or the absence of both these abnormalities (group B, 37 pts). Baseline clinical characteristics were homogeneous, except for a higher rate of ≤ 3 bone lesions in pts of group A. The rate of best complete or near complete response was 40% in group A and 14% in group B (p = 0.04). With a median follow-up of 36 months, the risk of progression was 46% for pts in group A and 19% for those in group B (p = 0.03). The average number of aberrations per group was overall higher in group A as compared to group B (165 vs. 103 CNAs, p =0.03). A comparison of expression profiles of the two subgroups of pts highlighted a deregulated expression of genes involved in the mechanisms of response to genotoxic stress, i.e. of damage sensor genes (ATM, RAD9, RAD 50, ATRip), of damage signal mediator genes (H2AFX, 14-3-3), of genes involved in regulation of cell proliferation (CDK6, CDC25, CCND2) and of anti-apoptotic genes (BCL2, p73) (one-way ANOVA plus multiple-test correction with FDR &lt;0,05). Finally, this group of pts significantly over-express the transcription factor YY1, which is known to interact with p53, thus inhibiting its transcriptional activity. In conclusion, pts carrying amplified MDM4 and/or deleted p53 showed a significantly higher number of CNAs and the significant over-expression of genes involved in the response mechanisms to genotoxic stress, as compared to pts lacking these chromosomal aberrations. This might account for the worse outcome of patients harboring del(17p) and/or amp(1q). The MDM4 locus amplification and the YY1 over-expression might contribute to maintain p53 in an OFF state by an indirect mechanism. Supported by: Fondazione Del Monte di Bo e Ra, Ateneo RFO grants (M.C.) BolognAIL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1873. doi:1538-7445.AM2012-1873

Long-term results of thalidomide and dexamethasone (thal-dex) as therapy of first relapse in multiple myeloma

Thal-dex (TD) is an effective therapy for advanced MM. We evaluated TD as salvage treatment of MM patients at first relapse. Thal was given at a daily dose of 100 or 200 mg until progression. Dex was administered 160 mg/month. One hundred patients were enrolled. First line therapy included ASCT (72%) and conventional CHT (28%). Fifty-nine percent received a fixed thal dose of 100 mg/day. The most frequent adverse events were constipation (42%), peripheral neuropathy (58%, 5% grade 3), bradycardia (20%), skin rash (11%), and VTE (7%). Discontinuation of thal due to adverse events was recorded in eight patients. On ITT, 46% of patients achieved at least a PR. Median DOR was 28 months, median time to next therapy was 15.5 months. Median OS, TTP, and PFS were 43, 22, and 21 months, respectively. TTP and PFS were significantly longer for patients with at least PR to TD. TD was an effective salvage treatment for MM patients at first relapse, as demonstrated by durable disease control and prolonged OS. TD was well tolerated, as reflected by the long stay on treatment without disease progression (median 25 months) and a low discontinuation rate due to toxicity (8%).

Multiple myeloma, venous thromboembolism, and treatment-related risk of thrombosis

Venous thromboembolism (VTE) is a disease with a high prevalence in elderly people, affecting > 5% of the population > 65 years of age. Cancer patients have a 4.3-fold higher incidence of thrombotic complications, due to multiple risk factors that are not always related to the disease. Among hematologic malignancies, multiple myeloma (MM) confers a high risk of developing such complications, with a VTE rate of nearly 10%. Multiple factors are involved in MM-related VTE, such as increased blood viscosity, high levels of immunoglobulin, procoagulant activity of monoclonal protein, and inflammatory cytokines. Since the introduction of the immunomodulatory derivatives (IMiDs) thalidomide and lenalidomide in the therapeutic armamentarium of MM, VTE has emerged as one of the leading complications, in particular in patients with newly diagnosed MM. In this setting, IMiDs-based treatments are associated with rates of VTE reaching values up to 14 to 26%, particularly when dexamethasone or chemotherapy are added. The optimal prophylaxis for patients receiving these antiangiogenetic agents is still a matter of debate. Due to the lack of prospective randomized clinical trials, different studies have used various anticoagulant prophylaxes, including fixed low-dose warfarin (1 mg or 1.25 mg), therapeutic doses of warfarin (international normalized ratio between 2.0 and 3.0), low molecular weight heparin, or low-dose aspirin. As yet, no study has clearly demonstrated a significant superiority of one prophylactic regimen in comparison with the others. Further investigation and more randomized clinical trials are needed to define the best thromboprophylaxis.

Thalidomide-dexamethasone as induction therapy before autologous stem cell transplantation in patients with newly diagnosed multiple myeloma and renal insufficiency

The aim of this study was to evaluate the efficacy and the toxicity of thalidomide-dexamethasone (Thal-Dex) as induction therapy before autologous peripheral blood stem cell (PBSC) transplantation in patients with newly diagnosed multiple myeloma (MM) with renal insufficiency. The study included 31 patients with a baseline creatinine clearance value <or=50 mL/min, 7 of whom required chronic hemodialysis. Patients received 4 months of Thal-Dex, followed by PBSC collection and subsequent transplantation. After induction, a partial response (PR) or greater was obtained in 23 patients (74%), including 8 (26%) who achieved a very good PR. Renal function improved more frequently in patients achieving a PR or greater (82%, vs 37% in patients achieving less than a PR; P = .04). Twenty-six patients underwent PBSC mobilization; in 17 of these patients (65%), >4 x 10(6) CD34(+) cells/kg were collected. Double autologous transplantation was performed in 15 patients, and a single autologous transplantation was performed in 7 patients. After a median of 32 months of follow-up, median event-free survival was 30 months, and median survival was not determined. According to our data, Thal-Dex is effective and safe in patients with newly diagnosed MM and renal insufficiency. Given the relationship between recovery of renal function and response to induction treatment, more intensive Thal + bortezomib regimens could be explored to rescue higher numbers of patients.

Short-term thalidomide incorporated into double autologous stem-cell transplantation improves outcomes in comparison with double autotransplantation for multiple myeloma

PURPOSE

To assess potential benefits with thalidomide incorporated into double autologous stem-cell transplantation (ASCT) for younger patients with newly diagnosed multiple myeloma (MM).

PATIENTS AND METHODS

One hundred thirty-five patients who received thalidomide from induction until the second ASCT were retrospectively analyzed in comparison with an equal number of pair mates treated with double ASCT not including thalidomide.

RESULTS

On an intention-to-treat basis, the addition of thalidomide to double ASCT effected a significant improvement in the rate (68% v 49%; P = .001) and duration (62% v 33% at 4 years; P < .001) of at least very good partial response (VGPR), time to progression (TTP; 61% v 41% at 4 years; P < .001) and progression-free survival (PFS; 51% v 31% at 4 years; P = .001). A trend was also noted for extended overall survival (OS) among thalidomide-treated patients (69% at 5 years v 53% for the control group), although the difference between the two groups was not statistically significant (P = .07). Benefits with thalidomide in increasing the rate of VGPR or better response, TTP, and PFS were confirmed in a multivariate analysis. Median OS after relapse was 24 months for patients receiving thalidomide added to double ASCT and 25 months for the control group. Overall, 17% of patients discontinued thalidomide, including 8% because of drug-related adverse events.

CONCLUSION

In comparison with double ASCT, the addition of first-line thalidomide to double ASCT improved clinical outcomes. Short-term thalidomide was generally well tolerated and had no adverse impact on postrelapse survival.

Evaluation of bone disease in multiple myeloma patients carrying the t(4;14) chromosomal translocation

T(4;14) chromosomal abnormality is one of the most adverse prognostic factors predicting for poor outcome in multiple myeloma (MM) patients. It has been recently suggested that bone disease, as evaluated by spinal magnetic resonance imaging (MRI), is relatively infrequent in these patients. In the present study, we aimed at further testing this hypothesis by analyzing the extent of whole bone involvement in patients showing t(4;14) chromosomal translocation as compared with negative patients. For this purpose, 53 consecutive newly diagnosed MM patients (35M, 18F, median age = 55 yr) underwent evaluation of total skeletal X-ray, whole spine MRI, and at the same time, quantification of markers of bone resorption (urinary N-terminal telopeptide, pyridinoline, deoxypyridinoline, serum crosslaps), and bone formation (bone alkaline phosphatase and osteocalcin) was performed. The presence of IgH/MMSET fusion gene as a surrogate marker for t(4;14), was detected in 11 patients (20.7%), whose clinical characteristics were similar to those observed in t(4;14) negative patients. The type of marrow involvement at spinal MRI (diffuse vs. focal vs. negative) was the same in both groups of patients, even though overt vertebral fractures were more frequently found in t(4;14) positive cases (82% vs. 43%, P = 0.05); in line with this finding, skeletal lesions were more common in t(4;14) positive patients (mean skeletal score = 8.54 +/- 1.36 SE, as compared with 3.42 +/- 0.57 SE in t(4;14) negative cases, P = 0.000). These data were confirmed by the evaluation of serum crosslaps, that were significantly increased in patients with t(4;14) abnormality as compared with negative individuals (10,400 pmol/L +/- 2160 SE vs. 5640 pmol/L +/- 859 SE P = 0.02) Our results indicate that, at variance to what has been previously reported, bone resorption is more prominent in t(4;14) positive patients.

A prospective comparison of 18F-fluorodeoxyglucose positron emission tomography-computed tomography, magnetic resonance imaging and whole-body planar radiographs in the assessment of bone disease in newly diagnosed multiple myeloma

BACKGROUND AND OBJECTIVES

Bone lesions in multiple myeloma (MM) have been traditionally detected by whole body X-ray (WBXR) survey although magnetic resonance imaging (MRI) has become the gold standard for detecting MM involvement of the spine and pelvis. The aim of this study was to compare a new technique, positron emission tomography (PET) with 18F fluorodeoxyglucose (FDG) integrated with computed tomography (18F-FDG PET-CT), with MRI and WBXR for baseline assessment of bone disease in MM.

DESIGN AND METHODS

We prospectively compared 18F-FDG PET-CT, MRI of the spine-pelvis and WBXR in a series of 46 patients with newly diagnosed MM. In 23 patients who received up front autologous transplantation, we also compared post-treatment PET-CT scans with MR images of the spine and pelvis.

RESULTS

Overall, PET-CT was superior to planar radiographs in 46% of patients, including 19% with negative WBXR. In 30% of patients, PET-CT scans of the spine and pelvis failed to show abnormal findings in areas in which MRI revealed an abnormal pattern of bone marrow involvement, more frequently of diffuse type. In contrast, in 35% of patients PET-CT enabled the detection of myelomatous lesions in areas which were out of the field of view of MRI. By combining MRI of the spine- pelvis and 18F-FDG PET-CT, the ability to detect sites of active MM, both medullary and extramedullary, was as high as 92%. Following transplantation, 15 patients had negative PET-CT scans (including 13 with a very good partial response or at least a near complete response), but only 8 had normal MRI.

INTERPRETATION AND CONCLUSIONS

MRI of the spine and pelvis still remains the gold standard imaging technique for the detection of bone marrow involvement in MM. 18F-FDG PET-CT provides additional and valuable information for the assessment of myeloma bone disease in areas not covered by MRI.