Annamaria Brioli

Prognostic relevance of 18-F FDG PET/CT in newly diagnosed multiple myeloma patients treated with up-front autologous transplantation

We prospectively analyzed the prognostic relevance of positron emission tomography-computed tomography (PET/CT) at diagnosis, after thalidomide-dexamethasone (TD) induction therapy and double autotransplantation (ASCT) in 192 newly diagnosed multiple myeloma (MM) patients. Presence at baseline of at least 3 focal lesions (FLs; 44% of cases), a standardized uptake value (SUV) > 4.2 (46%), and extramedullary disease (EMD; 6%) adversely affected 4-year estimates of progression-free survival (PFS; ≥ 3 FLs: 50%; SUV > 4.2: 43%; presence of EMD: 28%). SUV > 4.2 and EMD were also correlated with shorter overall survival (OS; 4-year rates: 77% and 66%, respectively). Persistence of SUV > 4.2 after TD induction was an early predictor for shorter PFS. Three months after ASCT, PET/CT was negative in 65% of patients whose 4-year rates of PFS and OS were superior to those of PET-positive patients (PFS: 66% and OS: 89%). In a multivariate analysis, both EMD and SUV > 4.2 at baseline and persistence of fluorodeoxyglucose (FDG) uptake after ASCT were independent variables adversely affecting PFS. PET/CT involvement at diagnosis, after novel agent-based induction and subsequent ASCT is a reliable predictor of prognosis in MM patients. This study is registered at www.clinicaltrials.gov as NTC01341262.

Bortezomib-thalidomide-dexamethasone is superior to thalidomide-dexamethasone as consolidation therapy after autologous hematopoietic stem cell transplantation in patients with newly diagnosed multiple myeloma

In a randomized, phase 3 study, superior complete/near-complete response (CR/nCR) rates and extended progression-free survival were demonstrated with bortezomib-thalidomide-dexamethasone (VTD) versus thalidomide-dexamethasone (TD) as induction therapy before, and consolidation after, double autologous stem cell transplantation for newly diagnosed myeloma patients (intention-to-treat analysis; VTD, n = 236; TD, n = 238). This per-protocol analysis (VTD, n = 160; TD, n = 161) specifically assessed the efficacy and safety of consolidation with VTD or TD. Before starting consolidation, CR/nCR rates were not significantly different in the VTD (63.1%) and TD arms (54.7%). After consolidation, CR (60.6% vs 46.6%) and CR/nCR (73.1% vs 60.9%) rates were significantly higher for VTD-treated versus TD-treated patients. VTD consolidation significantly increased CR and CR/nCR rates, but TD did not (McNemar test). With a median follow-up of 30.4 months from start of consolidation, 3-year progression-free survival was significantly longer for the VTD group (60% vs 48% for TD). Grade 2 or 3 peripheral neuropathy (8.1% vs 2.4%) was more frequent with VTD (grade 3, 0.6%) versus TD consolidation. The superior efficacy of VTD versus TD as induction was retained despite readministration as consolidation therapy after double autologous transplantation. VTD consolidation therapy significantly contributed to improved clinical outcomes observed for patients randomly assigned to the VTD arm of the study. The study is registered at www.clinicaltrials.gov as #NCT01134484.

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.

Intraclonal heterogeneity is a critical early event in the development of myeloma and precedes the development of clinical symptoms

The mechanisms involved in the progression from monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) to malignant multiple myeloma (MM) and plasma cell leukemia (PCL) are poorly understood but believed to involve the sequential acquisition of genetic hits. We performed exome and whole-genome sequencing on a series of MGUS (n=4), high-risk (HR)SMM (n=4), MM (n=26) and PCL (n=2) samples, including four cases who transformed from HR-SMM to MM, to determine the genetic factors that drive progression of disease. The pattern and number of non-synonymous mutations show that the MGUS disease stage is less genetically complex than MM, and HR-SMM is similar to presenting MM. Intraclonal heterogeneity is present at all stages and using cases of HR-SMM, which transformed to MM, we show that intraclonal heterogeneity is a typical feature of the disease. At the HR-SMM stage of disease, the majority of the genetic changes necessary to give rise to MM are already present. These data suggest that clonal progression is the key feature of transformation of HR-SMM to MM and as such the invasive clinically predominant clone typical of MM is already present at the SMM stage and would be amenable to therapeutic intervention at that stage.

Single-cell genetic analysis reveals the composition of initiating clones and phylogenetic patterns of branching and parallel evolution in myeloma

Although intratumor heterogeneity has been inferred in multiple myeloma (MM), little is known about its subclonal phylogeny. To describe such phylogenetic trees in a series of patients with MM, we perform whole-exome sequencing and single-cell genetic analysis. Our results demonstrate that at presentation myeloma is composed of two to six different major clones, which are related by linear and branching phylogenies. Remarkably, the earliest myeloma-initiating clones, some of which only had the initiating t(11;14), were still present at low frequencies at the time of diagnosis. For the first time in myeloma, we demonstrate parallel evolution whereby two independent clones activate the RAS/MAPK pathway through RAS mutations and give rise subsequently to distinct subclonal lineages. We also report the co-occurrence of RAS and interferon regulatory factor 4 (IRF4) p.K123R mutations in 4% of myeloma patients. Lastly, we describe the fluctuations of myeloma subclonal architecture in a patient analyzed at presentation and relapse and in NOD/SCID-IL2Rγnull xenografts, revealing clonal extinction and the emergence of new clones that acquire additional mutations. This study confirms that myeloma subclones exhibit different survival properties during treatment or mouse engraftment. We conclude that clonal diversity combined with varying selective pressures is the essential foundation for tumor progression and treatment resistance in myeloma.

Global methylation analysis identifies prognostically important epigenetically inactivated tumor suppressor genes in multiple myeloma

Outcome in multiple myeloma is highly variable and a better understanding of the factors that influence disease biology is essential to understand and predict behavior in individual patients. In the present study, we analyzed combined genomewide DNA methylation and gene expression data of patients treated in the Medical Research Council Myeloma IX trial. We used these data to identify epigenetically repressed tumor suppressor genes with prognostic relevance in myeloma. We identified 195 genes with changes in methylation status that were significantly associated with prognosis. Combining DNA methylation and gene expression data led to the identification of the epigenetically regulated tumor modulating genes GPX3, RBP1, SPARC, and TGFBI. Hypermethylation of these genes was associated with significantly shorter overall survival, independent of age, International Staging System score, and adverse cytogenetics. The 4 differentially methylated and expressed genes are known to mediate important tumor suppressive functions including response to chemotherapy (TGFBI), interaction with the microenvironment (SPARC), retinoic acid signaling (RBP1), and the response to oxidative stress (GPX3), which could explain the prognostic impact of their differential methylation. Assessment of the DNA methylation status of the identified genes could contribute to the molecular characterization of myeloma, which is prerequisite for an individualized treatment approach.

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.

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.

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.

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.