Search

Key Points Quantitative evaluation of the tumor load in patients with IgM monoclonal gammopathies in tDNA and cfDNA samples., Visual Abstract, We describe a novel method for the detection of MYD88L265P mutation using a competitive allele-specific polymerase chain reaction (Cast-PCR) assay. This assay has a sensitivity of 1 × 10−3, is applicable in reactions containing very low amounts of DNA (as low as 20 pg), and allowed the detection of MYD88L265P somatic mutation in both tumor-derived DNA (tDNA) and cell-free DNA (cfDNA). In addition, using the Cast-PCR assay, we were able to determine the mutation allele fraction (MAF) in each tested sample. We then analyzed baseline tDNA and cfDNA samples from 163 patients (53 with immunoglobulin M monoclonal gammopathy of undetermined significance and 110 with Waldenström’s macroglobulinemia [WM], of whom 54 were asymptomatic and 56 were symptomatic) and also in sequential samples of 37 patients. MAF in both cfDNA and tDNA was higher among patients with symptomatic compared with asymptomatic WM and in those with asymptomatic WM compared with those with immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance. In addition, the evaluation of sequential samples showed that MAF decreased after treatment, whereas it increased in patients who relapsed or progressed to symptomatic WM. Thus, Cast-PCR is a highly sensitive, cost-effective diagnostic tool for MYD88L265P detection, applicable in both tDNA and cfDNA samples, that also provides a quantitative evaluation of the tumor load in patients with IgM monoclonal gammopathies.

Contemporary information is sparse on the frequency of skeletal-related events (SREs) in multiple myeloma (MM) patients at a population-based level in the era of novel agents. In this context, we conducted this single-center, prospective, observational study to determine the incidence of SREs among newly diagnosed MMs (NDMM) and to explore the possible correlations with disease characteristics, imaging finding, and patient prognosis. A total of 370 patients with available baseline MRIs were included. Among them, 208 (56%) presented with at least one SRE at diagnosis. Fractures were the most common reported SREs (48%). The incidence of SREs at diagnosis was higher in patients with osteolytic lesions, abnormal MRI pattern, hypercalcemia, and at least 60% bone marrow infiltration by plasma cells. Importantly, the patients with normal MRI pattern, who did not present with SREs at diagnosis, had statistically significant improved median OS in comparison with the patients who had abnormal MRI patterns and/or the presence of SREs at diagnosis (9.3 vs. 6.6 years, p = 0.048). Our data, which represent one of a few systematic reports on the incidence and characteristics of SREs in the era of novel agents, was indicative of a high incidence of SREs at the time of MM diagnosis. Early detection of myeloma bone disease and tailored patient management are essential to optimize patient outcomes.

The diagnosis of Waldenström’s macroglobulinemia (WM), an IgM-associated lymphoplasmacytic lymphoma, can be challenging due to the different forms of disease presentation. Furthermore, in recent years, WM has witnessed remarkable progress on the diagnostic front, as well as a deeper understanding of the disease biology, which has affected clinical practice. This, together with the increasing variety of tools and techniques available, makes it necessary to have a practical guidance for clinicians to perform the initial evaluation of patients with WM. In this paper, we present the consensus recommendations and laboratory requirements for the diagnosis of WM developed by the European Consortium of Waldenström’s Macroglobulinemia (ECWM), for both clinical practice as well as the research/academical setting. We provide the procedures for multiparametric flow cytometry, fluorescence in situ hybridization and molecular tests and with this offer guidance for a standardized diagnostic work-up and methodological workflow of patients with IgM monoclonal gammopathy of uncertain significance, asymptomatic and symptomatic WM.

Background Overexpression of c-Myc is commonly seen in human ovarian cancers, and this could be a potentially novel therapeutic target for this disease. JQ1, a selective small-molecule BET (Bromodomain and extraterminal domain family) bromodomain (BRDs) inhibitor, has been found to suppress tumour progression in several cancer cell types. Results Using a panel of ovarian cancer cell lines and primary cell cultures from human ovarian cancer ascites, we demonstrated that JQ1 significantly suppressed cell proliferation and induced apoptosis in an ovarian cancer cell by targeting BRD4 and c-Μyc. In addition, JQ1 sensitized ovarian cancer cells to cisplatin, the most commonly used chemotherapeutic agent in ovarian cancer. Importantly, this effect was observed in ovarian cells, which exhibited resistance to cisplatin alone. Finally, we show that JQ1 interacts with the JAK-STAT signalling pathway, a pathway important in supporting ovarian cancer cell survival by suppressing or inducing genes involved in cell survival and apoptosis, respectively. Conclusion Our data, taken together, suggest that JQ1 is an attractive antitumour candidate for further investigation in the treatment of ovarian cancer, as it associates with cell proliferation, apoptosis, and alterations in the JAK-STAT signalling pathway, especially in patients with a platinum-resistant profile or in patients with relapsed disease.

Despite recent biomedical improvements in treating Multiple Myeloma (MM), the disease still remains incurable. Toll like receptors (TLRs) provide a link between innate and adaptive immune responses and hence potentially correlate inflammation to cancer. Although the regulatory role of TLRs in MM has been under investigation the underlying mechanisms remain unclear. In this study we assayed the function of TLR4 in MM cell lines and in MM patients’ samples. We found that lipopolysaccharide-mediated TLR4 activation increased MM cells proliferation and decreased endoplasmic reticulum (ER) stress-induced apoptosis. Furthermore, we observed that either the endogenous CHOP expression or the ER stress-mediated CHOP induction, were suppressed by TLR4 activation or its overexpression in MM cell lines; TLR4 induction also suppressed ER stress-induced apoptotic signals. In support, TLR4 gene expression silencing in MM cell lines significantly decreased cell proliferation and promoted CHOP and ATF4 upregulation. TLR4 activation was also able to partially abrogate the effect of bortezomib in MM cell lines by suppressing PERK, ATF4 and phospho-eIF2A. We suggest that TLR4-mediated disruption of ER stress responses contributes to MM cells proliferation and suppresses ER-dependent death signals.

Early responses to vaccination are important in shaping both humoral and cellular protective immunity. Dissecting innate vaccine signatures may predict immunogenicity and help optimizing efficacy of mRNA and other vaccine strategies. We characterized the cytokine and chemokine responses to the 1st and 2nd dose of the BNT162b2 mRNA (Pfizer/BioNtech) vaccine in antigen-naive vaccine recipients and individuals previously infected by COVID-19 (NCT04743388). Transient increases in IL-15 and IFN-γ levels early after boost correlated with Spike-RBD antibody levels, supporting their possible use as biomarkers of successful vaccination. We identified a systemic signature including IL-15, IFN-γ and IP-10/CXCL10 increase after the 1st vaccination, which was enriched by TNF-α and IL-6 after the 2nd vaccination. In vaccine recipients with history of COVID-19 infection, a single vaccine dose resulted in both strong cytokine induction and antibody titers similar to the ones observed upon booster vaccination in antigen-naive individuals, a result with potential implication for future public health recommendations. Funding Information: Funding: This research was supported [in part] by the Intramural Research Program of the NIH, NCI to G.N.P. and B.K.F. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: All study procedures were carried out in accordance with the declaration of Helsinki (18th World Medical Association Assembly), its subsequent amendments, the Greek regulations and guidelines, as well as the good clinical practice guidelines (GCP) as defined by the International Conference of Harmonization. The study was also approved by the local ethic committee of Alexandra General Hospital (no 15/23 December 2020).

Liquid biopsyis being integrated into cancer diagnostics with profound therapeutic implications. However, its role in Waldenström’s Macroglobulinemia (WM) and IgM monoclonal gammopathies is still unclear. In this study, we evaluated the role of peripheral blood (PB) cell-free DNA (cfDNA) in characterizing the mutational status of MYD88 and CXCR4 of patients with IgM monoclonal gammopathies. Paired bone marrow (BM) tumor DNA (tDNA) and PB cfDNA samples from 98 patients (9 MGUS, 45 with WM in remission, 44 with smoldering WM, newly diagnosed or relapsed WM) and 10 controls with non-IgM monoclonal gammopathies were analyzed. Regarding MYD88L265P mutation, 76 patients had paired tDNA and cfDNA informative samples. Among patients with WM in remission, 65% harbored the MYD88L265P mutation, whereas the corresponding percentage among smoldering/newly diagnosed or relapsed WM was 92%. The overall concordance rate was 94% (72/76). For CXCR4 mutations, 65 patients had paired informative tDNA and cfDNA samples. The overall concordance rate was 90% (59/65). All controls had wild-type MYD88 and CXCR4. In conclusion, PB cfDNA is a useful, minimally invasive, cost-effective, and time-effective tool for the identification of the presence of MYD88 and CXCR4 mutations in patients with IgM monoclonal gammopathies avoiding unnecessary BM assessment.

Multiple myeloma (MM) is characterized by bone destruction due to increased bone resorption and decreased bone formation. Semaphorin 4D (CD100, Sema4D) is expressed by osteoclasts, binds to its receptor Plexin-B1, and acts as a mediator of osteoclast–osteoblast interaction that ultimately inhibits osteoblastic bone formation. Preclinical data suggest that Sema4D/Plexin-B1 pathway is implicated in MM-induced bone disease. However, there is no information on the role of Sema4D in MM patients. Thus, we evaluated Sema4D and Plexin-B1 in six myeloma cells lines in vitro; in the bone marrow plasma (BMP) and serum of 72 newly diagnosed symptomatic MM (NDMM) patients and in 25 healthy controls. Only one myeloma cell line produced high Sema4D. BMP and circulating Sema4D and Plexin-B1 levels were significantly higher in MM patients compared to controls (p p p p p = 0.07), while patients with diffuse MRI pattern had higher BMP Sema4D levels (p = 0.02). Our data suggest that Sema4D is elevated in MM patients and correlate with adverse myeloma features and increased bone resorption, providing a possible target for novel therapeutic approaches in MM.

Background: COVID-19 has been associated with hypercoagulability, endothelial cell injury and frequent thrombotic complications resulting both from direct effects of the virus on the endothelium and from the 'cytokine storm' resulting from the host's immune response. Since the COVID-19 vaccines have been shown to effectively prevent symptomatic infection including hospital admissions and severe disease, the risk of COVID-19-related thrombosis should be expected to (almost) disappear in vaccinated individuals. However, some rare cases of venous thrombosis have been reported in individuals vaccinated with mRNA vaccines. Thus, there is a sharp contrast between the clinical or experimental data reported in the literature on COVID-19 and on the rare thrombotic events observed after the vaccination with these vaccines. This phenomenon raised some scepticism of even some fear about the safety of these vaccines which could compromise the adhesion of the citizens in the vaccination program. Aims: We conducted a prospective observational study, to explore the impact of vaccination with the BNT162b2 (Pfizer/BioNTech) on blood hypercoagulability and endothelial cell activation and to investigate if this is modified by the presence of active cancer. Methods: In total 229 subjects were prospectively included in the study from April to June 2021. Subjects were stratified in three predefined groups: 127 vaccinated patients with active cancer (VOnco group), 72 vaccinated health care workers (VHcw group) and 30 non vaccinated health individuals (Control group). Blood samples were obtained 2 days after the administration of the first dose of BNT162b2 vaccine and collected in Vacutainer® tubes (0.109 mol/L trisodium citrate). Platelet poor plasma (PPP) was prepared by double centrifugation at 2000 g for 20 minutes at room temperature and plasma aliquots were stored at -80°C until assayed. Samples of PPP were assessed for thrombin generation (TG) with PPP-Reagent® (Thrombogram-Thrombinoscope assay with PPP-Reagent®TF 5pM), E-selectin, D-dimers, (D-Di), Tissue Factor (TFa), procoagulant phospholipid-dependent clotting time (Procag-PPL) and von Willebrand factor (vWF), thrombomodulin (TM), tissue factor pathway inhibitor (TFPI), and platelet factor 4 (PF4). All assays were from Diagnostica Stago (France). The upper and lower normal limits (UNL and LNL) for each biomarker were calculated by the mean±2SD for the control group. Results: All vaccinated subjects showed significantly increased levels of PF4 (71% >UNL, pUNL, pUNL, pUNL, pUNL, pUNL, pUNL, p Conclusion: The ROADMAP-COVID-19-Vaccine study shows that administration of the first dose of the BNT162b2 vaccine induced significant platelet activation documented by shorter Procoag-PPL associated with increased levels of PF4. Plasma hypercoagulability was less frequent in vaccinated individuals whereas there was no evidence of significant endothelial cells activation after vaccination. Interestingly, the presence of active cancer was not associated with an enhancement of platelet activation, hypercoagulability, or endothelial cell activation after the vaccination. Probably, the generated antibodies against the spike protein or lead to platelet activation in a FcyRIIa dependent manner that results in PF4 release. The implication of the mild inflammatory reaction triggered by the vaccination could be another possible pathway leading to platelet activation. Nevertheless, vaccination does not provoke endothelial activation even in patients with cancer. The findings of the ROADMAP-COVID-19-Vaccine study support the concept administration of mRNA based vaccines does not directly cause a systematic hypercoagulability. Disclosures Gligorov: Roche-Genentech: Research Funding; Novartis: Research Funding; Onxeo: Research Funding; Daichi: Research Funding; MSD: Research Funding; Eisai: Research Funding; Genomic Heatlh: Research Funding; Ipsen: Research Funding; Macrogenics: Research Funding; Pfizer: Research Funding. Terpos: Novartis: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Genesis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; BMS: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; GSK: Honoraria, Research Funding. Dimopoulos: Amgen: Honoraria; BMS: Honoraria; Janssen: Honoraria; Beigene: Honoraria; Takeda: Honoraria.

The genomic landscape of Waldenström Macroglobulinemia (WM) is characterized by recurrent somatic mutations in MYD88, with a lower incidence of mutations affecting CXCR4, ARID1A, CD79B and the NFKB signaling pathway (Hunter et. al. Blood 2014). We aimed to characterize the relationship between single base substitutions (SBS), mutational signatures, copy number aberrations (CNA) and structural variants (SV) in WM. We performed whole genome sequencing (WGS) on 14 primary samples from WM patients at various clinical stages, including IgM monoclonal gammopathy (n=1), smoldering (n=5), newly diagnosed (n=7) and relapsed WM (n=1). We identified a median of 2806 clonal SBS per sample (IQR 1870-3079), and 12/14 (85%) samples harbored MYD88 mutations. To investigate which mutational processes are involved in shaping the genomic landscape of WM we performed a mutational signature analysis. Four previously reported SBS signatures were detected: SBS1 and SBS5 (aging), SBS9 (germinal center; GC) and SBS8, with the contribution of age-related signatures SBS1/SBS5 being directly correlated with age at presentation (R 2=0.44, p=0.014). The GC signature SBS9 demonstrated sustained GC activity, as evidenced by the same proportion of mutations attributable to SBS9 at both the clonal and subclonal level (24%). At the immunoglobulin loci, we observed evidence of clustered SBS84 (AID), reflecting somatic hypermutation, with SBS84 accounting for 30% of signature contribution from subclonal mutations. Overall, these data suggest that, similarly to MM and other hematological malignancies, the interaction between WM and the GC is sustained over time. We have previously demonstrated that SV and complex events are critical in the pathogenesis and clinical outcomes of multiple myeloma. In contrast, in this WM WGS cohort, we found a low prevalence of complex SV, with no chromothripsis detected, and a single chromoplexy event found in 3 patients (21%), all of whom had progressed to symptomatic WM. To explore WM CNA features in a larger cohort, we examined the WGS data together with 38 MYD88-mutated WM samples for which targeted sequencing was available (MSK-IMPACT-Heme 400 gene panel). In this combined dataset (n=52), GISTIC analysis identified significantly deleted regions at 6q16.1, 7q34, 17p13.1 (TP53) and 21q22.2, along with significant amplification at 6p22.1 (HLA-A). To better characterize the HLA loci using the loss of heterozygosity in human leukocyte antigen (LOHHLA) tool (McGranahan et. al. Cell 2017) we found the presence of HLA-specific loss of heterozygosity in 1 sample, while 4 samples had HLA CN >2.5 (all from patients who progressed to symptomatic WM). CNA analysis demonstrated that while some samples harbored typical CNA features, others had minimal changes, with MGUS / smoldering WM samples having less CNA compared with those who progressed to symptomatic WM. The 2 MYD88 wild type WGS contained a clonal gain affecting chromosome 12, which is typically an early event in chronic lymphocytic leukemia. Molecular time analysis (the corrected ratio between duplicated and non-duplicated clonal mutations within large chromosomal gains [Maura et al. Nat Comm 2019]) demonstrated that these 2 chromosomal gain events occurred early in cancer development (relative timing 0.5) and tended to be subclonal. This data suggests that, while MYD88-mutations are central to WM clone establishment and can be observed in precursor disease, CNA may contribute to later phases and disease progression. In summary, WGS in WM allows the demonstration that germinal center activity is sustained over time. CNA in WM are not random in distribution, with specific loci being significantly amplified or deleted, and a potential role for HLA CNA. In contrast to MYD88 mutations, which are carried by stable precursor patients, the subclonal status and late molecular time of most CNA changes suggest a late role in cancer progression. Disclosures Kastritis: Pfizer: Consultancy, Honoraria, Research Funding; Takeda: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Genesis Pharma: Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Diamond: Sanofi: Honoraria; Medscape: Honoraria. Kazandjian: Arcellx: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees. Papaemmanuil: Isabl Technologies: Divested equity in a private or publicly-traded company in the past 24 months; Kyowa Hakko Kirin Pharma: Consultancy. Dogan: Roche: Consultancy, Research Funding; Seattle Genetics: Consultancy; EUSA Pharma: Consultancy; Peer View: Honoraria; Takeda: Consultancy, Research Funding; Physicians' Education Resource: Honoraria. Lesokhin: Trillium Therapeutics: Consultancy; Serametrix, Inc: Patents & Royalties; Genetech: Research Funding; Iteos: Consultancy; bristol myers squibb: Research Funding; Behringer Ingelheim: Honoraria; pfizer: Consultancy, Research Funding; Janssen: Honoraria, Research Funding. Landgren: Janssen: Other: IDMC; Janssen: Honoraria; Celgene: Research Funding; Amgen: Honoraria; Janssen: Research Funding; Amgen: Research Funding; Takeda: Other: IDMC; GSK: Honoraria. Palomba: Rheos: Honoraria; Pluto: Honoraria; Lygenesis: Honoraria; Ceramedix: Honoraria; Seres: Honoraria, Other: Stock, Patents & Royalties, Research Funding; Nektar: Honoraria; PCYC: Consultancy; Wolters Kluwer: Patents & Royalties; Notch: Honoraria, Other: Stock; Priothera: Honoraria; Kite: Consultancy; Novartis: Consultancy; Magenta: Honoraria; WindMIL: Honoraria; BeiGene: Consultancy; Juno: Patents & Royalties. Maura: OncLive: Honoraria; Medscape: Consultancy, Honoraria. Dimopoulos: Amgen: Honoraria; BMS: Honoraria; Janssen: Honoraria; Takeda: Honoraria; BeiGene: Honoraria.

Patients with lymphoproliferative disorders are at high risk for severe COVID-19. For patients with AL amyloidosis, in which there is also critical organ involvement, this risk may be even higher. Vaccination against SARS-CoV-2 is the best strategy to avoid severe COVID-19, but response to vaccines may be compromised in patients with B-cell lymphoproliferative or plasma cell malignancies, as in AL amyloidosis. Although modest in size, the plasma cell clone in AL may cause immunosuppression while anticlonal therapies further compromise immune responses. To evaluate immunization efficacy, we measured the titers of neutralizing antibodies (NAbs) against SARS-CoV-2 after vaccination with BNT162b2 in patients with AL amyloidosis. As a control group we used volunteers, matched (ratio 1:2) for age and gender, who had no autoimmune or active malignant or infectious disease. Serum was separated within 4 hours from blood collection and stored at -80°C until the day of measurement on (A) day 1 (D1; before the first dose of BNT162b2) (B) day 22 (D22; before the 2nd dose) and (C) day 50 (D50; ie 30 days after the 2nd dose). NAbs against SARS-CoV-2 were measured using FDA approved methodology (cPass™ SARS-CoV-2 NAbs Detection Kit; GenScript, Piscataway, NJ, USA). According to the manufacturer of the assay, a titer ≥ 50% is considered a clinically relevant threshold for viral inhibition. The study included 144 patients with AL amyloidosis, of which 120 had NAbs titers assessed on all time points and were included in the final analysis (53% males; median age: 66, IQR: 57-72 years) and 240 matched controls (53% males; median age: 66, IQR: 57-72 years). 66 (55%) AL patients were on active therapy, 17.5% were on daratumumab (DARA)-based therapy, 52 (43%) had discontinued therapy >3 months from the date of the first shot, 19% had prior exposure to DARA and 94 (78%) were in hematologic remission (CR or VGPR). Prior to the 1st dose (D1), NAb titers were similar between patients and controls (median 14.9% (IQR 7.8-23.1%) vs 14% (IQR 6.8-22.9%), p=0.439); 6 AL patients had baseline NAbs >50%, of which 5 reported a history of COVID-19 infection. On D22, there was a significant increase of NAbs titers both in controls and AL patients (both p On D50, there was further increase in NAbs titers both in controls and AL patients (both p Among AL patients, factors associated with NAb titers on D50 included age (p Generalized linear models were used for evaluation of multiple factors associated with D50 NAb titers: at least 3 months since the last dose of anticlonal therapy (p3 months of treatment-free interval (HR:7.75, p In conclusion, patients with AL amyloidosis have an attenuated response to vaccination with BNT162b2 especially among those on active therapy or with less than 3 months since the last dose of treatment. For such patients, an anamnestic dosing strategy could be considered, especially after completion of anticlonal therapy. Figure 1 Figure 1. Disclosures Kastritis: Genesis Pharma: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Takeda: Honoraria; Pfizer: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding. Terpos: Novartis: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Genesis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; BMS: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; GSK: Honoraria, Research Funding. Gavriatopoulou: Sanofi: Honoraria; GSK: Honoraria; Karyopharm: Honoraria; Takeda: Honoraria; Genesis: Honoraria; Janssen: Honoraria; Amgen: Honoraria. Dimopoulos: Amgen: Honoraria; BMS: Honoraria; Janssen: Honoraria; Takeda: Honoraria; BeiGene: Honoraria.

Waldenström macroglobulinemia (WM) is a low-grade B- cell lymphoproliferative disorder characterized by bone marrow (BM) infiltration by small lymphoplasmacytic lymphoma (LPL) cells that secrete monoclonal IgM immunoglobulin. Our understanding of the pathogenesis of WM has improved significantly by the discovery that the vast majority of patients with WM harbor the somatic mutation L265P in MYD88 gene on their clonal cells. However, the small fraction of patients (3-10%) that lack mutations in MYD88 is characterized by a different clinical course, with an increased risk of disease transformation and probably shorter overall survival. WM is a clonal disease but there may be significant heterogeneity within the clone, which may be associated with clinical outcomes, however, this has not been extensively explored. Recent advances in the area of single-cell RNA sequencing (scRNA-Seq) technologies have improved so that it is feasible to sequence and analyze thousands of cells per tumor delivering significant insights into a tumor's cellular heterogeneity and the biological features that distinguish different cell populations. To better understand the differences occurring in the B cell composition between WM patients harboring the MYD88 L265Pmutation and those with MYD88 WT respectively, we performed single-cell RNA sequencing on CD19+ sorted cells from BM aspirates of these patients. Both patients were wild type to CXCR4 mutations. Overall, we characterized 8,517 cells from one MYD88 L265P WM patient (3,116 cells), one MYD88 WT patient (3,348 cells) and one healthy donor as control (2,053 cells). Clustering of these cells based on their gene expression profile, revealed that the majority of the cells form a large cluster corresponding to B cells (naïve, immature and mature;6852 cells) while the rest of the cells were classified into four broad cell types ranging from pro-B cells (1243 cells) to only few cells belonging to mature populations engaged in the immune response such as plasma cells (190 cells), T cells (124 cells) and monocytes (53 cells) indicating a high purity of the samples (≥95%) (Fig 1A). Clonality assessment showed high lambda light chain expressing populations in both patients and as expected an evenly distributed polyclonal population in the healthy donor. To investigate the relative composition of the different cell types between the two genetically distinct WM patients (MYD88 L265P vs MYD88 WT) we searched for populations that were enriched in the B cell repertoire compared to the normal BM. From our data we observe a significant enrichment of pro-B cells in the MYD88 WT patient which is almost completely missing in the MYD88 L265P patient and an enhanced naïve B cell population in MYD88 L265P patient compared to both MYD88 WT patient and the healthy donor (Fig 1B, C). In addition, immature B cells are 3-fold higher in WM patients compared to the healthy donor. Differential gene expression analysis in B cells showed that among both patients several genes are highly expressed (>1.5 log2 fold-change) compared to the healthy donor such as CD52, FCMR, CD74, CD37 and HLA-DPA1. Genes that were highly upregulated in the MYD88 mutant compared to the wild-type WM patient include CXCR4, TXNIP, ID3, LLT1, MTRNR2L8, ZFP36L2 and ZNF331. On the other hand, genes that are highly upregulated in the wild-type phenotype compared to the mutant phenotype include MS4A1, CD79A, CD82, CD1C, KIAA0040, CD72, EGR1, SYK, and LGALS1 (Fig 1D, E). Distinct pathways enriched by genes differentially expressed by the MYD88 mutant B cell population include response to corticosteroid and hypoxia whereas in the MYD88 wild type patient unique processes include B cell activation and receptor signaling pathways, immune response and NFκB signaling. In summary, our results show that there is a distinctive transcriptional profile in the B cells from the MYD88 WT patient where most differentially expressed genes do not overlap with the gene expression of the B cells from the MYD88 L265P patient, which may provide further mechanistic insights into the differences in biology and clinical presentation in patients with MYD88 WT versus those harboring MYD88 L265P. Further evaluation in additional patient samples is ongoing to gain additional insights in pathways that may be involved in disease transformation and response to therapy with targeted therapies, either targeting CD20 or BCR pathway. Figure 1 Figure 1. Disclosures Gavriatopoulou: Genesis: Honoraria; Sanofi: Honoraria; Karyopharm: Honoraria; Takeda: Honoraria; GSK: Honoraria; Janssen: Honoraria; Amgen: Honoraria. Terpos: Genesis: Consultancy, Honoraria, Research Funding; GSK: Honoraria, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding; Novartis: Honoraria; Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; BMS: Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Dimopoulos: BMS: Honoraria; Takeda: Honoraria; Beigene: Honoraria; Janssen: Honoraria; Amgen: Honoraria. Kastritis: Amgen: Consultancy, Honoraria, Research Funding; Genesis Pharma: Honoraria; Takeda: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding.

Specific genetic polymorphisms (SNPs) have been correlated with the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in small series. We screened 140 myeloma patients (36 patients with and 104 without BRONJ) for the presence of previously identified SNPs in PPARG and CYP2C8 genes. All the patients received exclusively zolendronic acid (ZA) therapy and were followed prospectively for BRONJ. SNPs in both genes were associated with a higher risk of development of early BRONJ, occurring within less than 2 years of ZA therapy (59% vs. 16%, p = .022 for PPARG and 29% vs. 7%, p = .07 for CYP2C8) and a shorter time to develop BRONJ (59% versus 12%, p = .011 for PPARG and 29% versus 0% at 2 years, p = .037 for CYP2C8), independently of indices of poor oral hygiene. Thus, although preliminary, our data indicate that the presence of SNPs in PPARG and CYP2C8 genes may be associated with increased risk of early BRONJ.

We retrospectively evaluated 55 consecutive patients who received at least one dose of lenalidomide for relapsed/refractory AL amyloidosis. Their median age was 63 years; 72% had heart and 75% kidney involvement and 13% were on dialysis; while 20%, 46% and 34% had Mayo stage -1, -2 and -3 disease, respectively. Median time from start of primary therapy to lenalidomide was 15 months (range 2–100) and median number of prior therapies was 1 (range 1–4); 73% of the patients had prior bortezomib and 42% were bortezomib-refractory. On intent to treat, haematologic response rate was 51% (5.5% CRs, 20% VGPRs) and was 56% versus 40% for patients with and without prior bortezomib and 47% versus 62.5% for bortezomib refractory versus non-refractory patients (p = .351). Organ response was achieved by 16% of evaluable patients (22% renal, 7% liver and 3% cardiac); however, 10 (21%) patients progressed to dialysis. Median survival post lenalidomide was 25 months. Bortezomib-refractory patients had worse outcome (median survival of 10.5 versus 25 months for bortezomib-sensitive patients versus not reached for bortezomib-naive patients, p = .011). Median lenalidomide dose was 10 mg and no patient received the 25 mg dose; however, in 60% a dose reduction was required. Median duration of lenalidomide therapy was 7.2 months and 46% discontinued lenalidomide before completion of planned therapy, mainly due to toxicity (26%) or disease progression/no response (13%). We conclude that although lenalidomide is a major salvage option for patients with relapsed/refractory AL amyloidosis, its toxicity in patients with AL amyloidosis is significant and doses should be adjusted for optimal tolerability.

In multiple myeloma, novel treatments with proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs) have prolonged survival but the disease remains incurable. At relapse, next-generation sequencing has shown occasional mutations of drug targets but has failed to identify unifying features that underlie chemotherapy resistance. We studied 42 patients refractory to both PIs and IMiDs. Whole-exome sequencing was performed in 40 patients, and RNA sequencing (RNA-seq) was performed in 27. We found more mutations than were reported at diagnosis and more subclonal mutations, which implies ongoing evolution of the genome of myeloma cells during treatment. The mutational landscape was different from that described in published studies on samples taken at diagnosis. The TP53 pathway was the most frequently inactivated (in 45% of patients). Conversely, point mutations of genes associated with resistance to IMiDs were rare and were always subclonal. Refractory patients were uniquely characterized by having a mutational signature linked to exposure to alkylating agents, whose role in chemotherapy resistance and disease progression remains to be elucidated. RNA-seq analysis showed that treatment or mutations had no influence on clustering, which was instead influenced by karyotypic events. We describe a cluster with both amp(1q) and del(13) characterized by CCND2 upregulation and also overexpression of MCL1, which represents a novel target for experimental treatments. Overall, high-risk features were found in 65% of patients. However, only amp(1q) predicted survival. Gene mutations of IMiD and PI targets are not a preferred mode of drug resistance in myeloma. Chemotherapy resistance of the bulk tumor population is likely attained through differential, yet converging evolution of subclones that are overall variable from patient to patient and within the same patient.

Due to increased immunoglobulin production and uncontrolled proliferation, multiple myeloma (MM) plasma cells develop a phenotype of deregulated unfolded protein response (UPR). The eIF2-alpha kinase 3 [EIF2&alpha, K3, protein kinase R (PKR)-like ER kinase (PERK)], the third known sensor of endoplasmic reticulum (ER) stress, is a serine-threonine kinase and, like the other two UPR-related proteins, i.e., IRE1 and ATF6, it is bound to the ER membrane. MM, like other tumors showing uncontrolled protein secretion, is highly dependent to UPR for survival, thus, inhibition of PERK can be an effective strategy to suppress growth of malignant plasma cells. Here, we have used GSK2606414, an ATP-competitive potent PERK inhibitor, and found significant anti-proliferative and apoptotic effects in a panel of MM cell lines. These effects were accompanied by the downregulation of key components of the PERK pathway as well as of other UPR elements. Consistently, PERK gene expression silencing significantly increased cell death in MM cells, highlighting the importance of PERK signaling in MM biology. Moreover, GSK2606414, in combination with the proteasome inhibitor bortezomib, exerted an additive toxic effect in MM cells. Overall, our data suggest that PERK inhibition could represent a novel combinatorial therapeutic approach in MM.

Context: Skeletal-related events (SREs) that include pathological fractures, spinal cord compression (SCC) and need for radiotherapy or surgery to the bone are frequent complications of multiple myeloma (MM). Objective: To evaluate the SRE rate in MM patients who received frontline and second-line therapy with proteasome inhibitors (PIs) or immunomodulatory drug (IMiD)-based therapies. Design: Prospectively maintained database. Setting: A referral center in Athens, Greece. Patients: MM patients who received frontline therapy in the Department of Clinical Therapeutics, University of Athens, Greece, between 20072017. Interventions: Patients had a whole-body skeletal survey using either conventional radiography (WBXR) or low-dose CT (WBLDCT) at diagnosis and whenever clinically indicated. Main outcome measures: SRE incidence. Results: 620 consecutive patients with symptomatic MM (316M/304F, median age: 65 years) were studied. The median follow-up was 54 months. SREs were observed in 271 (44%) patients at diagnosis: 213 (34%) presented with pathological fractures, while 34 (5.5%) needed bone surgery, 45 (7.2%) radiotherapy, and 31 (5%) patients presented with SCC. SRE incidence was higher in patients with osteolytic lesions (76.4% vs. 12.4%, P Conclusions: SREs remain a significant complication in MM.

Myeloma cells thrive in an environment of sustained inflammation, which impacts the development and evolution of the disease, as well as drug resistance. We evaluated the impact of genetic polymorphisms in the Toll-like receptor 4 (TLR4) pathway, which have been implicated in different inflammatory responses in the outcomes of patients with symptomatic multiple myeloma (MM) who have received contemporary therapies. We found that the presence of single nucleotide polymorphisms (SNPs) in both the TLR4 and toll/interleukin-1 receptor (TIR)-associated protein (TIRAP) genes was associated with lower response to primary therapy mainly for patients who received immunomodulatory drugs but not in patients treated with bortezomib-based therapies. Furthermore, TIRAP SNP was associated with a significantly shorter progression-free survival and overall survival, independently of other prognostic factors, such as age, transplant, International Staging System stage, lactate dehydrogenase and cytogenetics. This is the first study to demonstrate the effect of SNPs in TLR4/TIRAP in MM. Our data indicate that genetic variability in the immune system may be associated with different responses to antimyeloma therapies and may be a critical component affecting the natural history of the disease, providing the basis for further investigation of the role of these pathways in myeloma.

International audience; In multiple myeloma, next generation sequencing (NGS) has expanded our knowledge of genomic lesions, and highlighted a dynamic and heterogeneous composition of the tumor. Here, we used NGS to characterize the genomic landscape of 418 multiple myeloma cases at diagnosis and correlate this with prognosis and classification. Translocations and copy number changes (CNAs) had a preponderant contribution over gene mutations in defining the genotype and prognosis of each case. Known and novel independent prognostic markers were identified in our cohort of proteasome inhibitor and IMiD-treated patients with long follow-up, including events with context-specific prognostic value, such as deletions of the PRDM1 gene. Taking advantage of the comprehensive genomic annotation of each case, we used innovative statistical approaches to identify potential novel myeloma subgroups. We observed clusters of patients stratified based on the overall number of mutations and number/type of CNAs, with distinct effects on survival, suggesting that extended genotype of multiple myeloma at diagnosis may lead to improved disease classification and prognostication.

Proteasome inhibitors, e.g. Bortezomib (BTZ) and Carfilzomib (CFZ), have demonstrated clinical efficacy against haematological cancers. Interestingly, several adverse effects are less common, compared to BTZ, in patients treated with CFZ. As the molecular details of these observations remain not well understood we assayed the pathophysiological effects of CFZ vs. BTZ in the Drosophila experimental model. Mass Spectrometry analyses showed that neither CFZ nor BTZ are hydrolysed in flies’ tissues, while at doses inducing similar inhibition of the rate limiting for protein breakdown chymotrypsin-like (CT-L) proteasomal activity, CFZ treatment resulted in less intense increase of oxidative stress or activation of antioxidant and proteostatic modules. Also, despite comparable cardiotoxicity likely due to disrupted mitochondrial function, CFZ did not affect developmental processes, showed minimal neuromuscular defects and reduced to a lesser extent flies’ healthspan. Studies in flies, human cancer cell lines and blood cells isolated from Multiple Myeloma patients treated with CFZ or BTZ revealed, that the increased BTZ toxicity likely relates to partial co-inhibition of the caspase-like (C-L) proteasomal activity Supportively, co-treating flies with CFZ and a C-L selective proteasome inhibitor exacerbated CFZ-mediated toxicity. Our findings provide a reasonable explanation for the differential adverse effects of CFZ and BTZ in the clinic.

In Multiple myeloma (MM) no treatment has a curative potential and even complete response to novel agents such as proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs) are followed by relapse over time. Next generation sequencing (NGS) has showed how MM at diagnosis is defined by several somatic mutations, but only few drivers, even fewer "druggable" mutations, and many found at a subclonal level. At relapse, targeted studies have shown occasional mutations in drug target genes but the genomic and transcriptomic determinants of chemoresistance in MM remains elusive. We selected 42 MM patients refractory to both lenalidomide and PIs. Whole exome sequencing was performed in 40 of them, and RNAseq in 27. Clinical annotation was available for all patients. Standard analysis pipelines where applied to analyze mutations, copy number alterations (CNAs), mutational signatures, gene expression and expressed mutations. Patients received a median of 3 lines of treatment, with median overall survival of 14.6 months from sampling. We found a median of 77.5 mutations per patient, which is more than what reported at diagnosis (Bolli et al, Nature Communications 2014;5:2997). 100% of samples showed evidence of subclonality, and 37% of them exhibited a higher number of subclonal than clonal variants. Therefore, even at this advanced stage the MM genome is evolving and is composed of different subclones that may display different chemosensitivity. The mutational landscape was also different. TP53 mutations were the second most common after KRAS (20% and 17.5%, respectively). Interestingly TP53 mutations all clustered in patients receiving bortezomib as the last line of treatment. Only 2 patients showed a CRBN mutation, both subclonal. Combining mutations and CNA analysis, the TP53 pathway was the most frequently inactivated (45% of patients). Altogether, mutations or deletions of genes in the CRBN E3 ubiquitin ligase complex were found in 32.5% of patients, while proteasomal subunit genes were infrequently hit. Refractory cases were also uniquely characterized by a novel signature linked to exposure to alkylating agents, whose activity was more pronounced after high-dose melphalan suggesting a mutagenic effect of the drug on residual cells at the time of transplant. Whether this has any pathogenetic role on the disease course remains to be elucidated. RNAseq analysis did not show any influence of treatment or mutational data on the clustering of samples, which was mainly influenced by karyotypic events. The main cluster was composed by non-hyperdiploid patients with both amp(1q) and del(13): these showed CCND2 and MCL1 upregulation, the latter representing a marker of venetoclax resistance and novel target of experimental treatments. Only 26.3% of mutations were expressed, and this correlated with the clonality level of the mutation. However, most mutations in driver genes were expressed, with the notable exception of those causing nonsense mediated decay. Overall, classical high-risk features or CRBN pathway mutations were found in 65% of the cohort. However, only amp(1q) predicted survival in our cohort. The lack of prognostic value of high-risk lesions is likely explained by a higher prevalence of such features in double-refractory stages. Our data suggest that gene mutation is not a preferred mode of evolution of drug resistance in MM. Chemoresistance of the bulk tumor population is likely attained though differential, yet converging evolution of different subclones that are overall highly variable from patient to patient and within the same patient. Disclosures Kastritis: Prothena: Honoraria; Genesis: Honoraria; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria; Pfizer: Honoraria. Dimopoulos:Sanofi Oncology: Research Funding. Cavo:bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Corradini:Janssen: Honoraria, Other: Travel Costs; Takeda: Honoraria, Other: Travel Costs; Jazz Pharmaceutics: Honoraria; Gilead: Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria; Celgene: Honoraria, Other: Travel Costs; Amgen: Honoraria; AbbVie: Consultancy, Honoraria, Other: Travel Costs; KiowaKirin: Honoraria; Kite: Honoraria; BMS: Other: Travel Costs; Sanofi: Honoraria; Servier: Honoraria; Roche: Honoraria; Novartis: Honoraria, Other: Travel Costs. Bolli:Celgene: Honoraria; Novartis: Honoraria; Gilead: Other: travel expenses.

Introduction: Skeletal-related events (SREs) that include pathological fractures, spinal cord compression (SCC) and need for radiotherapy or surgery to the bone are frequent complications of multiple myeloma (MM). Although the incidence of SREs at diagnosis is well-documented, there is limited information for the natural history of SREs during treatment with novel agents. Thus, we evaluated the SRE rate in MM patients who received frontline and second line therapy with proteasome inhibitors (PIs) or immunomodulatory drug (IMiD)-based therapies and explored possible correlations with disease or genetic features and type of treatment. Methods: MM patients who received frontline therapy in our center (Department of Clinical Therapeutics, University of Athens, Greece), between 2007-2017, were included in this analysis. Patients had a whole-body skeletal survey using either conventional radiography (WBXR) or low-dose CT (WBLDCT) at diagnosis and then at the time of relapse or whenever clinically indicated. Magnetic Resonance Imaging (MRI) of the spine and pelvis at diagnosis was recorded when available. SNPs in genes that are involved in bone destruction in osteoporosis were also evaluated: LRP5 (rs4988321), GC vitamin D (rs4588), TNFRSF11A (rs3018362), DKK1 (rs1569198), RANKL (rs9594759), OPG (rs6469804) and ERS1 (rs1038304). Results: In total, 620 consecutive patients with symptomatic MM (316M/304F, median age: 65 years) were studied. The median follow-up was 54 months. At diagnosis, osteolytic disease was present in 408 (66%) patients. MRI was available in 390 patients: 149 (38%) patients had focal, 139 (36%) diffuse, 81 (21%) normal and 21 (5%) variegated pattern of marrow involvement. SREs were observed in 271 (44%) patients at diagnosis: 213 (34%) presented with pathological fractures (183 with vertebral fractures, 18 with rib fractures and 15 with long bone fractures; 32 patients had both vertebral and long bone or rib fractures), while 34 (5.5%) patients needed surgery to bone, 45 (7.2%) radiotherapy and 31 (5%) patients presented with SCC. The incidence of SREs was higher in patients with osteolytic lesions (76.4% vs. 12.4%, p Conclusions: Our data, which constitutes one of the few systematic reports on the incidence and characteristics of SREs in the era of novel agents, indicate that SREs remain a significant complication in MM. Despite high response rates after first line therapy and the broad use of BPs, more than 20% of patients develop a new SRE during the first and second line treatment or at the time of first relapse. Importantly, patients who do not receive BPs due to renal impairment develop very frequently SREs, suggesting an unmet need in this setting. More effective frontline therapies or more potent bone-targeted agents (denosumab or anti-sclerostin drugs) may manage to further reduce the SREs rate in MM patients, especially in those who cannot receive BPs. Disclosures Terpos: Celgene: Honoraria; Janssen: Honoraria, Other: Travel expenses, Research Funding; Amgen: Honoraria, Research Funding; Takeda: Honoraria, Other: Travel expenses, Research Funding; Genesis: Honoraria, Other: Travel expenses, Research Funding; Medison: Honoraria. Kastritis:Pfizer: Honoraria; Prothena: Honoraria; Genesis: Honoraria; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria. Gavriatopoulou:Amgen: Honoraria; Takeda: Honoraria, Other: Travel expenses; Janssen: Honoraria, Other: Travel expenses; Genesis: Honoraria, Other: Travel expenses. Dimopoulos:Sanofi Oncology: Research Funding.

Multiple myeloma (MM) is a hematologic malignancy characterized by infiltration of the bone marrow (BM) by malignant plasma cells. Multiple myeloma diagnosis is made by the presence of one or more of the CRAB criteria or one of the recently added biomarkers of malignancy. Smoldering MM (SMM) is a plasma cell dyscrasia preceding multiple myeloma, characterized by bone marrow infiltration of 10-60% and/or serum monoclonal protein ≥3g/dL or urinary monoclonal protein ≥500 mg per 24h, along with the absence of myeloma-defining events. MicroRNAs (miRNA) are single-stranded, small non-coding RNA molecules (~21 nt) that regulate protein-coding gene expression at the post-transcriptional level, mainly through interactions with the 3′-untranslated region of target mRNAs. The results of such interactions can be mRNA degradation and/or translational repression, depending on the complementarity of the miRNA seed sequence with the mRNAs 3′-untranslated region. They can function as oncogenes or tumor suppressors, possessing a vital role in several aspects of all stages of tumorigenesis and cancer progression. In the present study, we have investigated the clinical value of a molecular signature consisting of 10 cancer-related miRNAs in MM: miR-15a, miR-16, miR-21, miR-221, miR-222, miR-25, miR-125, miR-155, miR-223, and miR-181a. These molecules were selected due to their well-documented role and clinical significance in numerous human malignancies. More specifically, miR-15a and miR-16 expression levels have been associated with chronic lymphocytic leukemia. The deletion 13q14, the most prevalent alteration in CLL, leads to the deletion of these miRNAs, which act on cell proliferation and in the process of apoptosis. miR-221 and miR-222 form a cluster that has been correlated with tumorigenesis and unfavorable prognosis in human malignancies, while miR-155 is a pro-inflammatory, oncogenic molecule, with a potential role in chronic lymphocytic leukemia. Bone marrow aspiration samples were collected from 94 patients with MM and SMM, and CD138+ plasma cells were positively selected using magnetic beads coated with an anti-CD138 antibody. Total RNA was isolated using TRIZol. Thereafter, 200ng RNA of each sample were polyadenylated at the 3´ end and reversely transcribed. An in-house developed real-time quantitative PCR assay was conducted and the results were biostatistically analyzed. For the normalization of the expression levels of each miRNA, the mean expression of two small nucleolar RNAs (RNU43 and RNU48) was used as reference. Seventy six out of the 94 BM aspiration samples were derived from MM patients and 18 of them from SMM patients, at the time of diagnosis. The MM patients were classified, according to the R-ISS staging system, as follows: 15 patients had stage I disease, 42 patients had stage II, and 19 patients stage III MM. Forty nine myeloma patients presented with osteolytic lesions at diagnosis. The statistical analysis revealed significantly lower expression levels of miR-16 (p=0.036) and miR-155 (p=0.045) in CD138+ cells of MM patients, compared to those from SMM patients, highlighting their potential value to discriminate MM from SMM. Furthermore, miR-221 and miR-222 expression levels were negatively correlated with R-ISS; thus, miR-221 and miR-222 expression was significantly downregulated in MM patients with R-ISS stage III (p=0.004 and 0.034, respectively). This tendency reveals a potential favorable prognostic value of miR-221/222 cluster in MM. Next, miR-15a and miR-16 expression was shown to be associated with the presence of osteolytic lesions. In this regard, the expression levels of miR-15a (p=0.048) and miR-16 (p=0.047) were decreased in MM patients with bone disease, compared to those without bone disease. The observed decreased expression of these two miRNAs in symptomatic MM patients could constitute a predictive biomarker for the occurrence of bone disease and, hence, a putative predictive biomarker of SMM patients at high risk of evolution to symptomatic disease with bone lesions. We conclude that miR-221/222 correlate with more favorable R-ISS stage, while miR-15a and miR-16 correlate with the presence of osteolytic disease in MM. This ongoing study will further reveal the possible prognostic significance of this 10 miRNAs signature studied, when response to therapy, progression-free and overall survival is available. Disclosures Kastritis: Genesis: Honoraria; Prothena: Honoraria; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria; Pfizer: Honoraria. Gavriatopoulou:Takeda: Honoraria, Other: Travel expenses; Janssen: Honoraria, Other: Travel expenses; Amgen: Honoraria; Genesis: Honoraria, Other: Travel expenses. Dimopoulos:Sanofi Oncology: Research Funding. Terpos:Takeda: Honoraria, Other: Travel expenses, Research Funding; Medison: Honoraria; Celgene: Honoraria; Janssen: Honoraria, Other: Travel expenses, Research Funding; Genesis: Honoraria, Other: Travel expenses, Research Funding.

Lenalidomide has significant antimyeloma activity but it is associated with a significant risk of venous thromboembolism (VTE). In this study, we assessed clinical and genetic risk factors that may predispose for VTE in myeloma patients who were treated with lenalidomide-based regimens. We analyzed common clinical and selected genetic factors in 200 consecutive, unselected myeloma patients who were treated with lenalidomide-based regimens in a single institution. Twelve patients (6%) developed a VTE (nine deep venous thrombosis and three pulmonary embolism). All VTEs occurred in patients who were receiving aspirin prophylaxis; no patient who received LMWH or acenocoumarol had a VTE. The frequency of VTEs was 9.4% in previously untreated and 4.5% in previously treated patients. VTEs were more frequent in patients >65 years (8.1% vs. 1.6%) especially among patients receiving aspirin as prophylaxis (10.4% vs. 1.8% for patients ≤65 years). In patients who received prophylaxis with low dose aspirin a single-nucleotide polymorphism in NFκB1 (rs3774968) gene was associated with increased risk of VTE (OR 3.76, 95%CI 1–16, P = 0.051). None of the patients who developed VTEs had common genetic variations that are associated with increased risk of VTEs in the general population, such as FVLeiden and FIIG20210A. Our data indicated that LMWH or vitamin K antagonists (with a target INR 2–3) effectively reduce the risk of VTEs. In patients who received prophylaxis with aspirin genetic variants of genes that are involved directly or indirectly in inflammatory response may be associated with increased risk of VTE. Am. J. Hematol. 88:765–770, 2013. © 2013 Wiley Periodicals, Inc.