ALBERT

Description: Background : TheHevylite assay (HLC Assay) is a novel assay using antibodies that recognize unique conformational epitopes presented by the association of the heavy and light chain constant regions of intact immunoglobulins (Ig) allowing quantitative measurement of each Ig class concentration and generating ratios for each pair (e.g. IgGK/IgGL). Recent studies indicate that HLC Assay can enhance the ability to detect and quantify monoclonal Ig, potentially providing greater sensitivity for detection of minimal residual disease or early relapse after treatment and providing a prognostic indicator of progression free survival (Ludwig, H. et al. Leukemia (2013) 27, 213-219; Kraj, M. et al. Adv Clin Exp Med 2014, 23, 1, 127-133). While HLC Assay could simplify and enhance the assessment of monoclonal protein response in multiple myeloma (MM), its utility as compared to standard assays (SA) (Serum Protein Electrophoresis (SPEP) and Immunofixation (IF)) is not well established. The goal of this retrospective study was to compare the performance of these tests in patients with MM seen at Memorial Sloan Kettering Cancer Center. Methods : We have previously reported on the patterns of relapse and/or progression (R/POD) in 179 patients with MM transplanted between 2001 and 2009 at MSKCC and determined the precise date of R/POD based on IMWG standard clinical criteria using serum and urine PEP and IF, as well as Free Light Chain Assay (FLCA) (Zamarin, Bone Marrow Transplant, 2013). Serum samples from 63 of these patients, collected at the time of R/POD and/or at time points preceding R/POD were analyzed by HLC Assay and compared to results obtained by SA. Results : Among the 63 patients, 22 had IgA and 41 had IgG isotype. Overall, 207 samples were available for all 63 patients, including 72 IgA and 135 IgG samples. Figure 1 shows the concordance of Hevylite ratio (on the Y-axis) with the results obtained by SA (on the X-axis), for IgA and IgG samples, respectively. These graphs reveal an excellent association between HLC Assay and SA results in the IgA samples: all IgA samples revealing an M spike by SPEP had an abnormal HLC ratio even for low M spike levels (between 0 and 0.5 g/dL). Among IgA samples with a monoclonal band detectable by IF, 43 out of 48 samples also had an abnormal ratio by HLC Assay; and among samples with no detectable band by IF, 18 out of 24 had a normal ratio by HLC Assay (sensitivity 90%, specificity 75%, p〈 0.001) (Table 1, Panel 1). Interestingly, when looking at samples taken prior to relapse in IgA patients having achieved CR, HLC Assay was abnormal in 4 out of 7 patients while SA was still reported as normal. In contrast, the lack of association between the SA and HLC Assay is striking for the IgG samples, with poor sensitivity for the HLC Assay to detect monoclonal gammopathies with M spikes below 1 g/dL on SPEP. Among IgG samples with a monoclonal band detectable by IF, only 48 out of 89 samples also had an abnormal ratio by HLC Assay; while among samples with no detectable band by IF, 40 out of 46 had a normal ratio by HLC Assay (sensitivity 53% and specificity of 86% , p 〈 0.001) (Table 1, Panel 2). Conclusions: Although retrospective, this analysis suggests the following: 1) HLC Assay may be more sensitive than IF or SPEP in patients with IgA disease, as it can detect an abnormal HLC ratio at a time prior to relapse by SA, when IF and SPEP are still normal; 2) HLC Assay appears to be less useful in IgG patients, as its sensitivity in these patients appears much lower than IF; 3) There is a need for further detailed analysis on larger prospective cohorts to test the utility of HLC Assay compared to SA in the management of multiple myeloma patients, especially those with IgA disease. Figure 1 Association between HLC Assay and SA (SPEP/IF) results in patients with IgA disease. Figure 1. Association between HLC Assay and SA (SPEP/IF) results in patients with IgA disease. Figure 2 Association between HLC Assay and SA (SPEP/IF) results in patients with IgG disease. Figure 2. Association between HLC Assay and SA (SPEP/IF) results in patients with IgG disease. Disclosures Hassoun: Celgene: Research Funding; Binding Site: Research Funding; Novartis: Consultancy; Takeda: Consultancy, Research Funding. Kazunori:Binding Site: Research Funding. Landau:Prothena: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx/Amgen: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy; Spectrum Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Korde:Medscape: Honoraria. Landgren:Takeda: Honoraria; Amgen: Honoraria, Research Funding; BMS: Honoraria; Medscape Myeloma Program: Honoraria; Merck: Honoraria; Celgene: Honoraria, Research Funding.

Description: Introduction: Multiple myeloma (MM) is a patchy bone marrow based malignancy of plasma cells, resulting in painful bone lytic lesions that can be visualized by 18F-FDG-PET-CT. We treated 45 NDMM patients with CRd-R therapy that resulted in high rates of minimal residual disease (MRD) negativity (62%)(Korde et al. JAMA Onc 2015). In this study, we assessed longitudinal FDG response through lenalidomide (Len) maintenance period and aimed to correlate with clinical findings and MRD status. Methods: The details of treatment received, study design and patients' characteristics have already been published. As part of the study design, all patients had serial PET imaging at baseline, after achievement of CR and/or at completion of 8 cycles of CRd, and at year-1 and -2 of Len maintenance, or termination of protocol therapy. Whole body (vertex to toes) static FDG imaging was performed at 1-hour post injection, implemented according to institutional practice. Focal lesions on FGD were defined as: increased uptake (above background reference) within the bone, (excluding articular regions due to high prevalence and likelihood of confounding arthritic disease), maximum standardized uptake value (SUV) 〉1.5 for lesion size on CT ranging from 0.5-1.0 cm, or maximum SUV 〉2.5 for lesions 〉1.0 cm. Results: At baseline, 37/45(82.2%) patients had FDG-positive lesions and 8/45(17.8%) were negative. Median follow-up for longitudinal analysis is 30.1 months. Among initial FDG-negative patients, 7/8 (87.5%) patients remained negative throughout follow-up; 1/8 (12.5%) patients developed a sclerotic FDG-positive lesion deemed not to be progression (rib 5 SUV 1.7). Among the 37 patients with baseline FDG-positive lesions, 12/37(32.4%) patients had complete resolution of FDG-PET-CTs (FDG-responders); 25/37(67.5%) remained FDG-long-term positive at time of last protocol scan. Eight of the 25(32%) FDG-long-term positive patients met IMWG criteria for progression, compared to 0/12 FDG-responders (p value=0.04). For patients with available data, MRD negative status after initial CRd (prior to Len maintenance) was not associated with long-term PET-CT response [19/24(79.2%) vs. 8/11(72.7%), FDG-long-term positive vs. FDG-responders, p=NS]. For the remaining FDG-long-term positive patients not meeting progression criteria, all 17 patients had low-positive persistent FDG with decreased or partial SUV response that decreased over time while on Len maintenance. Conclusions: In patients receiving CRd followed by long-term Len maintenance, 68% of baseline FDG-positive patients have persistent longitudinal FDG-positive myeloma lesions. While there is an increased risk of clinical progression among these patients, the majority showed low-positive FDG lesion uptake that decreased over time with long-term Len maintenance. Long-term resolution of FDG-positive lesions is not associated with MRD status after initial CRd therapy. Further follow-up is needed to examine the significance of persistent FDG-positive lesions in relationship to residual disease and mechanisms of resistance. Figure Figure. Disclosures Korde: Medscape: Honoraria. Hassoun:Takeda: Consultancy, Research Funding; Celgene: Research Funding; Novartis: Consultancy; Binding Site: Research Funding. Landgren:Medscape Myeloma Program: Honoraria; BMS: Honoraria; Merck: Honoraria; Takeda: Honoraria; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding.

Description: BACKGROUND: Cardiovascular (CV) events are a known complication to proteasome inhibitor therapy in myeloma. Underlying mechanisms are unknown. We recently completed an investigator initiated, single institution Phase II study of high dose carfilzomib (56mg/m2) in patients with relapsed/refractory MM (NCT01351623). Among 42 response evaluable patients, 11 patients (25%) developed treatment-emergent heart failure of any grade, and 5 patients (11%) developed severe heart failure requiring mechanical ventilation. We undertook a study to identify potential biomarkers that may point to underlying mechanisms of CV events among multiple myeloma patients treated with carfilzomib therapy. METHODS: We performed a nested case-control study with 7 patients who experienced a CV event on our high dose carfilzomib study and had pre-treatment (baseline) plasma stored and 19 case matched controls treated on the same study who did not have a CV event. We screened for 90 proteins known to be associated with CV disease using O-linked glycosylation. We used the Proseek Multiplex CVD I 96x96 platform which is based on the Proximity Extension Assay (PEA) technique. PEA is a 96-plex immunoassay that allows high throughput detection of protein biomarkers in liquid samples. For each biomarker, a matched pair of antibodies linked to unique oligonucleotides (proximity probes) binds to the respective protein target. Upon binding, the unique proximity probes can hybridize to each other and subsequently be detected and quantified by real-time PCR. Mean biomarker levels were compared using a t-test. False discovery rate (FDR) was used for multiple comparisons adjustment. RESULTS: Using samples collected prior to initiation of carfilzomib therapy, in an agnostic statistical model we identified the following four proteins to have altered levels in myeloma patients who developed CV events (p=0.002-0.004, unadjusted; p=0.089, after FDR correction): matrix metalloproteinase-1 (MMP-1, heparin-binding EGF-like growth factor (HB-EGF), TNF-related apoptosis-inducing ligand (TRAIL), and myoglobin (MB). Myeloma patients who developed CV events had 37% lower MMP-1, 15% lower MB, and 4% lower HB-EGF, while TRAIL was 7% higher in patients who developed CV events. Matrix metalloproteinases are a family of proteolytic enzymes responsible, among other functions, for myocardial extracellular protein degradation. Interestingly, several MMP species, including MMP-1, have been identified within the human myocardium and are thought to be dysregulated in congestive heart failure. HB-EGF is a mitogenic and chemotactic glycoprotein that is essential for maintaining normal cardiac function and is known to play an important role in myocardial remodeling. CONCLUSIONS: We found that there was a trend towards lower MMP-1, HB-EGF, and MB levels and higher TRAIL levels in patients with CV events while receiving proteasome therapy. MMP-1 appears to be the most promising potential biomarker based on our data. Our study supports further investigation of these proteins as potential biomarkers for patients at risk of CV events when treated with carfilzomib. Table 1. CV event No CV event N=7 N=19 CKD Proteins1 Mean (SD) Mean(SD) Unadjusted P-value Adjusted P-value MMP_1 1.7 (0.5) 2.7 (0.9) 0.002 0.089 HB_EGF 6.9 (0.2) 7.2 (0.3) 0.004 0.089 TRAIL 8 (0.3) 7.5 (0.5) 0.004 0.089 MB 5 (0.5) 5.9 (0.8) 0.004 0.089 HSP_27 2.2 (0.3) 2.7 (0.8) 0.032 0.528 PDGF_subunit_B 4 (0.7) 5 (1.5) 0.036 0.528 CD40_L 3.4 (0.6) 4.2 (1.2) 0.042 0.533 EGF 3.7 (0.9) 4.7 (1.4) 0.053 0.592 CX3CL1 5.9 (0.2) 5.6 (0.6) 0.092 0.895 TRAIL_R2 4.2 (0.4) 4.6 (0.6) 0.101 0.895 1. Proteins are listed based on the p-value associated with the difference between patients who did and did not have CV events, with lowest p-value on the top. The top 10 biomarkers are shown. Disclosures Ekman: Olink Bioscience: Employment. Grundberg:Olink Bioscience: Employment. Hassoun:Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda: Research Funding; Novartis: Consultancy. Lesokhin:Aduro: Consultancy; Efranat: Consultancy; Genentech: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Janssen: Consultancy, Research Funding. Landau:Janssen: Consultancy; Prothena: Consultancy, Honoraria; Janssen: Consultancy; Spectrum Pharmaceuticals: Honoraria; Onyx: Honoraria, Research Funding; Takeda: Research Funding. Giralt:TAKEDA: Consultancy, Honoraria, Research Funding; JAZZ: Consultancy, Honoraria, Research Funding, Speakers Bureau; AMGEN: Consultancy, Research Funding; SANOFI: Consultancy, Honoraria, Research Funding; CELGENE: Consultancy, Honoraria, Research Funding. Landgren:Onyx: Honoraria; Celgene: Honoraria; BMJ Publishing: Consultancy; International Myeloma Foundation: Research Funding; Bristol-Myers Squibb: Honoraria; Onyx: Research Funding; Medscape: Consultancy; Medscape: Honoraria; BMJ Publishing: Honoraria; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Onyx: Consultancy.

Description: Background: Programmed cell death 1 (PD-1) protein downregulates T cell activation and is related to immune tolerance. PDL1 up regulation, T cell infiltration, and T cell exhaustion are features, which suggest susceptibility to PD-1 blockade antibodies. Blockade of PD-1 or its ligand PD-L1 has shown promising responses in several malignancies. Although little clinical activity has been seen in patients with relapsed multiple myeloma (MM), the role of the PD-1 pathway and T cell exhaustion in newly diagnosed MM has not been explored. Objective: To determine whether T-cell infiltrate or expression of PD-1 correlates with clinical features and prognosis among patients with newly diagnosed multiple myeloma. Methods: We screened a clinically annotated database of 341 patients seen at MSKCC between 1998 and 2012 that had Multiple Myeloma, received a bone marrow transplant and were consented to a biospecimen research protocol for availability of pre-treatment bone marrow specimens. A total of 64 bone marrow biopsy specimens were identified. Immunohistochemistry (IHC) was performed in formalin-fixed paraffin-embedded specimens using an anti human CD3 monoclonal antibody (mAb) (Dako, Clone F7.2.38) and an anti human PD-1 mAb (Cell Marque, catalog #315M-95). CD3 and PD1 IHC staining were graded as negative (

Description: Background Monoclonal gammopathy of undetermined significance (MGUS) is a precursor condition to multiple myeloma (MM) and other lymphoproliferative disorders. Patients with MM have an increased risk of venous and arterial thrombosis. Results from previous studies have also shown an increased risk of thrombosis in MGUS. However, these studies have been performed on clinically established cohorts, and no previous study has examined the risk of thrombosis in light chain MGUS (LC-MGUS). Methods We performed a population-based study on the longitudinal cohort of the AGES-Reykjavik Study, consisting of 5,764 elderly Icelandic men and women. Through screening all participants with free light chain analysis and serum protein electrophoresis, MGUS and LC-MGUS were identified in 299 and 52 individuals, respectively. The outcome was first incidence/occurrence of venous or arterial thrombosis, as diagnosis or as cause of death. Information on outcomes was supplemented by health care records, available from nine years prior to study baseline and for a median follow-up time of 8.8 years. Through logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate history of arterial and venous thrombosis, respectively, at study baseline. A Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% CIs for the risk of first incidence of thrombosis during follow-up. Results A history of any thrombosis during the nine years prior to diagnosis was present in 30 (10.0%) of individuals with MGUS, 13 (25.0%) of individuals with LC-MGUS, and 643 (12.0%) of individuals without MGUS. In a model adjusting for age, sex, smoking, serum cholesterol levels, diabetes, hypertension, and family history of thrombosis, the odds of having had a thrombosis was not significantly different for neither MGUS (OR = 0.75, 95% CI 0.50-1.12) nor LC-MGUS (OR = 1.81, 0.92-3.58), compared to those without MGUS. During a median follow-up time of 8.8 years, 80 (26.8%) of individuals with MGUS, 14 (26.9%) of individuals with LC-MGUS, and 1,344 (25.0%) of individuals without MGUS were diagnosed with thrombosis. Individuals with MGUS and with LC-MGUS had no increased risk of arterial thrombosis, when adjusted for age, sex, cholesterol, diabetes, hypertension, smoking, and family history of thrombosis (HR 1.04, 0.82-1.32). Similarly, no increased risk was found in MGUS or LC-MGUS for venous thrombosis, in a model adjusted for age, sex, body mass index, and previous or current cancer (HR 0.89, 0.41-1.89). Excluding individuals with a diagnosis of thrombosis occurring before baseline, or adjusting for a personal history of thrombosis, did not affect the results. Summary and conclusions In this large, population-based, screening cohort study, we found no increased risk of arterial or venous thrombosis in MGUS. A history of thrombosis was more common in individuals with LC-MGUS, which might be an effect of higher age in LC-MGUS individuals. To our knowledge, this is the first study to investigate risk of thrombosis in LC-MGUS. The results from our screened study contradict previous findings from clinically established cohorts. Future work is needed to better understand observed differences between studies and across populations. For example, potential underlying factors may include aggregation of underlying comorbidities in clinically diagnosed MGUS patients, and biological variations (shared germline genetic susceptibility) by ethnic groups. Table. Risk of thrombosis in individuals with MGUS and LC-MGUS, compared to individuals without MGUS. MGUS LC-MGUS No MGUS No. HR (95% CI) No. HR (95% CI) No. HR (95% CI) Any thrombosis* 80 (26.76%) 1.01 (0.80-1.26) 14 (26.92%) 1.13 (0.80-1.26) 1,344 (25.02%) 1.00 (Reference) Arterial thrombosis† 76 (25.42%) 1.04 (0.82-1.32) 14 (26.92%) 1.16 (0.67-2.01) 1,240 (23.08%) 1.00 (Reference) Venous thrombosis†† 7 (2.34%) 0.89 (0.41-1.89) 0 (0.0%) - 151 (2.81%) 1.00 (Reference) *Results adjusted for age and sex. † Results adjusted for age, sex, smoking, hypertension, cholesterol, diabetes, and family history of arterial thrombosis. †† Results adjusted for age, sex, body mass index, and previous or current cancer. MGUS: monoclonal gammopathy of undetermined significance, LC-MGUS: light-chain monoclonal gammopathy of undetermined significance. HR: hazard ratio, CI: confidence interval. Disclosures Landgren: Celgene: Consultancy; BMJ Publishing: Consultancy; Onyx: Research Funding; International Myeloma Foundation: Research Funding; Bristol-Myers Squibb: Consultancy; Onyx: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria; Medscape: Honoraria; BMJ Publishing: Honoraria; Onyx: Consultancy; Medscape: Consultancy.

Description: Introduction: Autologous hematopoietic stem cell transplantation (Auto HSCT) has been shown to prolong progression free (PFS) and overall survival (OS) in patients with multiple myeloma (MM), with the depth of response pre-transplant previously correlated with PFS, but not OS. Even in patients receiving proteasome inhibition and immunomodulatory agents as induction, up to 25% of newly diagnosed patients achieve less than a partial response (PR). We aimed to evaluate outcomes after Auto HSCT for patients with primary refractory MM. Methods: Between 1/2009 and 12/2012, we identified 95 newly diagnosed symptomatic MM patients treated at our institution with novel agent induction regimens and upfront Auto HSCT. Based on IMWG criteria, patients were separated into those achieving 〉= PR (CR, VGPR, PR) and those who are primary refractory (PrRef) as defined by stable or progressive disease (SD/PD) to first line therapy. Characteristics were compared by the Fisher's Exact test. PFS and OS were calculated in a landmark analysis from transplant and estimated by Kaplan-Meier methods and compared by the log rank test. Results: Sixteen patients (17%) had PrRef disease, with a median age of 53 vs 59 yrs in those who achieved 〉=PR (p=0.04). Demographic and clinical characteristics were otherwise not statistically different between the two groups: 56 vs 65% were male; 69 vs 80% Caucasian; 69 vs 48% had ISS Stage I disease with 19 vs 14% having high risk cytogenetics; 81 vs 84% had lytic lesions; and 31 vs 51% had extramedullary disease at diagnosis in PrRef pts vs 〉PR pts, respectively. All patients received induction regimens including either bortezomib (44 vs 38%), lenalidomide (31 vs 24%), or both (25 vs 37%) (p=0.68). Compared with 32% of 〉=PR pts, 94% of the PrRef pts were treated with additional therapy prior to Auto HSCT (p= PR patient. Response to Auto HSCT was a 38 vs 58%, 25 vs 25%, 38 vs 14%, and 0 vs 4% for CR, VGPR, PR, and SD/PD, in PrRef vs responding pts respectively (p=0.19). Maintenance therapy, primarily with lenalidomide, was given to 69 vs 78% (p=0.52). Median PFS from transplant was 41 months (95% CI 16 - not reached ) in PrRef pts compared to 53 months, (95%CI: 31 - not reached) in 〉=PR pts (p=0.51). With a median follow-up of 36.5 months (range 9.5-63 months) in surviving patients, median OS from transplant was not reached in either group (p=0.77)(Figures 1 and 2). For the PrRef pts, 3-yr OS from transplant was 77% (95%CI 43-92%) compared to 87% (95%CI 77-93%) in 〉=PR pts. Conclusion: A small portion of MM patients have primary refractory disease after induction therapy with bortezomib and lenalidomide. Demographic and disease characteristics, other than age, were not able to differentiate these patients. However, Auto HSCT was an effective therapy regardless of response to novel agent based induction therapy. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Hassoun: Celgene: Research Funding; Novartis: Consultancy; Takeda: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Lesokhin:Efranat: Consultancy; Aduro: Consultancy; Janssen: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Genentech: Research Funding. Landgren:BMJ Publishing: Honoraria; BMJ Publishing: Consultancy; Onyx: Research Funding; International Myeloma Foundation: Research Funding; Onyx: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria; Medscape: Honoraria; Celgene: Consultancy; Bristol-Myers Squibb: Consultancy; Medscape: Consultancy; Onyx: Consultancy. Landau:Onyx: Honoraria, Research Funding; Spectrum Pharmaceuticals: Honoraria; Takeda: Research Funding; Prothena: Consultancy, Honoraria; Janssen: Consultancy; Janssen: Consultancy. Giralt:SANOFI: Consultancy, Honoraria, Research Funding; CELGENE: Consultancy, Honoraria, Research Funding; AMGEN: Consultancy, Research Funding; JAZZ: Consultancy, Honoraria, Research Funding, Speakers Bureau; TAKEDA: Consultancy, Honoraria, Research Funding.

Description: Introduction: Multiple myeloma (MM) is the second most common hematologic malignancy. Recent sequencing studies show evidence of massive genetic heterogeneity reflected in multiple parallel subclones already at diagnosis. Different subclones respond differently to given therapy. The role of treatment-driven subclonal skewing and intrinsic acquired mutations is poorly understood in the relapse setting. At relapse, the distribution of subclones throughout the bone marrow and at extramedullary sites is currently unknown. Methods: We performed a research autopsy on a single individual with IgG kappa MM who survived with multiple metastatic sites of disease for 10 years after diagnosis. Genomic DNA was extracted from histologically confirmed snap frozen normal tissue and nine independent sites of extraosseous disease. Whole exome sequencing (150X) was performed by the MSK Genomics Core. Data were filtered to remove germline polymorphisms and enrich for high quality somatic variants. Phylogenetics and subclonal analyses were performed using Treeomics and SCHISM. Results: The average on target coverage was 177X with 73% of bases covered a minimum of 100x. A total of 6348 somatic variants were initially identified. After filtering for high quality somatic variants, 1330 remained with 220 of these variants common to all MM samples and an average of 628 variants per sample. Annotation of high quality variants revealed potentially deleterious somatic mutations in NRAS, FAM46C, DYNC1, CREBBP, ATM, BIRC3, MGA, PPP6C and SMARCA4. Phylogenetics analyses (shown below) indicated the metastases arose through a combination of branched and parallel evolution, with the ATM mutation arising in one branch (one metastasis) that was distinct from a second clonal population containing the NRAS, FAM46C, BIRC3, CREBBP, DYNC1 and PPP6C mutations that were present in all eight other metastases. The MGA and SMARCA4 mutations further identified two additional subclones arising in from the NRAS/FAM46C mutant common ancestral clone. Clonality analyses independently supported this hierarchy by identifying NRAS and FAM46C as early clonal events and MGA and SMARCA4 as late events in the progression of this patient's disease. It also suggested a degree of subclonal mixing within each metastatic site. Conclusions: Using whole exome sequencing from nine independent sites of extraosseous disease in a single MM patient with relapse 10 years after initial diagnosis, we show that extramedullary disease arise through a combination of branched and parallel evolution. Two additional patients have also undergone research autopsy and results will be presented at the meeting. Figure Figure. Disclosures Landau: Prothena: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx/Amgen: Research Funding; Spectrum Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy. Hassoun:Binding Site: Research Funding; Novartis: Consultancy; Celgene: Research Funding; Takeda: Consultancy, Research Funding. Korde:Medscape: Honoraria. Landgren:Medscape Myeloma Program: Honoraria; Takeda: Honoraria; Amgen: Honoraria, Research Funding; BMS: Honoraria; Merck: Honoraria; Celgene: Honoraria, Research Funding.

Description: Introduction: Maintenance therapy with lenalidomide (LEN) is considered standard of care in the US, supported by meta analysis showing that LEN maintenance is associated with significantly longer progression free survival (PFS) and overall survival (OS). In a previously reported study of MM patients (pts) treated with extended courses of LEN, we have described a polyclonal Ig and FLC elevation exceeding the upper limit of normal (up to 3-4 X the ULN) and associated with striking polyclonal bone marrow (BM) plasmacytosis (up to 20% of plasma cells (PCs)), occurring with a relatively high frequency (20% of pts) and associated with better outcome (Zamarin, Leukemia, 2013). Importantly, we cautioned about the risk of misinterpretation of this polyclonal Ig response and plasmacytosis. Since Immuno-histochemical staining (IHS) may often be an unreliable tool to distinguish between a reactive polyclonal plasmacytosis from monoclonal disease, especially when the percentage of PCs in the BM is relatively low (5 -15%), we aimed at confirming the polyclonal nature of this often unrecognized and paradoxical response to prolonged LEN exposure, and at validating the important role of BM assessment by flow cytometry (FACS) in this setting. Methods: Pts analyzed in this study were enrolled at MSKCC on three randomized, first line therapy, clinical trials (NCT01109004, NCT01208662, and NCT00807599). All pts were kept on LEN maintenance until POD, toxicity, or major event. BM aspirate and biopsy with IHS were performed as per standard of care. Eight-fluorochrome FACS method (minimum of 1 x 106 cells) was used for 2014 samples employing a surface marker cocktail (CD117 PC5.5, CD19 BV421, CD138 APC, CD56 PC7, CD45 APC-H7, CD38 BV510) and cytoplasmic Kappa FITC/Lambda PE staining. Ten-fluorochrome (minimum of 5 x 106 WBCs) method was used in 2015 and performed employing a surface marker cocktail (CD117 PC5.5, CD19 PC7, CD138 APC, CD56 APC-R700, CD45 APC-H7, CD81 Pacific Blue, CD38 BV510, CD27 BV605) and cytoplasmic Kappa FITC/Lambda PE staining. Results: Among 147 pts enrolled in the three trials, 55 achieved serologic CR after first line therapy. Of those, 46 had a BM biopsy with FACS analysis available. Among these 46 patients, bone marrow plasmacytosis as assessed by light microscopy of BM aspirate and biopsy ranged from 2% to 15% (32 pts had PCs ≤ 5%, 14 PCs 〉 5%). Among the 14 pts with 〉 5% PCs, 2 had PCs = 15%, 9 had PCs = 10%, and 3 between 6% and 9%. By FACS, 9 of 14 pts showed no clonal or phenotypically aberrant PCs. The percentage of aberrant PCs among all PCs in the other 5 pts remained low (≤7.3%). Among the 2 pts with PC = 15%, the percentage of aberrant PCs among all PCs was 0% and 7.3%. In pts with PC = 10%, the percentage of aberrant PCs among all PCs was 0% (6 pts), or ranged from 0.17% to 5.1% (3 pts). Figure 1 depicts representative pt cases with BM plasmacytosis estimated at 15% by light microscopy. PCs were gated based on CD38 and CD138 expression as well as forward and side scatter (not shown). Blue dots represent kappa LC expression; Red lambda LC. Proportion of aberrant PCs among total PCs in the sample is quantitated and shown using high sensitivity MRD detection with 10-color panel with 6-million event acquisitions. Panel A shows a pt with 15% PC in the BM with no residual disease confirming the polyclonal nature of the plasmacytosis. Panel B shows a pt with 15% PC exhibiting a low proportion of aberrant PCs (green) among a predominant background of normal polytypic PCs. In contrast, Panel C shows a pt with early relapsed disease with 15% PCs exhibiting a high proportion of aberrant PCs (99% of all PCs). Conclusions: These results confirm the common and striking polyclonal plasmacytosis (up to 15% PCs in this cohort) associated with prolonged LEN exposure, and the importance of FACS in the assessment of BM plasmacytosis in these MM pts. In the setting of current MM response criteria established by the IMWG and NCCN guidelines, mandating a BM plasmacytosis

Description: Background: All multiple myeloma (MM) cases are preceded by the premalignant state, monoclonal gammopathy of undetermined significance (MGUS). The etiology of MM and MGUS is to a large extent unknown. Few studies on the effect of diet on MM have been conducted and the results have been inconclusive. No studies have been conducted on the effect of diet on MGUS. Studying dietary patterns offers broader view of food consumption and possible effects of diet on diseases since many nutrients and other substances in foods act together. The aim of this study was to identify different dietary patterns at three time points throughout the lifespan and examine whether adherence to these patterns was associated with risk of MGUS and light chain MGUS (LC-MGUS) and progression to MM and other lymphoproliferative diseases. Methods: This study was based on participants from the AGES-Reykjavik Study (N=5,764; mean age 77 years). Participants gave information on frequency of intake of common foods from early life (14-19 years old), midlife (45-55 years old), and currently at study baseline (67 years and older). All participants were screened for MGUS and LC-MGUS by serum protein electrophoresis and serum free light-chain assay. We identified MM and other lymphoproliferative diseases by cross linking with the Icelandic Cancer Registry. Principal component analysis was used to extract dietary patterns. This method is data driven and forms new linear factors, (dietary patterns) by reducing data dimension and grouping correlated variables (food intake). For each pattern extracted a new variable is created, ranking participants on their adherence to that particular pattern. We used logistic regression to test association between adherence to the early life and midlife dietary patterns and MGUS and LC-MGUS, and Cox proportional hazard regression to test association between adherence to the late life patterns and progression to MM and other lymphoproliferative diseases. Results: A total of 300 (5.2%) MGUS cases and 52 (0.9%) LC-MGUS cases were identified. During 11 years of follow-up 18 cases had progressed to MM and 10 to other lymphoproliferative diseases. We extracted four dietary patterns from early life, four from midlife, and six from baseline. When analyzing MGUS and LC-MGUS cases combined we found that high adherence to pattern I from early life, the old traditional Icelandic diet (high intake of salted/smoked meat and fish, blood and liver sausage, rye bread, milk, oatmeal, and potatoes), decreased the risk (odds ratio (OR) = 0.89, 95% confidence interval (CI) 0.79-1.00), however no association was found when analyzing MGUS and LC-MGUS separately (Table 1). When analyzing midlife patterns we found that the estimate for pattern I, the old traditional Icelandic diet (high intake of salted/smoked meat and fish, blood and liver sausage, fish in salad or on bread, and meat meals) was similar to the findings from early life, although it did not reach a statistical significance (OR = 0.90, 95% CI 0.80 - 1.02). High adherence to pattern III (high intake of potatoes, whole wheat bread, milk, rye bread, and fish) from midlife decreased the risk of combined MGUS (OR = 0.88, 95% CI 0.79-0.98). When analyzing MGUS and LC-MGUS separately we found that high adherence to pattern III decreased the risk of LC-MGUS (OR = 0.69, 95% CI 0.53-0.90) but not MGUS. We did not find an association between the six patterns from late life and progression to MM. However when analyzing progression to MM and other lymphoproliferative diseases combined we found that high adherence to pattern VI (high intake of meat and milk, low intake of fish) increased the risk of progression (HR = 1.82, 95% CI 1.24-2.67). Further results can be seen in Table 1. Conclusion: Our findings suggest that high adherence to the old traditional Icelandic diet consumed during early and mid 19th century, including salted or smoked meat and fish, blood or liver sausage, rye bread, and potatoes decreases the risk of MGUS/LC-MGUS later in life. They additionally suggest an increased risk of progression to MM and other lymphoproliferative diseases, with high adherence to a pattern with high meat and low fish intake. The mechanisms for these findings are unknown but our study suggests that food intake can alter the risk of developing MGUS/LC-MGUS as well as the risk of progression to MM. Disclosures Korde: Medscape: Honoraria. Landgren:Medscape Myeloma Program: Honoraria; BMS: Honoraria; Takeda: Honoraria; Merck: Honoraria; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding.