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Abstract Introduction: Chemotherapeutic options for patients with systemic light chain amyloidosis (AL) who are not transplant candidates include bortezomib based therapy, melphalan with dexamethasone, and less commonly, immunomodulatory drugs (IMiDs). However, prospective clinical trial data comparing these regimens are lacking. This study aims to compare efficacy of bortezomib-based treatment to other therapies. Methods: All patients with AL seen within 90 days of diagnosis at our institution over a 10-year period (2006 to 2015) who did not undergo a stem cell transplant were identified from our institutional database. Data pertaining to demographics, diagnosis, treatment and follow-up were extracted from electronic medical records. Analyses were carried out by chi-square and Fisher's exact test for categorical variables and Kruskal-Wallis and Wilcoxon rank sum test for ordinal and continuous variables. Progression free survival (PFS) is defined as time to death, progression requiring treatment change or relapse requiring re-institution of treatment. PFS and overall survival was analyzed via the Kaplan-Meier method. Results: Seven hundred and twenty five patients met the inclusion criteria, of which 38% (n=275) received bortezomib containing regimens and 62% (n=450) received non-bortezomib based therapies. Bortezomib was used with dexamethasone in 24% (n=67) patients; and with other drugs, most commonly cyclophosphamide, in 76% (n=208) patients. Non-bortezomib treatment regimens included melphalan-based treatment in the majority (92%, n=414) followed by IMiDs with steroids and other drugs (8%, n=36). Baseline variables similar in both groups and their distribution in the entire cohort was as follows: gender distribution (63.3% males, n=459), median age of diagnosis (66.3 years, range 32.2 to 93.6), type of involved free light chain (FLC) (lambda 73%, n=523) and median plasma cell burden (10%, range 0 to 91). Median difference between the involved and uninvolved free light chain (dFLC) was higher in the bortezomib group (29 mg/dL vs. 23 mg/dL; p=0.017). There was no difference in organ involvement. In the bortezomib group, organ involvement was as follows: cardiac (81%, n=219), renal (62%, n=168) and hepatic (18%, n=48). In the non-bortezomib group, the rates of organ involvement were similar: cardiac (78%, n=346), renal (57%, n=247) and hepatic (19%, n=85). Median duration of first line treatment was similar in the 2 groups, with 178 days in the bortezomib cohort and 187 days in the non-bortezomib cohort. Response rates are illustrated in Table 1. Rates of very good partial response (VGPR) or better response were higher in the bortezomib group (64 % vs. 54%, p=0.0002). Patients treated with bortezomib achieved VGPR faster with higher rates of VGPR or better response seen at 3 months (48% vs. 27%, p <0.0001) and 6 months (57% vs. 34%, p < 0.0001) after initiation of therapy compared to non-bortezomib treatment. Rates of organ response were similar amongst the 2 groups as shown in Table 1. However, median time taken to achieve a cardiac response was shorter in the bortezomib group (23 vs. 38 weeks, p=0.0026). In a multivariable model, bortezomib-based treatment and dFLC at diagnosis were predictors of VGPR. Relapse or progression requiring change in therapy was more common in patients treated with non-bortezomib based therapy (38%, n=143/372) compared to bortezomib-based treatment (28%, n=67/236); p =0.01). However, no difference in overall survival was observed in patients treated with bortezomib (2.2 years; 95% confidence interval (CI): 1.7 to 3.3) vs. non-bortezomib therapies (1.7 years; 95% CI: 1.3 to 2.5). Conclusion: Treatment with bortezomib-based regimens results in a deeper response including higher rates of early VGPR at 3 and 6 months from starting therapy. Moreover, these patients achieve cardiac response faster and have lower rate of relapse. However, no difference in overall survival was seen, which may be explained by subsequent use of bortezomib-based therapies in this population. Disclosures Dispenzieri: Celgene: Research Funding; Alnylam: Research Funding; pfizer: Research Funding; Jannsen: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees. Kumar:Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; AbbVie: Research Funding; Janssen: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; BMS: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Array BioPharma: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Kesios: Consultancy; Glycomimetics: Consultancy.

Abstract AL amyloidosis is a systemic disease with profound effects on organ function. However, despite the broad array of disease manifestations, the effect of AL amyloidosis on thyroid function is underreported. We explored the frequency of thyroid function abnormalities in 961 untreated AL amyloidosis patients seen in our clinic between 8/2005-8/2015, with emphasis on association with other organ involvement and tumor burden. Thyroid function was assessed using the thyroid stimulating hormone assay (TSH, normal range 0.3-5 mIU/L). If TSH was abnormal, measurement of free thyroxine (FT4) and thyroid peroxidase (TPO) antibodies was routinely performed. Patients' median age was 62 [interquartile range (IQR) 56-69], 62% were male (Table). The median number of organs involved was 2 (IQR 1-3), 29% of patients had more than 2 involved organs. Seventy-seven percent of patients had cardiac involvement, 61% renal, 23% peripheral/autonomic neuropathy, 19% hepatic and 15% gastro-intestinal (GI) involvement. The median difference between involved and uninvolved light chains (dFLC) was 24.4 [interquartile range 10.6-65.2 mg/dL]. The median TSH was 3 mIU/L (range 0.1-50.1); 22% had levels above the normal range and 8% of patients had TSH greater than 7.5 mIU/L. Baseline characteristics by TSH ≤5 mIU/L and TSH >5 mIU/L subgroups can be viewed in Table. Patients with renal or hepatic involvement had higher TSH values compared to no renal or no hepatic involvement (3.2 vs 2.6 and 2.8 vs 3.8, respectively; P<0.001 for both comparisons). There was a borderline significance for higher TSH in patients with >2 organ involvement compared to 1-2 affected organs (3.3 vs 2.8; P=0.05), with a strong trend for higher TSH for dFLC ≥18 mg/dL compared to dFLC<18 mg/dL (P=0.07). In patients with renal involvement, presence of proteinuria > 2 grams/day was associated with a higher likelihood of TSH >7.5 mIU/L (13% vs 5%; P=0.003). Free thyroxine (FT4) measurements were performed in 214 (22%) of patients with a median value of 1.1 ng/dL(range 0.3-72), 6% had levels below the lower limit (0.8 ng/dL). One-hundred and sixty five patients (17%) were screened for TPO antibodies, of which 16% (n=27) had an elevated titer. L-thyroxine (median dose 100 mcg/d, range 25-350 mcg/d) was already prescribed to 157 of the patients (16%) at their first visit, but duration of treatment prior to AL amyloidosis diagnosis could not be determined. Seventeen patients (1.5%) were prescribed amiodarone (median dose 200mg/d, range 100-400 mg/d), and although numbers were low, patients with amiodarone treatment had a TSH twice as high as patients without this treatment (6 vs 2.9 mIU/L, P=0.006). In conclusion, thyroid function abnormalities are frequent at the time of AL amyloidosis diagnosis and are influenced by type of organ involvement as well as disease burden assessed by dFLC and/or number of affected organs. Amiodarone, although infrequently used in this disease, can cause a profound disturbance in thyroid function among these patients. Disclosures Dispenzieri: Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; pfizer: Research Funding; Celgene: Research Funding; Alnylam: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding. Kumar:AbbVie: Research Funding; Array BioPharma: Consultancy, Research Funding; Glycomimetics: Consultancy; Celgene: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Kesios: Consultancy; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Janssen: Consultancy, Research Funding.

Abstract Background Despite significant progress, MM remains an incurable disease. Synergistic activity of immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) has been established in preclinical and clinical studies. Data with respect to combination of newer IMiDs and PIs are scant. Recently, a small study (n=32) found the novel therapeutic regimen consisting of carfilzomib, pomalidomide and dexamethasone (KPd) to be well-tolerated and active in RRMM patients, but only 7% of patients in that study had ECOG > 1. KPd has not been extensively studied outside of clinical trials. Therefore, we evaluated real-world outcomes of KPd in RRMM patients seen in our routine dysproteinemia practice. Methods Records of MM patients consecutively seen at Mayo Clinic, Rochester from 01/ 2013 to 05/ 2016 were reviewed. Forty-five MM patients who received KPD in the R/R setting were identified and included in the analysis. The international uniform response criteria (IMWG 2006) were used to assess response rates. Additionally, minor response (MR) was assessed to determine the clinical benefit rate (CBR or ≥MR). Toxicity was evaluated using the Common Terminology Criteria for Adverse Events version 4. Duration of response was calculated for patients who have achieved a PR or greater response from time of first response to progression of disease. The time-to-event analyses were performed from the time of initiation of KPd therapy using the Kaplan-Meier method. All but one patient received K at 20/27 mg/m2 (days 1, 2, 8, 9 15, 16) dosing, P at 2 mg or 4 mg (day 1-21), and dexamethasone at 20 or 40 mg (day 1, 8, 15, 22), with 28-day cycles. Results The median age at KPd initiation was 65 years (range 29-75), 25 (56%) patients were males. 71% had an ECOG performance score of 0 to 1, and 29% had an ECOG >1. Forty percent were mSMART standard risk, while 60% were intermediate to high risk. Median time from MM diagnosis to KPd was 44 months (range 6-188), and the median number of prior treatment lines was 4 (range 1-14). Three (7%) patients were quadruple refractory to bortezomib (V), lenalidomide (R), P, and K. Ten (23%) were triple refractory to V, R, and P or K. Twenty seven (60%) were dual refractory to V and R. Table 1 shows prior treatment agents and refractoriness. The median duration of treatment with KPd was 2 months (range 0.3-16.4). KPd was used as a bridge to autologous stem cell transplant (ASCT) in 5 patients. One patient discontinued therapy due to toxicity (infection, weakness). Response was evaluable in 44 patients. The median time to first response was 1.4 months (range 0.5-6). Overall response rate (ORR) was 36%, [stringent complete response (sCR) in 1 (2%) patient, complete response (CR) in 3 (7%) patients, very good partial response (VGPR) in 2 (5%) patients, partial response (PR) in 10 (22%) patients]. Minimal response (MR) was seen in 3 (7%), leading to a CBR of 43%, while an additional 10 (23%) patients had stable disease (SD). Progressive disease (PD) was noted in 15 (34%) patients. At the time of analysis 20 (43%) patients were deceased, all from PD. The median follow up from initiation of KPd was 16.3 months (95% CI: 8.6-19.4). The median overall survival (OS) from KPd was 16.1 months (95% CI: 10.6-20.4). Median OS for dual refractory was 15.6 (95% CI: 10.6-20.5). Median OS for triple/quadruple refractory was similar to those with lesser degree of refractoriness [19.1 (95% CI: 0.92 - 27.1) months vs 13.6 (95% CI: 8.9-20.5), p= 0.82]. The median progression-free survival (PFS) was 3.3 months (95% CI: 1.9-6.4) and the median time-to-next therapy (TTNT) was 3.5 months (95% CI: 2.2-6.7). The media duration of response was 12.9 months (95% CI: 2.5-19.6). The median OS from KPd for patients who achieved at least a PR was 20.4 months (95% CI: 13.6-NR), compared to 11 months (95% CI: 8.3-NR) for others (p=0.05). Grade ≥3 hematologic toxicity was seen in 19 (42%) of evaluable patients [grade ≥3 neutropenia (29%), thrombocytopenia (31%) and anemia (22%)]. The most common non-hematologic adverse events were fatigue (38%), infections (31%), diarrhea (12%) and dyspnea (12%). Of the 4 (9%) patients who developed venous thromboembolism (VTE), two were on aspirin prophylaxis while the other two were not receiving any VTE prophylaxis. Conclusions KPd shows activity in RRMM patients although the short PFS reflects the challenges encountered with managing heavily pretreated and often less fit patients in the real world setting outside of clinical trials. Disclosures Dispenzieri: Prothena: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; pfizer: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Alnylam: Research Funding. Kumar:BMS: Consultancy; Kesios: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Noxxon Pharma: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Glycomimetics: Consultancy; AbbVie: Research Funding; Onyx: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Kapoor:Amgen: Research Funding; Celgene: Research Funding; Takeda: Research Funding.

Abstract Introduction: Hematologic response criteria for light chain amyloidosis (AL) requires that difference in involved and uninvolved free light chains (dFLC) be at least 5 mg/dL (or 50 mg/L). However, many patients do not meet these criteria and are often excluded from clinical trials. These patients are challenging to follow clinically as organ response takes much longer and therefore response to treatment is difficult to evaluate in the first few cycles. This study aims to evaluate patients who had non-evaluable FLC (dFLC< 5 mg/dL) at diagnosis and compare them to those who had evaluable FLC (dFLC≥ 5 mg/dL). Methods: All patients with newly diagnosed AL seen within 90 days of diagnosis at our institution over a 10-year period (2006-2015) were identified from an institutional database. Data pertaining to demographics, diagnosis, treatment and follow-up was extracted from electronic medical records. Analysis was carried out by chi-square and Fisher's exact test for categorical variables and Kruskal-Wallis and Wilcoxon rank sum test for ordinal and continuous variables. Progression free survival (PFS) is defined as time to progression requiring treatment change or relapse requiring re-institution of treatment or death. PFS and overall survival (OS) were analyzed via the Kaplan-Meier method. Results: Of 1336 patients meeting inclusion criteria, dFLC at diagnosis was known in 1290. 85.4% (n=1101) had dFLC ≥ 5 mg/dL, while 14.6% (n=189) had non-evaluable FLC. Median age at diagnosis (65.2 vs. 63.9 years), gender distribution (males 56.1% vs.64.8%) and involved FLC (lambda: 72.2% vs. 72.9%) was similar in FLC < 5 mg/dL and FLC ≥ 5 mg/dL group. Cardiac (38.1 vs. 76.3%, p <0.0001) and liver (10.2% vs. 16.3%, p=0.03) organ involvement were less common in patients with non-evaluable FLC (table 1). NT-ProBNP was significantly lower in the group with dFLC < 5 mg/dL in patients with and without cardiac involvement, as was Mayo cardiac stage (table 1). A trend towards less gastrointestinal (GI) involvement (17.1% vs. 24%, p=0.09) was also seen with dFLC < 5 mg/dL. In contrast, a trend towards higher renal involvement was seen in patients with dFLC < 5 mg/dL (64.6% vs. 55.9%, p=0.08), though this was not statistically significant. Median 24 hour urine protein was significantly higher in all patients (with and without renal involvement) with dFLC < 5 mg/dL compared to dFLC ≥ 5 mg/dL group (table 1). Treatment details are listed in Table 1. ASCT (autologous stem cell transplant) was utilized more commonly in patients with dFLC < 5 mg/dL compared to patients with dFLC ≥ 5 mg/dL(43.2% vs. 26.1%, p <0.0001), including ASCT alone without chemotherapy (35.4% vs. 15.3%, p <0.0001).Rates of cardiac response (53.3% vs. 50.3%, p=0.88), and time to response (27.7 weeks vs. 35.6 weeks, p=0.67), were similar in both groups. Similarly, there was no difference in rates of renal and liver response and time taken to achieve a response (table 1). In patients with evaluable FLC, hematologic response was complete response (27.3%, n=245), very good partial response (21%, n=189), partial response (18%, n=160), no response (8%, n=74), progression (2%, n=15) and not known in 26.1% (n=216). In patients who had follow up data available, 30.6% (44/144) with dFLC < 5mg/dL experienced a relapse/progression with median PFS of 4.1 years (95% confidence interval (CI): 3 to 5.7), while 34.7% (304/875) with FLC ≥ 5 mg/dL experienced a relapse/progression with median PFS of 1.3 years (95% CI 1.1 to 1.5); p<0.0001. Median OS was higher in patients with dFLC < 5 mg/dL at diagnosis at 8.3 years compared to 2.4 years in patients with dFLC ≥ 5 mg/dL (p < 0.0001) as depicted in Figure 1. Conclusions: Patients with non-evaluable FLC at diagnosis have significant differences in organ involvement and survival compared to those with FLC ≥ 5 mg/dL at diagnosis. They have less cardiac and liver involvement and a trend towards less GI involvement, which may be secondary to low serum FLC burden and consequent less organ deposition. However, a trend towards higher renal involvement was seen in dFLC < 5 mg/dL group, with significantly higher urinary protein excretion. Loss of FLC in urine may result in lower serum FLC levels in this group. Survival was significantly better in patients with dFLC < 5 mg/dL, which may be explained by less cardiac involvement, lower cardiac stage and lower median FLC at diagnosis. Disclosures Dispenzieri: GSK: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees; pfizer: Research Funding; Celgene: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Alnylam: Research Funding; Jannsen: Research Funding. Kapoor:Amgen: Research Funding; Takeda: Research Funding; Celgene: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Janssen: Research Funding; Sanofi: Consultancy, Research Funding; Skyline: Consultancy, Honoraria; BMS: Consultancy; AbbVie: Research Funding; Noxxon: Consultancy, Honoraria; Amgen: Consultancy, Research Funding; Takeda: Consultancy, Research Funding.

Abstract Background: Renal impairment is a common feature of multiple myeloma (MM) seen in over a quarter of newly diagnosed patients (pts). Studies have confirmed the presence of renal impairment (RI) as a strong predictor of inferior survival in MM. Some studies have also indicated that reversibility of RI is associated with improved survival. However, it is not clear if normalization of renal function improves the outcome to that expected for MM pts without RI at diagnosis. Methods: We evaluated 1,135 consecutive pts with newly diagnosed MM seen at the Mayo Clinic, Rochester between December 2002 and January 2011. Renal function was assessed by the estimated creatinine clearance (CrCl) which was calculated by the modified MDRD formula. We examined these pts for improvement in renal function based on their CrCl at diagnosis and their highest CrCl during their disease course. RI was defined as having a CrCl of < 60. Pts were categorized based on their renal function at diagnosis and response to therapy: Group 1- CrCl >60 at diagnosis, Group 2- CrCl <60 at diagnosis but improved to >60 after therapy and Group 3- CrCl <60 at diagnosis and remained <60 after therapy. The degree of restoration of renal function was evaluated according to the IMWG criteria. Survival analysis was performed by the Kaplan-Meier method and differences assessed using the log rank test. Results: The median age at diagnosis was 65 years (range; 22 - 93) and 682 (60%) were male. The median follow up for the entire group from diagnosis was 73 mos (95% CI; 69 - 77). At diagnosis, 123 (11%) pts had a CrCl < 30, 322 (28%) had a CrCl of 30-59 and 690 (61%) had a CrCl >60. Most pts (N=754, 67%) received novel agent induction (NAI) therapy. The median PCLI was 0.7 (range: 0 – 22) and 91 (21%) pts had high-risk cytogenetics by FISH. The median OS for the pts with CrCl at diagnosis of < 30, 30-59 and >60 were 41 mos, 60 mos and not reached respectively (P < 0.001). Of the 445 patients with RI, the median absolute creatinine and CrCl at diagnosis were 1.6 mg/dL (range: 1 – 11) and 44 (range: 4 – 59) respectively. Among pts with RI, any improvement in CrCl was seen in 295 (66%) with median time to highest CrCl of 5 months and 228 (51%) had complete reversal of their RI. The median OS for pts with RI at diagnosis receiving and not receiving NAI therapy was not reached (NR) vs. 46 mos (P < 0.001). The median OS for Groups 1, 2 and 3 were NR, 60 and 49 mos respectively (Figure 1, P < 0.001). At a 6 month landmark analysis, the median OS for Groups 1, 2 and 3 were NR, 67 and 62 mos respectively (P < 0.001). The complete renal response and no renal response rates for pts with RI at diagnosis receiving and not receiving NAI induction therapy was (57% vs. 44%, P=0.004) and (29% vs. 39%, P=0.04) respectively. In a univariable analysis, presence of RI at diagnosis, no NAI therapy, older age, ISS stage 3, high-risk FISH, elevated PCLI, diagnosis prior to 2007 and increased LDH were found to predict for worse OS; however only older age (P<0.001), high-risk FISH (P=0.037) and lack of NAI therapy (P=0.023) retained their negative prognostic significance in a multivariable analysis. Conclusion: MM pts with RI treated with novel agent induction therapy demonstrate improved responses in their renal function and OS. The results also demonstrate improved outcome for pts with improvement in renal function, but it remains inferior to pts with normal renal function at diagnosis. These results have implications for early treatment strategies for pts at risk of developing renal insufficiency. Figure 1: OS based on improvement in CrCl upon receiving treatment Figure 1:. OS based on improvement in CrCl upon receiving treatment Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Abstract Waldenströms Macroglobulinemia (WM) is a unique form of lymphoplasmacytic lymphoma, in which the tumor compartment is comprised of B-lymphocytes, plasmacytoid lymphocytes and plasma cells. The majority of WM cases are immunophenotypically characterized by expression of surface antigens that are present on both B-cells (CD19/20) and plasma cells (CD38/138). However, in advanced stage disease, which has been treated with various chemoimmunotherapeutics the molecular profile of WM cells can drastically shift resulting in a majority of the WM tumor compartment exhibiting loss of CD20 and concurrent upregulation of atypical surface antigens (Barakat et al, Am J Clin Pathol 2011; Morice et al Mod Pathol 2009). These external immunophenotypic changes are associated with underlying epigenetic and genomic alterations, whose integrated study may provide further insight into the biology of advanced stage WM. Moreover, such an analysis holds clinical potential by uncovering of therapeutic vulnerabilities, which can direct the selection of appropriate therapeutics for patients with CD20- WM. With this in mind, we conducted comprehensive molecular testing coupled with functional studies to understand if underlying genomic/epigenetic changes correlated with drug sensitivity using appropriate preclinical models of CD20+ WM (BCWM.1 cell line) and CD20- WM (RPCI-WM1 cell line). Importantly, the index patient from whom the CD20- cells were developed had received a total of 6 lines of treatment, two of which contained rituximab and was documented as being refractory to rituximab. Immunophenotyping of CD20- cells showed differential downregulation of 19 and upregulation of 7 CD antigens relative to CD20+ WM cells (cutoff at 1.5 fold; >20% gated expression). Upregulated antigens were associated with a phenotype reminiscent of a memory B-cell with plasmacytoid features. Next, we conducted RNA-Seq analysis (Illumina HiSeq), which revealed downregulation of 6,673 and upregulation of 4,594 genes (>1.5 fold cutoff) in CD20- WM cells compared with CD20+ cells. Gene pathway enrichment analysis (NextBio, Illumina Inc.) of mRNA differentially expressed in CD20- cells showed significant enrichment of upregulated genes corresponding to Protein Transport (p<1.8E-98) and Response to Unfolded Protein Gene Ontology groups (p<5.9E-20). Interestingly, pathway analysis of downregulated genes in CD20- WM cells showed enrichment within the B-cell receptor-signaling (BCR) pathway (Broad MSigDB) (p<6.1E-14) relative to CD20+ WM cells. BCR signaling has been linked to dysregulated expression of several micro-RNAs (miRs). Consistent with pathway analysis results, we observed decreased levels of numerous miRs (Exiqon qPCR) in CD20- vs. CD20+ WM cells, which target and regulate components involved in BCR activation. To examine further epigenetic changes that may account for decreased BCR signaling, we examined the global methylation profile (Infinium HumanMethylation 450K array) of CD20- and CD20+ WM cells and noted hypermethylation of the promoter sites (200 base pairs upstream) for a number of transcription factors involved in the BCR pathway. We therefore examined sensitivity of CD20- WM cells to the BTK inhibitor ibrutinib, which abrogates BCR signaling. As anticipated, CD20- WM cells retained >90% viability and demonstrated significantly less apoptosis in presence of ibrutinib (4uM) compared to CD20+ cells, suggesting decreased reliance on canonical BCR signaling for survival. In parallel and guided by pathway analysis results, we exposed both CD20- and CD20+ WM cells to a novel 19S proteasome inhibitor (VLX1570), which caused profound proteotoxicity and ER stress at concentrations ranging between 250 – 500nM. We noted CD20- cells were significantly more sensitive (p<0.01) to 19S proteasome inhibition than CD20+ WM cells indicating the formers critical dependence on tightly regulated protein homeostasis. In summary we describe for the first time, a comprehensive molecular and immunophenotypic investigation of CD20- WM cells compared to CD20+ WM cells, using validated preclinical models of the two disease phenotypes. Overall our data suggests significant architectural differences between CD20+ and CD20- WM, which can potentially impact the behavior of the cells and their sensitivity towards novel therapeutics being developed for treatment of advanced stage WM. Disclosures Martin: Janssen: Honoraria.

Abstract Introduction Diffuse or polyclonal hypergammaglobulinemia has been associated with multiple medical conditions such as autoimmune diseases, infections, and chronic liver diseases. However, the possibility of differences in gamma globulin levels in different races and its association with environmental and socioeconomic factors is not well studied. Method A randomized sample of 917 adult males (50–74 years) in an urban community in Ghana underwent in-person interview and health examination. Serum from all persons was analyzed by electrophoresis performed on agarose gel. Those found to have a monoclonal protein (n=54) were excluded from further analysis. Gamma globulin levels were measured in the remaining 863 samples. Associations between selected characteristics and gamma globulin levels were assessed by Chi-square test and logistic regression models. Results The median gamma globulin level was 1.86 gm/dl. Seventy three percent of the study population had gamma globulin levels above the 1.6 gm/dl reference level and will be considered to have hypergammaglobulinemia. Surprisingly, 25% had gamma globulin levels above 2.17 gm/dl. In univariate analysis increased gamma globulin levels were associated with older age within the study population. Only 54% of the males aged 60 yrs or younger had gamma globulin levels above 1.6 gm/dl compared to 69% in those older than 60 yrs (p=0.007). Higher education level was associated with a low prevalence of hypergammaglobulinemia 51% compared with 74% in those with less than high school education (p <0.0001). Smoking was not associated (p=0.16) with gamma globulin levels. Although a higher proportion (71%) of people with history of alcohol use had hypergammaglobulinemia compared to the control (63%) this was not statistically significant (p=0.07). Self-reported history of genital warts, genital herpes and meningitis was associated with hypergammaglobulinemia, whereas syphilis, malaria, cholera, gonorrhea, hepatitis, measles and tuberculosis had no association with gamma globulin levels in univariate analysis. Conclusion Three quarters of this randomized sample of Ghanaian adult males has hypergammaglobulinemia based on current laboratory definitions. More work is needed to uncover underlying causes for the observed high gamma globulin levels in this population. Further evaluation of a younger population with less environmental influence may help explain whether this is due to genetic differences, environmental exposures, or a combination.

Abstract Waldenstrom’s macroglobulinemia (WM) is a serious and frequently fatal disorder characterized by the production of a monoclonal IgM protein, a lymphoplasmacytic infiltrate in the bone marrow, and associated symptoms including anemia, lymphadenopathy and hyperviscosity. Many of the mechanisms leading to this disease are not yet known. It is clear, however, that there is dysregulation of the balance between cell proliferation and programmed cell death. BLyS (B-lymphocyte stimulator) is a TNF family member expressed by monocytes, neutrophils, macrophages, and dendritic cells. BLyS has been shown to be critical for maintenance of normal B cell development and homeostasis, and has been found to stimulate lymphocyte growth. BLyS is overexpressed in a variety of B-cell malignancies and has been shown to inhibit apoptosis in malignant B-cells. Studies of the effects of BLyS on B cell physiology have shown that it also regulates immunoglobulin secretion. In previous work, we have shown that malignant B cells from patients with WM are able to bind soluble BLyS and variably express the BLyS receptors, BAFF-R, TACI and BCMA. We also found expression of BLyS in bone marrow specimens by immunohistochemistry and elevated serum BLyS levels in patients with WM. The goal of this study was to determine the functional role of BLyS-receptor ligand system in Waldenstrom’s macroglobulinemia and its relevance to the increased immunoglobulin production seen in this disease. Using cells from WM patients, we first examined the ability of BLyS to increase the secretion of IgM by malignant B cells. BLyS, alone or in combination with cytokines that induce plasmacytic differentiation and immunoglobulin production (IL-2, IL-6, IL-10 and IL-12), was found to increase IgM secretion by malignant B cells. Mean baseline IgM levels significantly increased in cells treated with BLyS (p=0.03), cytokines (p=0.0002) and a combination of BLyS and cytokines (p<0.0001). We then determined the effect of BLyS on the survival of malignant B cells using Annexin-V/PI staining. Compared to cells cultured in media alone, BLyS was found to increase viability of malignant B cells from WM patients. Cell viability was normalized relative to the media-alone control and the median relative viability increased significantly compared to controls (median increase 41.2%; range 8 – 46%). Next, we examined the ability of BLyS to modulate cell proliferation using thymidine incorporation. Using WM patient samples, BLyS was found to significantly enhance the proliferation of malignant B cells (p=0.0002). Furthermore, addition of anti-Ig antibody further enhanced the ability of BLyS to promote the proliferation of malignant B cells (p<0.0001). In summary, we have demonstrated that BLyS enhances IgM secretion by malignant B cells from patients with Waldenstrom’s macroglobulinemia. We have also demonstrated the ability of BLyS to enhance the survival and proliferation of malignant B cells. Strategies to inhibit BLyS may potentially have therapeutic efficacy in Waldenstrom’s macroglobulinemia.

Background: Primary Systemic Amyloidosis (AL) is a fatal disorder characterized by uncontrolled deposition of light chain derived amyloid with variable survival dependent on extent of organ involvement and degree of individual organ dysfunction. We previously demonstrated that troponin T (cTnT) and N-terminal fragment of brain natriuretic peptide (NT-ProBNP) together can allow prognostic stratification in AL. Uric acid (UA) is a marker of increased mortality in congestive heart failure and we examined its prognostic value in AL. Methods: A cohort 1977 patients with AL seen at our institution and 293 patients with AL undergoing stem cell transplant (PBSCT) were studied retrospectively to examine the value of serum UA. Results: The median OS for those with UA>8mg/dL was 9 months from diagnosis (95% CI; 7.4, 10.6) compared to 20.3 months for those with UA<=8mg/dL (95% CI; 17.8, 22.7), P<0.001 (Figure 1). As previously demonstrated both cTnT≥0.035μg/L and NT-ProBNP≥332ng/L were prognostic for OS. The median OS for patients (n=617) with a cTnT>0.035g/L was 6.7 months (95% CI; 5.0, 8.4) compared to 35.2months (95% CI; 29.4, 41.0) for those with cTnT<=0.035μg/L, P<0.0001. Similarly, the median OS for patients with NT-ProBNP > 332ng/L was 11.8 months (95% CI; 9.4, 14.2) compared to 36.2 months (95% CI; 26.7, 45.8) for those with NT-ProBNP <=332ng/L; P<0.0001. The prognostic value of UA was independent of cTnT and NT-ProBNP and together with these allowed a novel prognostic classification. Patients with none (Stage-I), 1 (Stage-II), 2 (Stage-III) or 3 (Stage-IV) of these risk factors (UA>8mg/dl, cTnT>0.035μg/L and NT-ProBNP>332ng/L) had a median OS of 36.6, 29.2, 11.1, and 3.6 months respectively (P<0.0001) (Figure 2). We also explored various predictors of OS in this large cohort of patients. The parameters that were significant for a shorter median OS included septal thickness>15mm, ejection fraction<50%, alkaline phosphatase>upper limit of normal, serum creatinine>2.0mg/dL, serum albumin<3.0gm/dl, 24-hour urine albumin>5gm, UA>8 mg/dL, cTnT>0.035μg/L and NT-ProBNP>332ng/L. We then performed a multivariate analysis with all these variables and those predicting for shorter OS were cTnT>0.035μg/L, serum uric acid>8mg/dL, and ejection fraction<50%. The stage determined at the time of PBSCT also predicted outcome with a median OS from PBSCT not reached in stages 1 and 2, 55 months for stage 3 and 16 months for stage 4 patients. Interpretation: The data confirms the prognostic value of serum UA in AL and allows development of a novel and simple but powerful, reproducible staging system with applicability at all stages of AL. Figure Figure Figure Figure

Abstract Background: Prior studies suggest that the presence of >5% polyclonal plasma cells (pPCs) among total plasma cells (PCs) within the bone marrow (BM) is associated with a longer progression-free survival, higher response rates, and lower frequency of high-risk cytogenetic abnormalities in patients with newly diagnosed multiple myeloma (MM). However, the incidence and prognostic utility of this factor in patients with relapsed and/or refractory MM has not been previously evaluated. Thus, we evaluated the prognostic value of quantifying the percentage of pPCs among the total PCs in the BM of patients with actively relapsing MM. Methods: We evaluated all MM patients with actively relapsing disease (biochemical and/or symptomatic) seen at the Mayo Clinic, Rochester, from 2012 to 2013, who had BM samples evaluated by seven-color multiparametric flow cytometry. All patients had at least 24 months of follow-up from the date of flow evaluation. Cell surface antigens were assessed by direct immunofluorescence antibodies for CD45, CD19, CD38, CD138, cytoplasmic Kappa and Lambda Ig light chains, and DAPI nuclear stain. The flow cytometry data was collected using the Becton Dickinson FACSCanto II instruments that analyzed 150,000 events (cells); this data was then analyzed by multi-parameter analysis using the BD FACS DIVA Software. PCs were selectively analyzed through combinatorial gating using light scatter properties and CD38, CD138, CD19, and CD45. Clonal PCs were separated from pPCs based on the differential expression of CD45, CD19, DAPI (in non-diploid cases), and immunoglobulin light chains. The percentage of pPCs was calculated in total PCs detected. Survival analysis was performed by the Kaplan-Meier method and differences were assessed using the log rank test. Results: There were 180 consecutive patients with actively relapsing MM who had BM biopsies analyzed via flow cytometry as part of their routine clinical evaluation. The median age of this group was 65 years (range: 40 - 87); 52% were male. At the time of this analysis, 104 patients had died, and the 2-year overall survival (OS) rate for the cohort was 58%. The median number of therapies received was 4 (range: 1 - 15). Of these patients, 61% received a prior ASCT, and almost all (99%) received prior regimens containing either immunomodulators or proteasome inhibitors. There were 55 (30%) patients with >5% pPCs among the total PCs in their BM. The median percentage of pPCs among total PCs in these 55 patients was 33% (range: 5 - 99). The median OS for those with >5% pPCs was not reached compared with 22 months for those with <5% pPCs (P = 0.028; Figure 1). Patients with <5% pPCs PCs had a higher likelihood of high-risk FISH cytogenetics compared with the rest of the patients. In a univariate analysis, increasing number of pPCs was associated with an improved OS, while higher labeling index, number of prior therapies, and the presence of high-risk FISH cytogenetics were associated with a worse OS. In a multivariate analysis, only the increasing number of pPCs (P = 0.006), higher labeling index (P = 0.0002) and number of prior therapies (P = 0.003) retained statistical significance. Conclusion: Quantitative estimation of the percentage of pPCs among the total PCs in the BM of patients with actively relapsing MM was determined to be a predictor of worse OS. As such, this parameter is able to identify a group of patients with MM with actively relapsing disease who have a particularly poor outcome. Further studies evaluating its biological significance are warranted. Figure 1 Kaplan-Meier curve comparing OS between patients with ≥5% pPCs and <5% pPCs among the total PCs in their BM. Figure 1. Kaplan-Meier curve comparing OS between patients with ≥5% pPCs and <5% pPCs among the total PCs in their BM. Disclosures Kapoor: Celgene: Research Funding; Amgen: Research Funding; Takeda: Research Funding. Gertz:Prothena Therapeutics: Research Funding; Novartis: Research Funding; Alnylam Pharmaceuticals: Research Funding; Research to Practice: Honoraria, Speakers Bureau; Med Learning Group: Honoraria, Speakers Bureau; Celgene: Honoraria; NCI Frederick: Honoraria; Sandoz Inc: Honoraria; GSK: Honoraria; Ionis: Research Funding; Annexon Biosciences: Research Funding. Kumar:AbbVie: Research Funding; Noxxon Pharma: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Research Funding; Kesios: Consultancy; Glycomimetics: Consultancy; BMS: Consultancy.