Muchtar, Eli

Abstract The plasma cell proliferative index (PCPI) provides an insight into plasma cell biology in plasma cell disorders. It recognizes cells that are actively synthesizing DNA and gives an indication of the proliferative rate of the malignant plasma cells.The PCPI has been shown to be a prognostic tool in patients with multiple myeloma and amyloidosis. We conducted a retrospective review analyzing the prognostic impact of PCPI in 306 patients with smoldering multiple myeloma (SMM). The median age was 66 (56-73) years and 61% (n=186) were males. The median follow-up for the entire cohort was 10.2 years (95% confidence interval: 9.0-10.9). One-hundred sixty-nine (55%) patients were alive at the time of study analysis while 118 (39%) had progressive disease. The median time to progression was 5.9 years (95% confidence interval: 4.8-8.2). Symptomatic events at the time of progression included anemia in 41% (n=48), bone complications in 37% (n=44), renal complications in 9% (n=11), hypercalcemia in 2% (n=2) and development of amyloidosis in 2% (n=2). Seventeen patients (14%) were categorized as having progression due to rapid progressive elevation in the serum free light chains (sFLC) and/or progressive increase in the size of their M-spike. The median time between the diagnosis and PCPI date was 0 months (interquartile range 0-1). An elevated PCPI was defined as a level >0.5%. Seventy-nine (26%) patients had an elevated PCPI. Patients with an elevated PCPI were significantly older (median age: 69 years for elevated PCPI vs 64 years for low PCPI (p= 0.008) and predictably had more proliferative disease with a higher rate of patients with bone marrow plasma cells >20% (48% for elevated PCPI vs 34% for low PCPI, p=0.03). An elevated PCPI predicted a shorter time to progression (TTP); median 3.0 years versus 7.1 years for those with a low PCPI (p= 0.0004). Within 24 months, the progression rate was significantly higher for patients with an elevated PCPI; 49% versus 20% (p<0.0001). We constructed two multivariable models using the conventional and recently proposed Mayo risk stratification tools. In both models, an elevated PCPI was an independent predictor of to multiple myeloma. PCPI is a valuable tool in risk stratifying patients with SMM and identifies patients with earlier progression who may benefit from closer follow up and consideration of early intervention trials. Disclosures Dispenzieri: Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Gertz:Research to Practice: Consultancy; spectrum: Consultancy, Honoraria; Abbvie: Consultancy; Amgen: Consultancy; janssen: Consultancy; Physicians Education Resource: Consultancy; Teva: Consultancy; celgene: Consultancy; annexon: Consultancy; Alnylam: Honoraria; Prothena: Honoraria; Medscape: Consultancy; Apellis: Consultancy; Ionis: Honoraria. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding. Kumar:Oncopeptides: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Introduction: IgM light chain amyloidosis (AL) is a rare complication of IgM associated disorders, with very limited data on biology and outcomes. Our study compares the clinical characteristics, laboratory findings and outcomes in a large cohort of patients with IgM vs. non-IgM AL to delineate the underlying disease biology of this entity. Methods: Patients with newly diagnosed AL (2006-15) were identified from a prospectively maintained institutional database and grouped by IgM heavy chain. Bone marrow (BM) morphology was reviewed by an expert hematopathologist (RLK). FISH testing included probes for t(11;14) and trisomies of odd numbered chromosomes. MYD88L265P testing was carried out by allele specific PCR and CXCR4WHIM mutation testing was performed by bridged nucleic acid (BNA)-enhanced Sanger sequencing. Results: Patients with IgM AL comprised 6.6% (75/1128) of the study cohort. Baseline characteristics are listed in Table 1. IgM AL patients were older and had a higher proportion of males. They had less frequent cardiac involvement (60 vs. 75%) and less frequent involvement of > 1 organ. Light chain burden was lower in this group (dFLC 12.5 vs. 22.7 mg/dL), while there was no difference in BM clonal cell percentage (10% each). Morphology: BM morphology in 71 patients with IgM AL revealed a pure plasma cell disorder (PPCD type) in 25% (n=18); low-grade B-cell lymphoma (LGBCL) with plasmacytic features (LPL type) in 62% (n=44) [well defined LPL: 38% (n=27), LGBCL with plasmacytic features: 24% (n=17)]; LGBCL, other: 6% (n=4). In the remaining 7%, three patients had other diagnoses and no BM disease in two patients. Median clonal cell % in LPL vs. PPCD type IgM AL was 20% vs. 5%, p<0.001. Genetics: In patients with IgM AL vs. non-IgM AL, t(11;14) was present in 27% vs. 49%, p=0.009 and trisomies in 9% vs. 24% of patients, p=0.06, respectively. In the IgM AL cohort, MYD88 mutation was seen in 56% (23/41) & CXCR4 mutation in 15% (5/34; S388 type: 3, other: 2) of patients. Importantly, MYD88 and CXCR4 mutations were found only in patients with LPL morphology, while t(11;14) was found only in the PPCD morphology group. There were no patients with both t(11;14) and MYD88 abnormalities (N=26 for both tested). Mutations seen in the LPL vs. PPCD type IgM AL were: MYD88, 88% (22/25) vs. 0% (0/14), p<0.001 and CXCR4, 26% (5/19) vs. 0% (0/13), p=0.02. Conversely, t(11;14) was seen in 0% (0/18) in LPL type vs. 60% (9/15) in PPCD type IgM AL, p <0.001. Treatment details were known in 63 patients with IgM AL; rituximab-based: 21 (33%), bortezomib/alkylator: 16 (25%), transplant 17 (27%), steroids: one and no treatment: 8 (13%). Treatment in IgM AL LPL type (n=36) was: rituximab based: 16 (44%),bortezomib/alkylator: 5 (14%), transplant: 10 (28%) and none: 5 (14%). In PPCD type [n=17), treatment was rituximab based: 2 (12%), bortezomib/alkylator: 8 (47%), transplant: 7 (41%). At 6 months, very good partial response or better was observed in 26% (10/39) vs. 41% (270/660) of patients with IgM vs. non-IgM AL, p=0.05. There was no difference in overall survival (OS) when all patients with IgM AL were compared to non-IgM AL (Fig 1a). However, when stratified by early (Stage 1/2) or advanced (stage 3/4) 2012 Mayo stage, patients with IgM AL fared worse (Fig 1b-c). On multivariate analysis, IgM AL was an independent predictor for inferior OS [HR with 95% CI: 1.6 (1.1-2.4), p=0.02] after adjusting for age, Mayo 2012 stage and type of therapy (transplant vs. not). However, when OS was adjusted for 6 month VGPR, there was no difference in OS for IgM AL vs. non IgM AL, p=0.2. In the IgM AL cohort, patients with LPL type IgM AL had inferior OS compared with PPCD type IgM AL, 21 vs. 82 months, p=0.01 (Fig 1d). Conclusions: Patients with IgM AL have distinct clinical and genetic features, with lower rates of cardiac involvement and a lower frequency of t(11;14) or trisomies compared with non-IgM AL. Even though IgM AL is a rare entity, we were able to delineate two distinct sub-types of IgM AL: LPL type and PPCD type, with implications for therapy and outcomes. Along with unique morphologic findings, presence of MYD88 and CXCR mutations was only seen in LPL type IgM AL and t(11;14) in PPCD type IgM AL. Despite lower cardiac involvement, IgM AL was associated with inferior OS outcomes, likely due to lower response rates, particularly in LPL IgM AL group, which had the lowest OS. Therapeutic approaches targeted towards disease biology to achieve deep responses are needed in this disorder. Disclosures Sidana: Janssen: Honoraria. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Lacy:Celgene: Research Funding. Kumar:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Research Funding; Novartis: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Gertz:Abbvie: Consultancy; Ionis: Honoraria; spectrum: Consultancy, Honoraria; Apellis: Consultancy; Amgen: Consultancy; Prothena: Honoraria; Teva: Consultancy; Alnylam: Honoraria; celgene: Consultancy; Medscape: Consultancy; janssen: Consultancy; Research to Practice: Consultancy; Physicians Education Resource: Consultancy; annexon: Consultancy.

Abstract Background The survival of patients with multiple myeloma (MM) has improved significantly over the past two decades with the introduction of novel treatment agents. However, MM is still largely considered an incurable malignancy with a relapsing-remitting course. A follow-up of at least 10 years from active disease is required to determine whether a plateau in progression-free survival has been attained. Prior literature has used 10 years as a cutoff for "long-term survivorship". In this study, we have assessed the biological disease characteristics and outcomes of long-term survivors with MM (≥10 years from active disease). Methods All patients with active MM evaluated at the Mayo Clinic, Rochester between January 1, 1999 and July 1, 2008 were included in the study after approval of the Institutional Review Board. Patients with smoldering multiple myeloma were excluded. The overall survival (OS) was calculated from the time of symptomatic disease requiring treatment. Patients were then divided into two cohorts: (1) long-term survivors, which included patients who had an overall survival of at least 10 years; and (2) short-term survivors, which included patients who had an overall survival of less than 5 years from the diagnosis of active MM. The baseline characteristics between these two groups were compared using Wilcoxon, chi-square, and Fisher's exact test as applicable. All time-to-event analyses were performed using the Kaplan-Meier method and the survival curves were compared using Log-Rank test. Results During the time frame of the study, 2,125 patients were identified who fulfilled the diagnostic criteria for active MM. The median follow-up for the entire cohort was 12.6 years (95% CI: 12.5-13.4).The median OS for the entire cohort was 4.4 years (95% CI: 4.2-4.7 years). Three-hundred and ninety nine (18.7%) patients survived at least 10 years whereas 872 patients (41%) survived less than 5 years from the date of initial diagnosis. The median OS was 14.1 years for the long-term survivors (95% CI: 13.9-14.6 years) and 2.1 years for the short-term survivors (95% CI: 1.8-2.2 years). The clinical features at diagnosis comparing long-term survivors and short-term survivors are shown in Table 1. Among long-term survivors (n=399), based on the available data regarding remission and ongoing treatment status, 331 patients were categorized into 6 cohorts (Table 2). The MM specific survival data of these 6 cohorts is depicted in Table 2.Figure 1 shows survival outcomes from the 10-year landmark. Of the 6 cohorts, 38 patients in Cohort 1 and 19 patients in Cohort 2 (total 57; 17% of long term survivors, ~3% of the entire cohort ) have been off therapy for at least 5 years and remain in remission, representing a distinct group of patients with 100% 15-year survival. Conclusion In our large database with prolonged follow-up, long-term survivors appear to have distinct baseline characteristics, but also constitute a heterogenous group of patients with disparate outcomes. A small subset (17% of long-term survivors) was identified that may represent patients closest to being considered as 'operationally cured'. Disclosures Lacy: Celgene: Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Gertz:Teva: Consultancy; spectrum: Consultancy, Honoraria; Medscape: Consultancy; Physicians Education Resource: Consultancy; Amgen: Consultancy; Apellis: Consultancy; Alnylam: Honoraria; Abbvie: Consultancy; janssen: Consultancy; celgene: Consultancy; Prothena: Honoraria; annexon: Consultancy; Ionis: Honoraria; Research to Practice: Consultancy. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding.

Abstract Introduction: Richter transformation (RT) refers to transformation of chronic lymphocytic leukemia (CLL) to an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). Most studies on the management of RT were either small retrospective series or early phase non-randomized trials before the era of novel agents. The natural history, prognostication and optimal treatment of patients with RT remain undefined. Here we report the clinical characteristics and outcomes of a large series of RT from a single center. Methods: Biopsy-confirmed RT (limited to non-Hodgkin lymphoma) diagnosed from 4/1993 to 4/2018 were identified from the Mayo Clinic CLL database. Clinical characteristics, treatment information and follow-up data were abstracted by chart review. Overall survival (OS) was defined as time from RT diagnosis to death from any cause and analyzed using the Kaplan-Meier method. Statistical analysis was done in SAS 9.4. Results: A total of 204 patients with CLL who developed RT were identified. The median age at CLL diagnosis was 62 years (range 22-85), and 148 (73%) were male. The median time to transformation was 4.7 years (range 0-34.5). Prior to RT, 68 (33.3%) patients received no treatment for CLL, 109 (53.4%) received chemoimmunotherapy (CIT) only, and 27 (13.2%) received at least one novel agent (idelalisib, ibrutinib, or venetoclax) for CLL. The median lines of CLL therapy prior to RT was 2 (range 0-13). The median age at RT diagnosis was 69 years (range 30-88). Pathology of RT was DLBCL and high grade B-cell lymphoma in 193 (94.6%) and 11 (5.4%) patients, respectively. The median LDH was 306 IU/L (range 99-9000). 62/125 (49.6%) patients had bulky disease (≥ 5 cm), and the median PET SUVmax was 13.9 (range 2.9-30.0). 45/131 (34.4%) patients had del(17p) or TP53 mutation, 12 (9.2%) had del(11q), 21 (16.0%) had trisomy 12, 27 (20.6%) had del(13q), and 25 (19.1%) had normal FISH. The CLL and RT were clonally related in 12/21 (57.1%) patients. For the transformed lymphoma, cell of origin by Han's algorithm was germinal center B cell-like (GCB) and non-GCB in 31/100 (31.0%) and 69/100 (69.0%) patients, respectively. EBV was positive in 14/52 (26.9%) patients. The median Ki-67 was 80% (range 10-100). Myc and Bcl-2 were positive by IHC in 31/43 (72.1%) and 83/103 (80.6%) patients, respectively; 27/56 (48.2%) were double-expressors. MYC, BCL2, and BCL6 rearrangement was positive by FISH in 18/68 (26.5%), 10/34 (29.4%), and 4/31 (12.9%) patients, respectively; 8/66 (12.1%) were double/triple-hit. The most common first-line treatment (Table 1 notes) of RT was R-CHOP-like regimen (n=114, 65.5%). Other treatments included R-EPOCH-like (n=6, 3.4%), high-intensity chemotherapy (n=15, 8.6%), novel agents (eg, ibrutinib, venetoclax, pembrolizumab; n=19, 10.9%), other chemotherapy (n=12, 6.9%), and palliative therapy (n=8, 4.6%). Response to first-line treatment was CR in 57 (38.0%), PR in 33 (22.0%), SD in 18 (12.0%), and PD in 42 (28.0%) patients. The median OS of the entire cohort after RT diagnosis was 12.0 months. The median OS for patients who received no prior CLL treatment, CIT only or at least one novel agent for CLL were 65.5, 7.3, and 12.0 months, respectively (P<0.0001; Figure 1). Of note, in patients who received CIT only for CLL, ~10% and 60% received high-intensity and R-CHOP/R-EPOCH-like chemotherapy, respectively, as first-line RT therapy. In contrast, in patients who had prior novel agents for CLL, 56% and 26% were treated with novel agents and R-CHOP/R-EPOCH-like chemotherapy, respectively, as first-line RT therapy. Patients with or without del(17p)/TP53 mutation had a median OS of 8.3 and 12.8 months, respectively (P=0.046). Patients who were treated with high intensity chemotherapy, R-CHOP/R-EPOCH-like regimens, novel agents, and other therapies for RT had a median OS of 35.1, 14.4, 10.9 and 6.1 months, respectively (P=0.02; Figure 2). OS comparisons by CLL/RT clonal relationship, double expressor or double/triple-hit status are shown in Table 1, with no significant differences noted. Conclusions: Over two thirds of RT were the non-GCB subtype, and about half were Myc/Bcl-2 double expressors. Patients who developed RT without prior CLL therapies had a significantly better OS. In contrast, patients who had received prior CLL therapies had poor outcomes. Myc/Bcl-2 double expressor and MYC/BCL2/BCL6 double/triple hit status had no impact on OS. Disclosures Kenderian: Humanigen: Research Funding; Novartis: Patents & Royalties; Tolero Pharmaceuticals: Research Funding. Kay:Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees. Parikh:Janssen: Research Funding; Abbvie: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; MorphoSys: Research Funding; Gilead: Honoraria; Pharmacyclics: Honoraria, Research Funding. Ding:Merck: Research Funding.

Abstract Background: Limited data exist regarding histological transformation in patients with Waldenström macroglobulinemia (WM). In this study, we present the disease characteristics, outcomes and risk factors for histological transformation in WM. Methods: Patients with WM seen at Mayo Clinic, Rochester, MN between January 1996 and December 2017 were included. Patients with aggressive non-Hodgkin lymphoma in the setting of WM were considered to have transformation. Univariate analysis for comparing baseline characteristics of transformed versus non-transformed WM was performed using Wilcoxon, Fisher's exact and Chi square tests, as appropriate. Multivariate analysis was performed using logistic regression analysis. Cox proportional hazard method was used to assess the impact on time-to-transformation. All time-to-event analyses were calculated by the Kaplan-Meier method. Results: Of 1014 patients with WM, 42 patients (4.1%) developed histological transformation. The median follow-up for the entire cohort was 9.5 years (95% CI: 8.8-10.5 years). The cumulative probability of transformation was 2.3% at 5 years, 5.3% at 10 years and 8.5% at 15 years from diagnosis of WM, respectively. There was no difference in the 5-year cumulative probability of transformation in patients with WM diagnosed between 1996-2000 (2.1%), 2001-2005 (2.9%), 2006-2010 (2.7%) and 2011-2015 (3.8%), p=0.61.The disease characteristics, laboratory parameters and histology at transformation are outlined in Table 1. In patients with DLBCL histology (n=39), Revised-International Prognostic Index was calculable in 28 patients, with 50% (n=14), 46% (n=13) and 4% (n=1) of DLBCL belonging to poor, good and very good risk groups, respectively. For DLBCL histology, 18 patients were classifiable using Hans algorithm into germinal center B-cell (GCB) type (n=3, 17%) and non-GCB type histology (n=15, 83%). The median lines of therapy received prior to transformation for the entire cohort was 2 (range 0-9), with 5 (11%) patients not having received any therapy for WM before transformation. Number of lines of alkylator-based therapy used prior to transformation [median 1 line (range 0-4)] was comparable to that used in patients in whom WM did not occur [median 1, (range 0-6); p=0.78]. The median time-to-transformation from diagnosis of WM was 4.8 years (95% CI: 2.6- 6.8 years). Overall survival (OS) from transformed disease was 3.2 years (95% CI 1.1-3.9 years). The 10-year OS of patients with WM who transformed was lower (46%) compared to patients without transformation (60%) with a trend towards statistical significance (p=0.08), Figure 1. The MYD88L265P mutation status was available in 333 patients in the entire cohort (22/42 pts in the transformed cohort and 311/972 in the non-transformed cohort. Of the 22 patients in the transformed WM cohort, 13 (59%) exhibited MYD88WT genotype and 9 (41%) exhibited MYD88L265P genotype. The risk of transformation was higher in patients with MYD88WT status [Odds ratio 6.3 (95% CI: 2.6-15.5); p<0.0001]. Additionally, serum lactate dehydrogenase (LDH) was higher at diagnosis of WM in patients who transformed, Table 2. On multivariate analysis, MYD88WT status remained an independent predictor of disease transformation [p=0.003; odds ratio 10 (95% CI: 2.1-48)]. On univariate Cox proportional hazard analysis for identifying predictors of time-to-transformation, only MYD88WT mutational status was associated with shorter time-to-transformation with a 5-year transformation rate of 15.5 % for MYD88WT versus 2.6 % with MYDL265P mutated patients [risk ratio 6.2 (95% CI: 2.5-16.4); p<0.0001]. Treatment-related details in the transformed cases were available for 37 (90%) patients; R-CHOP was the most common (41%) frontline therapy for transformation; 33% patients underwent autologous stem cell transplantation for transformed disease during their disease course. Conclusion: Histological transformation is an uncommon event in WM but confers poorer survival. MYD88WT genotype is independently associated with histological transformation a shorter time-to- transformation in patients with WM. Disclosures Ansell: Trillium: Research Funding; Pfizer: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; Takeda: Research Funding; Celldex: Research Funding; Regeneron: Research Funding; Merck & Co: Research Funding; Bristol-Myers Squibb: Research Funding. Gertz:Apellis: Consultancy; Alnylam: Honoraria; spectrum: Consultancy, Honoraria; janssen: Consultancy; annexon: Consultancy; Prothena: Honoraria; Abbvie: Consultancy; Amgen: Consultancy; celgene: Consultancy; Teva: Consultancy; Medscape: Consultancy; Ionis: Honoraria; Research to Practice: Consultancy; Physicians Education Resource: Consultancy. Dingli:Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Witzig:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Lacy:Celgene: Research Funding. Kumar:Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kapoor:Takeda: Research Funding; Celgene: Research Funding.

Abstract Background: Cardiac involvement is integral in staging and prognosis of immunoglobulin light chain (AL) amyloidosis. The N-terminal prohormone of brain natriuretic peptide (NT proBNP) is a cardiac biomarker used in screening for cardiac involvement and staging the disease. Transthoracic echocardiogram (TTE) and cardiac magnetic resonance (CMR) are the imaging modalities recommended to determine cardiac involvement and function. Methods: We conducted a retrospective review of all patients with biopsy proven systemic AL amyloidosis seen at the mayo clinic between Jan 1, 2006 and Dec 30, 2015. The aim of the study is to identify the nature of abnormalities in cardiac biomarkers and echocardiographic features in patients with AL amyloidosis and the ability of these investigations to diagnose cardiac involvement. We first identified all patients with AL amyloidosis that underwent endomyocardial biopsy for suspicion of cardiac involvement (Cohort 1). We then analyzed a cohort (Cohort 2) which consisted of patients who had serum NT proBNP and a comprehensive echocardiographic evaluation at time of diagnosis. Results: 179 patients with AL amyloidosis underwent endomyocardial biopsy (Cohort 1) of whom 173 had evidence of amyloid deposition. In this cohort, 159 patients had NT proBNP performed at the time of the procedure. The NT proBNP was elevated (>300) in all 159 patients with a median NT proBNP of 4917 (range 355-69541). The median left ventricular ejection fraction (LVEF), interventricular septal (IVS) thickness and strain rate were 54 (range 10-77), 15 (range 8-30) and -9 (range -21 to 0) respectively. CMR findings were consistent or suggestive of light chain amyloidosis in 38/42 patients, yielding a sensitivity of 90 percent. The LVEF, IVS thickness and strain rate were abnormal in 89/168 (53%), 102/64 (61%) and 92/95 (97%) respectively. 95 patients with biopsy proven cardiac amyloidosis had complete echocardiogram data available on LVEF, IVS thickness and strain rate, with 97% (n=92) presenting with an abnormality in at least one of these variables . CMR findings were consistent or suggestive of light chain amyloidosis in 38/42 patients, yielding a sensitivity of 90 percent. Patients with a normal NT proBNP and normal echocardiogram were considered disease free (true negative), based on our initial analysis of these investigations in Cohort 1. Cohort 2 consisted of 342 consecutive patients. The median NT pro BNP was 1878 (25-48214). The median LVEF, IVS thickness and strain rate were 63 (22-90), 14 (6-25) and -13 (-25 to -3) respectively. 259 (76%) patients had a positive NT proBNP (above 300), of whom 237 (92%) had an abnormality detected on TTE. 83 patients had a negative NT proBNP, of whom 27 (33%) had an abnormality in either LVEF, IVS thickness or strain rate. 19 of these 27 patients had a borderline reduced strain rate between -17 and -18, whilst the remaining 8 patients had a strain between -14 and -15. Only 6/27 patients were considered to have possible early cardiac involvement and none have any other diagnostic or classical features of amyloidosis on TTE. Conclusion: The combination of NT proBNP and comprehensive echocardiographic evaluation provides substantial information to diagnose cardiac amyloidosis in a significant portion of patients negating the need for endomyocardial biopsy. A negative NT proBNP rules out clinically meaningful cardiac involvement and may obviate the routine use of TTE in patients with a low clinical suspicion of cardiac amyloidosis. Disclosures Dispenzieri: Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Gertz:Research to Practice: Consultancy; Physicians Education Resource: Consultancy; Ionis: Honoraria; celgene: Consultancy; spectrum: Consultancy, Honoraria; Teva: Consultancy; Amgen: Consultancy; Medscape: Consultancy; janssen: Consultancy; Alnylam: Honoraria; Abbvie: Consultancy; annexon: Consultancy; Apellis: Consultancy; Prothena: Honoraria. Lacy:Celgene: Research Funding. Dingli:Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Kumar:AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Roche: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Introduction: Immunoglobulin light chain (AL) amyloidosis is associated with significant morbidity and mortality. Several models were developed to allow survival prediction, but head-to-head model comparison is lacking. Patients and Methods: Five prognostic models were compared: Mayo 2004; Mayo 2012; 2013 European modification of Mayo 2004 (where Mayo 2004 stage 3 is subdivided into 3 subgroups based on NT-proBNP at 8500 ng/L and systolic blood pressure at 100 mmHg); 2015 European modification of Mayo 2004 (where Mayo 2004 stage 3 is subdivided into 2 subgroups based on NT-proBNP at 8500 ng/L); and organ model (a model based on number of involved organs). All patients with available baseline data for the 5 models were included in this study (n=1005). Improvements in predictive accuracy of the various models were determined by calculating a net improvement in survival prediction for each pair of prognostic models. Net improvement was considered as the proportion where model A outperforms model B minus the proportion where model B outperforms model A. Results: For all models, there was increasing risk for death with increasing stage. The organ model was the least powerful system with a hazard ratio of 2.8 for ≥4 organs compared to 1 involved organ. The organ model was consistently outperformed by the other 4 systems. In the cohort as a whole, the biomarker models (Mayo 2004; Mayo 2012; European 2013; European 2015) were comparable in ability to predict survival (Figure). However, a slightly superior performance of the European 2013 modification of the Mayo 2004 system was seen over the Mayo 2004 system in the group as a whole (net improvement 4.1%, P=0.023) and when restricted to non-ASCT population (net improvement 6.3% P=0.014). The European 2015 modification performed slightly better than the Mayo 2004 system in the ASCT population (net improvement 3.4%, P=0.025). 1-year mortality was better predicted by the European models (net improvement 11-14%, P<0.05), while the Mayo 2012 had better survival prediction to all other biomarker models in 3-year landmark comparison (net improvement 7-9%, P<0.05). Conclusion: Using biomarker based staging is a clear improvement over the organ staging system. The different biomarker staging systems' abilities to predict for survival were relatively comparable, solidifying the importance of soluble cardiac biomarkers and free light chain measurement as prognosticators in AL amyloidosis. Mayo 2004-based models better predict for early death while Mayo 2012 model has a better prediction for long-term survival. Figure. Figure. Disclosures Gertz: Ionis: Honoraria; celgene: Consultancy; spectrum: Consultancy, Honoraria; janssen: Consultancy; Amgen: Consultancy; Abbvie: Consultancy; Medscape: Consultancy; annexon: Consultancy; Teva: Consultancy; Research to Practice: Consultancy; Apellis: Consultancy; Alnylam: Honoraria; Prothena: Honoraria; Physicians Education Resource: Consultancy. Lacy:Celgene: Research Funding. Dingli:Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Celgene: Research Funding; Takeda: Research Funding. Russell:Vyriad: Equity Ownership. Kumar:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.

Abstract Introduction: Light chain burden in light chain (AL) amyloidosis is often low, making accurate response assessment challenging. Methods: AL amyloidosis patients achieving very good partial or complete response to first line therapy and had serial sFLC studies during and after completion of therapy were included (n=396). Involved free light chain (iFLC), difference in involved-to-uninvolved free light chains (dFLC) and sFLC ratio (sFLCR) were assessed at the end of first line therapy and at nadir iFLC. Survival analysis was done using the Kaplan-Meier method. Hematological progression-free survival (hemPFS) was defined as the time from diagnosis until hematological progression or death, where patients known to be alive and progression-free at the end of follow-up were censored. Hematological progression was defined according to consensus criteria or upon initiation of second line therapy, whichever came first. Results: The median iFLC and dFLC at the end of therapy was 1.7 mg/dL and 0.5 mg/dL, respectively. sFLCR normalization occurred in 70% of patients. iFLC ≤2 mg/dL and dFLC ≤0.5 mg/dL were associated with a longer hemPFS compared to their counterparts (Figure). Only iFLC ≤2 mg/dL was associated with a significantly longer overall survival (Figure). sFLCR normalization did not predict hemPFS or overall survival. Organ response was predicted by iFLC ≤2 mg/dL and dFLC ≤0.5 mg/dL (Table), with best discrimination seen with iFLC ≤2 mg/dL. Organ response was not predicted by sFLC normalization (Table). The median nadir iFLC was 1.4 mg/dL and was reached 3.9 months from the end of therapy, longer in transplanted patients compared to patients treated with non-transplant regimens (7.3 vs 1.8 months, respectively; P<0.001). iFLC ≤2 mg/dL at the completion of therapy and nadir iFLC reached >12 months from the end of therapy were favorable predictors of hemPFS/OS in a multivariate analysis. Conclusion: iFLC at the end of first line therapy better predicts for organ response and survival than dFLC among deep responders. Normalization of sFLCR does not predict for organ response or survival and should not be used as measure of therapeutic efficacy. Figure. Figure. Disclosures Dispenzieri: Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding. Russell:Vyriad: Equity Ownership. Kumar:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Gertz:Alnylam: Honoraria; celgene: Consultancy; Ionis: Honoraria; Abbvie: Consultancy; annexon: Consultancy; janssen: Consultancy; spectrum: Consultancy, Honoraria; Research to Practice: Consultancy; Medscape: Consultancy; Apellis: Consultancy; Teva: Consultancy; Amgen: Consultancy; Prothena: Honoraria; Physicians Education Resource: Consultancy.

Abstract ATTRwt (formerly known as senile) amyloidosis and plasma cell disorders share a common demographic of occurrence with increasing prevalence with age. We aimed to identify the prevalence of plasma cell disorders in patients diagnosed with ATTRwt. We retrospectively reviewed all patients seen at Mayo Clinic Rochester between 1st January 2009 and 31st of December 2017 who were diagnosed with ATTRwt. The start date of the study was chosen to coincide with routine clinical availability of laser microdissection mass spectrometry (LCMS) for subtyping of amyloidosis. 492 patients with ATTRwt were evaluated during the study period. Serum immunofixation electrophoresis (SIFE), urine immunofixation electrophoresis (UIFE) and serum free light chain (FLC) assay testing was performed in 74% (n=362), 53% (n=261) and 79% (n=386) respectively. Of the 492 ATTRwt seen during this period, 139 (28%) had abnormal monoclonal protein studies, the vast majority (92%, n=128) of which were monoclonal gammopathy of undetermined significance (MGUS). Monoclonal protein testing in this cohort included SIFE, UIFE and FLC in 96% (n=134), 71% (n=99) and 99% (n=137) respectively. The non-MGUS diagnoses included smoldering multiple myeloma in <1%% (n=2), multiple myeloma (MM) in 6% (n=8), AL amyloidosis in 2% (n=3), and lymphoplasmacytic lymphoma (LPL) in 3% (n=4). MM and LPL developed after progression from MGUS in 2 and 3 patients respectively. Two patients with MGUS also had a diagnosis of low grade non Hodgkin lymphoma (chronic lymphocytic leukemia in one and marginal zone lymphoma in the other). The abnormal monoclonal protein studies included SIFE in 55%, UIFE in 26% and an abnormal serum free light chain ratio (FLCr) in 73%. The organ biopsied for the diagnosis of ATTRwt was heart in 43% (n=60), bone marrow in 24% (n=33), fat in 9% (n=12) and other sites in 5% (n=8, 3 lung, 2 lip, 2 bladder and 1 small bowel). LCMS confirmed the subtype of amyloidosis as ATTRwt in all patients with a biopsy positive for amyloidosis by congo red staining. 19% (n=26) of patients were diagnosed with ATTRwt based on clinical features and a strongly positive PYP scan. PYP scan was positive for ATTR in 55/56 patients in whom the test was performed. The most common monoclonal protein isotypes detected were light chain (45%) and IgG (28%). Light chain subtype was kappa in the majority of patients (80%). Plasma cell disorders are not uncommon in patients with ATTRwt amyloidosis. The diagnosis of a plasma cell disorder and ATTRwt are not mutually exclusive, and their coexistence can confuse the diagnosis if amyloid typing is not performed. Patients with ATTRwt may be misclassified as AL amyloidosis due to the presence of amyloid and a clonal plasma cell disorder with significant prognostic and therapeutic implications. Disclosures Kumar: Novartis: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Gertz:Ionis: Honoraria; Research to Practice: Consultancy; Amgen: Consultancy; Prothena: Honoraria; Alnylam: Honoraria; Medscape: Consultancy; celgene: Consultancy; Teva: Consultancy; Abbvie: Consultancy; janssen: Consultancy; spectrum: Consultancy, Honoraria; annexon: Consultancy; Apellis: Consultancy; Physicians Education Resource: Consultancy. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.

Abstract Background: The combination of a proteasome inhibitor (PI), an immunomodulatory drug (IMiD), and dexamethasone is the current standard induction therapy for myeloma. Daratumumab, a monoclonal antibody directed against CD38, is highly effective in treating myeloma and improves response rates and progression free survival (PFS) when added to PI or IMiD. Ixazomib, lenalidomide and dexamethasone (IRd) is an effective, all oral, induction regimen that has been studied in phase 2 and 3 trials. We designed this trial to examine the feasibility and efficacy of adding daratumumab to the IRd regimen. Patients and Methods: Patients with previously untreated MM, with measurable disease and adequate organ function were enrolled irrespective of their transplant eligibility. The primary objective was to determine the rate of complete response to the IRD-Dara combination in patients with NDMM. Treatment consisted of Ixazomib 4mg days 1, 8, 15; lenalidomide 25 mg days 1-21, dexamethasone 40 mg, weekly and daratumumab 16 mg/kg, weekly for two cycles, every other week during cycles 3-6 and then every 4 weeks after that. Overall, 40 patients were accrued; data on 38 patients were available for analysis as of July 02, 2018 (Table 1). Results: The median age was 62 (41-81); 52.6% female. All patients were alive and progression free at last assessment with a median follow up of 5.2 (2.0-12.9) months (median 5 cycles, range 2-13). One patient had gone off for alternate therapy. Responses were rapid with 90% partial response or better (32% VGPR) after 2 cycles, and 100% PR or better (50% VGPR) for 32 patients who have completed 4 cycles. The overall best confirmed response rate among the 38 patients was 95% including 11% CR and 47% VGPR. Overall, 231 cycles have been administered across the study, with dose modifications/ hold required for ixazomib, lenalidomide, daratumumab and dexamethasone in 3 (8%), 11 (29%), 2 (5%), and 8 (21%) patients respectively, the most common reasons being hematologic and skin rash. A grade 3 or higher adverse event at least possibly attributed to the study drugs was seen in 42% of patients, hematologic in 37% and non-hematologic in 11% (Figure). 11 patients have so far proceeded to stem cell collection, all have collected adequate numbers of stem cells for one or two intended transplants(median CD34+ collected 8.4 million/kg; range 3.8-12.3). Updated results with additional 6 months of follow up and MRD testing will be presented at the meeting. Conclusion: This represents the first reported results of this combination for treatment of newly diagnosed myeloma. The early results from the use of IRd-Dara in newly diagnosed myeloma suggests excellent efficacy with rapid responses that deepen quickly over the initial cycles of therapy. The regimen was well tolerated with limited dose modifications and no discontinuation for toxicity and no influence on the ability to collect stem cells. Figure. Figure. Disclosures Kumar: Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding. Lacy:Celgene: Research Funding. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Gertz:Prothena: Honoraria; Amgen: Consultancy; Abbvie: Consultancy; Teva: Consultancy; annexon: Consultancy; janssen: Consultancy; celgene: Consultancy; Alnylam: Honoraria; Medscape: Consultancy; Apellis: Consultancy; spectrum: Consultancy, Honoraria; Physicians Education Resource: Consultancy; Ionis: Honoraria; Research to Practice: Consultancy.