Chakraborty, Rajshekhar

Abstract Background: Light chain Amyloidosis (AL) is characterized by deposition of light chain derived amyloid fibrils in major organs and/or soft tissue. An observational study on natural history and outcome of localized immunoglobulin light-chain amyloidosis without vital organ (liver, heart, kidney, peripheral and autonomic nervous system) involvement has shown extremely low rate of progression (1%) to systemic amyloidosis at a median follow-up of 74.4 months (Mahmood S et al. The Lancet Haematology; 2015; 6:e241-e250). There is, however, limited evidence in published literature on natural history of AL amyloidosis confined to fat and/or bone marrow biopsy, without involvement of vital organs or other soft tissues. Methods: We retrospectively identified patients with AL amyloidosis limited to fat and/or bone marrow aspirate in a single-institution database. Patients were evaluated for progression to systemic amyloidosis. Statistical analysis was done using JMP 10.0.0 (SAS Institute Inc.). Results: We identified 117 patients, with a median age of 70 years, who had light chain amyloidosis detected in abdominal fat aspirate and/or bone marrow biopsy, without systemic involvement. Amyloid was seen in fat only in 39%, marrow only in 54% and in both sites in 7%. The median follow up was 45.6 months (95% CI-38.1-57.7) from detection of amyloid. Of these, 64% were alive at the time of analysis. Among 117 patients, 65 were treated for a diagnosis of another plasma cell disorder made prior to or concurrent with detection of amyloid. The remaining 52 patients only had isolated fat or marrow amyloid. Among 65 patients with another diagnosis of plasma cell disorder requiring treatment, 3 progressed to systemic amyloidosis, one each with cardiac, renal and lymph node (LN) involvement detected at 32, 42 and 65 months respectively from the detection of amyloid. The first 2 patients had underlying multiple myeloma, and the third patient with LN involvement had underlying Waldenström macroglobulinemia. Among 52 patients without another diagnosis of a plasma cell disorder requiring treatment, at a median follow up of 32 months, no progression to systemic amyloidosis was observed. Median overall survival (OS) in 117 patients from detection of amyloid, using Kaplan-Meier survival estimates, was 60.2 months (95% CI-48.9-146.1). Conclusion: Our study highlights the fact that isolated amyloidosis detected in fat and/or bone marrow aspirate, in the absence of another plasma cell dyscrasias that require therapy, is unlikely to progress to systemic amyloidosis. Watchful waiting might be considered in such patients after a thorough evaluation to rule out systemic involvement. Disclosures Gertz: Smith Kline: Honoraria; Novartis: Honoraria; Onyx: Honoraria; millenium: Consultancy, Honoraria; Celgene: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Abbvie: Research Funding; Millenium: Consultancy, Research Funding; Novartis: Research Funding; Onyx: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; BMS: Consultancy, Research Funding.

Abstract Background Induction with novel agents, including proteasome inhibitors and immunomodulators, prior to autologous stem cell transplantation (ASCT) is the standard of care frontline treatment of transplant-eligible patients with multiple myeloma (MM). Common novel agent-based induction regimens include three drug combinations with a backbone of bortezomib (V), thalidomide (T) and/or lenalidomide (R). There is limited information on the comparative efficacy of novel regimens used as part of initial therapy prior to an ASCT in terms of overall survival (OS). To address this question, we retrospectively analyzed 1096 consecutive patients undergoing ASCT for MM at Mayo Clinic. Methods Study patients included those who underwent first transplant within 12 months of diagnosis, did not receive more than one induction regimen, did not relapse prior to transplant and did not receive treatment for smoldering MM in the past. Baseline characteristics, response rates and survival data were extracted from an electronic medical record and statistical analysis was done using JMP 10.0.0 (SAS Institute Inc.). Choice of induction regimen was almost exclusively made by the referring physician. Results Median age at diagnosis was 60.3 years (Interquartile range 53.9-65.9). ISS staging at diagnosis was available for 49.7% of patients, of which, 34.2%, 39.3% and 26.5% of patients had ISS stage 1, 2 and 3 disease, respectively. Estimated median follow up was 65.6 months (95% CI 58.3-73.3). Baseline characteristics of patients by initial treatment have been summarized in table 1. Major subgroups by induction therapy included patients receiving Cy-Bor-d (n=193, 17.6%), Vd (n=64, 5.83%), Rd (n=253, 23.1%), VRd (n=126, 34.6%), Td (n=157, 14.3%) and VAD or dexamethasone alone as the non-novel agent comparator group (n=229, 20.9%). Median overall survival (OS) was significantly different between novel agent-based and conventional regimens (Log-rank test; p=0.0029), which were 102.7 months (95% CI, 95.2-112.2) and 78.8 months (95% CI, 67.8-92.6) respectively. Median OS with each regimen is shown in table 1. Among novel agent-based regimens, there was no significant difference in median OS, except Td, which was inferior to Rd (HR 1.62; 95% CI 1.17-2.24). Conclusion We cannot demonstrate with overall survival as an endpoint that the doublets of Vd and Rd are inferior to VRd or Cy-bor-d. There were insufficient patients treated with VTd to be included. Our study shows that the choice of novel induction regimen prior to ASCT does not affect survival (with the exception of Td being inferior to Rd), reflecting the wide array of effective salvage options. However, further prospective randomized clinical trials comparing these regimens are required to validate these findings. Table 1. Baseline characteristics and overall survival. Baseline characteristics and survival Cy-Bor-d (n=193) Vd (n=64) Rd (n=253) VRd (n=126) Td (n=157) VAD or Dex (n=229) p-value Median age 61.9 62.15 60.8 60.8 59.3 58.5 0.0041 Sex (percent males) 56.48 57.81 56.92 61.91 57.96 59.82 0.9271 ISS at diagnosis 1:24.82% 2:40.69% 3:34.48% 1:29.73% 2:24.32% 3:45.94% 1:40% 2:43.78% 3:16.22% 1:41.76% 2:34.06% 3:24.18% 1:28% 2:36% 3:36% 1:20% 2:60% 3:20% 0.0005 Median follow-up (95% CI) 20.3 (17.1-22.7) 49.5 (44.7-55.7) 59 (54.5-67) 26.9 (22.8-30.7) 126.7 (120.2-132.9) 143.4 (132.5-152.6) <0.0001 Median OS Not reached (Estimated 5 year OS rate 75%) 97.2 months (95% CI, 66.6-NR) 112 months (95% CI, 97.4-124.3) Not reached (Estimated 5-year OS rate 77%) 81.1 months (95% CI, 59.1-99.1) 78.8 months (95% CI, 67.8-92.6) 0.0019 Figure 1. Figure 1. Disclosures Kumar: Onyx: Consultancy, Research Funding; Novartis: Research Funding; Abbvie: Research Funding; Celgene: Consultancy, Research Funding; Millenium: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Janssen: Consultancy, Research Funding. Gertz:Smith Kline: Honoraria; Novartis: Honoraria; Onyx: Honoraria; millenium: Consultancy, Honoraria; Celgene: Honoraria.

Abstract Background: The presence of circulating plasma cells (CPCs) is associated with an adverse prognosis in multiple myeloma along the entire spectrum of disease. However, the impact of CPCs prior to autologous stem cell transplantation (ASCT) has not been defined in the era of novel agents. The objective of this study is to assess the impact of the presence and number of CPCs before transplant using 6-color multiparameter flow cytometry (MFC). We also explored the additional prognostic implications of CPCs over the current paradigm for risk stratification at transplant, including high-risk (HR) cytogenetics and disease status at transplant by the IMWG criteria. Methods: A total of 1113 consecutive patients transplanted between 2007 and 2015 in Mayo Clinic were included in the study. Flow-cytometry of peripheral blood to identify clonal CPCs is routinely performed in all patients before ASCT in Mayo Clinic, Rochester. The mononuclear cells from peripheral blood samples are isolated by Ficoll gradient and subsequently stained with antibodies to CD19, CD38, CD45, CD138 and cytoplasmic kappa (κ) and lambda (λ) immunoglobulin light chains. Clonality is assessed by light chain restriction (κ:λ expression ratio of 4:1 [κ restricted] or <1:2 [λ restricted]). The target for collection is >150,000 cellular events. For samples where less than 150,000 clonal events are examined, the number of final clonal events is adjusted to 150,000 events. HR cytogenetics by fluorescence in situ hybridization (FISH) on bone marrow (BM) plasma cells was defined by one of the following abnormalities: t(4;14), del(17p), t(14;16), t(14;20) or +1q, detected at any time point from diagnosis to transplant. Patients who had insufficient plasma cells for FISH analysis in BM specimens were not included in the denominator to calculate the percentage of patients with HR cytogenetics. The primary end-points of this study were post-transplant response, PFS and OS. Result: CPCs were detected in 238 out of 1113 (21.4%) patients, with the median number of CPCs being 82 (range, 1-102381) per 150,000 events. The median age of patients at transplant was 62 years. A total of 1097 (99%) patients had received novel agent based induction therapy with PIs and IMiDs, including 458 (41%) patients who had received both PIs and IMiDs. 401 (36%) patients had received post-transplant maintenance or consolidation therapy. The frequency of t(4;14) in BMPCs was significantly higher in patients with CPCs compared to those without [15.2 vs 7.0% for t(4;14); P<0.001]. The median follow-up from transplant for survivors was 45 months. The 5-year OS rate in patients with and without CPCs was 34% (95% CI, 27-42) and 70% (95% CI, 66-74) respectively (P<0.001). After exploring several cut-offs for the number of CPCs per 150,000 events, we chose a simple pre-transplant risk stratification model: No CPCs (n=874; 78.5%), 0<CPCs≤400 (n=188; 16.9%) and CPCs>400 (n=51; 4.6%). The number of patients achieving stringent complete response post-transplant in groups with no CPCs, 0<CPCs≤400 and CPCs>400 was 310 (36%), 31 (16%) and 3 (6%) respectively (P<0.001). The median PFS in the 3 groups was 27 months (95% CI, 25-30), 15 months (95% CI, 13-18) and 6 months (95% CI, 4-10) respectively (P<0.001) and 5-year OS rates were 70% (95% CI, 66-74), 42% (95% CI, 34-51) and 12% (95% CI, 5-26) respectively (P<0.001). Kaplan-Meier curves for PFS and OS are depicted in Figure I (A and B). In a multivariate model (Table I), the groups with 0<CPCs≤400 and CPCs>400 had an increased risk of death, independent of the presence of HR cytogenetics and disease status at transplant. Conclusion: Our study shows the strong negative prognostic impact of CPCs prior to transplant on post-transplant response and survival in MM in the era of novel agents. The proposed risk stratification model can be easily employed with simple equipment and should be routinely incorporated in the pre-transplant workup. Detailed epigenomic, genomic and transcriptomic analysis of CPCs is urgently needed to uncover the biological basis of resistance to both high-dose cytotoxic therapy and novel agents and identify potential avenues of targeted therapy against CPCs. Disclosures Kumar: Onyx: Consultancy, Research Funding; Kesios: Consultancy; Celgene: Consultancy, Research Funding; Glycomimetics: Consultancy; AbbVie: Research Funding; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding. Dispenzieri:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Alnylam: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; pfizer: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Jannsen: Research Funding. Kapoor:Celgene: Research Funding; Amgen: Research Funding; Takeda: Research Funding. Gertz:Sandoz Inc: Honoraria; NCI Frederick: Honoraria; Celgene: Honoraria; Alnylam Pharmaceuticals: Research Funding; GSK: Honoraria; Novartis: Research Funding; Research to Practice: Honoraria, Speakers Bureau; Med Learning Group: Honoraria, Speakers Bureau; Ionis: Research Funding; Prothena Therapeutics: Research Funding; Annexon Biosciences: Research Funding.

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 The impact of fluorescence in-situ hybridization (FISH) on outcome in AL amyloidosis remains uncertain. We analyzed the response and overall survival (OS) of 692 AL amyloidosis patients with available FISH testing at diagnosis. First line treatment was categorized as autologous stem cell transplant or three non-transplant regimens (melphalan-based; bortezomib-based, and immunomodulatory drug (IMiD)-based). Forty-nine percent of patients had t(11;14), 37% del 13q/monosomy 13 and 19% had trisomy/tetrasomy. Analysis by abnormality type was restricted to t(11;14) and trisomy/tetrasomy sub-groups as chromosome 13 abnormalities were commonly associated with the other abnormalities. Patients with t(11;14) had lower rate of very good partial response or better (≥VGPR) compared to those lacking t(11;14) (56% vs 70%, P=0.001). By regimen stratification, this difference was maintained for bortezomib-based (52% vs 77%; P=0.004) and IMiD-based therapy (13% vs 54%; P=0.04) (Figure 1). Patients with trisomy/tetrasomy had no difference in the rate of ≥VGPR compared to those who did not (66% vs 63%, P=0.62), with no difference within regimen types. OS was similar between t(11;14)-positive and negative patients (median 43 vs 57 months; P=0.58). However, sub-analysis by regimen type showed a significantly inferior OS among t(11;14)-positive bortezomib-treated patients (median 15 vs 27 months; P=0.05) and t(11;14)-positive IMiD-treated patients (median 12 vs 32 months; P=0.05) (Figure 2). Among t(11;14)-positive bortezomib-treated patients, the OS difference was maintained among favorable-prognosis patients, but was absent for poor-prognosis sub-groups (Table). Trisomy/tetrasomy was associated with inferior OS (median 29 vs 69 months; P=0.001), a difference that was maintained for melphalan (median 15 vs 32 months; P=0.01) and borderline significance for bortezomib (median 14 vs 38 months; P=0.09). Multivariate analysis confirmed an independent effect on OS for trisomy/tetrasomy in the study cohort and for t(11;14) among bortezomib-treated patients. FISH analysis is essential in newly diagnosed AL amyloidosis, as it provides prognostic information among treatment groups and may influence the selection of induction treatment. Patients with t(11;14) should be considered for ASCT at diagnosis. Disclosures Dispenzieri: Celgene: Research Funding; Alnylam: Research Funding; pfizer: 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; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jannsen: Research Funding. Kumar:Glycomimetics: Consultancy; AbbVie: Research Funding; Array BioPharma: Consultancy, Research Funding; Kesios: Consultancy; Onyx: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; BMS: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Kapoor:Amgen: Research Funding; Takeda: Research Funding; Celgene: Research Funding.

e19532 Background: The diagnosis of amyloidosis requires histological confirmation of Congo-red (CR) deposits. The tissue source is preferably fat and/or bone marrow biopsy, but at times organ biopsy is required. Methods: We studied 612 patients with systemic light chain amyloidosis to characterize the tissues used to establish the diagnosis Results: The median number of tissue samples biopsied for CR staining was 3. Ninety-five percent of bone marrow (BM) biopsies were stained for CR, while 79% of patients had fat aspiration performed for CR staining. Overall, 76% of patients underwent both procedures. CR stain sensitivity was 69% in BM samples, 75% in fat aspiration and in 89% for both sources combined. CR stain sensitivity was 97-100% for heart, renal and liver biopsies. 42% of patients with renal involvement, 21% of patients with liver involvement and 13% of patients with heart involvement underwent organ biopsy, when a less invasive safer biopsy would have established the diagnosis. Predictors of need for organ biopsy were male sex, limited organ involvement and lack of fat aspiration (Table). Conclusions: Fat aspiration is underutilized for histologic confirmation of amyloidosis. Organ biopsies (particularly renal biopsies) were performed at a high rate, which represents a failure to recognize the disease (i.e. failure to screen with a light chain assay etc.). Early awareness of amyloidosis in the differential diagnosis of patients with organ dysfunction may lead to fewer unnecessary organ biopsies [Table: see text]

8020 Background: Circulating plasma cells (CPCs) at diagnosis, prior to transplant and at relapse have a negative prognostic impact on survival in multiple myeloma (MM). However, the impact of changes in CPCs along the course of illness has not been defined. Methods: We evaluated 247 patients with newly diagnosed MM (NDMM) undergoing early autologous stem cell transplantation (ASCT) in the era of novel agents (2007 to 2015), who had serial evaluation of CPCs at diagnosis and pre-ASCT by 6-color flow cytometry. Results: The median age at transplant was 62 years.A total of 117 (47%) patients had no detectable CPCs at both time points (CPC-/-), 82 (33%) had CPCs at diagnosis followed by complete eradication after induction therapy (CPC+/-) and 48 (19%) had detectable clonal CPCs at transplant, with persistence of cells (CPC+/+; n=45) or emergence of new CPCs (CPC-/+; n=3) after induction. The incidence of t(11;14) by iFISH was lower in the CPC-/- group (19%) compared to CPC+/- (29%) and CPC +/+ or -/+ (39%) groups ( p=0.033). Conversely, the incidence of hyperdiploidy was significantly higher in patients with CPC-/-, compared to those with CPC+/- and CPC+/+ or -/+ (64%, 44% and 39% respectively; p=0.005). The rate of post-ASCT stringent complete response was 32% in the CPC-/- group, 30% in CPC+/- group and 12% in CPC+/+ or -/+ group ( p=0.018). At a median follow-up of 58 months from ASCT, the median progression-free survival (PFS) from transplant in the 3 respective groups was 30, 24 and 14 months and the 5-year overall survival (OS) rates were 83%, 70% and 43% ( p<0.001 for both comparisons). On a multivariate analysis, using CPC-/- group as the comparator, PFS and OS was significantly inferior in CPC+/- (RR 1.6; p=0.020 and RR 2.7; p=0.008 for PFS and OS respectively) and CPC +/+ or -/+ groups (RR 2.9; p<0.001 and RR 5.8; p<0.001 for PFS and OS respectively). Conclusions: Clonal CPCs are detectable in more than 50% of newly diagnosed MM patients undergoing upfront ASCT. Monitoring for CPCs before initiation of induction therapy and before ASCT by 6-color flow cytometry is highly predictive of outcome in NDMM and should be incorporated into prospective clinical trials.

e18154 Background: Due to an increase in the elective decision to pursue contralateral prophylactic mastectomy (CPM), the incidence of bilateral mastectomy (BM) with/without postmastectomy reconstruction (R) [BM+/-R] has increased in the last decade. While prior studies at academic centers have investigated concerns regarding its impact on subsequent cancer therapy, we hypothesized that BM+/-R is associated with a delay in initiation of adjuvant therapy (AT) in a community oncology clinic. Methods: This study involved chart review of all patients who underwent mastectomy as definitive surgery for stage I-III breast cancer between 2007 and 2012 and were subsequently followed at Essentia Health Cancer Center. The primary endpoint of the study was the proportion of patients receiving subsequent AT within 6 weeks of surgery (TST6) when compared between different surgical groups. Results: A total of 478 patients were included in the study, with a median age of 63 years. Patients were divided into 4 groups, BM-R (n = 133), BM+R (n = 73), unilateral mastectomy (UM) –R (n = 244) and UM+R (n = 28). Significant demographic differences were identified between the groups including age ( p< 0.001), medical comorbidities ( p< 0.001), and BMI ( p< 0.001). The incidence of any major post-operative complication (including flap/implant failure, infection and wound necrosis/dehiscence) or additional surgeries within 6 weeks of surgery was higher in patients undergoing reconstruction, [BM+R (19%) and UM+R (18%)] compared to those who did not [BM-R (6%) and UM-R (4%)] ( p< 0.001). Patients having major complications or needing additional surgeries within 6 weeks had a lower adjusted likelihood of achieving TST6 compared to those who did not (OR = 0.35; p= 0.009). However, there was no significant difference in TST6 between the surgical groups ( p= 0.31). Conclusions: Immediate post-mastectomy reconstruction is associated with a significantly increased risk of postoperative complications or need for additional surgeries within 6 weeks. In an appropriately selected patient population, CPM and reconstruction do not significantly delay subsequent AT in a community oncology clinic.