Kyle, Robert A.

Abstract Introduction: Localized immunoglobulin light chain amyloidosis (LAL) is a rare disease. Systematic data regarding its presentation, management and patient outcomes are limited to small case series. Our objective was to systematically describe the Mayo clinic experience of patients with LAL. Methods: We retrospectively reviewed clinical records of 403 patients with biopsy proven localized amyloidosis seen at the Mayo Clinic between 1969-2014. Median follow-up for survival and progression were 72 months and 39 months, respectively Results: OF 5551 patients with light chain amyloidosis seen at the Mayo clinic during the study period, 403 (7%) had LAL. Median age at diagnosis was 60 years (range, 13-93) and 51% of them were male. Sites involved included: urothelial (bladder, ureter, renal pelvis), 75 (19%), larynx, 51 (13%), lung parenchyma, 42 (11%), skin, 44 (11%), synovial tissue 36 (9%), tracheobronchial, 31 (8%), gastrointestinal tract, 30 (8%), seminal vesicles, 22 (6%), eyes, 23 (6%), pharynx 22 (6%) and other 24 (6%). Typing was performed in 178 (45%) cases. A monoclonal protein was detected in 23 of 351 (7%) evaluated cases, 5 of which had different light restriction from that of LAL. Thirty one (8%) patients had a co-existent autoimmune disease. No patients progressed to systemic AL. Of 403, 109 (27%) were observed or received supportive care only and 241 (60%) underwent local removal of the amyloid deposits. Sixty-four (16%) patients required repeated interventions (median 1, range 1-4, upper decile requiring 4 interventions) for progressive disease. The most common sites requiring repeated interventions were: urothelial (33%), laryngeal (19%) and tracheobronchial (8%). Ten year overall survival (OS) and progression free survival were 79% and 61%, respectively and there was no difference according to site of involvement. Of the 70 patients that died during the follow-up period, cause of death was known for 29 and death was attributed to LAL in only 2 cases. Conclusions: In the largest series of patients with LAL reported so far we demonstrated that LAL has an excellent prognosis but can sometimes be associated with significant morbidity. Although our study was limited by incomplete typing in 55% of cases, it appears that true LAL does not "progress" to systemic amyloidosis. However, systemic amyloidosis can frequently involve organs typical involved only in LAL;, therefore a complete work-up for systemic disease should be performed in all patients with LAL. Treatment usually involves local excision for symptom palliation. In 16% of cases, repeated interventions for relapse/progression were required and as a result, follow-up is recommended, especially for cases involving the urothelial and upper respiratory tract. Disclosures Kumar: Skyline, Noxxon: Honoraria; Celgene, Millennium, Onyx, Novartis, Janssen, Sanofi: Research Funding; Celgene, Millennium, Onyx, Janssen, Noxxon, Sanofi, BMS, Skyline: Consultancy.

Abstract Background WM remains an incurable cancer despite recent advances. While a phase II trial has demonstrated efficacy of dexamethasone, rituximab and cyclophosphamide (DRC) in the treatment-naïve (TN) patients, this regimen has not been studied systematically in the relapsed/refractory (R/R) setting. Recent data has suggested the MYD88mutation status in WM patients can serve as a predictive marker with therapies such as ibrutinib. We examined the efficacy and tolerability of up to 6 cycles of DRC, with focus on R/R population and activity of this regimen with respect to the patients' MYD88L265Pstatus. Methods Records of WM patients seen consecutively at Mayo Clinic campuses in Rochester, Arizona and Florida from 01/2007 to 12/2014 were reviewed. MYD88L265P status, as assessed by AS-PCR, was recorded when available. Data obtained from symptomatic patients treated with DRC (dexamethasone 20 mg intravenously followed by rituximab 375 mg/m2 intravenously on day 1 and cyclophosphamide 100 mg/m2 orally bid on days 1 to 5) were analyzed. Time-to-event analyses were performed from DRC therapy using the Kaplan-Meier method. We used the Consensus response criteria (6th International Workshop). Results Of 100 symptomatic patients who received DRC, 50 had R/R WM (40% refractory) and 50 were TN. Table 1 shows the patients' baseline characteristics. In the R/R population, DRC was 2nd line (range 2-8) therapy in 58% of patients. The median IgM levels declined from 3,870 mg/dL to 1,846 mg/dL (p=0.0001) at best response. Median follow-up from DRC was 51 months (95% CI: 38-55). The median time-to-best response was 6.8 (0.5-28) months. Overall response rate (ORR) was 87% [VGPR 4%, PR 64%, MR 19%]. Four patients (9%) achieved SD and 2 patients (4%) had PD. Of the sixteen deaths (32%) noted at time of analysis, 11 were related to progressive disease. The median disease-specific survival (DSS) from DRC was not reached (NR) (95% CI: NR-NR). The median progression-free survival (PFS) and time-to-next-therapy (TTNT) were 32 months (95% CI: 15-51) and 50 months (95% CI: 35-60), respectively. In contrast, in the TN patients the median IgM levels declined from 4,130 mg/dL to 1,250 mg/dL (p=0.0001) at best response; median time to best response was 11 (0.6-47) months; median follow-up from DRC was 30 months (95% CI: 21-36). ORR was 96% [VGPR 17% (n=8), PR 70% (n=32), MR 9% (n=4)]. Of the 7 deaths (14%) at time of analysis, 4 were related to WM progression. Median DSS from DRC was NR (95% CI: NR-NR); median PFS and TTNT were 34 months (95% CI: 23-NR) and NR (95% CI: 37-NR), respectively. Among 29 genotyped patients in whom MYD88 mutation status was available, MYD88L265P was present in 25 patients (8 of 10 TN and 17 of 19 R/R patients). The response rates and the time-to-event outcomes were similar in the MYD88L265P and wild-type patients. Grade ≥3 adverse effects included neutropenia (20%), thrombocytopenia (7%) and infections (3%). Conclusions Similar to the frontline setting, DRC is an active and well-tolerated salvage regimen. In contrast to ibrutinib, DRC offers a less expensive, limited-duration treatment option, with preliminary data suggesting activity independent of patients' MYD88 mutation status. Disclosures Ailawadhi: Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Kumar:Glycomimetics: Consultancy; Sanofi: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; AbbVie: Research Funding; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Kesios: Consultancy; Array BioPharma: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy. Dispenzieri:Jannsen: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; pfizer: Research Funding; Celgene: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees. Ansell:BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Kapoor:Amgen: Research Funding; Celgene: Research Funding; Takeda: Research Funding.

Abstract Background: Aberrant B-cell receptor (BCR) and MYD88 signaling cooperatively drive Waldenstrom macroglobulinemia (WM) tumor cell survival. To sustain BCR-driven growth and maintain optimal cellular homeostasis, WM cells upregulate proteasome function. We have recently described the role of two distinct 19S proteasome-associated deubiquitinating enzymes (DUBs), USP14 and UCHL5, in maintaining WM-cell viability. Pharmacologic inhibition with b-AP15 (commercial compound) results in WM-cell death and accumulation of high molecular weight ubiquitinated protein conjugates; an event that is phenocopied by siRNA knockdown of USP14 and UCHL5. VLX1570 is a lead-optimized clinical grade analog of b-AP15 with enhanced solubility, stability and target residence time. We investigated the effect of VLX1570 on BCR components, WM cell survival proteins and its in vivo activity in a human xenograft model of WM. Materials: VLX1570 was obtained from Vivolux AB and bortezomib from Sellekchem. Human WM cell lines (BCWM.1, MWCL-1 and RPCI-WM1) and their drug-resistant derivatives were used (total n=12). Bone marrow aspirates from WM-patients and from healthy donors were obtained from the Mayo Clinic biospecimens core. PBMCs from healthy donors were used as comparators where needed. NOD/SCID mice were obtained from Taconic Labs and used for profiling the in vivo properties of VLX1570. Results: We first examined for USP14/UCHL5 protein expression by immunohistochemical analysis in primary tumor tissue from WM patients and compared it to healthy donor cells. WM patient-derived cells exhibited greater staining intensity of both DUBs. Preferential binding of VLX1570 to USP14 and UCHL5 in WM cells was probed in a WM cell using an enzyme-based competition assay (HA-Ub-Vs), which demonstrated time-dependent decrease in labeled USP14 and UCHL5 after treatment with VLX1570. In drug-resistant (bortezomib or ibrutinib-resistant) WM cells, VLX1570 induced >50% tumor-specific apoptosis and displayed synergistic activity with ibrutinib (median CI: 0.5). In addition to ER stress markers, we had previously observed that gene expression of BCR-signalosome components were reduced in VLX1570-treated WM cells (NanoString platform) and this was substantiated at the protein level where p-SYK, SYK and BTK decreased in a time-dependent manner. BCR end-effectors were probed in response to VLX1570 and a decrease in nuclear translocation of NFkB (p65) was noted. USP14 has been shown to control the availability of the chemokine receptor CXCR4, which regulates homing of WM cells to bone marrow. After VLX1570 treatment, we noted a significant decrease in CXCR4 surface receptor expression in all WM cell lines tested and primary WM cells. Lastly, to determine the in vivo anti-WM effects of VLX1570, we injected NOD/SCID mice (xenotransplanted with RPCI-WM1-Luc cells) with VLX1570 (I.P. route, 4.4mg/kg every other day) and measured tumor burden along with pharmacodynamic indicators. VLX1570-treated mice (n=7) demonstrated significantly lower tumor volumes by caliper measurement and bioluminescent signal (p=0.01 - 0.003) as well as reduced serum human-IgM, compared to vehicle-treated mice (n=7). Importantly, mice treated with VLX1570 survived longer vs. vehicle-treated mice (median survival, 62 vs. 44 days, respectively, p=0.0008). No unforeseen toxicities were noted and weight of the mice in vehicle vs. VLX1570-treated mice did not significantly change. IHC analysis in mice tumor tissues demonstrated reduced CXCR4, human-IgM, Ki67 and increased cleaved caspase-3 and ubiquitinated (k48-linked) protein level, the latter serving as a more specific indicator of USP14/UCHL5 inhibition. Conclusions: We provide substantial in vitro and in vivo evidence on the anti-WM effects of a novel first-in-class clinical grade USP14/UCHL5 inhibitor, VLX1570. In addition to anticipated induction of ER stress machinery, we describe for the first time VLX1570-mediated modulation of BCR components and WM cell survival proteins as well as demonstrate its robust activity in an aggressive human xenograft model of WM. These data provide the rationale for a clinical trial of single agent VLX1570 in patients with symptomatic WM. Disclosures Martin: Janssen: Consultancy, Honoraria; Acerta: Consultancy; Gilead: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Bayer: Consultancy. Gullbo:Vivolux AB: Other: Shareholder. Linder:Vivolux AB: Other: Shareholder.

Abstract Abstract 4990 Background: Although there have been improvements in 5-year overall survival (OS) rates among patients with AL amyloidosis over the past decades, OS is still poor, and death rates within the first 3–6 months after diagnosis have not changed significantly. This retrospective study was performed to identify risk factors for and causes of death during the first 90 days following diagnosis of AL amyloidosis. Method: From July 2002 to April 2009, 301 patients with a diagnosis of AL amyloidosis who were seen at Mayo Clinic within 30 days of diagnosis were identified from the dysproteinemia database. The 100 who died within 90 days were the focus of our study. The other 201 who were alive beyond 90 days were used as a comparator group. Outside physician offices were contacted to obtain further information pertaining to treatment and cause of death for our study group. Results: Of the 100 patients with early death, median age at diagnosis was 63.7 years (range: 34.7–89.4). 25 patients were diagnosed with concurrent multiple myeloma (MM) based on MM-specific end-organ damage. Overall, the number of patients with 2, 3 and 4 organs (cardiac, renal, nerve or liver) involved with amyloidosis was 37, 15 and 4, respectively. Using the cardiac biomarker staging system, 78% of 46 evaluable patients were stage III at diagnosis followed by 22% stage II and no stage I. Table 1 describes the characteristics of the studied population. Amyloid-related deaths were identified in 61 patients with the most common cause being cardiac arrest or sudden death (33%) followed by end-organ failure (24%). Treatment was started in 50% of patients; 34% received no treatment; and no treatment information was available for the remainder. OS was 54.5 days in patients who received treatment as compared to 7.5 days in those who received no treatment (p<0.0001); outcomes were similar in the group in whom no treatment information was available and those patients who were known to have received treatment. Melphalan with dexamethasone was the most common treatment (21%) and was associated with improved OS compared to other treatments including novel agents (57 vs. 26 days, p=0.003). Outcomes were no different if the patients had received novel therapies, but numbers were small. When compared to patients who lived for more than 90 days from their diagnosis, patients with early mortality had higher median intraventricular septum (IVS) (15 vs. 13 mm, p<0.0001), lower ejection fraction (EF) (50 vs. 64%, p<0.0001), and higher troponin-T (0.125 vs. 0.01 ng/ml, p<0.0001) and NT-proBNP (9020 vs. 1292 pg/ml, p<0.0001). We also found that patients who died within 90 days of their diagnosis had significantly higher plasma cell labeling index (PCLI), uric acid, beta-2 microglobulin, involved free light chain (FLC) and creatinine. Conclusion: This study highlights the characteristics of patients who died within 90 days of diagnosis of AL amyloidosis. The majority of patients died from arrhythmia and organ failure. This implies that other interventions aside from treatment of the underlying plasma cell (PC) disorder will likely be required to change the early outcomes of this disease. Disclosures: Lacy: Celgene: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Dispenzieri:Celgene: Honoraria, Research Funding; Binding Site: Honoraria.

Abstract Background Waldenstrom macroglobulinemia (WM) is an IgM-associated lymphoplasmacytic lymphoma, first described over seven decades ago. Although WM is typically a disease of the elderly, with a median age at diagnosis of ~ 67 years, approximately 10% of patients are ≤50 years (y) of age at diagnosis. Data for young patients are sparse and the few available studies demonstrate inconsistent findings, with potential overestimation of survival owing to inclusion of patients with smoldering WM. In this case-control study, we evaluate outcomes, prognostic features and impact of changing therapies in a large cohort of young symptomatic WM patients compared to matched older patients seen over the course of the past five decades. Methods The medical records of all WM patients seen consecutively at Mayo Clinic from 01/1960 to 10/2013 were reviewed. Of 1181 patients, 140 (11.8%) were ≤ 50 y of age at diagnosis. A cohort of patients 65 y or older at diagnosis, matched 1:1 by the time of diagnosis, served as the control population. The patients were divided into 3 groups based on the timing of initiation of therapy: Group 1 (1960-1977), Group 2 (1978-1995) and Group 3 (1996-2013). The baseline characteristics were compared. Initiation of frontline therapy was used for all time-to-event analysis using the Kaplan Meier method. Results Younger patients were more likely to present with adenopathy and splenomegaly, have higher IgM levels and hyperviscosity symptoms (Table 1). The median follow-up from the frontline therapy was similar (10.7 y vs. 10 y for the control population). At the time of analysis, 91% of the deaths for the younger cases were WM-related compared to 58% in the control arm (p=0.0001). Younger patients had a better OS with a median disease-specific survival (DSS) of 15.6 y (95% CI: 13-21; 10-y OS of 77%) vs. 11 y (95% CI: 7.8-12; 10-y OS of 51%) for the older patient (p=0.0003). Among the young patients, there was no difference in the median DSS across the 3 groups (p=0.42). However, the median DSS for the control group incrementally improved (p=0.02) over the 3 time periods (Table 1). In the younger patients, no improvement in DSS was noted with the use of either frontline rituximab-based therapy compared to non-rituximab based regimens [median NR (95% CI: 7.6-NR) vs. 15.8 y (95% CI: 13-22) with other regimens, p=0.30], or frontline chlorambucil-based compared to non-chlorambucil based regimens [median 16 y (95% CI: 12-22) vs 15.6 y (95% CI: 12-NR) with other regimens, p=0.73]. In the control group, however, there was significant difference in DSS among patients who received frontline rituximab-based compared to non-rituximab based regimens [median NR (95% CI: 8.3-NR) vs 9.1 y (95% CI: 5.6-12) with other regimens, p=0.04], or frontline chlorambucil-based vs non-chlorambucil based regimens [8 y (95% CI: 5-12) vs 12.3 y (95% CI: 11-NR) in other regimens; p=0.001]. Conclusion Striking differences in presentation are evident in young WM patients compared to their older counterparts. The incorporation of rituximab to the previously existing anti-WM regimens and the transition to non-chlorambucil based regimens has resulted in substantial survival gains in the older WM population over the past five decades. However, such improvement in outcome has not yet been observed in the young patients. The majority of younger patients, despite a protracted disease course, succumb to their disease. Disclosures Ansell: BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Ailawadhi:Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Reeder:Novartis: Research Funding; Celgene: Research Funding; BMS: Research Funding; Millennium: Research Funding. Kumar:Kesios: Consultancy; Janssen: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; AbbVie: Research Funding; BMS: Consultancy; Onyx: Consultancy, Research Funding; Glycomimetics: Consultancy; Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees. Dispenzieri:Alnylam: Research Funding; Celgene: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, 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; pfizer: Research Funding; Jannsen: Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding; Amgen: Research Funding.

Abstract Abstract 3893 Background: When screening for clonal disease, the kappa (k) to lambda (l) FLC ratio (FLC-R) is employed to correct for both impaired catabolism (renal function) and non-specific production (generalized immune overstimulation). This adjustment makes it possible to identify patients with relative imbalances between k and l levels, which typically qualifies for clonal excess and has been of value in screening for and prognosticating in patients with most clonal plasma cell disorders. We previously performed a population-based study among Olmsted County residents to ascertain the prevalence of monoclonal gammopathy of undetermined significance (MGUS) and light chain MGUS. We hypothesized that by using this cohort, we could identify whether the FLC assay provides information that would be prognostic in a general population of people 50-years and older. Methods: The Olmsted MGUS prevalence cohort was comprised of 21,463 of the 28,038 enumerated individuals over the age of 50 who were living Olmsted between 1/1/95 and 11/21/2003. The final sample size of individuals for the present study was 15839 due to patient losses secondary to blinding, inadequate sample to perform the FLC assay, and known MGUS or LC-MGUS. For the multivariate analyses, another 772 were excluded due lack of coincident creatinine measurement. The FLC measurements were performed using the FLC assay (Binding Site, Birmingham, UK). The respective reference ranges for k FLC and l FLC are 0.33–1.94 mg/dL and 0.57–2.63; therefore, the reference range for the sum of k and l FLC (S FLC) is 0.90–4.57 mg/dL. Survival time was calculated from the time of sample ascertainment. Results: Forty-five percent of the cohort was male. The median age was 63 years (range 50, 109). On univariate analysis, the hazard ratio for death for those patients with the highest decile of S FLC relative to the other 90% of patients in the cohort was 4.3 (95%CI 4.01, 4.62), Figure 1. Because serum immunoglobulin FLC rise with age and with renal insufficiency, a multivariate analysis was performed to exclude the possibility that S FLC was merely a surrogate for these other parameters. Table 1 shows both univariate and multivariate risk for death. With these other variables included, the hazard ratio for death with highest S FLC decile was lower, but remained significant; hazard ratio, 2.0 (95%1.88, 2.2). Conclusions: The finding that S FLC above the normal range (i.e. highest decile) is associated with inferior overall survival among individuals above the age of 50, excluding patients with known MGUS or LC-MGUS, is important and merits further investigation. Although there is an association between S FLC, renal function, gender, and age, excess risk of death still exists after adjusting for these risk factors on multivariate analysis. The mechanism by which S FLC predicts for outcomes is uncertain, but one could postulate that conditions resulting in overactivation of the immune system contributes to excess risk of death. Whether the S FLC adds above and beyond other conventional inflammatory markers like ESR or CRP cannot be determined by the present study, but is worthy of further investigation. Disclosures: Dispenzieri: Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Off Label Use: No FDA approved indication. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Mead:Binding Site: Employment. Bradwell:Binding Site: Equity Ownership, Patents & Royalties.

Abstract Amyloid fibrils consist in part of immunoglobulin light chains. Because light chains are synthesized by plasma cells, it seems reasonable to treat patients with amyloidosis with alkylating agents. Two patients who had primary amyloidosis and were treated with melphalan subsequently developed a rapidly fatal acute leukemia. Since melphalan may play a significant role in the development of acute leukemia, we suggest that alkylating agents not be used in the treatment of patients with amyloidosis without full consideration of risks involved, particularly until it has been proved that these drugs are beneficial.

Abstract Background Bendamustine/rituximab (BR) and dexamethasone/rituximab/cyclophosphamide (DRC) combination therapy are acceptable options for the treatment of WM, both in the frontline or salvage setting. Prospective data, however, are only available in treatment-naïve (TN) WM patients, and no direct comparison between BR and DRC has been reported. We compared outcomes of BR and DRC in relapsed/refractory (R/R) and TN WM patients seen at a single institution. Methods Records of WM patients seen consecutively at Mayo Clinic from 01/2007 to 12/2014 were reviewed. The MYD88L265P status, as assessed by AS-PCR, was recorded when available. The data obtained from symptomatic patients treated with DRC or BR were analyzed. The time-to-event analyses were performed from DRC or BR therapy using the Kaplan-Meier method. We used the Consensus criteria (6th International Workshop) for response assessment. Results Of 160 WM patients, 60 patients received BR (73% in R/R setting) and 100 patients received DRC (50% in R/R setting). In the R/R population, BR was the 2nd line (range 2-11) therapy in 47% of patients, while DRC was 2nd line (range 2-8) in 58% of patients. Rituximab monotherapy was the only prior line of therapy in 8 (20%) patients in the BR group and 20 (40%) in the DRC group (p=0.66). Baseline characteristics were similar in patients treated with BR or DRC (Table 1). Six patients received both BR and DRC during their disease course and overlapped between the 2 cohorts. Among the previous untreated patients, the median IgM levels decreased from 3,785 mg/dL to 724 mg/dL (p=0.0001) at best response with BR, while it decreased from 4,130 mg/dL to 1,250 mg/dL (p=0.001) with DRC. The median time to best response was 6.1 (1-25) months in the BR group and 11 (0.5-47) months in the DRC group (p=0.13). For patients treated with BR, the overall response rate (ORR) was 93% [VGPR 29% (n=4), PR 57% (n=8), MR 7% (n=1)]. One patient (7%) had progressive disease. For patients treated with DRC, ORR was 96% [VGPR 17% (n=8), PR 70% (n=32), MR 9% (n=4)]. One patient (4%) achieved SD. Median follow up in the BR and DRC groups were similar (30 months). The 2-year progression-free survival (PFS) was 88% and 61% in the BR and DRC groups, respectively (p=0.08). The 2-year time-to-next therapy (TTNT) was 88% and 76% in the BR and DRC groups, respectively (p=0.35). Median PFS, TTNT and disease specific survival (DSS) were not reached with either regimen. In the R/R setting, the median IgM levels decreased from 3,880 mg/dL to 659 mg/dL (p=0.0001) at best response with BR, and from 3,870 mg/dL to 1,846 mg/dL (p=0.001) with DRC. The median time to best response was similar [7 (1-39) months with BR and 7 (0.5-28) months with DRC (p=0.77)]. For patients treated with BR, ORR was 95% [CR 3% (n=1), VGPR 38% (n=14), PR 41% (n=15), MR 13% (n=5)]. Two patients (5%) had progressive disease. With DRC, the ORR was 87% [VGPR 4% (n=2), PR 64% (n=30), MR 19% (n=9)]. Four patients (9%) achieved SD and 2 patients (4%) had progressive disease. Median follow up from BR was 32 months and 51 months from DRC (p=0.24). The 2-year PFS was 66% and 53% in the BR and DRC groups, respectively (p=0.08). The 2-year TTNT was 75% and 68% in the BR and DRC groups, respectively (p=0.24). The median DSS in the BR group was 69 months (95% CI: 65-69) and NR (95% CI: NR-NR) in the DRC group (p=0.57). The proportion of patients with R/R disease was significantly higher in the BR cohort (Table 1). In a bivariate analysis of the entire cohort for PFS, incorporating the setting (TN vs. RR) and the regimen involved (BR vs. DRC), the latter emerged as a significant factor (hazard ratio 0.52, p=0.019) in favor of BR. Time-to-event outcomes and response rates were similar in the MYD88L265P and MYD88WT patients. Grade ≥ 3 adverse events were neutropenia (12%), infections (7%) and nausea/vomiting (2%) with BR, and neutropenia (20%), thrombocytopenia (7%) and infections (3%) with DRC. Conclusions Although both DRC and BR regimens show activity and comparable toxicities, BR regimen shows a trend for superior PFS in WM patients, both in the TN and R/R setting. No difference was seen in TTNT. MYD88 L265P mutation status does not appear to impact activity of BR or DRC. Randomized controlled trial(s) are needed to confirm our findings. Disclosures Ailawadhi: Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Ansell:BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Reeder:Millennium: Research Funding; BMS: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Dispenzieri:Jannsen: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; pfizer: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Alnylam: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees. Kumar:Sanofi: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; AbbVie: Research Funding; Array BioPharma: Consultancy, Research Funding; BMS: Consultancy; Kesios: Consultancy; Glycomimetics: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Noxxon Pharma: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding; Amgen: Research Funding.

Abstract A patient with symptomatic primary cryoglobulinemia was followed for 9 yr and was found at autopsy to have generalized amyloidosis. There was a monoclonal serum protein spike of IgG kappa type that was cryoglobulin. The cryoglobulin was further characterized as IgG2 kappa Gm (n-). This case constitutes, to our knowledge, the first example of amyloidosis associated with monoclonal IgG cryoglobulinemia, with characterization of the monoclonal serum cryoglobulin, and also the first reported case of successful symptomatic treatment of cryoglobulinemia by plasmapheresis.

Abstract BACKGROUND: Necrobiotic Xanthogranuloma (NXG) is a rare chronic granulomatous disorder of the skin associated with monoclonal gammopathies (MG). Due to its rarity, data on response to various therapies are largely limited to single case reports or small case series. Hence, we described the clinical features in patients with NXG and MG as well as their subsequent disease course and response to treatment. METHODS: This was a retrospective study evaluating 35 patients with NXG and coexisting MG from 1994-2015 who were evaluated in the Hematology Outpatient Clinic at the Mayo Clinic, Rochester. All patients had a biopsy proven diagnosis of NXG with the concurrent presence of a serum monoclonal gammopathy. RESULTS: The median age at diagnosis was 56 years (range: 26-88). Most patients had a plasma cell dyscrasia (28 MGUS; 5 Smoldering myeloma) while 2 had chronic lymphocytic leukemia. Themost common monoclonal (M) protein was IgG kappa (60%). The median M-spike was 1.1 g/dL (range: 0-3). The most common site of NXG was periocular (66%). All patients received treatment, with over half requiring >3 different lines of treatment. The treatments were heterogeneous and included excision, intra-lesional injection, radiotherapy as well as systemic treatment. The types of systemic treatment used and clinical response are reported in Table 1. The median follow up was 46 months (range: 4-234) and the median survival was not reached but at the time of analysis 80% were still alive. At last follow-up, 80% of patients had signs of either clinical improvement or stable skin disease. Eight patients (23%) had disease progression to multiple myeloma at a median of 67 months (Range: 21 - 107). CONCLUSIONS: We report the clinical findings and treatment outcomes of one of the largest series of patients with NXG associated with MG. The clinical course is generally indolent but malignant transformation is not uncommon. Cutaneous objective responses can be achieved with various systemic agents used in the treatment of lymphoproliferative malignancies. Table 1. Treatment Types and Clinical Response Rates Treatment No of patientsA Clinical Benefit Rate B Response rateC Chemotherapy - Chlorambucil +/- Steroids - Melphalan/Steroids - Cytoxan/Steroids - Cladribine - Vincristine/doxorubicin/dexamethasone - High dose therapy with stem cell rescue - Fludarabine/cyclophosphamide/rituximab 5 3 4 3 2 3 1 2/5 (40%) 0/3 (0%) 1/4 (25%) 1/3 (33%) 1/2 (50%) 2/3 (67%) 1/1 (100%) 1/5 (20%) 0/3 (0%) 0/4 (0%) 1/3 (33%) 0/2 (0%) 2/3 (67%) 1/1 (100%) Novel agents - Thalidomide +/- Steroids - Lenalidomide +/- Steroids - Bortezomib +/- Steroids - Bortezomib/Lenalidomide/Dexamethasone 11 14 4 1 5/11 (45%) 10/14 (71%) 2/4 (50%) 1/1 (100%) 4/11 (36%) 7/14 (50%) 1/4 (25%) 1/1 (100%) Intravenous immunoglobulin 4 3/4 (75%) 2/4 (50%) Systemic steroids alone 11 4/11 (36%) 4/11 (36%) Rituximab 6 2/6 (33%) 1/6 (17%) AntibioticsD 3 0/3 (0%) 0/3 (0%) ImmunosuppressantsE 6 1/6 (17%) 0/6 (0%) ANo of patients who underwent a particular therapy amongst the 35 patients in the study cohort. BClinical Benefit: Improvement or stable skin disease CResponse: Improvement in skin disease DAntibiotics: Fluoroquinolones, Tetracycline EImmunosuppressants: Cyclosporine, Methotrexate, Plaquenil Disclosures Kumar: Celgene, Millennium, Onyx, Novartis, Janssen, Sanofi: Research Funding; Celgene, Millennium, Onyx, Janssen, Noxxon, Sanofi, BMS, Skyline: Consultancy; Skyline, Noxxon: Honoraria.