Gonsalves, Wilson I.

Abstract Background: Among patients with immunoglobulin light chain (AL) amyloidosis, there is little consensus on when reinstitution of chemotherapy should occur (Milani and Dispenzieri, International Society of Amyloidosis 2016). AL amyloidosis patients who are treated with high dose chemotherapy followed by autologous stem cell transplant (ASCT) are a relatively low-risk and homogenous population, making them an ideal group to study practice patterns. Methods: We conducted a retrospective study to evaluate the patterns of relapse or progression and the timing of re-initiation of therapy among 146 patients who were initially treated with ASCT at Mayo Clinic between 1996 and 2009 and who received second-line therapy between 7/9/1997 and 4/12/2012. Results: The median time from ASCT to second-line therapy was 23.6 months and the median follow up post ASCT was 57.5 months. The indications for second-line treatment were: 1) both hematologic and organ progression 24.7% (36 patients); 2) organ progression only 41.1% (60); 3) hematologic relapse only 34.2% (50). The median dFLC at the time of starting second-line therapy was 10.5 mg/dL (1.6 - 59.5 mg/dL), which was 44.9% (13.8-167.2%) of dFLC level at diagnosis. Increase in proteinuria by > 50% from nadir (that was also at least 1g/24 hours, i.e. renal progression) was present in 35.8%. Increase in NT proBNP by >30% from nadir and minimum of 300 pg/mL was present in 48.9% of patients. The respective 4 years overall survival rates from the time of ASCT were 87.8%, 63.9%, and 56.7% (p=0.0016) for patients who had hematologic relapse, organ progression only and both organ and hematologic progression. Comparisons of laboratory markers at diagnosis, nadir of post ASCT and initiation of second-line therapy are listed in the table. Conclusions: Our study investigated the patterns of relapse / progression following upfront ASCT. This provides some insights on practice patterns of when physicians re-initiate therapy. Table Table. Disclosures Gertz: NCI Frederick: Honoraria; Celgene: Honoraria; Med Learning Group: Honoraria, Speakers Bureau; Research to Practice: Honoraria, Speakers Bureau; Novartis: Research Funding; Prothena Therapeutics: Research Funding; GSK: Honoraria; Sandoz Inc: Honoraria; Ionis: Research Funding; Alnylam Pharmaceuticals: Research Funding; Annexon Biosciences: Research Funding. Kumar:Millennium: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; AbbVie: Research Funding; Glycomimetics: Consultancy; Janssen: Consultancy, Research Funding; BMS: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Consultancy, Research Funding; Kesios: Consultancy. Kapoor:Celgene: Research Funding; Amgen: Research Funding; Takeda: Research Funding. Dispenzieri:Prothena: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding; Celgene: Research Funding; Jannsen: Research Funding; pfizer: Research Funding; 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.

Abstract Introduction High dose chemotherapy and autologous stem cell transplantation (ASCT) is an effective therapy for eligible patients with newly diagnosed systemic AL amyloidosis. Dose attenuated melphalan is used in patients with older age, renal dysfunction, and multi-organ involvement in an effort to limit treatment related mortality. Reducing the dose of melphalan compromises response rates and survival outcomes, but this is often contributed to frailty of these patients. The revised Mayo staging (MS) system improves risk stratification and helps develop risk-adapted therapies. We analyzed the outcomes of ASCT following standard [(200 mg/m2); SD group] versus risk adapted [(140-160 mg/m2); RD group] melphalan conditioning, in the context of the factors typically leading to dose modification. Methods Three hundred and twenty nine patients with newly diagnosed systemic AL amyloidosis who underwent conditioning with melphalan followed by ASCT at Mayo Clinic between 2006 and 2015 were identified using existing databases. The clinical and laboratory data, treatment and follow - up details were collected by chart review and analyzed retrospectively. Overall survival(OS) was defined as the time from start of initial therapy until death from any cause or last follow up. Progression free survival(PFS) was defined as the time to relapse or progression requiring change or reinstitution of treatment or death from any cause. The OS and PFS curves were estimated using Kaplan-Meier method while log rank test was used to estimate their difference. Multivariate survival analysis was performed using the Cox proportional hazards model. Results Among the 329 patients, 240 patients were in SD group and 89 patients were in RD group (1 patient received 120 mg/ m2, 2 received 160 mg/m2 and the rest received 140 mg / m2). In the SD group, median age was 58.5 years (25.6 - 72.3); 59.6% were males; 38.7% / 61.7 %/ 7.5% had cardiac / renal /hepatic involvement; and 47.1% / 35.7% / 8.8% / 8.4% had MS I/II/III/IV. In the RD group, median age was 60.8 years (40 - 73.7); 62.9% were males; 66.3% / 71.9 %/ 11.2% had cardiac / renal /hepatic involvement; and 26.2% / 32.5% / 21.2% / 20% had MS I/II/III/IV. The response rates for patients in the SD group [complete response (CR) - 53.7%, very good partial response (VGPR) - 19.6%, partial response (PR) - 12.5%, no response (NR) - 1.2%, progressive disease (PD) - 1.6%] were significantly higher than patients in the RD group (CR - 34.8%, VGPR - 20.2%, PR - 15.7%, NR - 10.1%, PD - 1.1%) (85.8 vs 70.7%; p < 0.002). The PFS and OS for both the groups according to Mayo stage are presented in Figure 1. Multivariate survival analysis for PFS and OS was performed using age (≤ vs > 70 years), serum creatinine (≤ vs > 2 mg/dL), number of major organs involved (heart, kidney, liver, gastrointestinal tract and autonomic neuropathy), MS (1 vs 2 vs 3 and 4) and dose of melphalan (SD vs RD). The dose of melphalan (p=0.0002), MS (p=0.03) and the number of organs involved (p=0.04) were significant for PFS while the dose of melphalan (p=0.0001) and the MS (p = 0.004) were significant for OS. Conclusion Reducing the dose of melphalan during conditioning for frontline ASCT in systemic AL amyloidosis renders more patients eligible for transplant but compromises on the response rates. There is no impact on PFS and OS in Mayo stage I patients. However the OS as well as PFS in Mayo stage II, III and IV were significantly lower in RD group as compared to SD group. These results suggest a suboptimal outcome with use of reduced dose melphalan, even after accounting for the pother prognostic factors, suggesting that high dose therapy should potentially be limited to those eligible to receive the full dose conditioning. Disclosures Dispenzieri: Jannsen: Research Funding; pfizer: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kapoor:Takeda: Research Funding; Amgen: Research Funding; Celgene: Research Funding. Kumar:Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Research Funding; BMS: Consultancy; AbbVie: Research Funding; Array BioPharma: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Glycomimetics: Consultancy; Kesios: Consultancy; Noxxon Pharma: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding.

Abstract Introduction Immunoglobulin light chain amyloidosis (AL Amyloidosis) is a monoclonal plasma cell proliferative disorder that is characterized by tissue deposits of misfolded insoluble κ or λ light chain derived amyloid fibrils, leading to organ dysfunction. The prognosis of patients depends on the number and severity of organ involvement, especially cardiac involvement. Autologous stem cell transplant (ASCT), if eligible, alkylator (melphalan) and novel drugs like proteasome inhibitors (PI) and immunomodulators (IMiD) have improved the overall survival (OS) during the past decades. But still, nearly half of the patients die within a year of diagnosis. We analyzed the factors predicting early relapse / progression or death (within 12 months) after first line therapy for systemic AL amyloidosis. Methods Clinical and laboratory data of all consecutive patients with systemic AL amyloidosis seen at Mayo Clinic within 90 days of their diagnosis, between 2006 and 2015, was collected by chart review and analyzed retrospectively. Patients who died within 3 months of starting the first line treatment were excluded from analysis. Early relapse (ER) was defined as relapse / progression requiring treatment change / re-institution or death within 12 months of starting first line treatment. Patients in the cohort with ER were compared with patients with a follow up of more than 12 months who had a relapse / progression beyond 12 months or had continuing response at the time of analysis. Categorical variables were analyzed using chi - square and Fisher's exact test and continuous variables using Kruskal- Wallis test and Wilcoxon rank sum test. Multivariate analysis was done using logistic regression model. Results Seven hundred and eighty six patients with newly diagnosed systemic AL amyloidosis met the study criteria and were included in the analysis. Among these, 230 (29.3%) patients had ER within 12 months of starting initial therapy while 556 (70.7%) patients either relapsed after 1 year or had continuing response at the time of analysis. Baseline demographics, organ involvement and type of first line therapy are presented in Table1. The median estimated follow up for the entire cohort from start of initial therapy was 62.9 months (95% CI; 59.9, 67.3). The variables included in the univariate and multivariate analyses for factors predicting ER were age at diagnosis (≤ vs > 70 years ), revised mayo stage (I and II vs III and IV), bone marrow plasma cell percentage (BMPC; ≤ 10% vs > 10%), presence of any chromosomal abnormalities, trisomies or IgH translocations by fluorescence in situ hybridization (FISH), multiorgan involvement [(>1 vs 1) (heart, liver, kidney, gastrointestinal tract, autonomic neuropathy), incorporation of ASCT in initial therapy. In univariate analysis, mayo stage (p<0.0001), multiorgan involvement (p=0.0008) and inclusion of ASCT as part of initial therapy (p<0.0001) were significantly associated with ER, while age (p=0.06), BMPC(p=0.9), FISH abnormalities (p=0.2) were not. However, in multivariate analysis, only mayo stage (III + IV vs I + II; p=0.01) and non-inclusion of ASCT in first line treatment (p=0.0001) were significantly predictive of ER. Conclusions Despite the introduction of ASCT and novel drugs, the early mortality in systemic AL amyloidosis remains high. This study demonstrates that patients with ER are older with higher prevalence of cardiac involvement and multiorgan involvement and higher Mayo stage (III and IV). Incorporation of ASCT as part of the initial therapy was associated with reduced early relapse, but it is difficult to separate the influence of the eligibility for ASCT from the effect of ASCT itself. This will help us in characterizing these patients to better understand their mechanisms of resistance to therapy and gives an insight to the type of initial therapy that benefits them. Disclosures Dispenzieri: GSK: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Alnylam: Research Funding; pfizer: Research Funding. Kapoor:Takeda: Research Funding; Amgen: Research Funding; Celgene: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Kesios: Consultancy; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Glycomimetics: Consultancy; Millennium: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; AbbVie: Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Research Funding.

Abstract Introduction Immunoglobulin light chain amyloidosis (AL Amyloidosis) is a plasma cell disorder characterized by deposition of misfolded insoluble protein fibrils (composed of monoclonal κ or λ light chains) in tissues causing progressive organ dysfunction. Chemotherapy and autologous stem cell transplant (ASCT), when eligible, are standard treatment options but relapses remain inevitable for most patients. However, there is a paucity of literature describing relapsed or refractory patients. We performed a retrospective study to analyze the outcomes upon relapse and the impact of type of therapy and retreatment with the same therapy at relapse. Methods Clinical and laboratory data of 1327 consecutive patients with systemic AL amyloidosis seen at Mayo Clinic within 90 days of their diagnosis, between 2006 and 2015, was collected by chart review and analyzed retrospectively. Of these patients, 219 (16.5%) were lost to follow-up. Among the remaining 1108 patients, 366 patients experienced a documented hematological or organ relapse or progression requiring change of first line or start of second line therapy and form the current study population. Overall survival (OS) was calculated from start of second line treatment or progression mandating therapy until death from any cause or the date of last follow up. The OS was estimated using the Kaplan-Meier method and log rank test was used to estimate the difference in survival curves. Results The median age was 62.8 years (36.1 - 85.3); 63.1% were males; 64.7% / 59.3% / 11.4% had cardiac / renal / hepatic involvement and 24.2% / 32.1% / 23.3% / 20.3% had MS I/II/III/IV. The median estimated follow up for this cohort was 69.4 months (95% CI; 64.4, 76.8) from the start of first line therapy and 45.2 months (95% CI; 36.5, 50.6) from the start of second line therapy or progression requiring treatment. The median time to second line treatment or relapse /progression mandating therapy was 16.2 months (1-93) from the start of first line therapy. At relapse, 14 patients underwent ASCT, 165 were treated with proteasome inhibitor (PI) based therapy, 83 with immunomodulator (IMiD) based therapy, 33 with alkylator based therapy, 15 with a combination of PI and IMiD, 10 with steroids, 8 with other therapies and 38 did not receive treatment. Among the 366 patients, 124 (33.9%) required change or reinstitution of therapy during follow up at the time of analysis. The median time to third line treatment or relapse /progression mandating therapy was 31 months (95% CI; 24, 40.5) from the start of second line treatment. The median overall survival (OS) was 76.4 months (95% CI; 65.2, 83.6) from the start of first line therapy and 38.8 months (95% CI; 29.6, 52.6) from the start of second line therapy. The type of therapy at relapse (ASCT vs PI vs IMiD vs melphalan vs steroids and others) did not alter the time to next therapy (ASCT, 43.1m; PI, 31m; IMiD, 37m; melphalan, 20.8m; steroids and others, 20m; p=0.3) and OS (ASCT, 66.9m; PI, 51.1m; IMiD, 51.3m; melphalan, 37.2m; steroids and others, 80.7m; p=0.9) from the start of the second line treatment; as depicted in Figure 1. Retreatment with a different drug class (as the first line treatment) at relapse significantly reduced the time to next treatment (32.3m vs 22 m; p= 0.01) as compared to same therapy; but did not have any impact on survival (30.8m vs 51.1m; p = 0.5); as presented in Figure 2. Conclusion This study provides novel information about outcomes of patients with systemic AL amyloidosis who relapse or progress after first line therapy which could be useful in planning salvage therapies and designing clinical trials. Retreatment with a different therapy at relapse improves time to next therapy but does not impact OS. Hence, we conclude that the patients can fare well post relapse/ progression and can benefit from various treatment regimens including retreatment with the same agent. Disclosures Dispenzieri: Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; pfizer: Research Funding; Alnylam: Research Funding; Celgene: Research Funding. Kapoor:Amgen: Research Funding; Takeda: Research Funding; Celgene: Research Funding. Kumar:BMS: Consultancy; Kesios: Consultancy; Glycomimetics: Consultancy; Onyx: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; AbbVie: Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding.

Abstract BACKGROUND Light-chain amyloidosis (AL) is the most common form of systemic amyloidosis, with an incidence of approximately 1 case/100,000 person-years. Clinically relevant data with regard to the very young (≤ 40 years) patients (pts) are scant. We present a case-control study of very young pts with AL seen at a single institution. METHODS We reviewed the medical records of all pts with AL who were consecutively evaluated at Mayo Clinic, Rochester, MN between 01/01/1995 and 12/31/2015. The clinical characteristics and survival outcomes of very young pts at the time of AL diagnosis (cases) were compared to a 2:1 matched cohort of pts (controls) with AL who were 65 years or older and matched by the time of diagnosis. Upfront autologous stem cell transplantation (ASCT) was defined as transplantation within 6 months of the diagnosis of AL. The Kaplan-Meier method was used to all time-to-event analyses. The average years of life lost was computed by subtracting the mean survival from diagnosis observed in the cohort from the mean survival expected in the population based on life-tables. RESULTS Of 3433 pts with AL, 50 (1.5%) pts were ≤ 40 years of age at diagnosis (cases). Fatigue, peripheral edema, dyspnea and bleeding were less common at presentation in cases compared to controls (table A). The cases were also more likely to have liver or GI involvement (OR= 3.45, 95% CI: 1.6-7.2). Unusual initial clinical features in the cases included unprovoked splenic rupture (2%) and erectile dysfunction (4%) observed 6-15 months prior to the diagnosis of AL in cases; no such features were observed in the control group. The median time between the onset of symptoms and definitive diagnosis was 0.4 years (95% CI: 0.3-0.7) for the cases and 1 year (95% CI: 0.8-1.2) for controls (p<0.0001). The ECOG performance score at diagnosis was ≥2 in 51% of cases compared to 78% of the controls (OR= 0.29, 95% CI: 0.14-0.63). The involvement by 3 or more organs at diagnosis was comparable [24 (48%) cases compared to 34 (34%) controls (p=0.11)]. Concomitant myelomatous (AL-CRAB) features were evident in 12% of each group and 27 (54%) cases and 37 (41%) controls had >10% BMPCs without active myeloma (AL-PCMM) (p=0.16). Monoclonal light chain involvement without involvement of heavy chain was seen in 23 cases (50%) and 31 controls (32%), (OR= 2.1, 95% CI: 1.04-4.37). The median follow-up was similar for cases and controls, [10.9 years (95% CI: 7.6-12) vs 9.9 years (95% CI 8-14)], respectively. The estimated average years-of-life lost was 8.6 years over 20 years of follow-up in cases, (Figure 1a). In cases, 1 and 10-year overall survival (OS) from diagnosis was 73% and 51%, respectively (median OS 12.7 years; 95% CI: 4.0-NR) while, in controls, 1 year and 10 year OS was 62% and 15% respectively (median OS 2.1 years; 95% CI (1.0-3.6), p<0.001), (Figure 1b). Cardiac involvement was associated with a worse OS in both cohorts, (cases: median OS was 3.2 years with cardiac involvement (95% CI: 0.6-8.7) vs NR (95% CI: 8.0-NR) in those without; p=0.003; controls: median OS was 1.1 years with cardiac involvement (95% CI: 0.53-1.6) vs 4.8 years (95% CI: 3.7-8.1) in those without; p=0.02. Thirty one of 47 (66%) cases were eligible and 20 of 79 (25%) controls were eligible for upfront ASCT. In cases, upfront ASCT was associated with a longer OS. Median OS was NR (95% CI: NR-NR) in pts who underwent upfront ASCT (n=25) vs 4.0 years (95% CI: 0.5-8) in pts who did not, p≤0.0001. For controls, the median OS was 9 years (95% CI: 0.5-11) for pts who underwent upfront ASCT (n=7) vs 1.6 years (95% CI: 1.0-2.8) for pts who did not (n=93), p=0.26. In cases, six (12%) pts underwent solid organ transplantation (kidney 5, heart 1) and none in the control arm. CONCLUSIONS AL amyloidosis is infrequently encountered at the age of ≤40 years, but the loss of productive years of life and the disease burden are substantial in this cohort. A substantial delay in diagnosis from the onset of symptoms was noted in our study in the control population. Cardiac involvement remains a primary determinant of prognosis irrespective to age. Although over one-half of young pts are alive 10 years after the diagnosis (contrast ≈15% ≥ 65 years), early mortality remains substantial irrespective of age. An ASCT-based approach is associated with superior outcome in the young. A greater proportion of the young pts is fitter and ASCT-eligible at diagnosis, and should therefore be offered this approach. Disclosures Dispenzieri: Jannsen: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; pfizer: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding. Kumar:Array BioPharma: Consultancy, Research Funding; Kesios: Consultancy; Onyx: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; AbbVie: Research Funding; Glycomimetics: Consultancy; Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; BMS: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kapoor:Amgen: Research Funding; Takeda: Research Funding; Celgene: Research Funding.

Abstract Introduction: Melphalan based chemotherapy is commonly used for treatment of light chain amyloidosis (AL). Patients with AL often receive chemotherapy before autologous stem cell transplantation (ASCT) if they have high plasma cell burden or while awaiting ASCT. Melphalan is an alkylator and can affect bone marrow stem cells. Limited data is available on the effect of melphalan on stem cell mobilization in patients with amyloidosis. This study aims to identify the impact of melphalan therapy on collection of stem cells and ASCT in amyloidosis. Methods: All patients with AL seen at our institution within 90 days of diagnosis over a 10-year period (2006 to 2015) who underwent stem cell harvest were identified from an institutional database. Data pertaining to demographics, diagnosis, treatment, stem cell harvest and ASCT was extracted from the electronic medical records. Analysis was carried out by chi-square and Fisher's exact test for categorical variables and Kruskal-Wallis and Wilcoxon rank sum test for ordinal and continuous variables. Results: Three hundred and seventy two patients with AL who met the inclusion criteria were identified, of whom 10% (n=38) received melphalan based chemotherapy prior to harvesting, 28.5% (n=106) received non-melphalan based chemotherapy and 61.3% (n=228) received no chemotherapy prior to stem cell collection. Bortezomib based regimens were the most common (78%, n=83) non-melphalan based chemotherapy. All three groups were similar in terms of median age at diagnosis (59.1 years), median age at collection (59.4 years), gender distribution (59% males, n=221) and type of involved free light chain (FLC), with lambda being more common (72.2%, n=268). Patients who received melphalan-based chemotherapy had more cardiac (73.8% vs. 45.2% vs. 46.4%, p=0.005) and renal (84.2% vs. 50.9% vs. 68%, p=0.0002) involvement compared to other chemotherapy and no chemotherapy groups, respectively. In contrast, patients who received non-melphalan based chemotherapy had higher plasma cell burden (15% vs. 6% vs. 10%, p< 0.0001) and greater difference between involved and uninvolved FLC (44.2 mg/dL vs. 13.3 mg/dL vs. 13.2 mg/dL, p< 0.0001) compared to melphalan and no chemotherapy, respectively. Median duration of melphalan based chemotherapy was shorter at 54 days (34.5 to 79.5) or estimated 2 cycles compared to 101 days (60 to 135.5) or estimated 4 cycles (p=0.0019). Despite shorter duration of chemotherapy, total stem cell yield (million CD34/kg) was lower in patients who received melphalan based chemotherapy (5.54) compared to non-melphalan based chemotherapy (8.14) or no prior chemotherapy (7.94); p<0.0001. Similarly, day one stem cell yield (million CD34/kg) was the lowest in the melphalan group (2.71), followed by other chemotherapy group (3.63) and highest in no chemotherapy group (4.84); p<0.0001. This trend persisted for average stem cell yield per collection as illustrated in table 1. Filgrastrim (GCSF) alone was the most common mobilizing agent. However, patients with any chemotherapy prior to harvesting had higher utilization of plerixafor; 26.3% (n=10) in the melphalan group and 39.6% (n=42) in the non-melphalan group compared to 11.6% (n=27) if no prior chemotherapy (p<0.0001). However, no statistically significant difference was seen for melphalan vs. non-melphalan chemotherapy groups (p=0.44). In patients who underwent ASCT (85%, n=315), median stem cell dose (million CD34/kg) was different in the melphalan (3.66), non-melphalan (4.2) and no chemotherapy groups (4.44) (p=0.047), though the difference was not statistically significant amongst the 2 chemotherapy groups (p=0.34). There was also no difference in time to engraftment (table 1). Conclusions: Melphalan based chemotherapy, even if used for a short duration of time, significantly decreases both total stem cell yield and the yield on day one. It therefore has the potential to add to resource utilization with more collections needed. As much as possible, limited cycles of melphalan based chemotherapy or non-melphalan based treatment should be utilized in patients who are transplant eligible. Disclosures Dispenzieri: GSK: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; Celgene: Research Funding; pfizer: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kapoor:Amgen: Research Funding; Takeda: Research Funding; Celgene: Research Funding. Kumar:Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Research Funding; Glycomimetics: Consultancy; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Kesios: Consultancy.

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

Abstract Introduction Plasmacytomas comprise approximately 3% of all plasma cell malignancies. There is a paucity of large studies assessing clinical features and outcomes of this relatively uncommon disease. Our objective was to describe the patterns of clinical presentation and survival of plasmacytomas using the National Cancer Data Base (NCDB). Methods This is a retrospective study of patients with histologically confirmed diagnosis of plasmacytoma from 2000-2011 using International Classification of Diseases for Oncology version 3 (ICD-0-3) code: 9930. Patients who had bone marrow involvement were excluded from the analysis. Plasmacytomas were grouped into two broad categories: extramedullary plasmacytoma (P-EM) and bone plasmacytoma (P-bone) based on their anatomical locations. Overall survival was analyzed using Kaplan-Meier estimates. Results A total of 6,939 patients were included in the study (median age 64 years; range 18-90 years). Approximately 62% of these patients were males and 46% patients were ≥ 70 years. Racial/ethnic distribution of the disease was as follows: 76% Whites, 13% Blacks, 7% Hispanics, and 4% others. The anatomical distribution and survival of patients is depicted in the Table. P-EM comprised 30% of the patients, with remaining 70% presenting as P-bone. Among P-EM, most common sites of presentation were upper aero-digestive tract (41%) and connective/soft tissue (20%). After a median follow up of 65 months, the overall survival of P-EM was significantly better than P-bone (113 vs. 78 months; Figure). Based on outcomes, we can categorize the P-EM patients into 3 groups: good (median overall survival > 120 months: upper aero-digestive tract, lymph nodes, endocrine and digestive system), intermediate (median overall survival 90-120 months: nervous system, eye/orbit, pulmonary), and poor (median overall survival <90 months: connective/soft tissue, cardiac/mediastinum, genitourinary, and hepatobiliary system). Males had better overall survival than females in P-bone (84 vs. 67 months; p<0.0001), but had no significant survival difference in P-EM (109 vs. 116 months; p=0.7). In the P-EM group, median overall survival was worst for Blacks (98 months vs. Whites- 108 months, Hispanics- not reached, others-145 months). Conversely, for P-bone, Blacks had a better overall survival than Whites (Blacks- 99 months, Whites- 72 months, Hispanics- 156, others-84 months). Patients who were treated at an academic center had better overall survival than patients treated at other/community centers both in case of P-EM (130 vs. 108 months) and P-bone (107 vs. 69 months). Conclusions This is the largest registry-based study on plasmacytoma in the United States. Plasmacytomas have varied clinical presentation, along with significantly different survival based on sites of presentation, race, sex, and treatment facility. Our study results point toward important differences in disease biology based on location and may aid in assessing prognosis for planning treatment. Table. Anatomical distribution and median overall survival of plasmacytomas. Table Overall survival based on location (P-EM: extramedullary plasmacytoma; P-bone: bone plasmacytoma) Table. Overall survival based on location (P-EM: extramedullary plasmacytoma; P-bone: bone plasmacytoma) Figure Figure. Disclosures Kumar: Noxxon Pharma: Consultancy, Research Funding; Kesios: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Consultancy, Research Funding; BMS: Consultancy; Array BioPharma: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Glycomimetics: Consultancy; AbbVie: Research Funding; Janssen: Consultancy, Research Funding.

Abstract Background: Autologous stem cell transplantation is an integral part of myeloma therapy for patients who are able to undergo the treatment. While high dose melphalan has remained the typical conditioning regimen for ASCT in MM, recently there have been efforts to enhance the conditioning therapy by adding newer drugs to melphalan. Addition of bortezomib as well as carfilzomib have been attempted in phase 2 trials. Previous studies have shown that the combination of melphalan and total body irradiation (TBI) is an effective conditioning regimen. Pre-clinical studies have shown that bortezomib can sensitize MM cells to radiation, and based on this finding, we designed a clinical trial to examine the feasibility of combining low dose TBI with a combination of melphalan and bortezomib. Patients and Methods: The primary goal of the phase 1 study was to determine the maximally tolerated dose (MTD) of bortezomib that can be added to high dose melphalan and low dose TBI as part of conditioning chemotherapy in patients undergoing an ASCT for MM. The secondary goals were to examine the toxicities associated with addition of bortezomib to high dose melphalan and TBI in patients with MM and to determine the progression free rate at 1 and 2 years. Patients eligible to receive full dose melphalan conditioning regimen for ASCT were included as long as they had no more than 2 prior regimens and had not received a prior transplant. An accelerated design that was later converted to a standard 3+3 cohort design was used for dose escalation. Three patients were treated at a given dose level combination and observed for at least 36 days to assess toxicity. Melphalan 80 mg/m2 was given days -4, -3, with bortezomib at increasing doses given on day -5, -2 along with TBI of 200 cGY given on the same days of bortezomib, timed after bortezomib administration. Stem cells were infused day 0. Results: Eleven patients were enrolled; 6 were males, and the median age was 60 years. Median time from diagnosis was 5.4 months (range 3.4-7.0). Four dose levels were explored with increasing doses of bortezomib (0.7 mg/m2 to 1.6 mg/m2). No dose limiting toxicities were observed. The dose levels and the best response after ASCT are as shown in the Table. The overall response rate was 100%, including 7/11 with a CR or sCR. With a median follow-up of 12.5 months, two patients have progressed; median OS was not reached. Toxicity was mostly hematologic, with other AEs being grade 3 or less and attributable to the conditioning therapy. All patients engrafted their counts adequately. Conclusion: The combination of melphalan, bortezomib, and low dose TBI is a safe conditioning regimen in patients with MM with good efficacy. The regimen should be further examined in the phase 2 setting. Table Table. Disclosures Kapoor: Celgene: Research Funding; Amgen: Research Funding; Takeda: Research Funding. Kumar:Noxxon: Consultancy, Honoraria; Celgene: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; BMS: Consultancy; AbbVie: Research Funding; Janssen: Research Funding; Skyline: Consultancy, Honoraria.

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.