Sidiqi, M Hasib

Abstract T cell large granular lymphocytic (T-LGL) leukemia has been reported to occur in patients with plasma cell disorders (PCD). We conducted a retrospective review of patients diagnosed with T-LGL leukemia and a PCD at the Mayo Clinic. 22 patients were identified with T-LGL leukemia and a plasma cell disorder. The T-LGL leukemia preceded the PCD in 18% (n=4), was synchronous in 50% (n=11) and diagnosed post plasma cell disorder in 32% (n=7) of patients. The PCD diagnosis varied and included monoclonal gammopathy of undetermined significance (MGUS, n=13), multiple myeloma (MM, n=5), smoldering multiple myeloma (SMM. N=2), lymphoplasmacytic lymphoma (LPL, n=1) and monoclonal gammopathy of renal significance (MGRS, n=1). 5 patients developed T-LGL leukemia after treatment for a PCD (4 with MM and 1 with LPL). 4 patients with MGUS progressed to a more aggressive disease, 3 to MM and 1 to LPL. Neutropenia (76%) and anemia (70%) were the most common clinical presentation. None of the patients had rheumatoid arthritis. Treatment for the TLGL was variable with a number of different agents used listed in Table 1. 45% (n=10) of patients had an indolent course and did not receive specific therapy for TLGL. 6 patients responded to a single line of therapy, all of whom received either cyclophosphamide or methotrexate based regimens. The remainder had a relapsing course with multiple lines of therapy including 2 patients that received splenectomy. Nine patients were identified as having symptomatic multiple myeloma and TLGL, Table 2. Four patients had progressed from a preexisting plasma cell disorder, 3 with MGUS and 1 with SMM. The diagnosis of TLGL preceded myeloma in 1 patient was concurrent in 4 and post myeloma diagnosis in 4 patients. Time to diagnosis of TLGL post myeloma ranged from 10 to 63 months. At time of LGL diagnosis neutropenia was present in 7/9 patients and anemia in 6/8 (data unavailable for 1 patient). Cytogenetics data was available in 7 patients. Hyperdiploidy was the most common abnormality (3/7) followed by deletion 13q (2/7), t(14;16) in 1 patient and 1q amplification in 1 patient. The majority of patients were treated with novel agents with 7 receiving bortezomib based therapy. 3 patients underwent autologous stem cell transplantation. Therapy directed at the TLGL was given to 4/9 patients. This consisted of a combination of cyclophosphamide and prednisone in 3/4 patients all of whom responded to therapy with resolution of cytopenias. One patient had TLGL with multiple relapses and required multiple lines of therapy including eventual splenectomy. 3 patients with TLGL diagnosed after the diagnosis of myeloma did not receive specific therapy directed at the TLGL. The clinical course of the TLGL in these 3 patients was indolent and did not appear to be affected by therapy for multiple myeloma. At last follow up 5 patients have died. After a median follow up of 76 months post TLGL diagnosis the median overall survival (OS) post TLGL diagnosis was not reached for the entire cohort. In the cohort of patients with multiple myeloma, median OS from time of myeloma diagnosis was 71 months. Median OS from time of TLGL diagnosis was not reached. T-LGL leukemia can present in patients with a variety of plasma cell disorders and occur at any stage of the disease process. It is an important differential to consider in patients with unexplained cytopenias that are incongruent with the activity of the plasma cell disorder. Disclosures Dingli: Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding.

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

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

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

Abstract We retrospectively reviewed all patients receiving bortezomib, lenalidomide and dexamethasone induction followed by autologous stem cell transplantation (ASCT) within 12 months of diagnosis for multiple myeloma at the Mayo Clinic. 243 patients treated between January 2010 and April of 2017 were included in the study. Median age was 61 (interquartile range, 55-67) with 62% of patients being male. High risk cytogenetic abnormalities (HRA) were present in 34% of patients. 166 (68%) patients received some form of maintenance/other therapy post transplant (no maintenance (NM, n=77), lenalidomide maintenance (LM, n=108), bortezomib maintenance (BM, n=39) and other therapy (OT, n=19)). Overall response rate was 99% with complete response (CR) rate of 42% and 62% at day 100 and time of best response post transplant respectively. The four cohorts categorized by post transplant therapy were well matched for age, gender and ISS stage. HRA were more common amongst patients receiving bortezomib maintenance or other therapy post transplant (NM 18% vs LM 22% vs BM 68% vs OT 79%, p<0.0001). Two year and five year overall survival rates were 90% and 67% respectively with an estimated median overall survival (OS) and progression free survival (PFS) of 96 months and 28 months respectively for the whole cohort. OS was not significantly different when stratified by post-transplant therapy (Median OS 96 months for NM vs not reached for LM vs 62 months for BM vs not reached for OT, p=0.61), however post-transplant therapy was predictive of PFS (median PFS 23 months for NM vs 34 months for LM vs 28 months for BM vs 76 months for OT, p=0.01). High risk cytogenetics was associated with a worse OS but not PFS when compared to patients with standard risk (median OS: not reached for standard risk vs 60 months for HRA, p=0.0006; median PFS: 27 months for standard risk vs 22 months for HRA, p=0.70). In patients that did not receive maintenance therapy presence of HRA was a strong predictor of OS and PFS (median OS: not reached for standard risk vs 36 months for HRA, p<0.0001; median PFS: 24 months for standard risk vs 7 months for HRA, p<0.0001). Patients receiving maintenance therapy appeared to have a similar PFS and OS irrespective of cytogenetics (median OS: not reached for standard risk vs 62 months for HRA, p=0.14; median PFS: 35 months for standard risk vs 34 months for HRA, p=0.79).On multivariable analysis ISS stage III and achieving CR/stringent CR predicted PFS whilst the only independent predictors of OS were presence of HRA and achieving CR/stringent CR. The combination of bortezomib, lenalidomide and dexamethasone followed by ASCT is a highly effective regimen producing deep and durable responses in many patients. Maintenance therapy in this cohort may overcome the poor prognostic impact of high risk cytogenetic abnormalities. Table Table. Disclosures Dispenzieri: Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Celgene: Research Funding; Takeda: Research Funding. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Gertz:Abbvie: Consultancy; Apellis: Consultancy; annexon: Consultancy; Medscape: Consultancy; celgene: Consultancy; Prothena: Honoraria; spectrum: Consultancy, Honoraria; Amgen: Consultancy; janssen: Consultancy; Ionis: Honoraria; Teva: Consultancy; Alnylam: Honoraria; Research to Practice: Consultancy; Physicians Education Resource: Consultancy.

Abstract Introduction: Outcomes in multiple myeloma have significantly improved in recent times owing to the availability of newer more effective therapies. Autologous stem cell transplantation (ASCT) has been used for over three decades to treat multiple myeloma. We aimed to evaluate the outcome of patients receiving ASCT at our institution between 1990 and 2015. Patients and Methods: A total of 2025 patients received ASCT at Mayo Clinic Rochester between 1st January 1990 and 31st December 2015. The patients were divided in to three cohorts of approximately equal time period, Cohort 1 (1990-1999, n=144), Cohort 2 (2000-2009, n=909) and Cohort 3 (2010-2015, n=972). Outcomes of interest were early mortality, progression free survival (PFS) and overall survival (OS). Disease characteristics were documented from time of diagnosis and PFS and OS were calculated from date of ASCT unless otherwise stated. Results: Median age for the whole cohort was 60 years (range 24-77) and increased over time (55 Cohort 1 vs 59 Cohort 2 vs 61 Cohort 3, p<0.0001). The proportion of males (60% for whole cohort) was not significantly different between the 3 time periods. Almost all patients (99%, n=2018) received chemotherapy prior to transplantation (median lines of therapy 1, range 0-6). The number of patients receiving >1 line of therapy prior to transplantation decreased over time (67% Cohort 1 vs 27% Cohort 2 vs 34% Cohort 3, p<0.0001). The use of novel agents was congruous with their availability and increased over time (0% Cohort 1 vs 59% Cohort 2 vs 100% Cohort 3, p<0.000). After a median follow up of 84 months (95% CI, 78-91 months), median PFS and OS for the whole cohort were 24 and 66 months respectively. Both PFS and OS improved significantly over time (median PFS: 12 months Cohort 1vs 18 months Cohort 2 vs 33 months Cohort 3, p<0.0001; median OS: 26 months Cohort 1vs 63 months Cohort 2 vs 83 months Cohort 3, p<0.0001), Figure 1. The improvement in PFS and OS over the 3 time periods was seen in patients receiving early (≤ 12 months from diagnosis) and delayed (>12 months) ASCT, Table 2. OS from diagnosis was no different for early versus delayed transplant in Cohort 1 and Cohort 2 (Cohort 1: median OS 57 months for early vs 56 months for delayed, p=0.24 and Cohort 2: median OS 81 months for early vs 82 months for delayed, p=0.70) and showed a trend towards a marginal benefit for delayed transplant in Cohort 3 (median OS 105 months for early vs 109 months for delayed, p=0.046).Treatment related mortality (100 days post transplant) improved over time (7.6% Cohort 1 vs 1.8% Cohort 2 vs 0.7% Cohort 3, p<0.0001), Figure 2A. Mortality within 12 months of ASCT also improved over time (24% Cohort 1vs 8% Cohort 2 vs 6% Cohort 3, p<0.0001). A landmark analysis of OS from 12 months post ASCT continued to reveal improved survival over time(median OS 26 months Cohort 1vs 63 months Cohort 2 vs 83 month Cohort 3, p<0.0001), Figure 2B. Conclusion: ASCT remains an important therapeutic option for eligible patients with multiple myeloma. There has been a marked improvement over time in PFS and OS and reduction in treatment related mortality and early mortality in myeloma patients receiving ASCT. This is likely to reflect the addition of novel agents to induction regimens and improved post transplant therapies. Despite these improvements myeloma remains incurable with patients continuing to relapse and die many years after ASCT. Disclosures Dispenzieri: Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Kumar:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding. Gertz:Research to Practice: Consultancy; Physicians Education Resource: Consultancy; Amgen: Consultancy; spectrum: Consultancy, Honoraria; celgene: Consultancy; annexon: Consultancy; janssen: Consultancy; Alnylam: Honoraria; Abbvie: Consultancy; Ionis: Honoraria; Teva: Consultancy; Apellis: Consultancy; Medscape: Consultancy; Prothena: Honoraria.

AbstractThe role of consolidation post autologous stem cell transplant in light chain amyloidosis is not well defined. We retrospectively identified patients who had light chain amyloidosis and underwent autologous stem cell transplant at the Mayo Clinic. Consolidation was defined as any treatment given after the day 100 evaluation post‐transplant to maintain or deepen the response. We identified 471 patients, of whom 72 (15%) received consolidation. Patients receiving consolidation had more advanced disease (Mayo 2012 stage ≥II in 67% vs 52%, P = .02), and had lower day 100 response rates (very good partial response or better: 35% vs 84%, P < .001). After consolidation, rates of very good partial response improved from 24% to 28%, and rates of complete response improved from 11% to 40%. Patients with less than very good partial response who received consolidation, had better progression‐free survival (median of 22.4 vs 8.8 months, P < .001), and the benefit was greater in those who deepened their response (median of 41 vs 8.8 months, P < .001). In patients with less than very good partial response, there was a trend for better overall survival in patients who responded to consolidation (median of 125.8 vs 74.4 months, P = .07). In patients who achieved very good partial response, or better, at day 100 post autologous stem cell transplant, consolidation did not improve progression‐free or overall survival. Consolidation after autologous stem cell transplant for light chain amyloidosis improves progression‐free survival for patients who achieve less than very good partial response.