Gertz, Morie A.

Abstract Abstract 201 Background: Pomalidomide at doses of 2 or 4 mg/d has demonstrated excellent activity in patients with relapsed multiple myeloma (MM). Between November 2007 and March 2012, we opened 6 sequential phase 2 trials and treated 345 patients with relapsed MM with pomalidomide at differing doses with weekly dexamethasone (Pom/dex). Results of 164 of these patients have been previously published. Here we describe long term follow up of these patients as well as results of an additional 181 patients with relapsed MM treated with the Pom/dex regimen. Methods: The six cohorts consisted of: Cohort 1 (N=60): relapsed MM with 1–3 prior regimens, 2 mg dose; Cohort 2 (N=34): lenalidomide (LEN) refractory, 2 mg dose; Cohort 3 (N=35): BZ)/LEN refractory, 2 mg dose; Cohort 4 (N=35): BZ/LEN refractory, 4 mg dose; Cohort 5 (N=60) LEN refractory, 1–3 prior regimens, 4 mg dose; and Cohort 6 (N=120) LEN refractory, 4 mg dose. Pomalidomide was given orally 2 mg daily or 4mg daily on days 1–28(cohorts 1–5) or 1–21 (cohort 6) of a 28-day cycle with oral dexamethasone given 40 mg daily on days 1, 8, 15 and 22. Response was assessed by the International Myeloma Working Group Uniform Response criteria. All patients received aspirin 325 mg daily for deep venous thrombosis (VTE) prophylaxis or full dose anticoagulation. Results: A total of 345 patients were enrolled across all 6 cohorts. One patient was ineligible and excluded from analysis. The median age was 64 years (32–88). The median time since diagnosis was 53 months. The median number of prior therapies was 3 (1–14). 147 (44%) had high-risk molecular markers by mSMART criteria. Prior therapies consisted of thalidomide 52%, lenalidomide 87%, bortezomib 75%, autologous stem cell transplant 70% and allogeneic transplant 3%. The median follow-up is 10.4 months (5.4–34 months). Sixty-seven percent are alive and 32% remain progression free. 46 patients are continuing to receive treatment. The most common toxicities (grade 3 or higher) were neutropenia (31%), anemia (16%), thrombocytopenia (12%), pneumonia (8%) and fatigue (8%). VTE was seen in 10 patients (3%). Outcomes are shown in Table 1. Across all 6 cohorts confirmed responses of partial response (PR) or better were seen in 34%. The response rate in all patients with mSMART high risk status was 30.6%. Responses and duration of response (DOR) in those with high risk molecular markers include: 17p– 19 of 56 (34%) DOR 8.2 months; t(4;14) 6 of 24 (25%) and DOR 4.8 months; t(14;16) 7 of 11(64%) and DOR 9.5 months; deletion 13 by cytogenetics 13 of 37 (35%) with DOR 8.2 months. In a multivariate analysis, only LDH > ULN, number of prior regimens, and prior BZ therapy were predictive of a shorter TTP and factors associated with a poor OS following initiation of pomalidomide therapy included B2M > 5.5, LDH > ULN,number of prior regimens, and prior BZ therapy. Conclusions: Pom/dex is active and well tolerated even in heavily pretreated patients and those with high risk molecular markers. Remissions are durable. Response rates and toxicity are similar between the 2 mg and 4 mg doses. Disclosures: Lacy: Celgene: Research Funding. Stewart:Celgene: Consultancy, Honoraria. Reeder:Celgene: Mayo Clinic receives funding from Celgene to support clinical trials Other, Research Funding.

Abstract Background:The pathological behavior of Waldenströms macroglobulinemia (WM) cells relies on aberrant B-cell receptor (BCR), and Toll-like receptor (TLR) signaling and is intricately supported by malfunctions in initiation of apoptosis. In this dynamic, a complex shift between functionally active pro-apoptotic and anti-apoptotic proteins from the Bcl-2 family occurs and bestows the malignant cells with a significant survival advantage. This defective apoptotic signaling is associated with aggressive clinical behavior, chemoresistance, and a poor prognosis in many B-cell cancers, including WM. Thus, BCR/TLR induced proliferation and abnormal apoptotic signaling due to dysregulation of Bcl-2 signaling, act in concert for the assurance of the malignant WM cells survival. Clinically, mitigation of BCR signaling with the first in class BTK inhibitor, ibrutinib, has shown promising results in WM and other B-cell cancers. However, clinical responses to the BTK inhibitor alone are less than optimal and development of ibrutinib-resistant disease is being recognized as an important and impending dilemma. We have previously shown the utility of disrupting pro-apoptotic Bcl-2 protein interactions in WM, chronic lymphocytic leukemia and multiple myeloma and that this functional interference results in re-sensitization (or heightened sensitivity) of tumor cells towards chemoimmunotherapy. As such, we examined the effects of ABT-199, a Bcl-2 specific small molecule inhibitor, in preclinical models of WM. Importantly; we conducted this investigation in proprietarily developed WM cells that have acquired resistance mechanisms towards either ibrutinib (IR WM subclones) or bortezomib (BR WM subclones). Materials:WM cell lines (BCWM.1, MWCL.1 and RPCI-WM1; WT cells) including their bortezomib resistant (BR) or ibrutinib resistant (IR) subclones were used in this study. Results: An initial comparison of Bcl-2 family members, Bcl-2, Mcl-1, BCL-xL, A1 (anti-apoptotic members), Noxa, Puma, Bim (pro-apoptotic initiators) and Bak and Bax (pro-apoptotic effectors), revealed that BR WM cells express increased levels of pro-apoptotic Bcl-2 family members, particularly Bcl-2, relative to WT cells. Similarly, A1 and Bcl-2 levels were up regulated in IR cell lines suggesting that the Bcl-2 mediated survival pathway is involved in resistance to both bortezomib and ibrutinib. Cell growth (MTS) assays using ABT-199 indicated that both BR and IR cells were equally sensitivity to Bcl-2 inhibition, with an IC50 ranging between 2 – 4mM. ABT-199 induced a dose dependent increase in MOMP with concomitant induction of apoptotic cell death, the latter confirmed by observation of PARP-1 cleavage. ABT-199 induced an intrinsic apoptotic program with the activation of caspase 9 and caspase 3 in all the cells tested. This data indicated the Bcl-2 pathway as being relevant and essential in WM cell lines even under drug resistant conditions. To evaluate the priming effect of ABT-199 on bortezomib and ibrutinib induced cell death, MTS assays were performed with these drugs in presence of IC25 concentrations of ABT-199. The addition of ABT-199 significantly reduced the IC50of both bortezomib and ibrutinib in WT, BR and IR cells. This suggested that re-sensitization of BR and IR cells towards either bortezomib or ibrutinib, respectively, was possible in presence of ABT-199. Further, combined addition of ABT-199 with bortezomib or ibrutinib showed synergistic cell death (combination index range: 0.004 – 0.6, CalcuSyn, Biosoft UK) in BR or IR WM cells, respectively. Conclusion: Dysregulation of Bcl-2 signaling is associated with the pathogenesis and promotion of drug resistance in B-cell cancers, including WM. Our report is first to highlight in WM preclinically, the antiproliferative effect of disrupting Bcl-2, through use of ABT-199. Altogether, our data suggests that therapeutic interference of Bcl-2 function with ABT-199 complements the anti-WM activity of ibrutinib or bortezomib in a synergistic manner and can in fact restore sensitivity of either drug in WM cells that are resistant to proteasome or BTK inhibitors. Focused mRNA and protein profiling analyses are currently underway to delineate the mechanisms accounting for synergy observed between concomitant Bcl-2/BTK inhibition as well Bcl-2/proteasome inhibition. Disclosures Ansell: Biothera: Research Funding. Martin:Janssen: Honoraria. Coleman:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx: Speakers Bureau.

Abstract Abstract 600 Background: Both MM and AL are plasma cell neoplasms. The underlying clone in both diseases appears to be different not only in terms of “tumor burden” but also in terms of their underlying biology. The overall “fitness” of patients with these two diseases is also different, with AL patients having more major organ dysfunction. Therapy for both diseases is directed at killing the underlying clone. ASCT is one method of reducing the clone size and thereby improving overall survival. Post-ASCT outcomes between the two diseases have never been formally compared. Methods: We compiled all patients with a diagnosis of AL or MM who received ASCT at the Mayo Clinic Rochester between June 1996 and January 2011 to compare outcomes. Patients were retrieved from two prospectively maintained clinical transplant data bases (M.A.G.). Differences between groups were compared using Fisher's exact and Wilcoxon tests. Survival was calculated using the method of Kaplan-Meier, and differences between survival outcomes were calculated by log rank. Cox regression modeling was done to determine how non-disease specific variables—i.e. age, time period of ASCT, number of prior regimens, time to ASCT from diagnosis and acquisition of complete response (CR)—affected outcomes. All statistical analyses were performed using JMP (SAS, NC) software. This study was approved by the Mayo IRB. Results: The data set was comprised of 454 patients with AL and 1116 patients with MM. There were significant differences between the two respective groups of patients in terms of number of prior regimens (0 vs 1, p<0.0001), time to ASCT (3.95 months vs 7.20 months, p<0.0001), intensity of conditioning regimen (non-attenuated in 69.4% vs 89.1%, p<0.0001), serum creatinine (1.1mg/dl vs 1mg/dl p<0.0001), creatinine clearance (72.5 ml/minute vs 80 ml/minute p<0.0001), albumin (2.61g/dl vs 3.50g/dl, p<0.0001) CRP (0.40mg/dl vs 0.63mg/dl p<0.0001), LDH (196 U/l vs 182U/l, p<0.0001), and bone marrow plasmacytosis at transplant (6% vs 9%, p<0.0001). Hematologic response rates were also significantly different between the groups, with higher overall hematologic response in the MM group (90.9% vs 79.5%, p<0.0001) and higher complete response (CR) rates (40.1% vs 29.4%, p<0.0001) in the AL group. With a median follow-up of surviving patients of 68 months, the respective median overall survival (OS) for the AL and MM patients was 113 and 59.5 months, p<0.0001. Notably, the 5-year OS of AL and MM patients achieving CR were 91.4% and 57.7%, respectively, p<0.0001. If only those patients who were transplanted within 1 year of their diagnosis are included in the analysis, the respective 5-year OS of AL and MM patients achieving CR were 90.4% and 61.3%, p<0.0001 (Figure 1). To correct for imbalances in non-disease specific parameters, 3 multivariate analyses were performed using: 1) all patients; 2) only those achieving CR; and 3) only those who achieved a CR and were transplanted within 12 months of their diagnosis (Table 1). Among those patients achieving CR, MM patients had nearly a 4-fold risk of death as compared to patients with AL. Conclusion: Although ASCT is not available to all patients with either AL or MM, there is a significant difference in outcomes based on the diagnosis. Patients with AL who undergo ASCT enjoy a superior survival as compared MM patients undergoing the same procedure. This difference is most notable among those patients who achieve CR suggesting very different plasma cell biology between the two diseases. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 599 Purpose: This study was undertaken to develop selection guidelines for transplant centers to determine eligibility for stem cell transplantation in patients with light chain amyloidosis. Patients and Methods: Patients with biopsy-confirmed immunoglobulin light chain amyloidosis who underwent stem cell transplantation between March 8, 1996, and December 31, 2011, were reviewed in 2 cohorts: those who underwent transplantation between March 8, 1996, and June 30, 2009, and those who underwent transplantation between July 1, 2009, and December 31, 2011 (table 1). A second comparison was undertaken among patients who died before posttransplant day 100 to determine features predictive of early death (table 2). Results: A total of 499 patients were identified, 410 in the earlier group and 89 in the later group. After July 1, 2009, significantly fewer transplant recipients had Mayo stage III cardiac involvement. Mortality before posttransplant day 100 was 10.5% (43/410) in the earlier group and 1.1% (1/89) in the later group. In the earlier group, one-quarter of transplant recipients with N-terminal pro-brain natriuretic peptide (NT-proBNP) levels higher than 5,000 pg/mL died by 10.3 months (fig 1, left). When the serum troponin T level was > 0.06 ng/mL, 25% died at 3.7 months (fig 2, right). Conclusion: The Mayo staging system is highly predictive for overall survival but not useful for selecting transplant recipients. Patients with serum troponin T levels higher than 0.06 ng/mL or NT-proBNP levels >5,000 pg/mL (not on dialysis) should not be considered acceptable candidates for stem cell transplantation because of unacceptable early mortality. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 3972 Background: The treatment paradigm for myeloma has undergone a dramatic shift in the past decade with the introduction of the novel agents and their application at every stage of the treatment. We and others had previously shown that survival of patients with myeloma had improved in the earlier half of the last decade and attributed this to a combination of novel therapies as well as increased use of stem cell transplant. It is not clear if this momentum in improving survival has been maintained. We examined the survival trends of patients with newly diagnosed myeloma seen within the past decade to examine this question. Patients and Methods: We studied 1056 patients with newly diagnosed myeloma, who were seen at Mayo Clinic between January 1, 2001 and December 31, 2010; who were seen within 30 days of their diagnosis. For examination of the time trends, we grouped the time interval into two five year periods, 2001–2005 and 2006–2010. Survival was estimated using Kaplan Meier method and survival curves were compared by log rank test. Impact of various prognostic factors was evaluated using Cox proportional hazards test. Results: The median age at diagnosis was 65 (range; 22–92), and 59% were male. The median estimated follow up for the entire cohort was 4.6 years (95% CI; 4.4, 4.9) and 57% of the patients were alive at last follow up. The median overall survival (OS) for the entire cohort was 5.4 years (95% CI; 5, 6.3). The overall survival for patients in the 2001–2005 group was 4.6 years compared with not reached for the 2006–2010 cohort (P< 0.001). The five-year estimated OS was 48% for the earlier group compared with 66% for the latter group. The estimated 1-year survival was 90% for the recent cohort compared with 83% for the earlier cohort, suggesting improvements in the early mortality. Interestingly, the improvement was predominantly seen in the older age group (>65 years; 49%). The 5-year survival of the older patients improved significantly from 31% (2001–2005) to 56% (2006–2010) (P<0.001). In contrast, among younger patients (≤65 years of age), the 5-year survival improved only marginally from 63% (2001–2005) to 73% (2006–2010) (P=NS). One or more novel agents (Lenalidomide, thalidomide or bortezomib) were used as part of initial therapy in 631 (62% of 1021 in whom treatment data was available). The OS among of this group was 7.3 years (95% CI; 5.9, NR) compared with 3.8 years (95% CI; 3.1, 4.6). In a multivariate model that included both use of novel agent and the year group, only the novel agent use was associated with improved survival suggesting that the improvement in the survival is related to the increased use of novel agents in the initial therapy. No significant differences were observed between the groups in terms of conventional prognostic factors. Conclusions: The current results confirm continued improvement in the overall survival of patients, even within the last 10 year period, and highlight the impact of initial therapy with novel agents. Most importantly, we demonstrate that the improved survival has primarily benefited older patients. Our study highlights that urgent need for additional new agents to provide further survival improvement for younger patients, and in order achieve a cure for this disease. Disclosures: Kumar: Merck: Consultancy, Honoraria; Celgene: Research Funding; Millennium: Research Funding; Novartis: Research Funding; Cephalon: Research Funding; Genzyme: Research Funding. Dispenzieri:Celgene: Research Funding; Millennium Pharmaceuticals, Inc.: Research Funding; Janssen Research & Development: Research Funding. Gertz:Binding Site: Honoraria.

Abstract Abstract 602 Although, MM remains the most common indication for ASCT in the US, a controversy exists about the timing of ASCT. Since early ASCT (eASCT) versus delayed ASCT (dASCT) results in similar progression free survival (PFS) and overall survival (OS) in the novel agent era, economic assessment of one strategy over the other may help both clinicians and policy makers in establishing guidelines in the MM treatment paradigm. Here we designed a study to model a decision tree of both the strategies and estimate their cost-effectiveness. A decision tree was developed to compare the outcomes of ASCT in newly diagnosed transplant eligible MM patients after chemotherapy with novel drug lenalidomide which formed the base case. The survival data was obtained from our published data on eASCT versus dASCT in MM patients who underwent initial therapy with dexamethasone + immunomodulatory agents (IMiDs). The initial decision node on the decision tree model was dichotomized based on the cutoff of 12 months for eASCT versus dASCT. The probabilities of events during the length of follow up (60 months) period which formed our base case were: (a) eASCT cohort: Induction chemotherapy for median of 6 months - ASCT - median 30 months to relapse (drug free interval) followed by median therapy of 24 months for relapsed MM; (b) dASCT cohort: Median initial therapy for 36 months - ASCT - median 24 months to relapse (drug free interval). The cost analysis was done from a US third party payer perspective. The cost data for MM ASCT was obtained from the published data in which direct hospital costs were obtained from Nationwide Inpatient Sample and were converted to Medicare cost-to-charge ratio for urban hospitals. Chemotherapy cost consisted of actual drug costs that calculated based on average wholesale prices AWP (2008), costs of medical oncology visits, and the costs of managing adverse events. Post-ASCT maintenance costs were not included in the analysis. TreeAge Pro 2012 software was used to perform a static decision analysis. The outcomes were expressed in the units of health utility values obtained from phase III HOVON trial which measured quality of life (QoL) using EORTC QLQ-C30 & EuroQoL-5D. All scales and items were linearly transformed to range from 0 to 100. The utilities measured by the EuroQol-5D ranged from 0.40 before induction therapy to 0.70 after ASCT and translated to QALYs using area under the curve method. Using a Consumer Price Index (CPI), the costs of ASCT and chemotherapy were converted into 2012 US$. The robustness of the decision model was tested through univariate analyses and tornado diagram to identify those variables which if varied across clinically relevant measures may result in difference in outcomes. The expected cost of providing treatment to newly diagnosed MM patients for a period of 5 years when they undergo eASCT after induction with IMiDs was calculated to be $211,869. This was $52,454 less than the expected cost of undergoing dASCT. Patients who underwent eASCT had an expected benefit of 2.06 QALYs following treatment, which was 0.19 QALYs more than the patients who received dASCT. This implies that eASCT is preferred over (dominates) dASCT. One-way sensitivity analysis was undertaken to identify factors that were found to be most influential and included OS, overall response rate (ORR) and 1 year ASCT related mortality rate (TRM). Specifically, eASCT showed dominance even if the probability of OS was lowered to 52.1% from the actual case base of 65%, or the probability of ORR was lowered to ≥ 75.8% from the actual case base of 92%, or the probability of 1 year TRM was increased to 11.5% from actual case base of 2%, indicating the robustness of the model favoring cost effectiveness of eASCT. In absence of a survival benefit, the cost savings of early ASCT as measured by ICER would favor this approach, and it would help clinicians, patients, policy makers and third party payers in decision making. Future prospective studies in MM ASCT should incorporate economic and QOL components in the analysis and also focus on the added cost of post-ASCT maintenance therapies with respect to ICER and QALYs. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 3992 Little is known about the rare entities of heavy and light chain amyloidosis (AHL) and heavy chain amyloidosis (AH). In this study, we report the renal and hematologic characteristics, pathology, and outcome of 17 patients with renal AH/AHL including 5 with AH (4 IgG and 1 IgA) and 12 with AHL (7 IgGλ, 3 IgAκ, 1 IgAλ, and 1 IgMλ), and compare them with 202 patients with renal AL amyloidosis (AL) diagnosed during the same time period. All cases were diagnosed by kidney biopsy that showed Congo red-positive deposits. Amyloid typing was done by laser microdissection and mass spectrometry (LMD/MS) (12 patients) or by immunofluorescence (5 patients). All patients with renal AH/AHL were Caucasians, with a M:F ratio of 2.4 and a median age at biopsy of 63 years. Compared with patients with renal AL, those with renal AH/AHL had less frequent concurrent cardiac involvement, higher likelihood of having circulating complete monoclonal Ig, lower sensitivity of fat pad biopsy and bone marrow biopsy for detecting amyloid, higher incidence of hematuria, and better patient survival. The hematologic and renal responses to chemotherapy were comparable to renal AL. In 42% of patients, AH/AHL could not have been diagnosed without LMD/MS. In conclusion, renal AH/AHL is an uncommon but under-recognized form of amyloidosis, and its diagnosis is greatly enhanced by the use of LMD/MS for amyloid typing. The accurate histological diagnosis of renal AH/AHL and distinction from AL may have important clinical and prognostic implications. Table 1. Demographics and hematologic characteristics AH/AHL AL p value No. of patients 17 202 Gender: Male/female 12/5 (71%/29%) 126/76 (62%/38%) 0.61 Age, median (range) 63 (50–77) 62 (36–86) 0.73 Additional organ involvement 8 (47%) 126 (62%) 0.3 Cardiac involvement 3 (18%) 100 (50%) 0.01* % of plasma cells in bone marrow, median (IQR) 8 (5–15) 6 (5–10) 0.82 ≥30 plasma cells 4 (24%) 11/198 (6%) 0.02* Positive SPEP/SIF for paraprotein 15 (88%) 158/200 (79%) 0.53 Presence of whole monoclonal protein on SPEP 14 (82%) 108/200 (54%) 0.04* Positive UPEP/UIF for paraprotein 13/16 (81%) 158/189 (84%) 0.73 Presence of whole monoclonal protein on UPEP 10/16 (63%) 61/189 (32%) 0.03* Abnormal serum FLC ratio (<0.26 or >1.65) 9/12 (75%) 150/188 (80%) 0.71 Markedly abnormal FLC ratio (< 0.125 or > 8) 5/12 (42%) 100/188 (53%) 0.55 Positive bone marrow for amyloid 6/16 (38%) 135/183 (74%) 0.004* Positive fat pad biopsy for amyloid 2/14 (14%) 105/145 (72%) <0.001* IQR, interquartile range. Table 2. Renal characteristics at kidney biopsy AH/AHL AL p value No. of patients 17 202 24h urine protein in g, median (IQR) 5.1 (3.2–9.0) 6.0 (3.2–10.0) 0.9 Full nephrotic syndrome 9/16 (56%) 132/197 (67%) 0.42 Serum albumin in g/dl, median (IQR) 2.7 (2.2–3.3) 2.5 (1.9–2.9) 0.29 % albuminuria on UPEP, median (IQR) 68 (61–72) 70 (60–76) 0.47 Serum creatinine in mg/dl, median (IQR) 1.4 (1.1–2.1) 1.2 (0.9–1.8) 0.25 Serum creatinine >1.2 mg/dl 10/16 (63%) 92/201 (46%) 0.3 eGFR, median (IQR) 47 (27–67) 58 (36–75) 0.29 Decreased eGFR 10/16 (63%) 103/201 (51%) 0.44 Microscopic hematuria 9/16 (56%) 44/169 (26%) 0.02* IQR, interquartile range. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 956 Background: Autologous SCT has been an integral part of myeloma therapy since randomized trials demonstrated improved survival for SCT compared to conventional therapy. However, the conventional treatment of MM has changed with the introduction of novel therapies such as IMiDs and there is an increasing trend towards delaying SCT. While trials in the pre-novel agent area have shown equivalent outcomes with early or delayed SCT, it is not clear if this holds true with novel agent induction. Patients and methods: We reviewed the outcome of patients seen at Mayo Clinic between 2001 and 2008, who received initial therapy with thalidomide-dexamethasone (TD) or lenalidomide-dexamethasone (LD) (n=410). All patients in whom a stem cell harvest was attempted (started on growth factor irrespective of collection success; n=292, 71%) were included as a method to identify transplant eligible patients. Patients undergoing SCT within 12 months of diagnosis and in whom the SCT was performed within 2 months of stem cell harvest were considered in the early SCT group vs. delayed SCT for the remaining patients irrespective of whether an SCT was actually done (immediate vs. collect and store approach). Variables were compared between the groups using a chi-square or t-test as appropriate. Survival curves were generated using Kaplan Meier method and compared using log rank test. Results: Among the 292 transplant eligible patients, 125 (43%) received TD and 167 (57%) received LD as initial therapy. An early SCT approach was undertaken in 174 patients 60%, with the remaining 118 in the delayed group, 46 of whom have been transplanted to date. The median estimated follow up for the entire group was 54 months from diagnosis, 52 and 61 months respectively for the early and delayed groups. The median estimated time to SCT was 5.3 months among the early group compared to 39 months in the delayed group COMMENTS/* MERGEFORMAT . 83 (66%) patients receiving TD had an early SCT compared to 91 (55%) patients in the LD group; p =0.04. At baseline, the groups were comparable for age and gender. The median overall survival from diagnosis was 86 months for the early SCT compared to NR for the late SCT; P=0.3. The median OS was similar between the Early and Delayed group in the TD group (86 vs. 64 months respectively) as well as in the LD group (NR for either group; 82% vs. 86% at 4 years respectively). Conclusion: In this group of newly diagnosed patients treated with thalidomide or lenalidomide as initial therapy, an approach of continued initial therapy and delayed transplant at the time of first relapse appears comparable to upfront transplant. This is consistent with the findings of randomized trials in the setting of alkylator based initial therapies. The timing of transplant in the era of novel agents remains the top question on the mind of physicians and patients, and this is the first study to examine this very important question. The rationale governing the decision to go forward with an early SCT or delayed transplant is difficult to ascertain for any particular patient in this retrospective study. These findings should be confirmed in prospective randomized trials. Disclosures: Kumar: celgene: Research Funding; millenium: Research Funding. Gertz:celgene: Honoraria; millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract Abstract 747 Background: Light chain amyloidosis is a monoclonal plasma cell proliferative disorder characterized by multiorgan deposition of monoclonal light chain derived amyloid fibrils. The diffuse organ infiltration by the amyloid fibrils leads to various AL related clinical features. Therapy of AL has been primarily aimed at elimination or control of the monoclonal plasma cells, thus decreasing the light chain available for amyloid formation. Assessment of response to therapy has been grouped into hematological response demonstrating elimination or reduction of the monoclonal population and organ response demonstrating actual improvement in its structure or function. Given the potentially long delay in observing organ improvement, hematological response has been the surrogate short term marker for long term outcome given the relatively rapid decline seen in the monoclonal protein with effective therapy, as well as studies showing improved long term outcome with a hematological response, especially complete response. However, conventional hematological response criteria give priority to the intact monoclonal protein rather than the light chain, which is the amyloidogenic protein. We hypothesized that a light chain response will correlate better with outcome than changes in the intact monoclonal protein levels. Methods: We identified 348 patients who had undergone stem cell transplant (SCT) for AL from among a large group of patients undergoing different treatments for AL, and in whom serial tests results were available. We identified the lowest value attained following SCT for various hematological response parameters (intact serum M-protein [MP], the difference between involved and uninvolved serum free light chain [FLC-diff], and urine M-protein [UP]) before an alternate therapy was instituted. We first estimated the best cutoff for the degree of change in each parameter that predicted 5-year survival from SCT. Cox proportional hazards model was used for multivariable analysis of factors influencing overall survival (OS). Results: We first examined the relative contribution of the MP and the FLC-diff on the overall survival following transplant. The best cutoff for reduction in FLC-diff to predict OS at 5 years from SCT was 88% if all patients were considered and 90% if only those with a baseline FLC diff > 7.5 mg/dL were considered. The best cutoff for MP reduction was 40% for 5 year survival for all patients and 67% for those with a baseline MP > 1.0 gm/dL. We then looked at the impact of FLC reduction and MP reduction in a multivariable analysis using OS as endpoint. For all patients, FLC reduction, but not MP reduction significantly impacted outcome, and results were similar when considering patients with MP>1.0 gm/dl and FLC-diff > 7.5 mg/dl at baseline. Among those with a baseline FLC-diff >7.5 mg/dL (n=125), the overall survival was 35 mos from SCT for those with less than 90% decrease in FLC-diff (45 pts) compared to not reached for those with at least 90% decrease (80 pts); P < 0.001 (Figure). Conclusions: The current study supports the notion that reductions in the free light chain parameters represent a more useful measure of hematological response that translates into better overall survival and possible better chance at organ improvement. A reduction in the FLC difference of 90% appears to correlate best with prolonged survival. Disclosures: Kumar: CELGENE: Research Funding; MILLENNIUM: Research Funding; BAYER: Research Funding; GENZYME: Research Funding; NOVARTIS: Research Funding. Gertz:celgene: Honoraria; millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees. Lacy:celgene: Research Funding.

Abstract Abstract 5152 Introduction: Cold agglutinin disease (CAD) is a rare and poorly understood disorder accounting for 15% of patients with autoimmune hemolytic anemia. Treatment has been largely controversial with few studies addressing safety and efficacy of various treatment regimens. This study reports a single institution's experience with cold agglutinin disease, defines the clinical features, prognosis and management. Methods: A retrospective analysis of Mayo Clinic medical records since 1960 was performed to identify all cases of CAD. Initial appraisal identified 89 patients after which an in depth review of clinical notes, laboratory evaluations, and treatment regimens was performed. Statistical analysis was performed via descriptive statistics and Kaplan-Meier survival. Results: The median age at onset of symptoms was 65 years (range: 40, 82), while the median age at diagnosis was 72 (42, 91). The most common sign at presentation was anemia (38. 4%). The most common symptom during the course of disease was similarly finger discoloration (43. 8%). Over half of patients had symptoms that were triggered by a cold environment (52. 8%) and a minority (22. 5%) had exacerbations precipitated by other factors. The median time from onset of symptoms to time of disease diagnosis was 37 months (0, 374). The majority of patients had an underlying hematologic disorder (48. 3%) of which the most common was monoclonal gammopathy of undetermined significance. At diagnosis the average hemoglobin was 10. 2 (6. 2, 17. 7) with positive coombs testing in 75% of patients. All patients had documented positive cold agglutinin titers. Approximately 40% of patients received transfusions at some point during their disease course and 83% needed drug therapy at some point. The most common reason to initiate drug treatment was progressive anemia (44. 9%). In 15% of patients, CAD was able to be managed with watchful waiting. The median duration between initial symptoms to initiation of treatment was 60 months. 56. 2% and 33. 7% of patients required second and third line therapy respectively. Treatment characteristics and responses are displayed in Table 1. Rituximab showed the longest duration of response and had the lowest percentage of patients needing further treatment, while 4 out of 5 patients on prednisone required additional therapies. Median survival in all patients with CAD was 127. 5 months and 76. 9% of patients were alive at 5-years after diagnosis (Figure 1). Conclusions: This is the largest study of patients with cold agglutinin disease to date. Symptoms were frequently ill-defined resulting in delay of diagnosis. Although drug therapy was frequently indicated, many patients were successfully observed. New treatment agents including Rituximab demonstrate promising response rates compared to traditional regimens, especially in patients with underlying hematologic abnormalities. These results support consideration of CAD as part of the differential diagnosis in the setting of new onset anemia and re-enforces the importance of evaluation for underlying B Cell abnormality in this patient population. Disclosures: Off Label Use: Rituximab, Cyclophosphomide, Chlorambucil, and Prednisone will be discussed as therapy modalatities for the treatment of cold agglutinin hemolytic anemia.