Citations

Abstract Introduction: The immunoglobulin free light chain (FLC) is the precursor protein of amyloid in primary systemic amyloidosis (AL). Historically, the ability to monitor the amyloid protein precursor has been crude. There is now a test that reproducibly measures serum levels of FLC. We evaluated the utility of this assay in patients with AL undergoing peripheral blood stem cell transplant (PBSCT). Methods: Between March 1, 1996 and July 31, 2004, 98 patients with AL undergoing PBSCT had serial FLC measurements performed either prospectively or on stored sera. Patients who died before their 100 day evaluation were excluded because response could not be estimated. FLC levels were performed using Freelite™ reagents on a Dade-Behring Nephelometer. In order to pool the data of the monoclonal kappa and lambda patients, the clonal free light chain was considered the involved] immunoglobulin free light chain for the purpose of these analyses and is henceforth referred to as FLC. The prognostic effects of the initial concentration and the extent of reduction of monoclonal FLC on survival were evaluated. Results: Pre-transplant, 94% of patients had an abnormal FLC ratio, with a median involved FLC of 152 mg/L [15.2 mg/dL]. Only 14% of 98 patients had a “measurable” serum M-spike (i.e. ≥ 10 g/L [1 g/dL]) on electrophoresis with a median of 1 g/L [0.1 g/dL]. Ten patients have died of their disease during a median follow-up time of 19.5 months, range 3.3 to 103 months. The 2- year and 4-year estimated survivals are 92% and 76%, respectively. Using the 75th percentile value of pre-PBSCT FLC (382 mg/L [38.2 g/dL]) as a grouping variable, there was a significantly higher risk of death 5.4 (95% confidence interval 1.5–19.3) in the patient quartile with the highest baseline FLC. Baseline FLC correlated with serum cardiac troponin T levels (rho 0.51, p<0.0001), suggesting that high FLC levels are associated with more advanced disease. After PBSCT, the median percent reduction of FLC was 81%. The percent FLC reduction did not predict for survival, but the absolute level of FLC achieved after therapy did. The hazard ratio for death for not achieving a post-transplant FLC of 20 mg/L [2 mg/dL] post-transplant was 5.1 (95% confidence interval 1.1–24.1). Of 91 patients evaluable for complete response by EBMT criteria, 45 had a complete hematological response. Sixty-five percent of the patients achieving a FLC level of less than 20 mg/L [2 mg/dL] also had a complete hematologic response. Free light chain response as defined by a post transplant FLC level 20mg/L [2 mg/dL] or lower was a more powerful predictor of survival than complete hematologic response, as defined by the EBMT multiple myeloma criteria. Post-PBSCT FLC level only weakly predicted for organ response, but median follow-up for surviving patients is relatively short at 19.6 months. Conclusion: FLC measurements both pre- and post-PBSCT are important predictors of patient outcome.

Abstract Purpose: Lenalidomide (CC-5013) is an analogue of thalidomide and a lead clinical compound in a new group of drugs called IMiDS® which have immunomodulatory properties. Lenalidomide has shown promising results in relapsed refractory myeloma. It has a markedly different side-effect profile compared to thalidomide, with significantly fewer non- hematologic adverse events; myelosuppression, especially neutropenia, is the most common toxicity. We report the results of a phase II trial using the combination of lenalidomide plus dexamethasone (Rev/Dex) as initial therapy for newly diagnosed multiple myeloma. Patients and Methods: 34 patients (23 male and 11 female) were enrolled. Lenalidomide was given orally 25 mg daily on days 1–21 of a 28-day cycle. Dexamethasone was given orally at a dose of 40 mg daily on days 1–4, 9–12, 17–20 of each cycle. Patients were allowed to go off treatment after 4 cycles of therapy to pursue stem cell transplantation, but treatment beyond four cycles was permitted at the physician’s discretion. For patients continuing therapy beyond 4 months, the dose of dexamethasone was reduced to 40 mg on days 1–4 of each cycle. Objective response was defined as a decrease in serum monoclonal (M) protein by 50% or greater and a decrease in urine M protein by at least 90% or to a level less than 200 mg/24 hours, confirmed by two consecutive determinations at least 4 weeks apart. Sub-classification as very good partial response (VGPR) required in addition to criteria for partial response, >=90% reduction in serum M protein, 24 hour urine M protein less than or equal to 100 mg, and 5% or fewer plasma cells on bone marrow examination. All patients received aspirin (81 mg or 325 mg daily) as prophylaxis against DVT. Results: The median age was 64 years (range, 32–78). All patients were evaluable for response and toxicity. Thirty-one of 34 patients (91%) achieved an objective response to therapy, including 2 patients (6%) achieving a complete response (CR) and 11 patients (32%) achieving very good partial response. Of the 3 patients not achieving an objective response, two met criteria for minor response and one had stable disease. Responses were rapid; the median time to response was 1 month. Adequate stem cells (>3.0 million CD34 cells/kg body weight) were obtained in all patients who proceeded to autologous stem cell transplantation. Forty-seven percent of patients experienced grade 3 or higher non-hematologic toxicity, most commonly fatigue (15%), muscle weakness (6%), anxiety (6%), pneumonitis (6%) and rash (6%). One patient died on study, and this was attributed to infection unrelated to therapy; the patient had stopped all therapy for over a month before the fatal infection occurred. One patient developed a pulmonary embolism, but recovered with therapy; no other patient developed deep vein thrombosis or pulmonary embolism. Conclusion: Rev/Dex is highly active and well tolerated in the treatment of newly diagnosed multiple myeloma with overall responses in over 90% of patients including complete and very good partial responses in 38%. Two large cooperative group trials are currently testing Rev/Dex as initial therapy for multiple myeloma in the United States.

Abstract Background: Although thalidomide induced neuropathy has been described for decades, many features such as incidence, risk factors, severity and character of the neuropathy are not well defined. We retrospectively reviewed the incidence and clinical course of peripheral neuropathy in patients treated with thalidomide or thalidomide/dexamethasone (Thal/Dex) on a Phase II Mayo Clinic trial. Methods: Patients who participated in a Mayo Clinic Phase II trial of thalidomide in myeloma were studied. In this trial, patients with SMM and RMM received thalidomide 200 mg per day escalated as tolerated to a maximum of 800 mg/day. Patients with NMM received thalidomide 200 mg/day plus dexamethasone 40 mg/day orally on days 1–4, 9–12, 17–20 (odd cycles) and 40 mg/day days 1–4 (even cycles) repeated monthly. The incidence and clinical course of neuropathy was assessed by chart review. The study was approved by the Mayo Clinic Institutional Review Board. Results: All 113 patients (70 male, 43 female) treated on trial were studied; 31 patients with smoldering/indolent myeloma (SMM), 32 patients with relapsed/refractory myeloma (RMM) and 50 patients with newly diagnosed myeloma (NMM). Patients were accrued to the parent protocol from April 1999 through March 2002. The median age was 62 years (range, 36–78). The median duration of thalidomide therapy on protocol was 15 months in SMM, 6 months in RMM and 4 months in NMM. Overall, 63 patients (56 %) developed symptoms of peripheral neuropathy. The incidence of neuropathy was 77%, 50%, and 46% in patients with SMM, RMM, and NMM, respectively. Neuropathy worsened during the treatment phase with/without dose reduction or after cessation in 15%, remained stable in 52%, and improved in 27%. Overall grade of neuropathy was grade 1 in most pts; 11% of all patients had grade 2 neuropathy and 2% had grade 3 neuropathy. Predominant symptoms of neuropathy were tingling and numbness involving both upper limb and lower limbs. Small subsets of patients complained of hearing loss 6 patients), and erectile dysfunction (4 patients). Electromyographic studies and nerve conduction studies were performed in 11 patients; the most common finding was a length dependent axonal neuropathy. Conclusion: Peripheral neuropathy is an important and common adverse event with thalidomide therapy that often limits the dose and duration of treatment. Its incidence and severity are likely related to dose and duration of therapy.

Abstract Background: IL-6 is important for proliferation and inhibition of apoptosis in malignant plasma cells. Understanding the role of IL-6 receptor alpha chain (CD126) in the pathogenesis of plasma cell disorders may help in developing future treatment therapies for these diseases. A previous study has shown that CD126 (alpha subunit of IL-6 receptor) is expressed distinctly in myeloma, monoclonal gammopathy of unknown significance (MGUS), and plasmacytomas when compared to normal. We performed this study in order to confirm and describe the expression of CD126 in different plasma cell disorders. Design and Methods: Using flow cytometry we assessed CD126 expression on clonal plasma cells from patients with Primary Amyloidosis (n=7), monoclonal gammopathy of undetermined significance (MGUS) (n=13), smoldering Myeloma (SMM) (n=19) and active Myeloma (n=22), as well as normal plasma cells (n=9). Plasma cells were identified by their characteristic CD38/45 expression. The expression of CD126 was separately analyzed on the CD45 positive and negative plasma cells. CD 126 expression was considered significant when more than 20% of the cells had expression. Results: CD126 expression was seen distinctly in plasma cell disorder plasma cells and not in normal plasma cells when all plasma cells were studied together. The highest expression percentages were found in Amyloid (28%) followed closely by MGUS 29(%), then SMM (23%), and Myeloma (12%) cells. The CD45 neg subset was similarly positive in the plasma cell disorder group. In this group, MGUS showed the highest expression percentage followed distantly by Amyloid, Myeloma, and SMM. The CD45 pos subset was uniformly positive in expression of CD126. If was found that this subset expressed higher levels of CD126 in all the studied plasma cell disorders and normal plasma cells when compared to the CD45 neg subset. Conclusion: The findings of this study confirm the increased expression of CD126 in plasma cell disorders when compared to normal plasma cells. The higher expression of CD126 in the CD45 pos plasma cell subset has not been previously described. In addition, the CD45 pos subset expressed higher levels of CD126 in all study groups when compared to the CD45 pos subset. This data contributes to the understanding of IL-6 receptor physiology and confirms the important role of the CD45 pos subset in the proliferation of neoplastic plasma cells. The findings are in accordance with the increased proliferative rates seen in the CD45 fraction of malignant plasma cells.

Abstract BAFF is a member of the tumor necrosis factor (TNF) family and plays a role in B cell survival including MM cells. We have previously established a role for BAFF in localization and survival of MM cells in the bone marrow (BM) microenvironment. (Cancer Res2006; 66(13): 6675–82). Here we validate the role of BAFF in MM patients and demonstrate the in vivo activity of anti-BAFF antibody in a SCID-hu MM model. We first performed gene expression profiling (GEP) on CD 138+ plasma cells isolated from 90 MM patients and 11 healthy controls using the Affymetrix U133A arrays. GEP analysis demonstrated increased BCMA expression (p<0.0001, student T test) on newly diagnosed and relapsed MM versus normal plasma cells. Flow cytometry performed on MM patient cells demonstrated the presence of all 3 receptors on CD 138+ cells. ELISA assays confirmed increased plasma BAFF levels in 51 MM plasma (mean: 1049 pg/ml; range: 176–4252 pg/ml) compared to 11 normal donors (mean: 461pg/ml; range: 317–652pg/ml) [p<0.001]. To understand the functional significance that BAFF might play in the biology of MM, we studied the effects of recombinant BAFF (rh-BAFF) on MM cells directly and in the context of its BM microenvironment. Our data demonstrate that rh-BAFF confers a survival advantage to MM cells and protects them against dexamethasone-induced cytotoxicity. Importantly, anti-apoptotic proteins Bcl2 and XIAP were upregulated, as were growth and survival signals belonging to the AKT and MAPKinase pathways. Because of the survival advantage conferred by BAFF on MM cells we evaluated the use of a clinical grade-neutralizing antibody to BAFF. To evaluate the in vivo activity of anti-Baff in MM we used the SCID-hu model, where MM cells grow in the context of human BM microenvironment. A cohort of SCID-hu mice bearing INA-6 MM cells, were treated i.p. weekly with anti-BAFF neutralizing antibody (10 mg/kg, n=3) or control isotype (10 mg/kg, n=3), respectively, for four weeks. Serum levels of soluble human IL-6 receptor (shuIL-6R) released by MM cells into the murine serum were monitored as a measure of MM growth. At the end of treatment we observed a significant (p=0.048) reduction in shuIL-6R level. This translated into a survival advantage of 3.1 weeks in the anti-BAFF treated animals versus the control group (p= 0.02). We also evaluated in vivo effects of anti-BAFF on the bone compartment by radiographic analysis and tartrate-resistant acid phosphatase (TRAP) staining of human bone implants. Our results demonstrate a decrease in radiologically evident lytic lesions in the anti-BAFF treated animals. This was accompanied by a significant decrease in TRAP + osteoclasts in bone sections from treated mice when compared to control mice. Our data therefore suggests that anti-BAFF antibody may impact MM cell growth directly and/or via effects on the BM microenvironment by impacting bone resorption. Taken together, these data show a role for BAFF mediating MM cell survival and its in vivo anti-tumor activities provide a preclinical rational for its clinical evaluation in MM.

Abstract Introduction: The association of amyloidosis with immunoglobulin light chain disorders is well recognized. It is less commonly appreciated that amyloidosis can be associated with IgM monoclonal gammopathies. One of the available therapies for treating amyloidosis is stem cell transplantation. It is unknown whether the clinical outcomes in patients with IgM amyloidosis differs from those patients with light chain amyloidosis. Patients: Among 242 amyloidosis patients receiving stem cell transplants 10 (4%) had an IgM monoclonal protein. Eight were Mλ. One was biclonal Mλ Mκ and one was biclonal Mκ Gλ. The age range was 56 to 71, median 64 years. Seven were men. The monoclonal protein ranged in size from 0.1 to 2.3 g/dL (median 1.2 g/dL). Patients were transplanted from 2 to 8 months (median 4 months) following histologic diagnosis of amyloid. The median time from the recognition of the IgM monoclonal protein to the diagnosis of amyloid was 1.3 months, but 2 patients, both of whom had overt Waldenström’s macroglobulinemia, were diagnosed 45 and 115 months respectively before amyloidosis developed. Of the cohort of 10, 3 fulfilled the criteria for symptomatic Waldenström’s macroglobulinemia. Results: Amyloid syndromes were recognized in the kidney, heart, peripheral nerve and liver in 8, 3, 3 and 1 patient, respectively. Of the 3 peripheral neuropathy patients one also had autonomic failure. Seven of the 8 renal amyloid patients were confirmed with a renal biopsy. Their urinary protein loss ranged from 0.1 to 9.5 g/24h with a median of 4.7 g/24h. Six of the 10 patients had single organ involvement, 3 had 2 organ involvement and 1 had 3 organ involvement. All 3 Waldenström’s patients had prior exposure to cytotoxic chemotherapy. Amyloid deposits were seen in the bone marrow, fat and lymph node in 6, 5 and 1 patient, respectively. Patients underwent from 1 to 7 (median 3) apheresis with a median CD34 yield of 4.5 x 106/kg. Conditioning was Melphalan at 140 and 200 mg/m2 in 2 and 8 patients respectively. Neutrophil engraftment 500/μL occurred between day 11 and 30 (median 14) and for platelets 20,000/μL between day 11 and 406 (median day 16). The median number of hospitalization days ranged from 0 to 32 (median 12). Nine of the 10 patients fulfilled criteria for a hematologic response and to date 3 of these 9 have also achieved an organ response, including normalization of urinary protein loss in 2 nephrotic patients and a greater than 50% reduction in urinary protein loss in the third. None of the patients with amyloid neuropathy responded. One of the patients with cardiac amyloid showed echocardiographic evidence of improvement. At this time 8 survive and 2 died; 1 a treatment-related death (day +40) and 1 of relapse post transplant with progressive amyloid at 45 months. The median follow-up of surviving patients is 29 months. Conclusion: The outcomes in patients with IgM amyloidosis following transplantation do not appear to be different from those with immunoglobulin light chain amyloidosis. There is no suggestion that the response rates are lower or that alternate conditioning schemes such as BEAM should be considered.

Abstract BAFF is a member of the tumor necrosis factor (TNF) family and is critical for the maintenance and homeostasis of normal B-cell development. Importantly, BAFF promotes the generation of rapidly dividing immunoglobulin secreting plasmablasts from activated memory B cells by enhancing their survival. Given that MM is a cancer of plasma cells and that the signaling cascades implicated in receptor ligand interactions of BAFF are crucial in MM cell biology, we hypothesized that this cytokine may play a critical role in MM cell development, survival, and proliferation. We performed gene expression profiling (GEP) on CD 138+ plasma cells isolated from 90 MM patients (45 newly diagnosed and 45 relapsed) and 11 healthy controls using the Affymetrix U133A arrays. Our data demonstrates increased expression of transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) and B-cell maturation antigen (BCMA), 2 receptors used by BAFF to exert its effects. Our data also shows an increased expression of a proliferation-inducing ligand (APRIL), another member of the TNF family with homology to BAFF. Expression levels of BAFF and BAFF-R could not be determined because of lack of these probe sets on the Affymetrix U133A arrays. GEP analysis shows increased BCMA expression (p<0.0001, student T test) on newly diagnosed and relapsed MM versus normal plasma cells. Flow cytometry on MM cell lines demonstrated a differential expression of the three receptors of BAFF, with BCMA present on most cell lines but BAFF-R expressed at low levels only on LR5 cells and DOX40 MM cells. In contrast, flow cytometry performed on MM patient cells demonstrated the presence of all 3 receptors on CD 138+ cells. ELISA assays performed on 30 MM sera demonstrated a mean BAFF level of 618 pg/ml (range: 128–2126pg/ml) versus 235pg/ml (range: 158–326pg/ml) in 7 normal donor sera. Fifty six% (17/30) of MM patients had BAFF levels in excess of the highest value noted in normals. To understand the role BAFF might play in the biology of MM, we studied the effects of recombinant BAFF (rh-BAFF) on MM cells directly and in the context of its bone marrow microenvironment. (abstract # 554746) rh-BAFF conferred a survival advantage to MM cells and protected them against dexamethasone-induced cytotoxicity. Importantly, anti-apoptotic proteins Bcl2 and Mcl-1 were upregulated, as were growth and survival signals belonging to the JAK/STAT and MAPKinase pathways. Conversely, neutralizing antibody to BAFF blocked, at least in part, blocked the upregulation of anti-apoptotic proteins with associated growth and survival, confirming that these effects were due to BAFF. Importantly, all of these signals were downregulated even in the presence of bone marrow stromal cells (BMSCs). These data therefore show a role for BAFF mediating MM cell survival and provide the framework for inhibiting BAFF, either alone or in combination with dexamethasone, to improve patient outcome in MM.

Abstract Background: Thalidomide is an active anti-myeloma agent with single agent activity in all stages of the disease. When combined with dexamethasone disease response is seen in nearly two-thirds of patients with newly diagnosed MM. Though initially evaluated for treatment because of its anti-angiogenic properties and the finding of increased bone marrow angiogenesis in MM, it has become clear that thalidomide exerts its anti-myeloma activity through several different mechanisms. While the mechanism of action of dexamethasone has been studied to a great extent in the setting of myeloma, the molecular basis for the activity of this combination is largely unknown. Methods: Myeloma cells from patients with newly diagnosed MM who were enrolled in a phase III trial (ECOG E1A00) comparing thalidomide and dexamethasone combination (T+D) with dexamethasone alone (D) were studied by gene expression profiling. Samples from diagnosis were compared to those at four months following therapy to study the effect of treatment. Four patients who achieved a partial response with T+D were studied and in addition compared to four patients achieving a partial response with D alone. Plasma cells from bone marrow aspirates were separated by magnetic bead selection of CD138 positive cells and studied using Affymetrix HG-U133A chips using standard methodology. The arrays were analyzed using Genespring 7.2 software following GCRMA normalization and genes with differential expression between the two datasets were examined. Differentially expressed genes were further analyzed using Ingenuity Pathways Analysis program Results: 549 genes were two fold or more differentially expressed between the pretreatment and post treatment samples in the T+D group, of which 275 genes were mapped to different networks using the Ingenuity program. Examination of the canonical pathways demonstrated several pathways that were altered as a result of the therapy. The most significant pathways included those related to immune function including antigen presentation (multiple HLA class II antigens), and PRG2 (NK cell activator). Several mediators of B cell signaling including CD45, PKC (α ,β), SHP2, and Erk1/2 were up regulated following treatment. Increase in the expression of several adhesion molecules including β integrins, fibronectin, VCAM1, L selectin, and LFA3 were noted. Up regulation of IL-6 signaling pathway including gp130, JAK2 and IL8 were noted following therapy. Striking increase in the gene expression for CXCR4 and its ligand SDF-1α was noted as well. 129 genes were differentially regulated by dexamethasone alone, of which 67 were mapped to different networks. The pathways influenced by the dexamethasone alone differed significantly from that of the combination. Conclusion: This exploratory analysis offers an interesting insight into the potential mechanisms of action of the T+D combination in MM. The up regulation of immune response related genes are in accordance with some of the mechanisms described for thalidomide. Also, the differences observed between the patients receiving T+D vs. D allows for assessment of the effects of thalidomide. These findings need confirmation in a larger study.

Abstract Background: The measurement of monoclonal (M) protein in the serum and urine is critical for response assessment and disease evaluation in patients with multiple myeloma (MM). The serum free light chain (FLC) assay offers a new and sensitive method of assessing response to therapy. An important question that has not been adequately addressed is the correlation between 24 hour urine M protein levels and serum FLC measurements, and the extent to which response to therapy estimated using the FLC assay correlates with that assessed using the 24 hour urine M protein level. Methods: A total of 2194 sets of data, with simultaneous UPEP and serum FLC measurement, were studied. These included 752 unique patients, with individual patients having 1–23 paired assessments over time. FLC estimation was carried out using the serum FLC assay (Freelite; The Binding Site Limited, UK) performed on a Dade-Behring Nephelometer. Based on the established reference range, kappa/lambda FLC ratio <0.26 or >1.65 were defined as abnormal indicating the presence of monoclonal lambda and kappa FLC, respectively. The monoclonal light chain isotype was considered the involved FLC isotype, and the opposite light chain type as the uninvolved FLC type. The Urine M protein by UPEP was compared to the serum levels of the involved light chain using Spearman Rank Correlation. For comparisons in individual patients over time, those with at least 10 measurements each were studied. Results: The median involved FLC level in patients with an undetectable urine M protein was 2.3 mg/dl compared to 32.2 mg/dL among those with a detectable urine M protein (P<0.001). Among the 1676 points with an abnormal FLC ratio, only 75% had an M protein detected in the urine, P < 0.001. Conversely, among patients with a positive urine M-protein, 91% had an abnormal FLC ratio. When all the 2194 data points were considered together, there was a significant correlation between the urine M protein level and the FLC levels (FLC level calculated as the difference between involved and uninvolved levels), rho=0.763, P < 0.001. The correlation did not change when patients with a serum creatinine of over 2.5 were excluded. The correlation between FLC levels and urinary M protein can be affected by several factors such as renal function that will differ across patients. Therefore, we examined whether the correlation between the two variables is stronger when the variations introduced by inter-patient differences in the relationship between the two variables are eliminated. In order to do this, we studied individual patients on whom multiple data points over time were available. One patient who had the maximum number of paired assessments (23 pairs) of serum FLC level and urinary M protein; the correlation between the two variables over time was highly significant, rho 0.981, p<0.001. Similarly 26 other patients who had measurable urine M protein levels in whom 10 nor more paired observations over time were available, also showed significant correlations, rho, range 0.726–0.981, p<0.01. Conclusion: There is a significant correlation between urine M-protein and serum free light chain across patients and the correlation is stronger in individual patients in whom the effect of inter-patient variation in other confounding factors can be eliminated. These data if confirmed in a clinical trial setting would support the use of serum FLC levels instead of urinary M protein measurements to assess response to therapy.

Abstract INTRODUCTION Stem cell transplant has been increasingly used in the initial therapy of newly diagnosed systemic AL. Introduction of the free light chain assay has made it easier to quantify responses in patients with AL. It is unclear whether the goal of therapy should be a hematologic response or, as in multiple myeloma, a complete response. This paper addresses the impact of the degree of response on outcome. PATIENTS AND METHODS 282 consecutively transplanted patients are included in this analysis. None of the patients were excluded. There were 169 men (59%). 28% of the cohort have died. 69% had renal involvement, 51% cardiac involvement, 11% peripheral nerve involvement, 16% hepatic involvement. The median percentage of plasma cells at the time of transplant was 7. Echocardiographic analysis revealed a median septal thickness of 12 and a median ejection fraction of 65%. Patients ranged in age from 31 to 71 with a median of 57 years and were transplanted at a median of 4.2 months following histologic diagnosis of amyloidosis. 27% of patients received reduced intensity conditioning usually due to moderate cardiomyopathy or renal insufficiency. 201 patients achieved a hematologic response and 93 of these achieved a complete response. The criteria for response were reported in accord with the consensus definition for response established at The Xth International Symposium on Amyloid and Amyloidosis. A complete response required immunofixation negativity of serum and urine with a normal free light chain ratio. A hematologic objective response required a 50% reduction of serum and urine monoclonal protein with a 50% reduction in the free light chain value. Figure 1 shows the Kaplan Meier curves demonstrating the survival of all patients based on whether they achieved a complete response, partial response, or failed to achieve response. There were 93 CR, 108 PR, and 81 nonresponders. The differences in all three curves are significant at P<.001. Figure 2 demonstrates the same cohort of patients using a six month landmark analysis to exclude the effect of treatment related mortality on outcome. There were 86 CR, 91 PR, and 36 NR for a total of 213 patients. There was a difference in response rate based on conditioning intensity (p<0.01) and age (p=0.046). The median survival was only reached in the NR at 40.1 months and, in the landmark analysis the differences between all three survival curves were statistically significant. CONCLUSION Patients who achieve a hematologic complete response following sct for AL do better than other patients. Patients who achieve an objective response have a superior outcome than patients who fail to achieve a hematologic response, in a landmark analysis at six months. It is unclear if consolidation chemotherapy should be offered to partial responders in an attempt to convert them into CR’s. Figure Figure Figure Figure