Kyle, Robert A.

Abstract Malignant plasma cell (PC) disorders are clonal diseases based on their immunoglobulin variable region sequence signature. However, intratumor phenotypic, genetic, and morphologic heterogeneity is often observed, fueling the notion that a subpopulation of the malignant PC clone may have extensive self-renewal properties whereas others may not. Little information exists regarding the relationship between these putative tumor subpopulations that is instrumental to our understanding of the growth, progression and therapeutic targeting of PC disorders. We recently described establishment of two novel cell lines from one patient initially diagnosed with primary amyloidosis (ALMC-1), who eventually progressed to a combination of AL and symptomatic multiple myeloma (MM; ALMC-2). Although both cell lines are clonally related, they exhibit a number of intriguing differences, including a marked variability in their makeup of mononuclear (MoN) and multinuclear cells (2 − >10 nuclei; MuN). The ALMC-1 cell line consistently displays a much larger fraction of MuN cells (~50%) than the ALMC-2 cell line (~20%). By contrast, the growth rate of the ALMC-2 cells is significantly higher than ALMC-1 cells suggesting an inverse relationship between growth rate and fraction of MuN cells. It has been demonstrated that MoN plasmablastic morphology is a predictor of poor survival in MM, however the clinical significance of MuN PCs, which are frequently observed in bone marrow biopsies, has yet to be determined. We therefore used the ALMC-1 and ALMC-2 cell lines to begin to test the hypothesis that the MoN fraction in both cell lines contains cells with extensive self-renewal properties whereas the MuN cells are no longer capable of cell division. The central questions become by what mechanism are MuN PCs generated and how are MoN PCs maintained? Two hypotheses that can explain the dual persistence of both types of cells are: random cell fusion; regulated or sporadic cell division of MoN cells into 2 daughter cells, one of which divides normally and the other one fails to undergo cytokinesis. To address the first possibility, each cell line was transfected with GFP or YFP. Single positive (GFP or YFP) cells were then mixed and cocultured for assessing the frequency of dual positive cells by flow cytometry at various time points. However, studies to date suggest this mechanism does not occur. To begin to address the second possibility and determine whether extrinsic factors, e.g., cytokines, may regulate the rate of generation of MuN PCs, we cultured both cell lines +/− IL-6 and IGF-I and assessed numbers of MoN and MuN PCs. Initial analyses suggest that IL-6, but not IGF-I, increases the proportion of MoN PCs in both cell lines. To address the hypothesis that MuN PCs are no longer capable of growth, cells were labeled with bromodeoxyuridine (BrDU) to assess the capability of MuN cells to synthesize DNA. We observed that MuN PCs incorporating BrDU did so uniformly in each nucleus present in the cell. We then assessed the ability of cell division of MuN cells by quantitating normal vs abnormal metaphases in both cell lines and observed that >90% of metaphases were present in MoN PCs, suggesting that MoN PCs largely give rise to MuN PCs and the latter are likely compromised in cytokinesis. As centrosomes play a critical role in regulating cell division and centrosome abnormalities have been noted in MM by others, we next used gamma-tubulin immunofluorescence to detect centrosomes. MoN PCs exhibited uniformly normal centrosome numbers and positioning while MuN PCs showed clear centrosomal abnormalities including accumulation of centrosomes, centrosome clustering, and multiple directional centrosome polarization, suggesting a mechanism by which the MuN cells may be generated. In summary, our data suggest that MuN PCs lack growth potential and that intrinsic and/or extrinsic factors may drive accumulation of these cells. These observations support the possibility that patients with a larger proportion of MuN PCs may have differences in clinical outcome from those patients with largely MoN PCs. To test this, we have begun hematopathological analysis of a large series of patients diagnosed with various plasma cell disorders. Knowledge of the signals that regulate the balance between MoN and MuN cells could lend itself toward identification of therapeutic modalities that may maximize differentiation of tumor cells into end-stage cells.

Abstract Background: Outcome of patients with Multiple Myeloma (MM) is influenced by a variety of baseline prognostic factors, most importantly presence of chromosomal abnormalities. Nevertheless, these biologically determined risk-factors do not account for a significant subset of patients whose outcome varies greatly from what one expects based on the underlying prognostic characteristics. We have previously demonstrated that outcome in myeloma is dictated not only by baseline risk-factors but also response to therapy (R2, risk and response dependent outcome). We studied response duration following initial therapy as a prognostic factor for long-term overall survival in myeloma in three ECOG clinical trials that enrolled patients with newly diagnosed myeloma. Methods: Data from three studies with long-term, mature follow up were analyzed: E9486, E5A93, and E1A00. The regimens used in these studies included Thalidomide/Dex, Dex, VBMCP, VBMCP + alpha-IFN, and VBMCP + Cyclophosphamide. Among progressed/relapsed patients, the association between time to progression and overall survival since relapse was explored using Cox proportional hazards model, in which time to progression was analyzed as a continuous variable. In addition, the association between response duration and overall survival since relapse was explored similarly among relapsed responders. Treatment effect and calendar time of diagnosis have been adjusted in the model. Also, to determine the best cut off point associated with the best differentiation of patients with short OS after relapse, an outcome-oriented method using log likelihood value was applied. Results: Among the 1136 patients enrolled in the three studies, 625 patients who have documented disease relapse have been included in the current study. Of these, 471 patients had responded to the treatment before relapse. Only 33 patients are alive as of Dec., 2007. For all 625 patients, the time to progression (continuous variable) was significantly associated with overall survival from the time of relapse/progression (P<0.0001), with hazard ratio of 0.77 (95%CI: 0.72~0.81) at time to progression increasing by 1 year (i.e., the later the progression/relapse, the lower the risk). The best cutoff point of the time to progression is 3 yrs (the 75th percentile). The hazard ratio of patients progressing within 3 yrs since randomization vs. after 3 yrs is 2.4 (95% CI: 1.9 ~ 2.9) and P-value<0.0001. The median OS from relapse was 0.96 years for the former vs. 2.43 years in the latter group (Figure). Among the 471 relapsed responders, the response duration (continuous variable) was also significantly associated with overall survival since relapse (P<0.0001), with hazard ratio of 0.76 (95%CI: 0.70~0.81) at response duration increasing by 1 year (i.e., the longer the response duration, the lower the risk). The effects seen with each regimen are detailed in the table. The best cutoff point of the response duration is 2 yrs (median). The hazard ratio of patients with response duration less than or equal to 2 yrs vs. more than 2 yrs is 2.1 (95% CI: 1.7 ~ 2.6) and P-value<0.0001. Conclusions: Among patients treated with alkylator based therapy, the duration of response from the initial therapy is an important predictor of the subsequent outcome among patients with myeloma. Given the heterogeneity of the disease and imprecise predictive ability of the known baseline prognostic factors, the duration of response to initial therapy should be taken into account, to deliver risk and response-adapted therapy. The prognostic value of this feature across different clinical trials, points towards the role of underlying disease biology, both disease aggressiveness and ability to rapidly develop resistance to therapies as two important determinants of outcome. Table 1: Hazard ratio of overall survival since relapse for patients progressed within 3 yrs since randomization vs. after 3 yrs in each treatment arm Treatment arm Treatment arm HR (95% CI) P-value TTP<=3yrs vs. >3 yrs Thal/Dex N/A N/A Dex 0.4 (0.05, 3.9) 0.46 VBMCP(E5A93+ E9486) 1.9 (1.4, 2.7) 0.0001 VBMCP+alpha2IFN (E5A93+ E9486) 3.0 (2.2, 4.1) <0.0001 VBMCP+CYCLOPHOSPHAMIDE 2.3 (1.5, 3.6) 0.0001 Response duration <=2 yrs vs. >2 yrs Thal/Dex 0.2 (0.003, 18.5) 0.51 Dex 0.15 (0.02, 0.98) 0.048 VBMCP(E5A93+ E9486) 1.7 (1.2, 2.3) 0.0009 VBMCP+alpha2IFN (E5A93+ E9486) 3.0(2.1, 4.3) <0.0001 VBMCP+CYCLOPHOSPHAMIDE 2.1 (1.4, 3.3) 0.006 Figure 1: Overall survival since relapse between patients progressed within 3 yrs since randomization vs. after 3 yrs. Figure 1:. Overall survival since relapse between patients progressed within 3 yrs since randomization vs. after 3 yrs.

Abstract Background AL amyloidosis can be associated with coagulopathy due to acquired factor X (FX) deficiency. Published experience, limited to case reports, suggests that infusion of fresh frozen plasma (FFP), platelets, plasma exchange, and vitamin K are of limited hemostatic efficacy for periprocedural management of coagulopathy. Therefore, we reviewed our cumulative experience of managing patients (pt) with FX deficiency due to AL amyloidosis who underwent an invasive procedure. Methods Pt with AL amyloidosis and isolated FX deficiency (≤ 50%), who underwent an invasive procedure between January 1975 and May 2007, were retrospectively identified from institutional databases. We excluded bone marrow biopsies as well as procedures >3 months prior to the diagnosis of FX deficiency. Endpoints of the study were bleeding, thrombosis, and death. Results Sixty-one pt fit the study criteria. They were arbitrarily classified as having severe (<10%; n=6), moderate (10–25%; n=16), or mild (26–50%; n=39) FX deficiency. The pt underwent a total of 115 procedures, 13 (11.3%) of which were considered major procedures and 102 (88.7%) were minor procedures. Major Procedures 13 pt underwent a major procedure; 4 had severe FX deficiency, 2 moderate, and 7 mild. Procedures included splenectomy, colon resection, renal transplant, and others. All 4 of the pt with severe deficiency were treated with hemostatic agents (FFP, plasma exchange, tranexamic acid, danazol, aminocaproic acid, and rFVIIa) in the perioperative period. Two (50%) of these patients had complications: intraabdominal hematoma and death. The death occurred in a patient with splenic rupture and uncontrolled hemorrhage refractory to rFVIIa and FFP. None of the pt with moderate deficiency experienced complications, despite not receiving hemostatic agents. Similarly, 0/7 patients with mild deficiency developed complications (2 received hemostatic agents FFP, platelets, vitamin K, and DDAVP). Minor Procedures All 61 pt underwent a minor procedure; central venous catheter placement was the most common (n=26), followed by EGD with biopsy (n=16) and renal biopsy (n=10). Six pt with severe deficiency underwent 7 minor procedures, 2 (29%) of which were associated with excess bleeding, despite rFVIIa treatment in both cases. An additional 3 procedures were performed with hemostatic agents and were uncomplicated. 2/16 (13%) pt with moderate deficiency had excess bleeding, 1 of whom was treated with rFVIIa and the other was not treated. Two others received perioperative treatment and did not have a complication. There were 7 complications in the 39 patients with mild deficiency (18%), including 1 AV fistula thrombosis after rFVIIa. Five of the patients with a bleeding complication did not receive treatment. One patient with mild deficiency received procoagulants and did not have excess bleeding. Conclusions -This is the largest series examining the perioperative management of pt with FX deficiency due to AL amyloidosis -Complications occurred in 11.3% of procedures, including one death -In this series, there were no clear predictors of bleeding -FX deficiency did not contribute to mortality, with the exception of 1 case -Bleeding risk is relatively infrequent in pt with mild or moderate FX deficiency, particularly with non-vascular procedures -Although optimal management of pt with severe FX deficiency is unclear, options include rhFVIIa +/− FFP and aminocaproic acid in those requiring procoagulant therapy.

Abstract Smoldering Waldenström’s Macroglobulinemia (SWM) is defined as a serum IgM monoclonal protein ≥3 g/dL and/or ≥10% bone marrow lymphoplasmacytic infiltration but no evidence of constitutional symptoms, symptomatic anemia, or hyperviscosity. Forty-eight patients with SWM were identified at Mayo Clinic from 1974 to 1995. Patients with a diagnosis of chronic lymphocytic leukemia or lymphoma or history of any antineoplastic therapy before diagnosis of SWM were excluded. The median age at diagnosis was 63 years (range 39–87 years). Only one patient (2%) was < 40 years of age, but 14 percent were < 50 years old. Thirty-two (67%) were men, and 16 (33%) were women. At diagnosis, hepatomegaly was noted in 10%, splenomegaly in 4%, and lymphadenopathy in 8%. The initial hemoglobin level ranged from 8.7 to 15.3 g/dL (median 11.8). The anemia in all 4 patients with an initial hemoglobin < 10 g/dL was due to other causes such as myelodysplastic syndrome, bronchopleural fistula, Barrett’s esophagus, and Coumadin administration. The initial leukocyte level ranged from 3.2 to 13.2 × 109/L (median 5.7), and platelets ranged from 101 to 578 × 109/L (median 285.5). Only one patient had a serum creatinine > 2.0 mg/dL and it was unrelated to SWM. The serum monoclonal protein level at the time of diagnosis ranged from 1.5 to 5.2 g/dL (median 3.3); 12 (25%) were < 3 g/dL, while 10 (21%) were ≥4 g/dL. IgM kappa accounted for 75%, IgM lambda 21%, and 2 (4%) were biclonal. Immunofixation of the urine was positive in 97% (kappa 80%, lambda 17%, indeterminate 3%) of those tested. The size of the urine M protein ranged from unmeasurable to 1.4 g/24h (median 0.04 g/24h). Serum albumin ranged from 2.5 to 4.3 g/dL (median 3.6). Five patients (10%) had an albumin value < 3 g/dL. Ten (26%) had a reduction of 1 uninvolved immunoglobulin, while 8 (21%) had a reduction of both IgG and IgA immunoglobulins. Lymphoplasmacytic infiltration of the bone marrow ranged from 3% to 80%, (median 30%). Three (6%) had less than 10% infiltration, while 13 (27%) had 50% or greater infiltration. The 48 patients were followed for a total of 292 (range 0.5 to 22.6 years; median 3.7) person-years, during which time 33 progressed to symptomatic WM and one to AL amyloidosis. The expected number of WM based on the SEER data was 0.004 cases. Thus, relative risk of progression to WM was increased 7,586-fold (95% CI, 5,083 to 10,373). The median time to progression was 4.6 years. The absolute risk of progression to WM was 6% at 1 year, 39% at 3 years, and 55% at 5 years. The median survival after progression to symptomatic WM was 5.1 years. Seventy-three percent of patients died, indicating a robust follow-up. We evaluated sex, hemoglobin level, size of serum M protein, reduction of uninvolved immunoglobulins, presence of urinary monoclonal light chains, serum albumin level, and the proportion of lymphoplasmacytic infiltration of the bone marrow as risk factors for progression. Significant risk factors for progression with univariate analysis included size of the serum M protein, hemoglobin level, reduction in uninvolved immunoglobulins, and degree of bone marrow lymphoplasmacytic cell infiltration. Multivariate modeling revealed that the size of the M protein and the degree of bone marrow infiltration were the most important risk factors. We conclude that smoldering WM is a distinct clinical entity that needs to be differentiated from IgM MGUS and symptomatic Waldenstrom’s Macroglobulinemia.

Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder associated with varying degree of organ infiltration with light chain derived amyloid protein and consequent organ dysfunction. Various acquired coagulopathies, predominantly Factor X (FX) deficiency have been previously described in AL. The factor deficiencies are thought to be due to the direct binding of blood coagulation proteins to amyloid fibrils. Little is known regarding the prognostic significance of abnormal coagulation parameters in AL patients (pts). Methods: After Institutional Review Board approval, we performed a retrospective review of the medical records of 625 consecutive pts who had presented within 3 months of a diagnosis of AL to be evaluated at Mayo Clinic from June 2001 to June 2006. 540 pts had coagulation studies performed within 2 months of presentation. 51 of those pts were on oral anticoagulation and were excluded from the analysis. Results: Of the 489 pts included in the analysis, the median age was 62 years and 61% were male. The median overall survival (OS) of the entire cohort was 26.8 months. Table 1 lists the prevalence of abnormal coagulation tests in the remaining 489 patients. Prothrombin time (PT) was available in the majority of pts. 61 pts (12.6%) had elevated PT, and 63 pts (20.4%) had a decreased FX. 37 of the 61 pts with elevated PT had available FX levels, of which 31 (84%) of those had a decreased FX, suggesting that the cause of elevated PT was mostly due to a low FX. Indicators of hepatic involvement such as alkaline phosphatase and bilirubin levels were higher among the patients with prolonged PT and low FX. An elevated PT (more than 12.4 seconds) was strongly predictive of an adverse outcome, with a median OS of 8.7 months compared to a median OS of 29 months (p<0.0001) in pts with normal PT (Figure 1). Similarly, pts with decreased FX (less than 60% activity), was associated with significantly worse outcomes with a median OS of 14.9 months versus a median OS of 33 months (p<0.0001) in pts with normal FX (Figure 2). In a Cox proportional hazards model containing cardiac troponin (cTnT), NT-Pro BNP, serum alkaline phosphatase, and free light chain difference (involved minus uninvolved), prolonged PT or FX deficiency were independently prognostic for overall survival. Conclusion: Abnormalities of PT and FX are seen in a sizable proportion of pts with newly diagnosed AL. An elevated PT and or FX deficiency appear to adversely affect the outcome of these patients. It is likely that the elevated PT in these patients relate to FX deficiency in the majority which in turn may reflect the amyloid ‘burden’. The effect of other organ involvement like the hepatic involvement may also have an impact on FX and PT. Table 1. Prevalence of abnormal coagulation testing in patients with newly diagnosed primary systemic amyloidosis. Coagulation study N (Test results available) N of abnormal results (%) Elevated prothrombin time 486 61 12.6 Elevated activated partial thromboplastin time 312 48 15.4 Elevated thrombin time 315 84 26.7 Elevated fibrinogen 140 118 84.3 Decreased Factor II activity 62 26 41.9 Decreased Factor V activity 63 9 14.3 Decreased Factor VII activity 63 17 27 Decreased Factor X activity 309 63 20.4 Elevated D-dimer 130 72 55.4 Figure 1. Survival grouped by normal versus elevated Prothrombin time. Figure 1. Survival grouped by normal versus elevated Prothrombin time. Figure 2. Survival grouped by normal versus low Factor X levels. Figure 2. Survival grouped by normal versus low Factor X levels.

Abstract Background: Monoclonal gammopathy of undetermined significance (MGUS) is defined by a monoclonal protein concentration in serum of 3 g/dL or less and a proportion of plasma cells in the bone marrow of 10% or less, absence of lytic bone lesions, anemia, hypercalcemia, and renal insufficiency related to the proliferation of the monoclonal plasma cells. Two major questions remain unanswered: What proportion of patients with MGUS in the population is unrecognized clinically? What is the likely duration of MGUS at the time of its discovery? Methods: We examined the serum of 21,463 (77%) of the 28,038 enumerated residents of Olmsted County, Minnesota, in a population-based screening study and found that MGUS was present in 1.3% of persons 50 years of age and 3.8% of those 70 years of age. The risk of progression of MGUS to multiple myeloma (MM), primary amyloidosis (AL), Waldenstrom’s macroglobulinemia (WM), or related plasma cell disorders was 1% per year. Results: By age 70, only 21% of Olmsted County residents with MGUS, as determined by the prevalence study, had been recognized by routine clinical practice (Fig. 1). This is probably higher in Olmsted County than elsewhere because serum protein electrophoresis is frequently ordered on Mayo Clinic patients. The incidence of MGUS, estimated from the prevalence data, indicates onset of the condition long before clinical recognition. The duration of MGUS prior to detection at age 70 is shown in Fig. 2. Thus, 30% of patients recognized to have MGUS at age 70 probably had MGUS onset before age 50 and 55% had a prior (unrecognized) MGUS already by age 60. The median duration of MGUS prior to its recognition on the basis of clinical practice is 11 years (median). Linear extrapolation of the incidence curve implies a first appearance of MGUS around 30 years of age. Figure 1 Figure 1 Figure 2 Figure 2

Abstract Background: Immunoglobulin free light chains (FLC) form the substrate for synthesis of amyloid fibrils in patients with AL amyloidosis. Development of FLC assay (Freelite) has allowed us to better assess the clonal cell burden in patients with AL amyloid. The relationship of the light chain types and their levels in serum to the clinical feature at presentation and the eventual outcome has not been systematically studied. Methods: We identified 730 patients with biopsy proven AL amyloidosis, who were seen at Mayo Clinic between January 1980 and July 2006, who were seen within 90 days of their diagnosis and in whom FLC levels were performed or had stored serum available for analysis. Cardiac biomarkers (cTnT, NT ProBNP) were also performed on stored serum for some of the patients as part of previous studies. Clinical data and follow up status are prospectively collected into the Dysproteinemia database, which was used for the study. Results: The median age of the study population was 63 years (range; 32–90) and 463 patients (63%) were male. The median estimated survival for the entire group was 37 months from diagnosis and the median follow up for the 263 patients (37%) alive at the time of the analysis was 27.8 months (range; 1–177 months). The plasma cell clone was lambda in 528 patients (72%) and kappa in 202 (28%) patients. The median absolute difference between the FLCs was 19.6 mg/dL for the entire group (range; 0.01–2478); for the kappa patients was 29.4 mg/dL (range; 0.01–1359) and for the lambda patients was 18.2 mg/dL (range; 0.03–2478). Kappa AL was associated with more involvement of the GI tract and liver as indicated by higher alkaline phosphatase (1.8 vs. 1.3 fold; P=0.03), higher total bilirubin (0.95 vs. 0.78 mg/dL, P = 0.04) and lower serum carotene (119 vs. 155 ug/dL; P = 0.0002). On the contrary, renal involvement was more in the lambda AL with the 24 hour urinary albumin higher in the lambda AL (2.4 gm vs. 1.4 gm; P = 0.0002) and lower serum albumin (2.77 vs. 2.97 mg/dL; P = 0.001). While there was no difference in the overall survival (OS) between the kappa and lambda AL, the median OS for those without a heavy chain was significantly shorter (12.6 months vs. 29.9 months; P= 0.01) compared to those with a heavy chain identified. There was also a correlation between high FLC difference and degree of organ involvement, especially cardiac. Among the 202 kappa AL patients, the median survival for those with a high FLC difference ( > 29.4 mg/dL) was 13 months vs. 48.8 months for those with low difference (P = 0.001). Similarly among the 528 patients with lambda AL, those with high difference (> 18.2 mg/dL) had a median OS of 9.3 months compared to 33 months for those with low difference (P < 0.0001) (Figure). The FLC difference was independent of the cTnT, NT Pro BNP, uric acid and fold-increase in alkaline phosphatase, all of which were significant in the multivariable analysis. Conclusions: The type of FLC impacts the spectrum of organ involvement, with gastrointestinal involvement observed more frequently with kappa, and renal involvement with lambda FLC. The FLC burden correlates with the degree of organ involvement, and is a significant predictor of overall survival in AL amyloidosis. Lambda FLC exerts similar effect as kappa FLCs, but at lower levels confirming the increased “amyloidogenicity” of lambda FLC. Finally, lack of a chaperone heavy chain is associated with a poorer outcome. Figure 1. Overall survival form diagnosis in patients with high vs. low FLC difference (using median values for cutoffs for kappa and lambda FLC) Figure 1. Overall survival form diagnosis in patients with high vs. low FLC difference (using median values for cutoffs for kappa and lambda FLC)

Abstract Background: The combination of lenalidomide and dexamethasone (Rev/Dex) has been shown to be a highly effective therapy for multiple myeloma (MM). Over half of the patients with newly diagnosed MM achieve a complete response with prolonged therapy. More recently, a phase III trial demonstrated improved survival with use of lenalidomide and low dose dexamethasone with one year survival in excess of 90%. We report the initial results from a phase II trial combining lenalidomide and low dose dexamethasone with cyclophosphamide (CRd) as initial therapy of newly diagnosed MM. Methods: The trial was initiated in July 2006 and completed the target accrual of 33 patients by July 2007. The treatment protocol consisted of lenalidomide given orally at a dose of 25 mg daily on days 1–21 of a 28-day cycle. Dexamethasone (dex) was given orally at a dose of 40 mg on days 1, 8, 15, and 22 of each cycle. Cyclophosphamide at a dose of 300 mg/m2 was given on days 1, 8, and 15 of each cycle. Patients also received an aspirin once daily as thromboprophylaxis. Response was defined as a decrease in serum monoclonal (M) protein by 50% or higher and a decrease in urine M protein by at least 90% or to a level less than 200 mg/24 hours, confirmed at least 4 weeks apart. Results: The median age was 63 years (range, 44–79). Eight patients (24%) had ISS stage III disease. At this time, 19 of the 33 patients are evaluable for confirmed responses (i.e., off-study or completed at least 4 cycles of therapy). Of these, 2 achieved VGPR and 13 had a partial response giving an overall response rate of 79%. The response rate was affected by 5 of 19 patients who went off study within three cycles due to toxicities [interstitial nephritis (1 pt), multiple grade 3 toxicities including infection (1 pt) atrial fibrillation and infection (1 pt)] or alternative treatment [no response and possible renal toxicity (1 pt) and progression at 4 cycles (1 pt)]. Overall, hematological toxicity was the most common with grade 4 toxicity seen in 6 patients (20%). Non-hematological grade 3 or higher toxicities included fatigue (4 pts), thrombosis (3 pts) and renal failure (2 pts). One patient with thrombosis came off study for other toxicities, and the other two continued on study with anticoagulation. Thirteen patients (43%) had dose reductions of both cyclophosphamide and lenalidomide, most commonly due to hematological toxicity. So far, 12 patients have gone off study, 6 went to stem cell transplant, 3 due to adverse events, 1 due to disease progression and 2 patients went to alternate treatment. Conclusions: CRd has excellent activity in newly diagnosed myeloma with an estimated overall response rate of 79%. Response evaluation of the entire 33 patients will be presented at the meeting. We believe that the initial use of a 300 mg/m2 dose of cyclophosphamide resulted in 5 of the first 19 pts experiencing early toxicity and withdrawal. As a result, an expansion of the current trial is evaluating lower doses of cyclophosphamide (300 mg fixed dose). Full analysis of this study will be needed to determine if CRd can improve outcome compared to Rd.

Abstract Background: In multiple myeloma (MM), a complete response (CR) is defined by the European Group for Blood and Bone Marrow Transplantation (EBMT) and the International Myeloma Working Group (IMWG) Uniform Response Criteria as absence of monoclonal protein in serum and urine by immunofixation (IFE), and a bone marrow (BM) aspirate/biopsy containing <5% plasma cells (PC). This definition of CR is widely adopted in clinical trials, but there is a high degree of non-compliance with the BM requirement. As a result, differences in CR rates across trials can occur not just as a result of treatment efficacy, but also on how rigorously the BM requirement for CR is implemented. Moreover, requiring BM examinations merely to confirm CR is cumbersome in clinical practice. The goal of this study was to determine the added value of BM examinations in patients who can otherwise be considered to be in CR by virtue of a negative IFE in the serum and urine. Methods: For the purpose of the study, we included only patients with MM who had measurable monoclonal (M) protein levels at baseline (defined as >1 gm/dL in the serum and/or >200 mg/24 hour in the urine) on protein electrophoresis; patients with non-secretory and oligo-secretory MM were excluded. We then identified patients who since 1995 had a negative IFE in the serum and urine and a BM aspirate/biopsy, all done at the same time (within 30 days of each other). Baseline demographics and clinical characteristics; date of diagnosis, last follow up, and follow up status; serum and urine M protein levels at diagnosis; and results of serum and urine IFE, serum free light chain (FLC) ratio and BM aspirate/biopsy within 30 days of complete response were all collected from the existing databases. Results: Ninety-five patients met the criteria for the study, all of whom had measurable disease at baseline and subsequently achieved negative IFE in serum and urine (‘IF- CR’). Of these, only 83 patients (87%) met criteria for CR by the EBMT/IMWG criteria with less than 5% PC in the BM; 13% of patients had 5% or more PC despite the apparent IF-CR on serum and urine IFE. In fact, the BM showed 10% or more PC in 5% of IF-CR patients. We then assessed whether a normal serum FLC ratio in addition to negative serum and urine IFE would eliminate the need for a BM biopsy. The additional requirement of the serum FLC ratio to negative IFE was not fully adequate in eliminating false positive CR’s. Among 34 patients who had IF- CR plus a normal serum FLC ratio, only 88% of patients met CR definition with <5% BM PC; 12% had 5% or more PC, and one patient (3%) had 10% or more PC. We studied the survival (from time of diagnosis) of patients who had true CR’s (negative IFE and <5% PC) versus patients who had IF- CR’s but BM had 5% or more PC. Overall survival from diagnosis between the two groups was 10.7 years versus 5.6 years, respectively, P=0.001 (see Figure 1). Conclusions: BM examination is essential to accurately estimate CR. Up to 13% of patients with negative IFE in serum and urine fail to meet the BM requirement. The addition of a normal serum FLC ratio to negative IFE did not significantly reduce the proportion of patients who fail to meet the BM requirement. Based on this study, we recommend that the CR definition in the EBMT and IMWG criteria should not be revised to eliminate the need for BM examination. Moreover, the consistent collection of BM samples is essential for future strategies to evaluate immunophenotypic CR and molecular CR in MM. Figure 1: Kaplan-Meier curve showing survival benefit (in years) of patients in complete response with less than 5% bone marrow plasma cells. Figure 1:. Kaplan-Meier curve showing survival benefit (in years) of patients in complete response with less than 5% bone marrow plasma cells.

Abstract Background: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder with a poor survival, especially in patients (pts) with multiple organ involvement. For pts with limited organ involvement, high dose chemotherapy with autologous stem cell (SCT) support is an effective approach. However, the toxicity of SCT limits its widespread use. Melphalan and dexamethasone has been previously shown to be effective in pts ineligible for SCT. Methods: We reviewed our experience with melphalan and dexamethasone for treatment of AL. Eighty one pts were treated between 2001 and 2003; median age at start of therapy was 63 years (range, 38–80) and 56 pts (69%) were males. Among these, 46 pts (57%) had 2 or more major organs (cardiac, renal, hepatic) involved. Intravenous melphalan (IV) was used in 45 pts (56%), 32 (40%) received oral melphalan (PO) and the rest received cycles of both. The most common doses were 16 mg/m2 for IV administration (every 4–6 weeks) and 0.22 mg/kg for PO administration (every 4 weeks). Dexamethasone was usually given at a dose of 40 mg for the first 4 days of each cycle. Results: Patients received a median of 5 cycles (range; 1–17). At the time of analysis, 53 (65%) pts were alive with a median follow up of 10.8 months (range, 1.4–47.1).The estimated median overall survival (OS) was 25.6 months for the entire group, with the number or type of organs involved not impacting survival. Hematological response (HR) was defined by a 50% reduction in either serum M-spike, urine M-spike, or the absolute difference between the involved and uninvolved immunoglobulin free light chains. A HR was observed in 43 pts (67%) of the 64 pts measurable for HR by conventional criteria. Achievement of HR was associated with a superior OS with a median post-therapy OS that was not reached, while non-responders had a median OS of 11.1 months (p<0.0001) (Figure 1). Among these pts, an organ response as defined by conventional criteria, was seen in 14 pts (22%), which was significantly correlated with obtaining a hematological response (33% vs. 5%, p=0.01). A 25% reduction in the difference between the involved and uninvolved FLC strongly predicted prolonged OS, with a median post-therapy OS that was not reached for responders vs. 11.3 months for non-responders (p<0.0001) (Figure 2). A decrease in post-therapy brain natriuretic peptide (BNP) also predicted for a survival improvement, with the median OS not reached for responders vs. a median OS of 17 months for non-responders (p<0.016). Conclusion: Treatment with melphalan and dexamethasone is effective and a significant survival advantage is achieved in patients with a hematological response. FLC and BNP response can help identify patients that are likely to benefit from this therapy. Figure Figure Figure Figure