Rajkumar, S. Vincent

Abstract Background: Venous thrombotic events (VTE) are a common complication of therapy with the lenalidomide plus dexamethasone regimen. The incidence of VTE with RD is approximately 20%, and can be lowered with the use of effective thromboprophylaxis, avoidance of erythropoietin, and the use of lower doses of dexamethasone. The goal of this study was to determine the impact of VTE on overall survival of patients with newly diagnosed myeloma by studying events occurring in ECOG E4A03 phase III trial of lenalidomide plus high (standard) dose dex (RD) versus lenalidomide plus low dose dex (Rd) in newly diagnosed myeloma (MM). Methods: Pts with untreated, symptomatic MM were eligible. Pts in the RD arm (Arm A) received lenalidomide 25 mg/day PO days 1–21 every 28 days plus dex 40 mg days 1–4, 9–12, and 17–20 PO every 28 days; pts in the Rd arm (Arm B) received lenalidomide at the same dose plus dex 40 mg days 1, 8, 15, and 22 PO every 28 days. The trial initially did not mandate routine thromboprophylaxis, but recommended that such treatment be considered. After the first 264 patients were enrolled the trial was amended to require mandatory thromboprophylaxis of aspirin for all patients, with a recommendation to use stronger thromboprophylaxis with either warfarin (target INR 2–3) or low molecular weight heparin among patients in the RD arm. Results: 445 pts (median age, 65 yrs) were accrued; 223 randomized to RD, 222 to Rd. Median follow-up time is 30 months. Overall VTE including deep vein thrombosis (DVT) and pulmonary embolism (PE) occurred in 18.5% of patients; 25.6% in Arm A and 11.4% in Arm B. Rates for the first 4 cycles of treatment were 20.2% in Arm A and 8.2% in Arm B, P<0.01. Rates did not change substantially before and after the prophylaxis amendment. A partial response (PR) or higher was seen in 82.1% of pts who experienced VTE compared with 74.6% of pts who did not experience VTE, P=0.19. Overall VGPR rates also were not inferior. Pts who had VTE, however, had significantly higher other grade 3–5 toxicities such as hyperglycemia (14.6% vs 7.5%, P=0.051), cardiac ischemia (4.9% vs 0.8%, P=0.002), non-neuropathic weakness (13.4% vs 6.4%, P=0.039), infection/pneumonia (17.1% vs 11.1%, P=0.138) and fatigue (18.3% vs 10.5%, P=0.060). In a Cox PH model, VTE status as a time-varying covariate was marginally significant: HR 1.54 95%CI (0.96–2.47), P=0.074, suggesting patients that develop VTE have a higher hazard of death. Conclusions: The occurrence of VTE may adversely affect the survival of patients with newly diagnosed myeloma receiving Rev-Dex. VTE was associated with a higher frequency of other serious adverse events. Prevention of VTE events is a priority. Besides lowering the dose of dexamethasone, studies investigating optimum thromboprophylaxis are needed.

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 Table 1. Samples to p53 deletions p 53 deletion FISH aCGH FISH and aCGH MGUS 142 - - SMM 108 - - Newly diagnosed MM - 182 - Relapsed/refractory MM 62 156 19 HMCLs - 48 - Total 312 386 19 Background: Inactivation of p53 by mutation or allelic loss is a rare event in multiple myeloma (MM) at the time of disease diagnosis and believed to be more common in the late stages of the disease. Here we defined the prevalence of p53 deletions in monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), newly diagnosed MM, relapsed MM and human myeloma cell lines (HMCLs). Indirect mechanisms of p53 inactivation such as amplification of MDM2, or deletion of CDKN2A (p14ARF) were also investigated. Patients and Methods: A total of 631 MM samples and 48 HMCLs were analyzed for p53 abnormalities (Table 1) and compared with a cohort of plasma cell leukemia (PCL) previously published by us. Interphase fluorescence in situ hybridization (FISH) and highresolution array-based comparative genomic hybridization (aCGH) were used to detect p53 deletions. MDM2 amplification and p14ARF loss were evaluated by aCGH. Overall survival (OS) was estimated through Kaplan Meier method. Results: The prevalence of p53 deletions was 1.4%, 3.7%, 8.9%, 20% and 87.5% in MGUS, SMM, newly diagnosed MM, relapsed MM and HMCLs respectively (Figure 1). Of interest patients in first relapse showed a p53 deletion prevalence of 18% in comparison with 33% for patients in second relapse or more. We obtained p53 deletion status in 8 patients noted to have deletion at the time of relapse and in whom we had previous samples stored. In 7 of 8 cases deletions had been acquired (absent in the previous samples). The median OS for relapsed MM patients with or without p53 deletion were 4.2 months and 37.8 months respectively (p <0.001). MDM 2 amplification and p14ARF loss was detected in 0.4% and 2% of new diagnosed MM, 0.6% and 5.1% of relapsed MM and 2% and 29% of HMCLs respectively. Discussion: Emergence of p53 deletion/mutations denotes progression genetic events in MM. Importantly we show for the first time the overriding importance of p53 deletions as prognostic markers in relapsed MM. A molecular staging system that is based on the presence of p53 inactivation may be more powerful than classifying patients based on the loss of p53. Other abnormalities involving p53 pathway regulators like MDM2 gain and p14ARF loss are infrequent events in MM, even in advanced disease. Figure 1. Prevalence of p53 deletions Figure 1. Prevalence of p53 deletions

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 Melphalan (M), Prednisone (P) and Lenalidomide (R) are active in the treatment of multiple myeloma (MM). We evaluated the toxicity and efficacy of MPR in a phase I/II trial. Results of phase I part were previously reported (Blood2006, 108(11) abst 3558). M 5 mg/m2 on days (d) 1–4, 60 mg/m2 d 1–4 and R 10 mg d 1–21 of a 28 day cycle was determined as MTD for the phase II study. Methods: Patients with previously untreated MM who were not candidates for stem cell transplantation, age ≥18 yr, ECOG PS 0–3, evaluable or measurable disease, ANC >1500, platelets > 100,000 and creatinine ≤ 3.0 mg/dL were eligible. All patients received aspirin 325 mg/d as DVT prophylaxis. Routine antibacterial prophylaxis was not used. G/GM-CSF was used at the discretion of the treating physician for neutropenia. Response rate (RR), confirmed on two consecutive determinations was the primary end-point. The study had 90% power to detect a RR of at least 45%. Results: Twenty-six patients were accrued between July ’06 and Feb ’08. The median age was 74 y (64 – 87y), 17 (65%) were men. Six, 13, 6, 1 (23%, 50%, 23%, and 4%) patients had ECOG PS 0, 1, 2, and 3, respectively. Three (12%), 11 (42%) and 10 (38%) patients were ISS stage 1, 2 and 3. A total of 106 cycles were administered; median 4.5 (1–13). Seventy-seven % patients experienced at least 1 grade 3 or 4 toxicity. Neutropenia (42%/8%) and thrombocytopenia (20%/8%) were the most common grade 3/4 adverse events followed by anemia (16%/0%), fatigue (8%/4%), rash (11%/0%), and hyperglycemia (4%/0%). There were 20 treatment delays in 9 patients, and 18 dose reductions (9 in R, 11 in M and 1 P) occurred in 7 patients, most commonly because of neutropenia or thrombocytopenia. Eleven patients (42%) required G-CSF treatment. Eleven patients are currently receiving treatment; 15 have gone off study (4 completed per protocol, 3 refused, 3 adverse effects, 3 unrelated illnesses, 2 other). Median follow up of survivors is 8 m (0 – 22m). Eighteen (69 %; 95%CI 48–86) patients had a PR or better according to International Myeloma Working Group Uniform Response criteria; 3 (12 %) CR, 5 (19 %) VGPR and 10 (38%) PR. Median number of cycles before achieving a response was 2 (1 – 11). Median Progression Free and Overall Survival is 16.7m (95% CI 11.2–23.0), and 23 m (95% CI: 22 – 23), respectively. Conclusions: MPR combination is feasible with a manageable toxicity profile and has significant activity in the treatment of patients with MM who are not candidates for stem cell transplant, with an overall response rate of 69%, and a CR plus VGPR rate of 31%. Grade 3 or 4 neutropenia and thrombocytopenia was the most common toxicity, seen in up to 50% of patients in this cohort of predominantly elderly patients. Dose reduction in R and/or M was required in 27% patients. No patient developed neuropathy or thromboembolic complications.

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: Primary systemic amyloidosis (AL) is an incurable plasma cell disorder. Lenalidomide, especially in conjunction with dexamethasone, has been shown to be highly active in patients with multiple myeloma. We previously reported a hematologic response rate of 41% and an organ response rate of 23% among 22 AL patients treated with lenalidomide and on-demand dexamethasone (Dispenzieri et al, Blood 2007). Long term outcomes of AL patients treated with lenalidomide have not yet been described. Methods: Thirty-seven patients were treated on an IRB approved treatment trial with single agent lenalidomide, starting doses of 25 mg in 22 and reduced dose of 15 mg in the last 15. If progression within or no evidence of hematologic response after 3 cycles, dexamethasone was added. Patients were classified according to cardiac biomarker stage (cut-offs for serum troponin T <0.035 ng/ml and NT-proBNP <332 pg/ml--Stage I neither above cutoff; Stage III, both above cut-off; and Stage II, any one above cut-off). Survival estimates were done according to the methods of Kaplan and Meier. Results: Median age was 64 years (range 44–88), with 70% male. Sixty-five percent of patients were previously treated, and the median time from diagnosis to study entry was 8.9 months (range 0.4–237). The biomarker staging breakdown was: I, 16%; II, 43%; and III, 41%. As of 7/11/08, 5 patients remain on active therapy. The overall hematologic response rate was 43% (1 CR and 15 PR), with only one patient responding to single agent lenalidomide, and the overall organ response rate was 20%. If one excludes the 13 patients who did not complete 3 months of therapy and have the opportunity of having dexamethasone added to their program, the respective hematologic and organ response rates were 62% and 32%. With a median follow-up of 33.6 months (range 14.4–42), twenty-two patients (59%) have died, but only 2 had deaths possibly related to treatment. Median duration of response, progression free survival and overall survival were 31 months, 14.8 months (95%CI: 5.7–28.1), and 18.8 months (95%CI: 11.7-not reached), respectively. Overall survival from diagnosis was 48 months (95%CI: 21.6–153.6). As shown in Table below, outcomes were dependent on underlying risk stratification and ability to stay on therapy. High risk patients were more likely to drop out early and less likely to respond. High risk patients had shorter OS All Patients Outcome Stage I Stage II Stage III p N 6 16 15 Survival from enrollment, mo NR 18.8 (11.7–33.6) 5.7 (3.2–18.3) 0.01 Survival from Diagnosis, mo NR 48.4 (20.4–62) 21.1 (11.2–31.7) 0.005 Progression Free Survival, mo 34.7 (33.7–NR) 18.3 (6.2–28.1) 4.4 (3–8.6) NS Drop out by cycle 4, % 17 31 60 NS Median # of cycles administered 31 6 3 0.04 Time to response, mo 6.2 (3.6–9.3) 6.4 (5.2–NR) 4.7 (3.8–NR) NS Hematologic response rate, % 83 38 27 0.05 Organ response rate, % 40 20 13 NS Duration of Response, mo NR 27.2 (13.6–NR) NR NS Subgroup analysis of patients receiving >3 cycles of therapy (i.e getting Len and Dex) N 5 12 7 Time on therapy, mo 35.2 8 10.5 Hematologic Response Rate, % 100 50 56 Organ response rate, % 50 27 25 Conclusions: Based on these data, single agent lenalidomide is not recommended for patients with AL; however, lenalidomide in combination with dexamethasone can be associated with good progression free and overall survival rates, even among patients with relapsed or refractory disease.

Abstract Background: The plasma cell labeling index (LI), a slide-based measure of the percentage of bone marrow plasma cells in the S-phase of cell cycle, is a powerful prognostic tool in multiple myeloma (MM). A high LI is a marker of poor outcome, and is a useful adjunct to cytogenetics and fluorescent in-situ hybridization to risk-stratify MM patients. It has been shown to provide additional prognostic information in International Staging System (ISS) stages 1 and 2 patients treated with conventional chemotherapy ± autologous stem cell transplantation. However, the impact of a high LI is not known in patients receiving novel agents that have been integrated into the current treatment paradigm of newly diagnosed MM. The objective of this study was to determine the value of LI in patients treated with thalidomide-dexamethasone (Thal/Dex) or lenalidomide-dexamethasone (Len/Dex). Patients and Methods : Data from 125 newly diagnosed MM patients enrolled in clinical trials with either thalidomide (200mg/d) plus dexamethasone (Thal-Dex; n=50), or lenalidomide (25 mg/d on days 1–21 of a 4-week cycle) plus dexamethasone (Len-Dex; n=75) as initial therapy, were utilized. Patients within both the studies were categorized into 2 LI groups based on baseline LI: high (≥1%) vs. low (<1%) LI. Overall survival (OS) and progression-free survival (PFS) were estimated using Kaplan Meier method, and compared between the two LI groups within the Thal Dex and Len-Dex studies using log rank tests. Results : The median follow-up for patients on Thal-Dex and Len-Dex was 7.5 and 3 years, respectively. 36% (18/50) of patients in the Thal-Dex study and 35% (26/75) in the Len-Dex study had high LI. The baseline patient-characteristics, including age, stage (ISS), lactate dehydrogenase, calcium, hemoglobin and creatinine were comparable between the 2 studies. The median OS for patients receiving Thal-Dex was 4.7 years (95% CI 3.1–8.1); 2.3 years (95% CI 1.3–4.6) for patients with LI ≥1 compared to 6.9 years (95% CI: 3.9–NA) for those with LI <1 (P=0.02). The median OS for patients on Len-Dex was not reached for either the high or low LI group (P=0.80). The median PFS for all Thal-Dex patients was 1.7 years (95% CI: 1.4–3.1); 1.3 years (95% CI: 0.2–2.0) for patients with high LI vs.2.3 years (95% CI: 1.3–3.3) for patients with low LI; P = 0.01. The median PFS for Len-Dex patients was 2.6 years (95% CI: 1.8–3.1) years, and no significant difference was observed between the 2 LI groups, with PFS of 2.3 years (95% CI: 1.4–3.1) for patients with high LI, and 3.1 years for patients in the low LI group. Due to a shorter median follow-up of Len-Dex patients, a separate analysis censoring all patients in both the studies at 3 years was performed with similar results. Conclusion : LI remains a significant determinant of PFS and OS in newly diagnosed MM patients treated with Thal-Dex, with high baseline LI predicting poorer outcome. In contrast, during first 3 years of follow-up, the unfavorable prognostic effect of LI is not apparent with Len-Dex therapy, and longer follow-up is needed to determine if Len-Dex therapy overcomes the poor prognostic effect of high LI. Figure Figure