Combining fluorescent in situ hybridization data with ISS staging improves risk assessment in myeloma: an International Myeloma Working Group collaborative project

The combination of serum β2-microglobulin and albumin levels has been shown to be highly prognostic in myeloma as the International Staging System (ISS). The aim of this study was to assess the independent contributions of ISS stage and cytogenetic abnormalities in predicting outcomes. A retrospective analysis of international studies looking at both ISS and cytogenetic abnormalities was performed in order to assess the potential role of combining ISS stage and cytogenetics to predict survival. This international effort used the International Myeloma Working Group database of 12 137 patients treated worldwide for myeloma at diagnosis, of whom 2309 had cytogenetic studies and 5387 had analyses by fluorescent in situ hybridization (iFISH). Comprehensive analyses used 2642 patients with sufficient iFISH data available. Using the comprehensive iFISH data, combining both t(4;14) and deletion (17p), along with ISS stage, significantly improved the prognostic assessment in terms of progression-free survival and overall survival. The additional impact of patient age and use of high-dose therapy was also demonstrated. In conclusion, the combination of iFISH data with ISS staging significantly improves risk assessment in myeloma.

Risk of progression and survival in multiple myeloma relapsing after therapy with IMiDs and bortezomib: a multicenter international myeloma working group study

Promising new drugs are being evaluated for treatment of multiple myeloma (MM), but their impact should be measured against the expected outcome in patients failing current therapies. However, the natural history of relapsed disease in the current era remains unclear. We studied 286 patients with relapsed MM, who were refractory to bortezomib and were relapsed following, refractory to or ineligible to receive, an IMiD (immunomodulatory drug), had measurable disease, and ECOG PS of 0, 1 or 2. The date patients satisfied the entry criteria was defined as time zero (T(0)). The median age at diagnosis was 58 years, and time from diagnosis to T(0) was 3.3 years. Following T(0), 213 (74%) patients had a treatment recorded with one or more regimens (median=1; range 0-8). The first regimen contained bortezomib in 55 (26%) patients and an IMiD in 70 (33%). A minor response or better was seen to at least one therapy after T(0) in 94 patients (44%) including ≥ partial response in 69 (32%). The median overall survival and event-free survival from T(0) were 9 and 5 months, respectively. This study confirms the poor outcome, once patients become refractory to current treatments. The results provide context for interpreting ongoing trials of new drugs.

Genetic polymorphisms of EPHX1, Gsk3beta, TNFSF8 and myeloma cell DKK-1 expression linked to bone disease in myeloma

Bone disease in myeloma occurs as a result of complex interactions between myeloma cells and the bone marrow microenvironment. A custom-built DNA single nucleotide polymorphism (SNP) chip containing 3404 SNPs was used to test genomic DNA from myeloma patients classified by the extent of bone disease. Correlations identified with a Total Therapy 2 (TT2) (Arkansas) data set were validated with Eastern Cooperative Oncology Group (ECOG) and Southwest Oncology Group (SWOG) data sets. Univariate correlates with bone disease included: EPHX1, IGF1R, IL-4 and Gsk3beta. SNP signatures were linked to the number of bone lesions, log(2) DKK-1 myeloma cell expression levels and patient survival. Using stepwise multivariate regression analysis, the following SNPs: EPHX1 (P=0.0026); log(2) DKK-1 expression (P=0.0046); serum lactic dehydrogenase (LDH) (P=0.0074); Gsk3beta (P=0.02) and TNFSF8 (P=0.04) were linked to bone disease. This assessment of genetic polymorphisms identifies SNPs with both potential biological relevance and utility in prognostic models of myeloma bone disease.

MDS-associated cytogenetic abnormalities (MDS-CA) after total therapy (TT) regimens for newly diagnosed multiple myeloma (MM): Apparent surge after introduction of post-transplant consolidation chemotherapy (CONS) in TT2 and TT3

8595

Background: We have previously reported on the variables associated with the development of MDS-CA in the context of autologous transplant-supported high-dose therapy regimens for MM (Barlogie et al, Blood 2008). Methods: Due to a perceived increase in MDS-CA frequency, our MM data base was reviewed again to determine the potential effect of CONS introduced in TT2 and retained in TT3 trials. The frequency of MDS-CA post-transplant was determined, using Kaplan-Meier estimate plots, for 183 patients who received TT1, 554 enrolled in TT2 and 305 receiving TT3. Persistence of MDS-CA implied their documentation on 3 successive occasions. Results: 3-year MDS-CA estimates were 2% for both TT1 and TT2 and 4% for TT3 (TT3 v TT2, p=0.04; TT3 v TT1, p=0.11); persistent MDS-CA were also more frequently observed in TT3 in comparison with TT2 and TT1 (2% v 0% v 0%, both p=0.01). Multivariate analysis of features associated with transient and persistent MDS-CA revealed TT3 as an adverse feature (HR=2.84, p=0.043), along with incomplete platelet recovery of <165,000/uL 3mo after 1st transplant. Conclusions: Despite reduced induction chemotherapy prior to and CONS after tandem melphalan (200mg/m2)-based autotransplants from 4 in TT2 to 2 in TT3, overall and persistent MDS-CA increased significantly in TT3. Clinical MDS and AML were rarely observed and a full account of hematopathologic findings will be presented.

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Use of bortezomib (BOR) pharmacogenomics (PG) to identify mechanisms of drug resistance and predict survival in multiple myeloma (MM) treated with total therapy 3 (TT3)

8538

Background: The prognosis of patients with MM is best captured by gene expression profiling (GEP) analysis of CD138-purified plasma cells (PC), distinguishing a high-risk group of 15% with dismal survival using a 70-gene baseline risk model (BLR). Translational research in TT3 was designed to investigate whether short-term BOR-induced GEP alterations could advance our understanding of BOR's novel mechanism of action. Methods: PG studies were performed as part of two TT3 trials (TT3a, n=303; TT3b, n=177), obtaining PC prior to and 48hr after a BOR test-dose (1.0mg/m2), which was accomplished in 142 patients in TT3a (training set) and 127 in TT3b (test set). Among 1051 genes significantly altered post-BOR in TT3a, 80 were identified as being significantly associated with EFS. A continuous risk score was calculated and an optimal cut-point for EFS separation determined. The independent prognostic power of the binary risk score was tested in TT3b. Multivariate analyses (MV) were employed to determine post-BOR risk (PBR) in relationship to standard prognostic variables and BLR. Results: The discriminatory power in TT3a (3-yr OS: 95% v 45%, p<0.0001; 3-yr EFS: 90% v 35%, p<0.0001) was confirmed in TT3b (18-mo OS: 100% v 65%, p=0.0004; 18-mo EFS: 95% v 45%, p<0.0001). Evaluating PBR in the context of BLR, 12/26 in TT3a and 7/21 in TT3b deemed as having low BLR had high PBR; conversely, 8/126 in TT3a and 14/106 in TT3b deemed as having high BLR had low PBR. In the context of our 8 molecular subgroup model, high PBR was over-represented in the Proliferation (PR) subgroup (7/15 in TT3a, 8/18 in TT3b) and absent in the Low Bone disease (LB) group (0/28). On MV, PBR was an independent adverse variable for both OS and EFS in TT3a (OS: HR=3.17, p=0.006, R2=55%; EFS: HR=4.40, p<0.001, R2=48%) and in TT3b (OS: HR=13.00, p=0.002, R2=48%; EFS: HR=15.57, p<0.001, R2=55%). Proteasome genes ranked first among those differentially up-regulated by BOR. Conclusions: PG identified a powerful 80-gene PBR model with unprecedented prognosis-discriminating power, dispelling BLR from MV analysis by altering BLR designation mainly from low to high risk. High PBR (18%) could be traced to up-regulation of proteasome genes, the target of BOR.

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Gene expression profiling (GEP)-defined risk and molecular subgroups assessed at baseline and at relapse: Collective impact on post-relapse survival of multiple myeloma (MM) treated with total therapies 2 and 3

8589

Background: GEP-defined risk has evolved as the most robust predictor of overall and event-free survival (OS, EFS) in MM with TT2 and TT3 protocols, distinguishing 85% with low-risk (LR) and 15% with high-risk (HR). Upon relapse, the original risk designation may change typically in the direction LR to HR. Here we examine, among patients with available GEP data at baseline (BL) and relapse (REL), the contributions of both observations on post-relapse survival (PRS). Methods: Paired REL-BL GEP data were available in 77 patients, while information on metaphase cytogenetic abnormalities (CA) was obtained in 76 patients at both time-points. Results: PRS was significantly affected by both BL and REL HR status so that, among the 52 patients with LR at BL, HR status at REL conferred significantly poorer outcome compared to those with LR at REL (p=0.0005) with 30-mo estimates of 71% v 13%; likewise, among the 25 patients with HR at baseline, HR present also at relapse further diminished PRS (p=0.09) with 30-mo estimates in both settings of less than 20%. Similar considerations for CA status revealed, among the 29 patients without CA at BL, marked attrition of PRS with CA v no CA at REL with 30-mo estimates of 29% v 81% (p=0.04); for the 47 patients with CA at BL, CA also at REL further diminished the poor PRS from 46% to 22% (p=0.06). When all standard BL and REL prognostic factors were examined in a multivariate model, GEP-derived HR contributed to poor PRS both when present at BL (HR=2.79, p=0.005) and at REL (HR=2.77, p=0.002), in addition to CA at BL (HR=2.44, p=0.018). Conclusions: In estimating PRS in TT protocols, genetic characteristics at BL (HR, CA) have enduring adverse consequences aggravated further by HR status at REL. Therefore, in HR/CA BL settings, aiming at REL prevention appears as the best overall treatment strategy.

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Bone marrow microenvironment (ME) associated genes identified prior to all altered 48 hours after bortexomib test-dose application and prognosis of multiple myeloma (MM) treated with total therapy 3 (TT3)

8520

Background: Total Therapy 3 (TT3) incorporated bortezomib (BOR) to co-target ME that plays an important role in MM progression and drug resistance. Consenting patients received a BOR test dose of 1mg/m2 to determine whether ME alterations induced 48hr post-BOR could clarify the drug's in-vivo mechanism of action in the context of achieving MM control. Methods: Bone marrow biopsies were obtained at baseline (BL) prior to and 48hr after BOR (PB) in 70 of 303 patients receiving TT3a (training set) and in 45 of 177 patients enrolled in TT3b (test set). Among 608 ME genes distinguishing BL and PB training samples, 58 were identified as being significantly linked to short event-free survival (EFS). A summary score was computed based on the percent change of these 58 genes (PB-ME-S). Additionally, 20 ME genes were selected whose BL expression predicted OS, arriving at a BL score (BL-ME-S). Results: Applying the PB-ME-S score, 3-yr OS and EFS estimates were 96% and 96% among the 49 patients with low PB-ME-S and 50% and 38% in the 21 with high PB-ME-S (both p<0.0001). Follow-up is too short to validate the PB-ME-S model in the test set of 45 patients in TT3b. The BL-ME-S distinguished OS and EFS in the training set of 70 patients, with 3-yr OS and EFS estimates of 92% and 91% among the 50 patients with low and 54% and 45% in the 20 patients with high BL-ME-S (both P<0.0001). These data were validated in 113 patients with only BL-ME data: 3-yr OS and EFS were 90% and 85% among the 89 patients with low as opposed to 70% and 55% among the 14 patients with high BL-ME-S (p=0.001, p=0.002). TT3 survival was independently significantly affected by PB-ME-S (OS: HR=12.74, p=0.002; EFS: HR=14.32, p<0.001) and BL-ME-S (EFS: HR=3.10, p=0.045), whereas the univariately significant role of BL-PC-S for both endpoints could not be confirmed on multivariate analysis. Conclusions: To our knowledge, this is the first report documenting a validated prognostic role of ME for cancer survival. Key genes shared by both PB-ME-S and BL-ME-S models are involved in endothelial and mesenchymal stem-cell signaling, the details of which will be reported at the meeting.

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Prognostic implications of comprehensive imaging with PET-CT, MRI, and X-rays and their biological and molecular correlates in multiple myeloma (MM) treated with total therapy 3 (TT3)

8532

Background: PET and MRI can reveal intramedullary focal lesions (FL) before osteolysis is detected on metastatic bone survey (MBS). Diagnostic merits, biological/molecular correlates, and outcome implications of the imaging techniques were prospectively and serially evaluated in 269 of 303 newly-diagnosed patients receiving TT3. Methods: Examined were FL number identified by PET (FDG-FL), CT portion of PET (CT-FL), MRI (MRI-FL), and MBS (MBS-FL); additionally, max-SUV of FL (SUV-FL), diffusely-involved bone marrow (SUV-DI), and extramedullary disease (EMD) on PET-CT. Results were compared, laboratory correlates examined (eg: gene expression profiling [GEP]-derived risk, molecular subgroups), and outcome implications determined. Results: Comparing anatomic sites, PET detected the highest mean FL followed by MRI and MBS (p<0.0001). Univariately significant implications on overall and event-free survival (OS, EFS) of FDG-FL, MBS-FL, and EMD may be explained by their link to other prognostic variables. Applying tertile frequency distributions of all imaging parameters, significant associations were seen for B2M with MBS-FL, FDG-FL, SUV-DI; CRP with MRI-FL, FDG-FL, CT-FL; GEP-defined high-risk with MRI-FL, FDG-FL, MBS-FL, SUV-FL; GEP low bone (LB) disease with MRI-FL, FDG-FL, SUV-FL; GEP Proliferation (PR) subgroup with MRI-FL, FDG-FL, MBS-FL, CT-FL. Yet on multivariate analysis, OS was independently adversely affected by both SUV-FL (>11) (p=0.001) and MRI >23 (p=0.043) in addition to cytogenetic abnormalities (CA) (p=0.005), B2M (>5.5mg/L) (p=0.005), and LDH ((ULN) (p=0.017). Even with GEP-defined high-risk (p=0.008), SUV-FL (>11) (p=0.009) retained independent significance in addition to CA (P<0.001) and CRP (>8mg/L) (p=0.020). Conclusions: This first prospective comprehensive imaging approach to MM showed that high SUV-FL had significant survival implications even after adjusting for powerful prognostic variables, especially GEP-defined risk. Multifaceted correlations of imaging variables also with molecular features of MM underscore the key role of bone (“soil”) for MM (“seed”) development and progression.

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Gene expression profiling (GEP) of cd 138-purified plasma cells (pc) in previously treated multiple myeloma (PTMM): Validating prognostic models developed in newly diagnosed MM (NDMM)

8598

Background: We have previously reported on the strong discriminatory power in NDMM of GEP-derived 70-gene risk in CD138-purified plasma-cells developed in 351 patients enrolled in TT2 and validated in 441 patients enrolled in two TT3 trials and in PTMM treated with single agent high-dose dexamethasone or bortezomib. Here we report on the overall survival outcomes in 137 patients with PTMM. Methods: Treatment regimens included further autotransplantation and novel agent combinations. The purpose of the investigation was to determine whether PTMM OS was also governed by GEP features, such as high-risk (HR) score, proliferation score (PS), proliferation (PR) molecular subgroup, gain/amplification of chromosome 1q (amp1q) and deletion of the short arm (del1p) and TP53 deletion. Results: Compared with NDMM, PTMM was characterized by greater proportions with HR (32% v 16%, p<0.001), PS (20% v 10%, p=0.002) and PR (24% v 11%, p < 0.001); no difference was observed for TP53 deletion (21% v 30%, p=0.11); amp1q/del1p was more common in PTMM (17% v 9%, p=0.01). OS was 60% at 8yr in NDMM compared to a median of only 2.4yr in PTMM. According to HR, 4-yr OS estimates were 80% for LR v 37% for HR in NDMM (p<0.0001) and 52% for LR v 24% for HR in PTMM (p<0.01). On multivariate analysis of both standard prognostic factors and GEP HR, OS in PTMM was adversely affected by HR status (HR=2.00, p=0.047) and albumin <3.5g/dL (HR=2.66, P=0.013), accounting for a cumulative R2 value of 20%. Conclusions: GEP-derived high-risk features are more prevalent in PTMM relative to NDMM in terms of HR, PS, PR and amp1q/del1p status. As in NDMM, HR status confers poor OS in PTMM. Consistent with serial sampling where LR to HR transformation routinely occurs, these data support the concept that HR in PTMM is derived from clonal evolution. Treatment strategies that presume the existence of underlying HR cells even in LR disease, should be pursued.

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High-dose melphalan (MEL) based autotransplants (AT) for multiple myeloma (MM): The Arkansas experience since 1989 in more than 2,800 patients

8043

Background: The dose-response effect for MEL has been safely exploited through the use of AT. Long-term follow-up studies from large centers are critical to understand who benefits most and who should be considered for alternative treatment approaches. Methods: 2,836 patients receiving at least one MEL AT were considered. Kaplan-Meier analysis was used to estimate median event-free survival (EFS) and overall survival (OS). Cox regression was used to evaluate independent prognostic factors of EFS and OS from AT. Results: Of the 2,836 patients, 979 were enrolled into front-line Total Therapy protocols 1/2/3 (TT); 1,064 were entered on protocols for previously treated patients (non-TT); and 793 were treated off protocol (non-P). Overall median EFS and OS from 1st AT are 31mo and 53 mo; 10-yr EFS and OS were 19% and 24%; 15% survived >15 yr. The 5 strongest favorable OS features included TT (HR 0.46, p<0.001), absence of cytogenetic abnormalities (no CA) (HR 0.48, p<0.001), B2M <3 mg/L (HR 0.46, p<0.001), albumin >=3g/dL (HR 0.45, p<0.001) and platelet count >=100.000/microL (HR 0.41, p<.001), so that 10-yr OS rates were 58% with 5, 24% with 4, 16% with 3, 4% with 2 and 0% with =<1 favorable parameter (p<0.0001). The corresponding median durations of EFS were 80 mo, 37 mo, 27 mo, 18 mo and 7 mo (p<0.0001). Conclusion: This large single institution experience demonstrates that > 10 yr OS can be accomplished in over one-half of the 16% of all patients presenting without CA, with low levels of B2M and albumin, high platelet count and receiving TT. The worst constellation affected 3% of all patients presenting with at most 1 good-risk feature whose 5-yr survival was only 7%. These data should serve as guidepost for MM investigators and patients alike, against which newer treatments should be measured.

No significant financial relationships to disclose.