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.

[Table: see text]

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.

[Table: see text]

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.

[Table: see text]

Benefit of thalidomide (THAL) in total therapy 2 (TT2) of multiple myeloma (MM) exhibiting both cytogenetic abnormalities (CA) and low-risk (LR) by gene expression profiling (GEP)

8590

Background: We recently reported an update of TT2 and observed an unexpected preferential benefit from THAL for OS in the subgroup of patients with CA (Blood, 2008). We now re-examined these results with further follow-up of 81 months in the context of GEP-defined risk. Methods: OS and EFS were examined in the 668 patients enrolled in TT2 according to treatment arm, CA status and by GEP risk status. Results: Median overall and event-free survival (OS, EFS) are 9yr and 5yr, with a significant benefit from THAL v the control arm (p=0.04, p=0.0004). We confirmed the ongoing unique survival benefit of THAL in the CA group with 6-yr OS estimates of 53% v 35% (p<0.001), while patients not exhibiting CA had similar OS of 70% and 68%. EFS was superior with THAL regardless of CA status, 56% v 45% without CA (p=0.02) and 38% v 20% with CA (p=0.008). With respect to GEP, THAL benefited the LR group with 6-yr OS/EFS rates of 73%/56% v 63%/36% without THAL (p=0.10/p=0.002); the corresponding data for high-risk (HR) patients showed OS/EFS with THAL of 35%/19% v 15%/10% without THAL (p=0.36/p=0.43). When examined in the context of both GEP and CA, THAL only benefited the 33 patients with both CA and LR with 6-yr OS of 72% v 37% among the 47 without THAL (p=0.003). For the remaining subgroups (CA/HR; no CA/LR, no CA/HR), the addition of THAL did not impact OS. Conclusions: The unique benefit of THAL to the CA/LR subgroup may be linked to its greater efficacy in proliferative MM (enabling CA detection) that can only be sustained in the LR (lacking amplification of 1q21?) but not in the HR subset. The concomitant examinations of MM genetics by both GEP and cytogenetics enabled the discovery of this subgroup-specific treatment benefit. Data on TT3 with the addition of bortezomib will be presented in the context of the CA/GEP-risk scenario.

[Table: see text]

Plerixafor (P) plus G-CSF (G) in previous peripheral blood progenitor cell (HPC) mobilization failures (MF)

7095

Background: Successful autologous stem cell transplantation (AT) requires harvesting sufficient HPC to ensure reliable engraftment, which cannot be accomplished in ∼10% of previously treated patients. Methods: MF was defined as the inability to collect at least 2 x106 CD34+ cells/kg with growth factor alone (GF) (n=38) or in combination with chemotherapy (GF-CT) (n=27). Of 65 patients reported here, 45 were enrolled in a compassionate use program and 20 were part of a clinical trial (AMD3100–2102); 55 had MM, 9 had lymphoma and 1 had primary amyloidosis. All patients had been treated previously and included prior AT in 26 patients, 15 of whom had 2 AT and 2 had ≥3 AT. The P+G regimen started with G (10 μg/kg) for 4 days, P (240 μg/kg) was added on the evening of day 4; both P and G were continued until completion of collection. In the case of MM, all collected products were analyzed for tumor contamination by DNA/cIg flow cytometry. Results: Of all 65 patients, 63 initiated apheresis which yielded a median 3.6x106 CD34/ kg (range, 0.3–17.8) during a median of 5 days (d) of collection (range, 2–7), with successive median daily CD34 yields of 1.1, 0.9, 0.6, 0.5, 0.3, 0.4 and 0.5 x106/kg. MM cells were mobilized in only 2/55 patients. Additional collection was undertaken in 25 patients, using GF or GF-CT in 19 (median, 3.2x106 CD34 cells; range, 0–8.5), further P+G in 5 (median, 1.7x106 CD34 cells/kg; range, 0.9–3.5), and 1 patient received P+G on a third occasion (2.2x106 CD34 cells /kg). Of 63 patients, 51 (81%) and 24 (38%), respectively, collected ≥2.0 and ≥5.0x106 CD34 /kg. AT was supported with P+G derived products in 43 patients including 7 who received 2 AT. With median infused CD34+cells of 3.6x106 / kg (range, 1.0–7.7), the median times to neutrophils > 500/μl and platelets >20,000/ μl were 14 d (range, 11–35) and 15 d (range, 9–253). Conclusions: P+G ensures collection of an adequate HPC product after MF in 81% that affords durable engraftment even though 40% had prior AT.

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Chemotherapy for resistant and relapsing multiple myeloma

This report summarizes a broad experience in the treatment of patients with multiple myeloma resistant to standard chemotherapy. The VAD regimen has induced remissions in about 50% of relapsing patients but in only about 25% of previously unresponsive patients. In patients resistant to VAD, high-dose therapies with intravenous melphalan, a CBV combination (cyclophosphamide-BCNU-VP-16) or an EDAP regimen (VP-16 -platinum) produced responses in about 40% of patients. However, these treatments usually required autologous bone marrow or blood stem cell support and the median duration of control was only 6 months. With an even more intensive program using high-dose melphalan and total body irradiation supported by autologous bone marrow, all patients who survived the early treatment period responded for a median duration of about 1 year. Results indicated a dose-response effect of chemoradiotherapy on VAD-resistant myeloma with the potential that such intensive regimens will prolong disease-free survival time.

VTD combination therapy with bortezomib-thalidomide-dexamethasone is highly effective in advanced and refractory multiple myeloma

Bortezomib (V) was combined with thalidomide (T) and dexamethasone (D) in a phase I/II trial to determine dose-limiting toxicities (DLT's) and clinical activity of the VTD regimen in 85 patients with advanced and refractory myeloma. The starting dose of V was 1.0 mg/m(2) (days 1, 4, 8, 11, every 21 day) with T added from cycle 2 at 50 mg/day, with 50 mg increments per 10 patient cohorts, to a maximum dose of 200 mg. In the absence of DLT's, the same reiteration of T dose increases was applied with a higher dose of V=1.3 mg/m(2). D was added with cycle 4 in the absence of partial response (PR). Ninety-two percent had prior autotransplants, 74% had prior T and 76% abnormal cytogenetics. MTD was reached at V=1.3 mg/m(2) and T=150 mg. Minor response (MR) was recorded in 79%, and 63% achieved PR including 22% who qualified for near-complete remission. At 4 years, 6% remain event-free and 23% alive. Both OS and EFS were significantly longer in the absence of prior T exposure and when at least MR status was attained. The MMSET/FGFR3 molecular subtype was prognostically favorable, a finding since reported for a VTD-incorporating tandem transplant trial (Total Therapy 3) for untreated patients with myeloma (BJH 2008).

Clinical-grade myeloma Ag pre-loaded DC vaccines retain potency after cryopreservation

BACKGROUND

The use of myeloma Ag-loaded mature DC vaccines, cryopreserved in single-use aliquots, is an attractive immunotherapeutic strategy. In this study we investigated the retention of phenotype, viability and potency of DC vaccines after freezing and thawing.

METHODS

Plastic-adherent monocytes, derived from a steady-state leukapheresis, were cultured in serum-free media containing GM-CSF and IL-4. DC were loaded on day 6 with myeloma lysate (ML) or idiotype (Id) Ag and keyhole limpet hemocyanin (KLH), induced to mature on day 7 with CD40-ligand and cryopreserved on day 9. Seventeen clinical-scale cultures were evaluated for DC yield, recovery and immunophenotype after potency was validated with allogeneic mixed lymphocyte culture and Ag presentation assays.

RESULTS

We produced 88 individual vaccines from 17 clinical-scale cultures. Median DC yield at harvest was 131 x 10(6) (range 37-375 x 10(6)) and median recovery of viable DC after thawing was 69% (range 11-100%). We confirmed viability (7AAD-), phenotype (CD14-, CD83+/CD40+, CD83+/CD80+, CD83+/CD86+, CD83+/CD54+, HLA-DR++) and the ability of the DC to present Ag and stimulate allogeneic T cells post-thawing.

DISCUSSION

We have validated a serum-free culture system for the production of DC. Cryopreservation did not interfere with DC activity, allowed time for rigorous quality control (QC) and flexible scheduling of intranodal vaccination, and reduced the time to prepare multiple vaccines.

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.

Phase II study of total therapy 3 (TT3) with added bortezomib (V) for multiple myeloma (MM)

8020

Background: Building on the success of TT2 with OS exceeding a median of 8 yr, TT3 incorporated V into induction and consolidation/maintenance of melphalan (MEL)-based tandem transplants. Methods: Newly diagnosed patients with MM up to age 75 yr (>59 yr, 47%) were enrolled in TT3, consisting of 2 cycles of V, thalidomide, dexamethasone, cisplatin, adriamycin, cyclophosphamide, etoposide (VTD-PACE) as induction prior to and as consolidation after MEL transplants, followed by maintenance with monthly VTD in year 1 and TD in years 2 and 3. The primary endpoint was complete response (CR). Results: 303 eligible patients were accrued between 02/04 and 07/06; median follow-up is 19 mo. Tandem transplants were completed in 84% with TT3 and 66% with TT2 (p<0.0001) with similar 12-mo TRM (4% v 5%). At 24 mo, 84% v 68% achieved n-CR including 59% v 44% CR (both p<0.0001). 24-mo EFS is superior (83% v 75%, p=0.02; <65 yr: 86% v 76%, p=0.008) while 24-mo OS is still similar (86% v 85%, p=0.44; <65 yr: 88% v 85%, p=0.16). In gene array-based high-risk MM, 24-mo EFS was 62% v 27% (p=0.006) and 24-mo OS was 74% v 43% (p=0.06). Independent adverse parameters for OS with TT3 were LDH>=190 U/L (27%; HR=3.78, p=0.002), high-risk gene array (14%; HR=3.30, p=0.006) and age >=65 yr (29%; HR=2.23, p=0.044). Compared to the T arm of TT2, fewer patients in TT3 experienced grade >2 tremor (3% v 13%, p<0.001), constipation (6% v 14%, p=0.002), syncope (1% v 12%, p<0.001) and thrombo-embolic events (27% v 38%, p=0.004). Conclusion: Compared to TT2, added V and shortened induction in TT3 increased tandem transplant compliance, effected higher CR and n-CR rates and extended EFS with a strong trend for superior OS in high-risk MM in patients <65 yr. TT3 toxicity was reduced in comparison with the T arm of TT2.

No significant financial relationships to disclose.

Determining familial risk of multiple myeloma

8111

Background: The etiology of multiple myeloma (MM) remains unknown although genetic and environmental factors have been implicated. Familial MM has been reported; however, whether this familial tendency is due to genetic factors or environmental exposures or both is not known. Analysis of SEER data showed that Iowa, an agricultural state, had the highest incidence of MM; however, once we adjusted for race, sex, age, and year of diagnosis, the effect of geographic area was small and the main effect was race. This project aims to build a Familial MM Registry of families and investigate the families’ pedigrees and environmental factors to determine the familial risk of MM. The long term goal is to identify myeloma susceptibility loci which ultimately could lead to finding myeloma prone germline mutations. Methods: Patients (n = 67) from the Myeloma Institute for Research and Therapy at the University of Arkansas for Medical Sciences and their family members with MM or a related malignancy (amyloidoses, lymphoma, chronic lymphocytic leukemia, chronic myelogenous leukemia, Waldenstrom's macroglobulinemia, Hairy cell leukemia, acute myelogenous leukemia, acute lymphocytic leukemia, Hodgkin's disease) were interviewed for environmental factors associated with MM and for family history data to complete pedigrees. Pedigrees were analyzed to determine the patterns of inheritance. Results: Data show that 26 patients (39%) have family members with MM (one having five family members with MM) and 34 patients (51%) have family members with related malignancies. Eighteen families (27%) have a putative autosomal dominant mode of genetic transmission of MM. Pancreatic cancer, malignant melanoma, breast cancer and lymphoma may be part of a myeloma syndrome. Pesticide/insecticide exposure, raising cattle or growing cotton were the most prevalent environmental risk factors. Conclusions: The pedigrees suggest the existence of genetic traits affecting MM susceptibility. This work will be part of the efforts to create an international consortium to study familial MM. Research in the area of molecular epidemiology is needed to discover the genetic and environmental determinants of this disease and the reasons for the racial and gender differences.

No significant financial relationships to disclose.