The initial analysis of the oral combination melphalan, prednisone, and thalidomide (MPT) in newly diagnosed patients with myeloma showed significantly higher response rate and longer progression-free survival (PFS) than did the standard melphalan and prednisone (

In a randomized, phase 3 study, superior complete/near-complete response (CR/nCR) rates and extended progressionfree survival were demonstrated with bortezomib-thalidomide-dexamethasone (VTD) versus thalidomide-dexamethasone (TD) as induction therapy before, and consolidation after, double autologous stem cell transplantation for newly diagnosed myeloma patients (intention-totreat analysis; VTD, n ‫؍‬ 236; TD, n ‫؍‬ 238). This per-protocol analysis (VTD, n ‫؍‬ 160; TD, n ‫؍‬ 161) specifically assessed the efficacy and safety of consolidation with VTD or TD. Before starting consolidation, CR/nCR rates were not significantly different in the VTD (63.1%) and TD arms (54.7%). After consolidation, CR (60.6% vs 46.6%) and CR/nCR (73.1% vs 60.9%) rates were significantly higher for VTDtreated versus TD-treated patients. VTD consolidation significantly increased CR and CR/nCR rates, but TD did not (McNemar test). With a median follow-up of 30.4 months from start of consolidation, 3-year progression-free survival was significantly longer for the VTD group (60% vs 48% for TD). Grade 2 or 3 peripheral neuropathy (8.1% vs 2.4%) was more frequent with VTD (grade 3, 0.6%) versus TD consolidation. The superior efficacy of VTD versus TD as induction was retained despite readministration as consolidation therapy after double autologous transplantation. VTD consolidation therapy significantly contributed to improved clinical outcomes observed for patients randomly assigned to the

Only limited data are available regarding myocardial iron overload in adult patients with transfusion dependent acquired anemias. To address this topic using MRI T2* we studied 27 consecutive chronic transfusion dependent patients with acquired anemias: (22 myelodysplastic syndrome, 5 primary myelofibrosis). Cardiac MRI T2* values obtained ranged from 5.6 to 58.7 (median value 39.8) milliseconds. Of the 24 analyzable patients, cardiac T2* correlated with transfusion burden (p=0.0002). No patient who had received less than 290 mL/kg of packed red blood cells (101 units=20 grams of iron) had a pathological cardiac T2* value (< 20 ms). All patients who had received at least 24 PRBC units showed MRI T2* detectable hepatic iron (liver T2* value ≤6.3 ms). Only patients with severe hepatic iron overload (T2* <1.4 ms) showed cardiac T2* value indicative of dangerous myocardial iron deposition. Serum ferritin was not significantly correlated with cardiac T2* (p=0.24). Gradient echo T2* magnetic resonance imaging provides a rapid and reproducible method for detecting myocardial iron overload which developed after a heavy transfusion burden equal to or greater than 290 mL/kg of packed red blood cell units.

Bortezomib (bort) has improved overall survival in patients with multiple myeloma (MM), but the majority of them develop drug resistance. In this study, we demonstrate that bone marrow (BM) fibroblasts (cancer-associated fibroblasts; CAFs) from bort-resistant patients are insensitive to bort and protect the RPMI8226 and patients' plasma cells against bort-induced apoptosis. Bort triggers CAFs to produce high levels of interleukin (IL)-6, IL-8, insulin-like growth factor (IGF)-1 and transforming growth factor (TGF) β. Proteomic studies on CAFs demonstrate that bort resistance parallels activation of oxidative stress and pro-survival autophagy. Indeed, bort induces reactive oxygen species in bort-resistant CAFs and activates autophagy by increasing light chain 3 protein (LC3)-II and inhibiting p62 and phospho-mammalian target of rapamycin. The small-interfering RNA knockdown of Atg7, and treatment with 3-methyladenine, restores bort sensitivity in bort-resistant CAFs and produces cytotoxicity in plasma cells co-cultured with CAFs. In the syngeneic 5T33 MM model, bort-treatment induces the expansion of LC3-II(+) CAFs. TGFβ mediates bort-induced autophagy, and its blockade by LY2109761, a selective TβRI/II inhibitor, reduces the expression of p-Smad2/3 and LC3-II and induces apoptosis in bort-resistant CAFs. A combination of bort and LY2109761 synergistically induces apoptosis of RPMI8226 co-cultured with bort-resistant CAFs. These data define a key role for CAFs in bort resistance of plasma cells and provide the basis for a novel targeted therapeutic approach.

No abstract

Bendamustine demonstrated synergistic efficacy with bortezomib against multiple myeloma (MM) cells in vitro and seems an effective treatment for relapsed-refractory MM (rrMM). This phase II study evaluated bendamustine plus bortezomib and dexamethasone (BVD) administered over six 28-day cycles and then every 56 days for six further cycles in patients with rrMM treated with ⩽4 prior therapies and not refractory to bortezomib. The primary study end point was the overall response rate after four cycles. In total, 75 patients were enrolled, of median age 68 years. All patients had received targeted agents, 83% had 1–2 prior therapies and 33% were refractory to the last treatment. The response rate⩾partial response (PR) was 71.5% (16% complete response, 18.5% very good PR, 37% partial remission). At 12 months of follow-up, median time-to-progression (TTP) was 16.5 months and 1-year overall survival was 78%. According to Cox regression analysis, only prior therapy with bortezomib plus lenalidomide significantly reduced TTP (9 vs 17 months; hazard ratio=4.5; P=0.005). The main severe side effects were thrombocytopenia (30.5%), neutropenia (18.5%), infections (12%), neuropathy (8%) and gastrointestinal and cardiovascular events (both 6.5%). The BVD regimen is feasible, effective and well-tolerated in difficult-to-treat patients with rrMM.

Purpose: To investigate the role of hypoxia-inducible factor-1a (HIF-1a) in angiogenesis and drug resistance of bone marrow endothelial cells of patients with multiple myeloma.Experimental Design: HIF-1a mRNA and protein were evaluated in patients with multiple myeloma endothelial cells (MMEC) at diagnosis, at relapse after bortezomib-or lenalidomide-based therapies or on refractory phase to these drugs, at remission; in endothelial cells of patients with monoclonal gammapathies of undetermined significance (MGUS; MGECs), and of those with benign anemia (controls). The effects of HIF-1a inhibition by siRNA or panobinostat (an indirect HIF-1a inhibitor) on the expression of HIF-1a proangiogenic targets, on MMEC angiogenic activities in vitro and in vivo, and on overcoming MMEC resistance to bortezomib and lenalidomide were studied. The overall survival of the patients was also observed.Results: Compared with the other endothelial cell types, only MMECs from 45% of relapsed/refractory patients showed a normoxic HIF-1a protein stabilization and activation that were induced by reactive oxygen species (ROS). The HIF-1a protein correlated with the expression of its proangiogenic targets. The HIF-1a inhibition by either siRNA or panobinostat impaired the MMECs angiogenesis-related functions both in vitro and in vivo and restored MMEC sensitivity to bortezomib and lenalidomide. Patients with MMECs expressing the HIF-1a protein had shorter overall survival.Conclusions: The HIF-1a protein in MMECs may induce angiogenesis and resistance to bortezomib and lenalidomide and may be a plausible target for the antiangiogenic management of patients with well-defined relapsed/refractory multiple myeloma. It may also have prognostic significance. Clin Cancer Res; 20(4); 847-58. Ó2013 AACR.

Interactions of multiple myeloma (MM) cells with endothelial cells (ECs) enhance angiogenesis and MM progression. Here, we investigated the role of Notch signaling in the cross talk between ECs and MM cells enabling angiogenesis. MMECs showed higher expression of Jagged1/2 ligands, of activated Notch1/2 receptors, and of Hes1/Hey1 Notch target genes than ECs from monoclonal gammopathy of undetermined significance patients, suggesting that homotypic activation of Notch pathway occurs in MM. MM cells co-cultured with MMECs triggered Notch activation in these cells through a cell-to-cell contact-dependent way via Jagged1/2, resulting in Hes1/Hey1 overexpression. The angiogenic effect of Notch pathway was analyzed through Notch1/2·siRNAs and the γ-secretase inhibitor MK-0752 by in vitro (adhesion, migration, chemotaxis, angiogenesis) and in vivo (Vk12598/C57B/6 J mouse model) studies. Activated Notch1/2 pathway was associated with the overangiogenic MMEC phenotype: Notch1/2 knockdown or MK-0752 treatment reduced Hes1/Hey1 expression, impairing in vitro angiogenesis of both MMECs alone and co-cultured with MM cells. MM cells were unable to restore angiogenic abilities of treated MMECs, proving that MMEC angiogenic activities closely rely on Notch pathway. Furthermore, Notch1/2 knockdown affected VEGF/VEGFR2 axis, indicating that the Notch pathway interferes with VEGF-mediated control on angiogenesis. MK-0752 reduced secretion of proangiogenic/proinflammatory cytokines in conditioned media, thus inhibiting blood vessel formation in the CAM assay. In the Vk12598/C57B/6 J mouse, MK-0752 treatment restrained angiogenesis by reducing microvessel density. Overall, homotypic and heterotypic Jagged1/2-mediated Notch activation enhances MMECs angiogenesis. Notch axis inhibition blocked angiogenesis in vitro and in vivo, suggesting that the Notch pathway may represent a novel therapeutic target in MM.