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Multiple myeloma (MM) remains incurable, but recent advances in genomics and proteomics have allowed for advances in our understanding of disease pathogenesis, identified novel therapeutic targets, allowed for molecular classification, and provided the scientific rationale for combining targeted therapies to increase tumor cell cytotoxicity and abrogate drug resistance. Besides these advances, recognition of the role of the bone marrow (BM) milieu in conferring growth, survival, and drug resistance in MM cells, both in laboratory and animal models, has allowed for the establishment of a new treatment paradigm targeting the tumor cell and its microenvironment to overcome drug resistance and improve patient outcomes in MM. In particular, thalidomide, bortezomib, and lenalidamide all overcome conventional drug resistance, not only by directly inducing tumor cell cytotoxicity, but by inhibiting adhesion of MM cells to BM. This abrogates constitutive and MM-binding–induced transcription and secretion of cytokines, inhibits angiogenesis, and augments host anti-MM immunity. These three drugs have rapidly translated from bench to bedside and in treatment protocols of MM, first in patients with relapsed refractory disease, and then alone and in combination in newly diagnosed patients. Promising novel targeted agents include the novel proteasome inhibitor NPI-0052 and the heat shock protein inhibitor KOS-953. Importantly, gene-array, proteomic, and cell-signaling studies have not only helped to identify in vivo mechanisms of action and drug resistance to novel agents, but also aided in the design of promising combination-therapy protocols. [Copyright &y& Elsevier]

Abstract: Caveolae are specialized flask-shaped lipid rafts enriched in cholesterol, sphingolipids, and structural marker proteins termed caveolins. Caveolins are highly conserved hairpin loop-shaped, oligomeric proteins of 22–24kDa. Besides the plasma cell membrane, caveolins are also present in mitochondria, the endoplasmatic reticulum, the Golgi/trans-Golgi network, and secretory vesicles. They play a critical role in normal vesicular transport, cholesterol homeostasis, and signal transduction. Conversely, dysregulation of caveolin-1 has been associated with several human diseases including multiple myeloma, an incurable malignancy characterized by excess monoclonal plasma cells within the bone marrow. In this mini-review, we characterize the functional role of caveolin-1 in multiple myeloma, and present the preclinical rationale for novel potential therapeutic approaches targeting caveolin-1 in multiple myeloma. [Copyright &y& Elsevier]

Editorial. Discusses Robert A. Kyle and colleagues' article on symptoms and signs, prognostic factors, complications and treatment outcomes of patients with diagnosed multiple myeloma (MM) evaluated at the Mayo Clinic from 1985 to 1998. Historical review of how the diagnosis and treatment of MM have evolved; Benchmark to establish the current state of the art in MM; Platform for future biologically based strategies to improve diagnosis, treatment and patient outcome.

Background: The primary analysis of the ICARIA-MM study showed significant improvement in progression-free survival with addition of isatuximab to pomalidomide-dexamethasone in relapsed and refractory multiple myeloma. Here, we report a prespecified updated overall survival analysis at 24 months after the primary analysis.Methods: In this randomised, multicentre, open-label, phase 3 study adult patients (aged ≥18 years) with relapsed and refractory multiple myeloma who had received at least two previous lines of therapy, including lenalidomide and a proteasome inhibitor, and had an Eastern Cooperative Oncology Group performance status of 0-2 were recruited from 102 hospitals in 24 countries across Europe, North America, and the Asia-Pacific regions. Patients were excluded if they had anti-CD38 refractory disease or previously received pomalidomide. Patients were randomly assigned (1:1), using an interactive response technology with permuted blocked randomisation (block size of four) and stratified by number of previous treatment lines (2-3 vs >3) and aged (<75 vs ≥75 years), to isatuximab-pomalidomide-dexamethasone (isatuximab group) or pomalidomide-dexamethasone (control group). In the isatuximab group, intravenous isatuximab 10 mg/kg was administered on days 1, 8, 15, and 22 of the first 4-week cycle, and then on days 1 and 15 of subsequent cycles. Both groups received oral pomalidomide 4 mg on days 1-21 of each cycle, and weekly oral or intravenous dexamethasone 40 mg (20 mg if aged ≥75 years) on days 1, 8, 15, and 22 of each cycle. Treatment was continued until disease progression, unacceptable toxicity, or withdrawal of consent. Here' we report a prespecified second interim analysis of overall survival (time from randomisation to any-cause death), a key secondary endpoint, in the intention-to-treat population (ie, all patients who provided informed consent and allocated a randomisation number) at 24 months after the primary analysis. Safety was assessed in all patients who received at least one dose or part dose of study treatment. The prespecified stopping boundary for the overall survival analysis was when the derived p value was equal to or less than 0·0181. This study is registered with ClinicalTrials.gov, NCT02990338, and is active, but not recruiting.Findings: Between Jan 10, 2017, and Feb 2, 2018, 387 patients were screened and 307 randomly assigned to either the isatuximab (n=154) or control group (n=153). Median follow-up at data cutoff (Oct 1, 2020) was 35·3 months (IQR 33·5-37·4). Median overall survival was 24·6 months (95% CI 20·3-31·3) in the isatuximab group and 17·7 months (14·4-26·2) in the control group (hazard ratio 0·76 [95% CI 0·57-1·01]; one-sided log-rank p=0·028, not crossing prespecified stopping boundary). The most common grade 3 or worse treatment-emergent adverse events in the isatuximab group versus the control group were neutropenia (76 [50%] of 152 patients vs 52 [35%] of 149 patients), pneumonia (35 [23%] vs 31 [21%]), and thrombocytopenia (20 [13%] vs 18 [12%]). Serious treatment-emergent adverse events were observed in 111 (73%) patients in the isatuximab group and 90 (60%) patients in the control group. Two (1%) treatment-related deaths occurred in the isatuximab group (one due to sepsis and one due to cerebellar infarction) and two (1%) occurred in the control group (one due to pneumonia and one due to urinary tract infection).Interpretation: Addition of isatuximab plus pomalidomide-dexamethasone resulted in a 6·9-month difference in median overall survival compared with pomalidomide-dexamethasone and is a new standard of care for lenalidomide-refractory and proteasome inhibitor-refractory or relapsed multiple myeloma. Final overall survival analysis follow-up is ongoing.Funding: Sanofi. [ABSTRACT FROM AUTHOR]

Evidence supporting the role of hematopoietic stem cell transplantation (SCT) in the therapy of multiple myeloma (MM) is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published medical literature and for grading the quality of the evidence, the strength of the evidence, and the strength of the treatment recommendations. Treatment recommendations based on the evidence presented in the review were made unanimously by a panel of MM experts. Recommendations for SCT as an effective therapy for MM include the following: SCT is preferred to standard chemotherapy as de novo therapy; SCT is preferred as de novo rather than salvage therapy; autologous peripheral blood stem cell transplantation (PBSCT) is preferred to bone marrow transplantation (BMT); and melphalan is preferred to melphalan plus total body irradiation as the conditioning regimen for autologous SCT. Recommendations that SCT is not effective include the following: current purging techniques of bone marrow. Recommendations of equivalence include the following: PBSCT using CD34+ selected or unselected stem cells. No recommendation is made for indications or transplantation techniques that have not been adequately studied, including the following: SCT versus standard chemotherapy as salvage therapy, tandem autologous SCT, autologous or allogeneic SCT as a high-dose sequential regimen, allogeneic BMT versus PBSCT, a preferred allogeneic myeloablative or non-myeloablative conditioning regimen, and maintenance therapy post–autologous SCT with interferon alpha post-SCT. The priority area of needed future research is maintenance therapy posttransplantation with nothing versus interferon alpha versus other agents such as corticosteroids or thalidomide or its derivatives. © 2003 American Society for Blood and Marrow TransplantationBiology of Blood and Marrow Transplantation 9:4-37 (2003) [Copyright &y& Elsevier]

Background: Bortezomib, lenalidomide, and dexamethasone (VRd) is a standard therapy for newly diagnosed multiple myeloma. Carfilzomib, a next-generation proteasome inhibitor, in combination with lenalidomide and dexamethasone (KRd), has shown promising efficacy in phase 2 trials and might improve outcomes compared with VRd. We aimed to assess whether the KRd regimen is superior to the VRd regimen in the treatment of newly diagnosed multiple myeloma in patients who were not being considered for immediate autologous stem-cell transplantation (ASCT).Methods: In this multicentre, open-label, phase 3, randomised controlled trial (the ENDURANCE trial; E1A11), we recruited patients aged 18 years or older with newly diagnosed multiple myeloma who were ineligible for, or did not intend to have, immediate ASCT. Participants were recruited from 272 community oncology practices or academic medical centres in the USA. Key inclusion criteria were the absence of high-risk multiple myeloma and an Eastern Cooperative Oncology Group performance status of 0-2. Enrolled patients were randomly assigned (1:1) centrally by use of permuted blocks to receive induction therapy with either the VRd regimen or the KRd regimen for 36 weeks. Patients who completed induction therapy were then randomly assigned (1:1) a second time to either indefinite maintenance or 2 years of maintenance with lenalidomide. Randomisation was stratified by intent for ASCT at disease progression for the first randomisation and by the induction therapy received for the second randomisation. Allocation was not masked to investigators or patients. For 12 cycles of 3 weeks, patients in the VRd group received 1·3 mg/m2 of bortezomib subcutaneously or intravenously on days 1, 4, 8, and 11 of cycles 1-8, and day 1 and day 8 of cycles nine to twelve, 25 mg of oral lenalidomide on days 1-14, and 20 mg of oral dexamethasone on days 1, 2, 4, 5, 8, 9, 11, and 12. For nine cycles of 4 weeks, patients in the KRd group received 36 mg/m2 of intravenous carfilzomib on days 1, 2, 8, 9, 15, and 16, 25 mg of oral lenalidomide on days 1-21, and 40 mg of oral dexamethasone on days 1, 8, 15, and 22. The coprimary endpoints were progression-free survival in the induction phase, and overall survival in the maintenance phase. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who received at least one dose of their assigned treatment. The trial is registered with ClinicalTrials.gov, NCT01863550. Study recruitment is complete, and follow-up of the maintenance phase is ongoing.Findings: Between Dec 6, 2013, and Feb 6, 2019, 1087 patients were enrolled and randomly assigned to either the VRd regimen (n=542) or the KRd regimen (n=545). At a median follow-up of 9 months (IQR 5-23), at a second planned interim analysis, the median progression-free survival was 34·6 months (95% CI 28·8-37·8) in the KRd group and 34·4 months (30·1-not estimable) in the VRd group (hazard ratio [HR] 1·04, 95% CI 0·83-1·31; p=0·74). Median overall survival has not been reached in either group. The most common grade 3-4 treatment-related non-haematological adverse events included fatigue (34 [6%] of 527 patients in the VRd group vs 29 [6%] of 526 in the KRd group), hyperglycaemia (23 [4%] vs 34 [6%]), diarrhoea (23 [5%] vs 16 [3%]), peripheral neuropathy (44 [8%] vs four [<1%]), dyspnoea (nine [2%] vs 38 [7%]), and thromboembolic events (11 [2%] vs 26 [5%]). Treatment-related deaths occurred in two patients (<1%) in the VRd group (one cardiotoxicity and one secondary cancer) and 11 (2%) in the KRd group (four cardiotoxicity, two acute kidney failure, one liver toxicity, two respiratory failure, one thromboembolic event, and one sudden death).Interpretation: The KRd regimen did not improve progression-free survival compared with the VRd regimen in patients with newly diagnosed multiple myeloma, and had more toxicity. The VRd triplet regimen remains the standard of care for induction therapy for patients with standard-risk and intermediate-risk newly diagnosed multiple myeloma, and is a suitable treatment backbone for the development of combinations of four drugs.Funding: US National Institutes of Health, National Cancer Institute, and Amgen. [ABSTRACT FROM AUTHOR]

• CALGB (Alliance) 100001 evaluated tandem autologous/allogeneic transplant for myeloma. • A fludarabine/cyclophosphamide conditioning regimen was associated with a very low treatment-related mortality rate. • Long-term follow-up demonstrates a subset of patients who derived benefit from this approach. CALGB (Alliance) 100001 was a phase II study evaluating autologous stem cell transplant (ASCT) followed by nonmyeloablative allogeneic stem cell transplant (alloSCT) in patients with multiple myeloma who had received no more than 18 months of prior therapy and had experienced no more than 1 prior progression event. Conditioning for ASCT was with high-dose melphalan (200 mg/m2). The alloSCT reduced-intensity conditioning (RIC) regimen consisted of fludarabine (30 mg/m2/d i.v. on days -7 through -3) and cyclophosphamide (1 g/m2/d i.v. on days -4 through -3). The primary objective was to determine the 6-month post-alloSCT treatment-related mortality (TRM) rate. Additional objectives included determining the proportion of patients who could complete this tandem ASCT-alloSCT approach in a cooperative group setting, overall response rates, rates of donor chimerism, rates of graft-versus-host disease (GVHD), disease-free survival, and overall survival (OS). Sixty patients were enrolled, of whom 57 (95%) completed ASCT and 49 (82%) completed tandem ASCT-alloSCT. The TRM rate was 2% (1/49; 90% confidence interval, 0.10% to 9.3%). Moderate to severe (grades 2 to 3) acute GVHD was observed in 13 of 49 alloSCT patients (27%). One patient died due to GVHD within 9 months of alloSCT. Twenty-seven of the 49 patients (55%) who underwent alloSCT reported chronic GVHD as either limited (15/49; 31%) or extensive (12/49; 24%) in the first year post-alloSCT and prior to the start of nonprotocol therapy for progressive disease. With a median follow-up for survival of 11 years, the median OS time is 6.6 years and the median time to disease progression is 3.6 years. Similar to other studies, this study confirmed that tandem ASCT/alloSCT is associated with durable disease control in a subset of patients. This study demonstrated the feasibility of performing tandem ASCT/alloSCT in a cooperative group setting and determined that a fludarabine/cyclophosphamide RIC regimen is associated with a very low TRM rate. [ABSTRACT FROM AUTHOR]

Treatment of multiple myeloma has substantially changed over the past decade with the introduction of several classes of new effective drugs that have greatly improved the rates and depth of response. Response criteria in multiple myeloma were developed to use serum and urine assessment of monoclonal proteins and bone marrow assessment (which is relatively insensitive). Given the high rates of complete response seen in patients with multiple myeloma with new treatment approaches, new response categories need to be defined that can identify responses that are deeper than those conventionally defined as complete response. Recent attempts have focused on the identification of residual tumour cells in the bone marrow using flow cytometry or gene sequencing. Furthermore, sensitive imaging techniques can be used to detect the presence of residual disease outside of the bone marrow. Combining these new methods, the International Myeloma Working Group has defined new response categories of minimal residual disease negativity, with or without imaging-based absence of extramedullary disease, to allow uniform reporting within and outside clinical trials. In this Review, we clarify several aspects of disease response assessment, along with endpoints for clinical trials, and highlight future directions for disease response assessments. [ABSTRACT FROM AUTHOR]

Carfilzomib, a recently FDA-approved proteasome inhibitor, has remarkable anti-myeloma (MM) activity. However, its effectiveness is limited by associated severe side-effects, short circulation half-life, and limited solubility. Here, we report the engineering of liposomal carfilzomib nanoparticles to overcome these problems and enhance the therapeutic efficacy of carfilzomib by increasing tumoral drug accumulation while decreasing systemic toxicity. In our design, carfilzomib was loaded into the bilayer of liposomes to yield stable and reproducible liposomal nanoparticles. Liposomal carfilzomib nanoparticles were efficiently taken up by MM cells, demonstrated proteasome inhibition, induced apoptosis, and exhibited enhanced cytotoxicity against MM cells. In vivo , liposomal carfilzomib demonstrated significant tumor growth inhibition and dramatically reduced overall systemic toxicity compared to free carfilzomib. Finally, liposomal carfilzomib demonstrated enhanced synergy in combination with doxorubicin. Taken together, this study establishes the successful synthesis of liposomal carfilzomib nanoparticles that demonstrates improved therapeutic index and the potential to improve patient outcome in MM. [ABSTRACT FROM AUTHOR]

Highlights: [•] Besides proteasomal degradation, Mcl-1 is also degraded by caspase cleavage. [•] Caspase-mediated Mcl-1 cleavage occurs at two highly conserved sites, Asp127 & Asp157. [•] The pro-apoptotic effect of Mcl-1128-350 is mediated via c-Jun upregulation. [•] We demonstrate drug-induced generation of pro-apoptotic Mcl-1 fragment Mcl-1128-350. [Copyright &y& Elsevier]

Summary: We performed massively parallel sequencing of paired tumor/normal samples from 203 multiple myeloma (MM) patients and identified significantly mutated genes and copy number alterations and discovered putative tumor suppressor genes by determining homozygous deletions and loss of heterozygosity. We observed frequent mutations in KRAS (particularly in previously treated patients), NRAS, BRAF, FAM46C, TP53, and DIS3 (particularly in nonhyperdiploid MM). Mutations were often present in subclonal populations, and multiple mutations within the same pathway (e.g., KRAS, NRAS, and BRAF) were observed in the same patient. In vitro modeling predicts only partial treatment efficacy of targeting subclonal mutations, and even growth promotion of nonmutated subclones in some cases. These results emphasize the importance of heterogeneity analysis for treatment decisions. [Copyright &y& Elsevier]

Summary: Background: We aimed to assess efficacy and tolerability of vorinostat in combination with bortezomib for treatment of patients with relapsed or refractory multiple myeloma. Methods: In our randomised, double-blind, placebo-controlled, phase 3 trial, we enrolled adults (≥18 years) at 174 university hospitals in 31 countries worldwide. Eligible patients had to have non-refractory multiple myeloma that previously responded to treatment (one to three regimens) but were currently progressing, ECOG performance statuses of 2 or less, and no continuing toxic effects from previous treatment. We excluded patients with known resistance to bortezomib. We randomly allocated patients (1:1) using an interactive voice response system to receive 21 day cycles of bortezomib (1·3 mg/m2 intravenously on days 1, 4, 8, and 11) in combination with oral vorinostat (400 mg) or matching placebo once-daily on days 1–14. We stratified patients by baseline tumour stage (International Staging System stage 1 or stage ≥2), previous bone-marrow transplantation (yes or no), and number of previous regimens (1 or ≥2). The primary endpoint was progression-free survival (PFS) in the intention-to-treat population. We assessed adverse events in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number 00773747. Findings: Between Dec 24, 2008, and Sept 8, 2011, we randomly allocated 317 eligible patients to the vorinostat group (315 of whom received at least one dose) and 320 to the placebo group (all of whom received at least one dose). Median PFS was 7·63 months (95% CI 6·87–8·40) in the vorinostat group and 6·83 months (5·67–7·73) in the placebo group (hazard ratio [HR] 0·77, 95% CI 0·64–0·94; p=0·0100). 312 (99%) of 315 patients in the vorinostat group and 315 (98%) of 320 patients in the placebo group had adverse events (300 [95%] adverse events in the vorinostat group and 282 [88%] in the control group were regarded as related to treatment). The most common grade 3–4 adverse events were thrombocytopenia (143 [45%] patients in the vorinostat group vs 77 [24%] patients in the placebo group), neutropenia (89 [28%] vs 80 [25%]), and anaemia (53 [17%] vs 40 [13%]). Interpretation: Although the combination of vorinostat and bortezomib prolonged PFS relative to bortezomib and placebo, the clinical relevance of the difference in PFS between the two groups is not clear. Different treatment schedules of bortezomib and vorinostat might improve tolerability and enhance activity. Funding: Merck. [ABSTRACT FROM AUTHOR]

Abstract: Histone deacetylases (HDACs) mediate protein acetylation states, which in turn regulate normal cellular processes often dysregulated in cancer. These observations led to the development of HDAC inhibitors that target tumors through multiple effects on protein acetylation. Clinical evidence demonstrates that treatment with HDAC inhibitors (such as vorinostat, panobinostat, and romidepsin) in combination with other antimyeloma agents (such as proteasome inhibitors and immunomodulatory drugs) has promising antitumor activity in relapsed/refractory multiple myeloma patients. This mini-review highlights the role of protein acetylation in the development of cancers and the rationale for the use of HDAC inhibitors in this patient population. [Copyright &y& Elsevier]

Abstract: Over-expression of the protein Dickkopf-1 (Dkk1) has been associated with multiple myeloma bone disease. Previous reports with the use of anti-Dkk1 neutralizing Ab directed strategies have demonstrated a pro-anabolic effect with associated anti-myeloma activity in 2 in vivo mouse models. However new insights on the role of the wnt pathway in osteoclasts (OC) are emerging and the potential effect of a neutralizing Ab to Dkk1 in osteoclastogenesis remains to be elucidated. In order to better define the effect of an anti-Dkk1 neutralizing Ab on osteoclastogenesis and myeloma, we studied a novel anti-Dkk1 monoclonal Ab in our preclinical models. In vivo data confirmed the pro-anabolic and anti-MM effect. In vitro data in part confirmed the in vivo observation, suggesting an indirect anti-MM effect secondary to inhibition of osteoclastogenesis and thus the interaction between MM and bone microenvironment. However, when studies on osteoclastogenesis were extended to samples derived from MM patients, we observed a variable response to anti-Dkk1 treatment without correlation to expression of surface receptors for Dkk1 in OCs suggesting potential heterogeneity in the efficacy of such a strategy. In conclusion, Dkk1 is a promising target for the treatment of both MM and bone disease, and ongoing clinical studies will help elucidate its efficacy. [Copyright &y& Elsevier]

Abstract: Relapse is the overwhelming cause of treatment failure after autologous transplantation for multiple myeloma (MM). For patients with a syngeneic donor, twin transplants provide a healthy graft that is free of myeloma. The relative impact of the graft on posttransplant relapse can be estimated by comparing risk of relapse after hematopoietic cell transplantation from genetically identical twins versus autotransplants because confounding differences in minor or major histocompatibility antigens are absent in the syngeneic transplant setting. Outcomes of 43 subjects who received twin transplants for MM were compared to 170 matched autotransplant recipients reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). Multivariate analysis was performed by fitting a Cox model stratified on matched pairs. The matched transplant patients studied were similar with respect to subject-, disease-, and transplant-related characteristics. Cumulative incidence of relapse/progression was significantly lower, and progression-free survival (PFS) was significantly higher following twin transplants. In multivariate analysis, the probability of relapse/progression was lower in twins (relative risk [RR] = 0.49, 95% confidence interval [CI] 0.28-0.86, P = .011). Twin transplants have a significantly lower relapse risk than autotransplants in MM, suggesting that graft composition may impact outcomes following high-dose chemotherapy. [Copyright &y& Elsevier]

Summary: Multiple myeloma (MM) evolves from a highly prevalent premalignant condition termed MGUS. The factors underlying the malignant transformation of MGUS are unknown. We report a MGUS/MM phenotype in transgenic mice with Eμ-directed expression of the XBP-1 spliced isoform (XBP-1s), a factor governing unfolded protein/ER stress response and plasma-cell development. Eμ-XBP-1s elicited elevated serum Ig and skin alterations. With age, Eμ-xbp-1s transgenics develop features diagnostic of human MM, including bone lytic lesions and subendothelial Ig deposition. Furthermore, transcriptional profiles of Eμ-xbp-1s lymphoid and MM cells show aberrant expression of known human MM dysregulated genes. The similarities of this model with the human disease, coupled with documented frequent XBP-1s overexpression in human MM, serve to implicate XBP-1s dysregulation in MM pathogenesis. [Copyright &y& Elsevier]

Abstract: Myeloablative high-dose therapy and single autologous stem cell transplantation (HDT) is frequently performed early in the course of multiple myeloma, supported by some randomized controlled trials (RCTs) indicating overall survival (OS) and progression-free survival (PFS) benefit compared with nonmyeloablative standard-dose therapy (SDT). Other RCTs, however, suggest variable benefit. We therefore undertook a systematic review and meta-analysis of all RCTs evaluating upfront HDT versus SDT in myeloma. The primary objective was to quantify OS benefit with HDT, with PFS benefit a secondary objective. Anticipating heterogeneity, sensitivity and subgroup analyses were undertaken to assess robustness of results. Assessment of harms (treatment-related mortality) was also undertaken. We searched the PubMed, Embase, and Cochrane Collection of Controlled Trials databases using the terms myeloma combined with autologous or transplant or myeloablative or stem cell. In total, 3407 articles were accessed, and 10 RCTs prospectively comparing upfront HDT with SDT, with ≥2-year follow-up, and reporting OS benefit on an intent-to-treat basis were identified. Two reviewers independently extracted study characteristics, interventions, and outcomes. Hazard ratios (with 95% confidence interval) were determined. Nine studies comprising 2411 patients were fully analyzed. Significant heterogeneity was present. The combined hazard of death with HDT was 0.92 (95% confidence interval, 0.74-1.13). The combined hazard of progression with HDT was 0.75 (95% confidence interval, 0.59-0.96). The totality of the randomized data indicates PFS benefit but not OS benefit for HDT with single autologous transplantation performed early in multiple myeloma. Sensitivity and subgroup analyses supported the findings and indicated that, contrary to current reimbursement criteria, PFS benefit with upfront HDT is not restricted to chemoresponsive myeloma. However, the overall risk of developing treatment-related mortality with HDT was increased significantly (odds ratio, 3.01; 95% confidence interval, 1.64-5.50). Hence, evaluating alternative therapeutic options upfront may also be reasonable. [Copyright &y& Elsevier]

Abstract: The close relationship between the biological behaviour of malignant cells and the local microenvironment where they reside is a feature of diverse neoplasias. Multiple myeloma (MM) is considered a main disease model for the study of such interactions and the mechanisms that can lead to bone-related clinical complications, as well as the role of these interactions in attenuating the activity of conventional anti-MM therapeutics, such as dexamethasone and cytotoxic chemotherapeutics. This review focuses on recent progress in the study of interactions of MM cells with their local microenvironment. Major emphasis is placed on how bone marrow stromal cells (BMSCs) and other normal constituents of the bone marrow milieu promote, through cell adhesion- and cytokine-mediated mechanisms, the ability of MM cells to resist conventional anti-MM therapies. The review also addresses ongoing research into these mechanisms, which has already provided several new molecular targets and corresponding therapeutic strategies, such as the proteasome inhibitor bortezomib and thalidomide derivatives (e.g. lenalidomide), for the management of myeloma. [Copyright &y& Elsevier]

Summary: To identify genetic events underlying the genesis and progression of multiple myeloma (MM), we conducted a high-resolution analysis of recurrent copy number alterations (CNAs) and expression profiles in a collection of MM cell lines and outcome-annotated clinical specimens. Attesting to the molecular heterogeneity of MM, unsupervised classification using nonnegative matrix factorization (NMF) designed for array comparative genomic hybridization (aCGH) analysis uncovered distinct genomic subtypes. Additionally, we defined 87 discrete minimal common regions (MCRs) within recurrent and highly focal CNAs. Further integration with expression data generated a refined list of MM gene candidates residing within these MCRs, thereby providing a genomic framework for dissection of disease pathogenesis, improved clinical management, and initiation of targeted drug discovery for specific MM patients. [Copyright &y& Elsevier]

Summary: Bortezomib therapy has proven successful for the treatment of relapsed and/or refractory multiple myeloma (MM); however, prolonged treatment is associated with toxicity and development of drug resistance. Here, we show that the novel proteasome inhibitor NPI-0052 induces apoptosis in MM cells resistant to conventional and Bortezomib therapies. NPI-0052 is distinct from Bortezomib in its chemical structure, effects on proteasome activities, mechanisms of action, and toxicity profile against normal cells. Moreover, NPI-0052 is orally bioactive. In animal tumor model studies, NPI-0052 is well tolerated and prolongs survival, with significantly reduced tumor recurrence. Combining NPI-0052 and Bortezomib induces synergistic anti-MM activity. Our study therefore provides the rationale for clinical protocols evaluating NPI-0052, alone and together with Bortezomib, to improve patient outcome in MM. [Copyright &y& Elsevier]

Interleukin-6 (LI-6) is a known growth and survival factor in multiple myeloma via activation of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling cascade. In this report we show that Grb2-associated binder (Gab) family adapter proteins Gab1 and Gab2 are expressed by multiple myeloma cells; and that interleukin-6 induces their tyrosine phosphorylation and association with downstream signaling molecules. We further demonstrate that these events are Src family tyrosine kinase-dependent and specifically identify the role of hematopoietic cell kinase (Hck) as a new Gab family adapter protein kinase. Conversely, inhibition of Src family tyrosine kinases by the pyrazolopyrimidine PP2, as in kinase-inactive Hck mutants, significantly reduces IL-6-triggered activation of extracellular signal-regulated kinase and AKT-1, leading to significant reduction of multiple myeloma cell proliferation and survival. Taken together, these results delineate a key role for Hck-mediated phosphorylation of Gab1 and Gab2 docking proteins in IL-6-induced proliferation and survival of multiple myeloma cells and identify tyrosine kinases and downstream adapter proteins as potential new therapeutic targets in multiple myeloma. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is a clonal B-lymphocyte malignancy, which is characterized by the accumulation of terminally differentiated antibody-producing cells in the bone marrow. Because current treatments offer only a median survival of 3 years, investigators continue to search for novel therapeutic strategies to combat the disease. Rational drug design is enhanced by understanding MM cell proliferation and key signaling pathways employed. In addition, a model system for preclinical evaluation of novel therapeutics is critical. Our laboratory has developed MM cell lines to study drug action and resistance, cell proliferation, and apoptosis. These cell lines are widely used in MM research. From a single MM patient, three separate cell lines were established that parallel the progression of the disease. These three cell lines, designated MM1.S, MM1.RE, and MM1.RL, can be distinguished on the basis of their sensitivity to steroid hormones such as glucocorticoids (GCs). Utilization of these cell lines to study the etiology of MM, effects of chemotherapeutic agents, and development of clinical resistance, will provide us with vital information for the evolution of new and more efficacious therapeutics. The aim of this review is to summarize the morphological, biochemical, and growth characteristics of these cells, and to review the results from investigations of the MM.1 signaling pathways. This information will enhance the study, treatment, and eventual eradication of MM. [Copyright &y& Elsevier]

Examines the role of caveolin-1 in multiple myeloma cells. Demonstration that the caveolin-1 is expressed in multiple myeloma cells; Effect of cholesterol depletion of by beta-cyclodextrin; Finding that cholesterol depletion by beta-cyclodextrin abrogates both interleukin-6- and insulin-like growth factor-I-triggered multiple myeloma cell survival via negative regulation of caveolin-1.

: ObjectiveTo evaluate the anti-tumor potential of β-lapachone in multiple myeloma (MM) cell lines (U266, RPMI8226, and MM.1S); MM cell lines resistant to dexamethasone (MM.1R), melphalan (RPMI8226/LR5), doxorubicin (RPMI8226/DOX40), and mitoxantrone (RPMI8226/ MR20); and MM cells from patients (MM1-MM4).: Materials and MethodsCytotoxicity of β-lapachone was assessed by MTT and [3H]-thymidine uptake assays. Apoptosis was analyzed using propidium iodide staining, DNA fragmentation, TUNEL assay, caspase-9 colorimetric assay, and immunoblotting for caspase-3, poly (ADP-ribose) polymerase (PARP), and caspase-8 cleavage products. Paracrine growth of MM cells was assessed by [3H]-thymidine uptake in cultures of bone marrow stromal cells (BMSCs) and MM cells. Interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) secretion in the culture supernatants was measured by specific enzyme-linked immunosorbent assays (ELISAs).: Resultsβ-lapachone showed significant cytotoxicity in MM cells (IC50: 4–8 μM). In contrast, normal peripheral blood mononuclear cells (PBMCs) and BMSCs from MM patients were relatively resistant (IC50: 8–16 μM). IL-6 did not protect against β-lapachone–induced apoptosis in MM.1S cells, and dexamethasone showed additive cytotoxicity. β-lapachone also decreased binding of MM.1S cells to BMSCs; abrogated IL-6 and VEGF secretion triggered by adhesion of BMSCs to MM.1S cells; reduced proliferation of MM.1S cells adherent to BMSCs; and decreased intracellular adhesion molecule-1 (ICAM-1) expression on MM.1S cells. Furthermore, β-lapachone induced typical PARP cleavage, increased caspase-9 proteolytic activity, and activation of caspase-3, without activation of caspase-8 in U266 cells.: ConclusionThese studies provide a framework for clinical evaluation of β-lapachone to improve the outcome for patients with MM. [Copyright &y& Elsevier]

: ObjectiveSince the central hallmarks of human multiple myeloma (MM) are abnormalities in immunoglobulin (Ig) gene rearrangement, IgH class switching, and DNA damage repair, and since Ku86 and Ku70 proteins are central to these processes, aberrant Ku function may play a role in MM pathogenesis. Our prior studies demonstrated a 69-kDa Ku86 variant in freshly isolated patient MM cells that confers sensitivity to DNA damage. We also showed that Ku86 on the cell surface of CD40-activated MM cells mediates homotypic tumor cell adhesion, as well as heterotypic adhesion to bone marrow stromal cells. We here define the mechanism and functional significance of CD40-induced Ku translocation from the cytoplasm to the cell membrane in MM cells vs normal B cells.Materials and Methods. We examined Ku86 and Ku70 translocation following CD40 activation in human MM cells vs normal tonsillar B lymphocytes. We then identified the functional sequelae of membrane Ku86 and Ku70 expression on CD40-activated human MM cells.Results. CD40 activation induces translocation of both Ku86 and Ku70 to the cell surface of MM cells, but not normal tonsillar B cells. Moreover, CD40 activation triggers Ku association with CD40 only in CD40-activated MM cells. Finally, CD40-activated MM cells adhere to fibronectin and are protected against apoptosis triggered by irradiation or doxorubicin; conversely, antibodies to Ku both inhibit tumor cell binding and restore sensitivity to these agents.Conclusion. These results demonstrate functional significance of Ku translocation to the cell membrane of CD40-activated human MM cells. Therefore, targeting Ku86 and Ku70, with blocking peptides for example, might serve as a novel treatment strategy in human MM. [Copyright &y& Elsevier]