Treatment of multiple myeloma: a comprehensive review

Discovery of an Inhibitor of the Proteasome Subunit Rpn11

The proteasome plays a crucial role in degradation of normal proteins that happen to be constitutively or inducibly unstable, and in this capacity it plays a regulatory role. Additionally, it degrades abnormal/damaged/mutant/misfolded proteins, which serves a quality-control function. Inhibitors of the proteasome have been validated in the treatment of multiple myeloma, with several FDA-approved therapeutics. Rpn11 is a Zn2+-dependent metalloisopeptidase that hydrolyzes ubiquitin from tagged proteins that are trafficked to the proteasome for degradation. A fragment-based drug discovery (FBDD) approach was utilized to identify fragments with activity against Rpn11. Screening of a library of metal-binding pharmacophores (MBPs) revealed that 8-thioquinoline (8TQ, IC50 value ∼2.5 μM) displayed strong inhibition of Rpn11. Further synthetic elaboration of 8TQ yielded a small molecule compound (35, IC50 value ∼400 nM) that is a potent and selective inhibitor of Rpn11 that blocks proliferation of tumor cells in culture.

Immunoglobulin A Lambda Multiple Myeloma in a Patient with HIV: An Unusual Cause of Massive Ascites

Multiple myeloma (MM) is a neoplastic proliferation of plasma cells with overproduction of monoclonal immunoglobulins and infiltration into the bone and other organs. Ascites can develop in patients with lymphoproliferative and solid malignancies involving the peritoneum. However, ascites is unusual in MM and rarely the initial presenting sign or symptom. The development of ascites can be due to peritoneal infiltration or secondary to hepatic involvement, heart failure, or kidney failure. Ascites in MM reflects a more aggressive stage, and the reported prognosis is poor, with a median survival of 1-2 months. Here we present a rare case of immunoglobulin A lambda MM presenting with massive myelomatous ascites.

Engineered Nanoplatelets for Enhanced Treatment of Multiple Myeloma and Thrombus

A platelet-membrane-coated biomimetic nanocarrier, which can sequentially target the bone microenvironment and myeloma cells to enhance the drug availability at the myeloma site and decrease off-target effects, is developed for inhibiting multiple myeloma growth and simultaneously eradicating thrombus complication.

4-Chlorbenzoyl Berbamine, a Novel Derivative of the Natural Product Berbamine, Potently Inhibits the Growth of Human Myeloma Cells by Modulating the NF-κB and JNK Signalling Pathways

Multiple myeloma (MM) remains incurable despite the development and the use of new agents. In our studies, we found that 4-chlorbenzoyl berbamine (BBMD9), a novel synthetic derivative of berbamine, inhibited the proliferation of MM cells in dose- and time-dependent manners. Flow cytometric (FCM) analysis revealed that MM cells were arrested in the G1 phase and that apoptotic cells increased in a time-dependent manner. Moreover, the BBMD9 treatment downregulated IKKα and IKKβ, inhibited p-IκBα, and blocked p65 nuclear localization. Consistently, NF-κB downstream targets, such as cyclinD1 and survivin, were also reduced. In addition, BBMD9 phosphorylated the activity of JNK and c-Jun.

Intracranial Involvement by Plasma Cell Neoplasms

OBJECTIVES

Intracranial plasma cell neoplasms (PCNs) arising from the skull, dura, or brain parenchyma are rare tumors and there is only a limited experience in the literature with these lesions.

METHODS

We performed a retrospective clinicopathologic study of fourteen cases of intracranial PCN at our institution encountered over a 26-year-period.

RESULTS

The fourteen patients ranged in age from 30-74 years (median 66 years) and included seven males. For eight patients, their intracranial lesions were the initial presentation of multiple myeloma (MM). Three patients had prior history of MM; their intracranial tumors showed blastic plasma cell morphology, and all three died secondary to MM. The remaining three patients did not or have not developed MM.

CONCLUSIONS

PCNs rarely arise in the intracranial compartment. Intracranial PCN may be the initial presentation of MM. Anecdotally, blastic morphology appears to manifest more aggressive behavior.

Multiple myeloma and persistence of drug resistance in the age of novel drugs (Review)

Multiple myeloma (MM) is a mature B cell neoplasm that results in multi-organ failure. The median age of onset, diverse clinical manifestations, heterogeneous survival rate, clonal evolution, intrinsic and acquired drug resistance have impact on the therapeutic management of the disease. Specifically, the emergence of multidrug resistance (MDR) during the course of treatment contributes significantly to treatment failure. The introduction of the immunomodulatory agents and proteasome inhibitors has seen an increase in overall patient survival, however, for the majority of patients, relapse remains inevitable with evidence that these agents, like the conventional chemotherapeutics are also subject to the development of MDR. Clinical management of patients with MM is currently compromised by lack of a suitable procedure to monitor the development of clinical drug resistance in individual patients. The current MM prognostic measures fail to pick the clonotypic tumor cells overexpressing drug efflux pumps, and invasive biopsy is insufficient in detecting sporadic tumors in the skeletal system. This review summarizes the challenges associated with treating the complex disease spectrum of myeloma, with an emphasis on the role of deleterious multidrug resistant clones orchestrating relapse.

Polyphyllin I induces cell cycle arrest and apoptosis in human myeloma cells via modulating β-catenin signaling pathway

Multiple myeloma (MM) is an indolent B-cell disease characterized by clonal proliferation of malignant plasma cells. Multiple myeloma remains incurable despite new targeted drugs and development of drug resistance or intolerable toxicity emerges as a major problem. Therefore, design, identification, and validation of novel chemicals with therapeutic potential are clearly needed for MM treatment. Here, we explore polyphyllin I (PPI), a major active constituent extracted from Paris polyphyllin, its inhibitory effects and its mechanisms in MM cells in vitro. We found that PPI inhibited the proliferation of myeloma cells. The combination of PPI with dexamethasone, doxorubicin, arsenic trioxide, or bortezomib enhanced the inhibition of cell growth. As analyzed by flow cytometry, MM cells were arrested at G2/M phase and apoptotic cells increased in a time-dependent manner. Morphological changes of cells undergoing apoptosis were observed under light microscope. To explore the mechanism of apoptosis induced by PPI, we next examined whether the Wingless-Int (Wnt)/β-catenin signaling pathway played a role in the PPI-induced growth inhibition in MM cells. The canonical Wnt signaling pathway is activated in MM cells through constitutively active β-catenin, a messenger molecule relevant to growth, survival, and migration of MM cells. Western blotting was used to measure the protein levels of β-catenin, and PPI treatment led to downregulating the expression of β-catenin protein and was followed by inhibition of β-catenin nuclear localization. As a result, β-catenin downstream targets, such as cyclin D1 and survivin, were downregulated. To the best of our knowledge, this is the first report identifying anti-proliferative potency of PPI against myeloma cells. PPI blocks β-catenin nuclear translocation and decreasing expression of the downstream targets of β-catenin. Our results suggest that PPI is a novel inhibitor of β-catenin activity with potential anti-myeloma efficacy.

Mangiferin induces apoptosis in multiple myeloma cell lines by suppressing the activation of nuclear factor kappa B-inducing kinase

Mangiferin is a naturally occurring glucosyl xanthone, which induces apoptosis in various cancer cells. However, the molecular mechanism underlying mangiferin-induced apoptosis has not been clarified thus far. Therefore, we examined the molecular mechanism underlying mangiferin-induced apoptosis in multiple myeloma (MM) cell lines. We found that mangiferin decreased the viability of MM cell lines in a concentration-dependent manner. We also observed an increased number of apoptotic cells, caspase-3 activation, and a decrease in the mitochondrial membrane potential. In addition, mangiferin inhibited the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated inhibitor kappa B (IκB) and increased the expression of IκB protein, whereas no changes were observed in the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase 1/2 (JNK1/2), and mammalian target of rapamycin (mTOR). The molecular mechanism responsible for mangiferin-induced inhibition of nuclear translocation of NF-κB was a decrease in the expression of phosphorylated NF-κB-inducing kinase (NIK). Moreover, mangiferin decreased the expression of X-linked inhibitor of apoptosis protein (XIAP), survivin, and Bcl-xL proteins. Knockdown of NIK expression showed results similar to those observed with mangiferin treatment. Our results suggest that mangiferin induces apoptosis through the inhibition of nuclear translocation of NF-κB by suppressing NIK activation in MM cell lines. Our results provide a new insight into the molecular mechanism of mangiferin-induced apoptosis. Importantly, since the number of reported NIK inhibitors is limited, mangiferin, which targets NIK, may be a potential anticancer agent for the treatment of MM.

Limiting early mortality: Do's and don'ts in the management of patients with newly diagnosed multiple myeloma

In the era of novel biological agents, multiple myeloma (MM) is often approached as a chronic condition. While survival continues to improve, population-level data indicate that early mortality remains a substantial barrier to advances in MM outcomes. Here we provide "do's and don'ts" management recommendations that may minimize the risk of early mortality and ensure that patients have the opportunity to benefit from the long term impact of new effective MM agents. Such recommendations encompass the early introduction of novel agents even in the presence of comorbidities and advanced age and aggressive management of MM-related complications.

Targeting the pro-survival protein MET with tivantinib (ARQ 197) inhibits growth of multiple myeloma cells

The hepatocyte growth factor (HGF)/MNNG HOS transforming gene (MET) pathway regulates cell growth, survival, and migration. MET is mutated or amplified in several malignancies. In myeloma, MET is not mutated, but patients have high plasma concentrations of HGF, high levels of MET expression, and gene copy number, which are associated with poor prognosis and advanced disease. Our previous studies demonstrated that MET is critical for myeloma cell survival and its knockdown induces apoptosis. In our current study, we tested tivantinib (ARQ 197), a small-molecule pharmacological MET inhibitor. At clinically achievable concentrations, tivantinib induced apoptosis by > 50% in all 12 human myeloma cell lines tested. This biologic response was associated with down-regulation of MET signaling and inhibition of the mitogen-activated protein kinase and phosphoinositide 3-kinase pathways, which are downstream of the HGF/MET axis. Tivantinib was equally effective in inducing apoptosis in myeloma cell lines resistant to standard chemotherapy (melphalan, dexamethasone, bortezomib, and lenalidomide) as well as in cells that were co-cultured with a protective bone marrow microenvironment or with exogenous cytokines. Tivantinib induced apoptosis in CD138 + plasma cells from patients and demonstrated efficacy in a myeloma xenograft mouse model. On the basis of these data, we initiated a clinical trial for relapsed/refractory multiple myeloma (MM). In conclusion, MET inhibitors may be an attractive target-based strategy for the treatment of MM.

Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to detect monoclonal immunoglobulin light chains in serum and urine

RATIONALE

Use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to monitor serum and urine samples for endogenous monoclonal immunoglobulins. MALDI-TOFMS is faster, fully automatable, and provides superior specificity compared to protein gel electrophoresis (PEL).

METHODS

Samples were enriched for immunoglobulins in 5 min using Melon Gel™ followed by reduction with dithiothreitol for 15 min to separate immunoglobulin light chains and heavy chains. Samples were then desalted using C4 ZipTips, mixed with sinapinic acid matrix, and analyzed on a Bruker Biflex III MALDI-TOF mass spectrometer.

RESULTS

Monoclonal immunoglobulin light chains were identified in serum and urine samples from patients with a known monoclonal gammopathy using MALDI-TOFMS with minimal sample preparation.

CONCLUSIONS

MALDI-TOFMS can identify a monoclonal immunoglobulin in serum and urine samples. The molecular mass of the monoclonal immunoglobulin light chain is obtained providing unprecedented specificity compared to PEL. In addition, the methodology can be automated, making it a practical alternative to PEL.

Sphingosine Kinase-1 Protects Multiple Myeloma from Apoptosis Driven by Cancer-Specific Inhibition of RTKs

Activation of acid sphingomyelinase (ASM) leads to ceramide accumulation and induces apoptotic cell death in cancer cells. In the present study, we demonstrate that the activation of ASM by targeting cancer-overexpressed 67-kDa laminin receptors (67LR) induces lipid raft disruption and inhibits receptor tyrosine kinase (RTK) activation in multiple myeloma cells. Sphingosine kinase 1 (SphK1), a negative regulator of ceramide accumulation with antiapoptotic effects, was markedly elevated in multiple myeloma cells. The silencing of SphK1 potentiated the apoptotic effects of the green tea polyphenol epigallocatechin-3-O-gallate (EGCG), an activator of ASM through 67LR. Furthermore, the SphK1 inhibitor safingol synergistically sensitized EGCG-induced proapoptotic cell death and tumor suppression in multiple myeloma cells by promoting the prevention of RTK phosphorylation and activation of death-associated protein kinase 1 (DAPK1). We propose that targeting 67LR/ASM and SphK1 may represent a novel therapeutic strategy against multiple myeloma.

MiR-301a promotes cell proliferation by directly targeting TIMP2 in multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a plasma cell malignancy characterized by clonal proliferation of plasma cells in the bone marrow and microRNAs play a crucial role in its tumorigenesis and development. The purpose of this study was to investigate the biological functions of miR-301a in MM.

METHODS

Quantitative real-time PCR was used to detect the expression level of miR-301a. Cell proliferation was assessed by MTT assay. Flow cytometry was performed to valuate cell apoptosis and cell cycle distribution. Moreover, luciferase reporter assay and western blot were conducted to determine the potential target of miR-301a in MM cells.

RESULTS

MiR-301a is significantly up-regulated in MM clinical bone marrow samples and cell lines compared with normal controls. Gain-of-function and loss-of-function studies in MM cell line U266 showed that miR-301a acts as an oncogene in MM by promoting cell proliferation and inhibiting apoptosis. Furthermore, a tumor suppressor gene, tissue inhibitor of metallopeptidases-2 (TIMP2) was identified as a direct target of miR-301a and knockdown of TIMP2 could mimic the effect of miR-301a in MM.

CONCLUSIONS

MiR-301a promotes cell proliferation and inhibits apoptosis by direct targeting TIMP2 in MM, and miR-301a might represent a novel molecular in MM and may provide helpful therapeutic strategies for MM treatment.

Clinical utility and patient consideration in the use of lenalidomide for multiple myeloma in Chinese patients

Multiple myeloma (MM) is an incurable hematologic malignancy caused by the autonomous growth of malignant plasma cells. In the last decade, the introduction of novel targeted agents such as thalidomide, bortezomib, and lenalidomide has dramatically improved the clinical outcome of MM patients in both the frontline and recurrent settings. Lenalidomide is a synthetic derivative of thalidomide, which has been shown to significantly improve overall survival, time to progression, and overall response rates in patients with MM. The China Food and Drug Administration approved the use of lenalidomide in patients with MM in 2013. In a Phase II trial, lenalidomide plus low-dose dexamethasone was associated with a high response rate and acceptable safety profile in heavily pretreated Chinese patients with relapsed/refractory MM, including those with renal impairment and IgD subtype. However, lenalidomide will remain as a second-line antimyeloma drug in the near future because of its high price and the policy of health insurance reimbursement in People’s Republic of China. In this review, we summarize the clinical utility and patient considerations in the use of lenalidomide for MM in Chinese patients. Further studies with larger sample sizes are required to investigate the better quality, longer duration, and more clinically meaningful outcomes of lenalidomide in the treatment of MM in Chinese patients.

Modulation of cell metabolic pathways and oxidative stress signaling contribute to acquired melphalan resistance in multiple myeloma cells

Alkylating agents are widely used chemotherapeutics in the treatment of many cancers, including leukemia, lymphoma, multiple myeloma, sarcoma, lung, breast and ovarian cancer. Melphalan is the most commonly used chemotherapeutic agent against multiple myeloma. However, despite a 70-80% initial response rate, virtually all patients eventually relapse due to the emergence of drug-resistant tumour cells. By using global proteomic and transcriptomic profiling on melphalan sensitive and resistant RPMI8226 cell lines followed by functional assays, we discovered changes in cellular processes and pathways not previously associated with melphalan resistance in multiple myeloma cells, including a metabolic switch conforming to the Warburg effect (aerobic glycolysis), and an elevated oxidative stress response mediated by VEGF/IL8-signaling. In addition, up-regulated aldo-keto reductase levels of the AKR1C family involved in prostaglandin synthesis contribute to the resistant phenotype. Finally, selected metabolic and oxidative stress response enzymes were targeted by inhibitors, several of which displayed a selective cytotoxicity against the melphalan-resistant cells and should be further explored to elucidate their potential to overcome melphalan resistance.

MDX-1097 induces antibody-dependent cellular cytotoxicity against kappa multiple myeloma cells and its activity is augmented by lenalidomide

MDX-1097 is an antibody specific for a unique B cell antigen called kappa myeloma antigen (KMA) that consists of cell membrane-associated free kappa light chain (κFLC). KMA was detected on kappa human multiple myeloma cell lines (κHMCLs), on plasma cells (PCs) from kappa multiple myeloma (κMM) patients and on κPC dyscrasia tissue cryosections. In primary κMM samples, KMA was present on CD38+ cells that were CD138 and CD45 positive and/or negative. MDX-1097 exhibited a higher affinity for KMA compared to κFLC and the latter did not abrogate binding to KMA. MDX-1097-mediated antibody-dependent cellular cytotoxicity (ADCC) and in vitro exposure of target cells to the immunomodulatory drug lenalidomide resulted in increased KMA expression and ADCC. Also, in vitro exposure of peripheral blood mononuclear cells (PBMCs) to lenalidomide enhanced MDX-1097-mediated ADCC. PBMCs obtained from myeloma patients after lenalidomide therapy elicited significantly higher levels of MDX-1097-mediated ADCC than cells obtained prior to lenalidomide treatment. These data establish KMA as a relevant cell surface antigen on MM cells that can be targeted by MDX-1097. The ADCC-inducing capacity of MDX-1097 and its potentiation by lenalidomide provide a powerful rationale for clinical evaluation of MDX-1097 alone and in combination with lenalidomide.

Surgery for plasma cell neoplasia patients with spinal instability or neurological impairment caused by spinal lesions as the first clinical manifestation

PURPOSE

Multiple myeloma (MM) and solitary plasmacytoma of bone (SPB) are two independent subtypes of plasma cell dyscrasias which often occur in spine. However, little is known about the surgical treatment of patients with spinal instability or neurological impairment caused by spinal lesions as the first clinical manifestation. The present study aimed to investigate the surgical outcome of these patients.

METHODS

We retrospectively reviewed the data of a total of 64 patients receiving spinal surgery in our center, in which 30 were diagnosed as MM and 34 as SPB. Univariate and multivariate analyses were used to identify factors associated with overall survival (OS) and progression-free survival (PFS) of patients.

RESULTS

Surgical treatment led to favorable results including pain relief, resumption of ambulatory ability as well as improvement of neurological function and life quality. Univariate analysis suggested that the potential prognostic factors for OS of MM patients were bisphosphonate treatment, post-surgical ambulatory status, Karnofsky Performance Score (KPS) and Frankel scale, and for PFS of MM patients were age at surgery, resection mode, postoperative ambulation status, KPS and Frankel scale, while the PFS of SPB patients was only significantly related to postoperative adjuvant therapies. Multivariate analysis indicated that postoperative ambulation status was the only independent risk factor for both OS and PFS of MM patients.

CONCLUSIONS

Surgery may be beneficial to patients with spinal instability or neurological impairment caused by spinal lesions as the first clinical manifestation, in which MM patients with postoperative ambulatory ability display better prognosis.

P, Anderson KC, Li C, Avet-Loiseau H, Munshi NC. Gene expression profile alone is inadequate in predicting complete response in multiple myeloma

With advent of several treatment options in multiple myeloma (MM), a selection of effective regimen has become an important issue. Use of gene expression profile (GEP) is considered an important tool in predicting outcome; however, it is unclear whether such genomic analysis alone can adequately predict therapeutic response. We evaluated the ability of GEP to predict complete response (CR) in MM. GEP from pretreatment MM cells from 136 uniformly treated MM patients with response data on an IFM, France led study were analyzed. To evaluate variability in predictive power due to microarray platform or treatment types, additional data sets from three different studies (n=511) were analyzed using same methods. We used several machine learning methods to derive a prediction model using training and test subsets of the original four data sets. Among all methods employed for GEP-based CR predictive capability, we got accuracy range of 56-78% in test data sets and no significant difference with regard to GEP platforms, treatment regimens or in newly diagnosed or relapsed patients. Importantly, permuted P-value showed no statistically significant CR predictive information in GEP data. This analysis suggests that GEP-based signature has limited power to predict CR in MM, highlighting the need to develop comprehensive predictive model using integrated genomics approach.

Bilateral atypical femoral fractures in a patient with multiple myeloma treated with intravenous bisphosphonate therapy

Bisphosphonates are currently the standard approach to managing bone disease in multiple myeloma. Bisphosphonates have high bone affinity that inhibits osteoclastic activity and additionally reduces the growth factors released from malignant or osteoblastic cells, thereby impairing abnormal bone remodeling which leads to osteolysis. However, patients of multiple myeloma may be at a higher risk of atypical femoral fractures because the treatment for malignant myeloma requires notably higher cumulative doses of bisphosphonates. Here we present a patient with bilateral atypical femoral fractures and multiple myeloma treated with intravenous bisphosphonate therapy.

Osteonecrosis of the jaw and renal safety in patients with newly diagnosed multiple myeloma: Medical Research Council Myeloma IX Study results

Bisphosphonates are recommended in patients with osteolytic lesions secondary to multiple myeloma. We report on the safety of bisphosphonate therapy with long-term follow-up in the Medical Research Council Myeloma IX study. Patients with newly diagnosed multiple myeloma were randomised to zoledronic acid (ZOL; 4 mg intravenously every 21-28 d) or clodronate (CLO; 1600 mg/d orally) plus chemotherapy. Among 1960 patients (5.9-year median follow-up), both bisphosphonates were well tolerated. Acute renal failure events were similar between groups (ZOL 5.2% vs. CLO 5.8% at 2 years; incidence plateaued thereafter). The overall incidence of confirmed osteonecrosis of the jaw (ONJ) was low, but higher with ZOL (ZOL 3.7% vs. CLO 0.5%; P < 0.0001). ONJ events were generally low grade and most occurred between 8 and 30 months (median time to ONJ, 23.7 months). Among 10 patients with ONJ recovery data, four patients in the ZOL group completely recovered, two patients improved, and three patients experienced no improvement; one CLO patient experienced no improvement. Dental surgery or trauma preceded ONJ in six ZOL patients. The incidence of renal adverse events was similar for ZOL and CLO. ONJ incidence remained low and was lower with CLO compared to ZOL. We have seen no further ONJ cases to date.

Vesiculovirus neutralization by natural IgM and complement

Because of its very low human seroprevalence, vesicular stomatitis virus (VSV) has promise as a systemic oncolytic agent for human cancer therapy. However, as demonstrated in this report, the VSV infectious titer drops by 4 log units during the first hour of exposure to nonimmune human serum. This neutralization occurs relatively slowly and is mediated by the concerted actions of natural IgM and complement. Maraba virus, whose G protein is about 80% homologous to that of VSV, is relatively resistant to the neutralizing activity of nonimmune human serum. We therefore constructed and rescued a recombinant VSV whose G gene was replaced by the corresponding gene from Maraba virus. Comparison of the parental VSV and VSV with Maraba G substituted revealed nearly identical host range properties and replication kinetics on a panel of tumor cell lines. Moreover, in contrast to the parental VSV, the VSV with Maraba G substituted was resistant to nonimmune human serum. Overall, our data suggest that VSV with Maraba G substituted should be further investigated as a candidate for human systemic oncolytic virotherapy applications.

IMPORTANCE

Oncolytic virotherapy is a promising approach for the treatment of disseminated cancers, but antibody neutralization of circulating oncolytic virus particles remains a formidable barrier. In this work, we developed a pseudotyped vesicular stomatitis virus (VSV) with a glycoprotein of Maraba virus, a closely related but serologically distinct member of the family Rhabdoviridae, which demonstrated greatly diminished susceptibility to both nonimmune and VSV-immune serum neutralization. VSV with Maraba G substituted or lentiviral vectors should therefore be further investigated as candidates for human systemic oncolytic virotherapy and gene therapy applications.

Inflammatory markers and development of symptom burden in patients with multiple myeloma during autologous stem cell transplantation

PURPOSE

Increasing research suggests that inflammation mediates symptom development. In this longitudinal study, we examined inflammatory factors related to the development of high symptom burden during autologous hematopoietic stem cell transplant (AuSCT) for multiple myeloma.

EXPERIMENTAL DESIGN

Patients (n = 63) repeatedly reported symptom severity on the MD Anderson Symptom Inventory multiple myeloma module (MDASI-MM) and contributed blood samples periodically for up to 100 days after AuSCT for inflammatory marker assays. The temporal associations between serum inflammatory marker concentrations and symptom severity outcomes were examined by nonlinear mixed-effect modeling.

RESULTS

Fatigue, pain, disturbed sleep, lack of appetite, and drowsiness were consistently the most severe MDASI-MM symptoms during the study. Peak symptom severity occurred on day 8 after AuSCT, during white blood cell count nadir. Patterns of serum interleukin (IL)-6 (peak on day 9) and soluble IL-6 receptor (sIL-6R; nadir on day 8) expression paralleled symptom development over time (both P < 0.0001). By univariate analysis, serum IL-6, sIL-6R, IL-10, C-reactive protein, macrophage inflammatory protein (MIP)-1α, sIL-1R2, sIL-1RA, and soluble tumor necrosis factor receptor 1 were significantly related to the most severe symptoms during the first 30 days after AuSCT (all P < 0.05). By multivariate analysis, IL-6 (estimate = 0.170; P = 0.004) and MIP-1α (estimate = -0.172; P = 0.006) were temporally associated with the severity of the component symptom score.

CONCLUSIONS

Systemic inflammatory response was associated with high symptom burden during the acute phase of AuSCT. Additional research is needed to understand how the inflammatory response is mechanistically associated with symptom expression and whether suppression of this response can reduce symptoms without compromising tumor control.

Plasmacytoma-like post-transplant lymphoproliferative disorder seen in pediatric combined liver and intestinal transplant recipients

Post-transplant lymphoproliferative disease (PTLD) is a lymphoproliferative disorder secondary to chronic immunosuppression and is the most common malignancy in transplanted patients [Kamdar et al. Curr Opin Organ Transplant, 2011; 16:274-280]. Although PTLD usually presents as B or T cell lymphoma, plasmacytomas have been reported, mostly in the adult population. Six cases of pediatric plasmacytoma-like PTLD have been reported, all of which were treated with vincristine, adriamycin, and dexamethasone (VAD), high dose dexamethasone alone, or dexamethasone + thalidomide [Tcheng et al. Pediatric Blood Cancer, 2006; 47:218-223; Perry et al. Blood, 2013; 8:1377-1383]. We present two cases of pediatric plasmacytoma-like PTLD in combined liver and small bowel transplant patients both successfully treated with bortezomib and dexamethasone based on multiple myeloma protocols [Kyle and Rajkumar, Clin Lymphoma Myeloma, 2009; 9:278-288; Adams and Kaufmann, Cancer Invest, 2004; 22:304-311].

Acute kidney injury and bisphosphonate use in cancer: a report from the research on adverse drug events and reports (RADAR) project

PURPOSE

To determine whether acute kidney injury (AKI) is identified within the US Food and Drug Administration's Adverse Events and Reporting System (FDA AERS) as an adverse event resulting from bisphosphonate (BP) use in cancer therapy.

METHODS

A search of the FDA AERS records from January 1998 through June 2009 was performed; search terms were "renal problems" and all drug names for BPs. The search resulted in 2,091 reports. We analyzed for signals of disproportional association by calculating the proportional reporting ratio for zoledronic acid (ZOL) and pamidronate. Literature review of BP-associated renal injury within the cancer setting was conducted.

RESULTS

Four hundred eighty cases of BP-associated acute kidney injury (AKI) were identified in patients with cancer. Two hundred ninety-eight patients (56%) were female; mean age was 66 ± 10 years. Multiple myeloma (n = 220, 46%), breast cancer (n = 98, 20%), and prostate cancer (n = 24, 5%) were identified. Agents included ZOL (n = 411, 87.5%), pamidronate (n = 8, 17%), and alendronate (n = 36, 2%). Outcomes included hospitalization (n = 304, 63.3%) and death (n = 68, 14%). The proportional reporting ratio for ZOL was 1.22 (95% CI, 1.13 to 1.32) and for pamidronate was 1.55 (95% CI, 1.25 to 1.65), reflecting a nonsignificant safety signal for both drugs.

CONCLUSION

AKI was identified in BP cancer clinical trials, although a safety signal for BPs and AKI within the FDA AERS was not detected. Our findings may be attributed, in part, to clinicians who believe that AKI occurs infrequently; ascribe the AKI to underlying premorbid disease, therapy, or cancer progression; or consider that AKI is a known adverse drug reaction of BPs and thus under-report AKI to the AERS.

An old drug with a new future: bendamustine in multiple myeloma

INTRODUCTION

Bendamustine is a unique bifunctional alkylating agent with promising activity in multiple myeloma (MM). It is currently licensed in Europe for use as frontline treatment with prednisolone for patients with MM who are unsuitable for transplantation and who are contraindicated for thalidomide and bortezomib therapy.

AREAS COVERED

Studies evaluating the safety and efficacy of bendamustine administered alone or in combination in both the upfront and relapse settings of MM patients, including those with renal insufficiency, were reviewed. The use of bendamustine as conditioning for autologous stem-cell transplantation and the possibility of stem-cell mobilization after bendamustine therapy are discussed.

EXPERT OPINION

Bendamustine seems to be efficacious either in monotherapy or in combination with other drugs in previously treated or untreated patients. This is due to its unique mechanism of action including its ability to activate apoptosis and inhibit mitotic checkpoints, making it potentially more effective than other alkylating agents. Moreover, it has an acceptable toxicity profile and is suitable for patients with renal impairment. Finally, this drug does not seem to compromise the possibility of achieving a stem-cell mobilization. Nonetheless, data from Phase III studies demonstrating its effectiveness in terms of overall survival are not yet available.

Multiple myeloma : recent progress in diagnosis and treatment

Multiple myeloma (MM) has been the most intractable hematological disease for many years. Recently, basic and clinical research has advanced remarkably and a new therapeutic strategy has been established. The introduction of high-dose melphalan with autologous stem-cell transplantation and the availability of molecular-targeted novel agents such as immunomodulatory drugs and proteasome inhibitors have dramatically changed the treatment strategies for MM. Achievement of a high response rate resulted in the extension of overall survival, but further research and the development of more multimodality therapeutic approaches is warranted to cure this disease.

Perspectives in the treatment of multiple myeloma

INTRODUCTION

The development of proteasome inhibitor (PI) and immunomodulatory drugs (IMiDs) and advances in supportive care have considerably changed the treatment paradigm of multiple myeloma (MM) and significantly improved survival. Nevertheless, almost all patients show disease relapse and develop drug resistance.

AREAS COVERED

We review the prognostic stratification and therapeutic strategy for newly diagnosed MM patients. Furthermore, mechanisms of drug resistance are discussed. Data regarding newer drugs, currently undergoing examination, such as PI (carfilzomib, ONX0912, MLN9708, and marizomib), IMiDs (pomalidomide), histone deacetylase inhibitors (vorinostat and panobinostat), kinase inhibitors (temsirolimus, everolimus, and tanespimycin), and immune-based therapies (elotuzumab, siltuximab, MOR03087, and MMBT062) are reported.

EXPERT OPINION

The use of three to four drug combination therapies including PI and IMiDs has significantly impacted on MM patient outcome. Moreover, new insights into MM biology from high-throughput technologies and availability of newer and more efficacious drugs will continue to influence our approach to MM treatment. In the immediate future molecular subgroup-specific trials using targeted agents may represent a very important step toward evaluating impact of interfering with relevant signaling pathways in MM. With the continued rapid evolution of progress in this field, MM will become a chronic illness having sustained complete response in a significant number of patients.

Reactive oxygen species-mediated activation of AMP-activated protein kinase and c-Jun N-terminal kinase plays a critical role in beta-sitosterol-induced apoptosis in multiple myeloma U266 cells

Although beta-sitosterol has been well known to have anti-tumor activity in liver, lung, colon, stomach, breast and prostate cancers via cell cycle arrest and apoptosis induction, the underlying mechanism of anti-cancer effect of beta-sitosterol in multiple myeloma cells was never elucidated until now. Thus, in the present study, the role of reactive oxygen species (ROS) in association with AMP-activated protein kinase (AMPK) and c-Jun N-terminal kinase (JNK) pathways was demonstrated in beta-sitosterol-treated multiple myeloma U266 cells. Beta-sitosterol exerted cytotoxicity, increased sub-G1 apoptotic population and activated caspase-9 and -3, cleaved poly (ADP-ribose) polymerase (PARP) followed by decrease in mitochondrial potential in U266 cells. Beta-sitosterol promoted ROS production, activated AMPK, acetyl-CoA carboxylase (ACC) and JNK in U266 cells. Also, beta-sitosterol attenuated the phosphorylation of AKT, mammalian target of rapamycin and S6K, and the expression of cyclooxygenase-2 and VEGF in U266 cells. Conversely, AMPK inhibitor compound C and JNK inhibitor SP600125 suppressed apoptosis induced by beta-sitosterol in U266 cells. Furthermore, ROS scavenger N-acetyl L-cysteine attenuated beta-sitosterol-mediated sub-G1 accumulation, PARP cleavage, JNK and AMPK activation in U266 cells. Overall, these findings for the first time suggest that ROS-mediated activation of cancer metabolism-related genes such as AMPK and JNK plays an important role in beta-sitosterol-induced apoptosis in U266 multiple myeloma cells.

Macrophages in multiple myeloma: emerging concepts and therapeutic implications

Multiple myeloma, a clonal plasma cell malignancy, has long provided a prototypic model to study regulatory interactions between malignant cells and their microenvironment. Myeloma-associated macrophages have historically received limited scrutiny, but recent work points to central and non-redundant roles in myeloma niche homeostasis. The evidence supports a paradigm of complex, dynamic and often mutable interactions between macrophages and other cellular constituents of the niche. We and others have shown that macrophages support myeloma cell growth, viability and drug resistance through both contact-mediated and non-contact-mediated mechanisms. These tumor-beneficial roles have evolved in opposition to, or in parallel with, intrinsic pro-inflammatory and tumoricidal properties. Thus, simple blockade of protective "don't eat me" signals on the surface of myeloma cells leads to macrophage-mediated myeloma cell killing. Macrophages also enhance the tumor-supportive role of mesenchymal stem/stromal cells (MSCs) in the niche: importantly, this interaction is bidirectional, producing a distinct state of macrophage polarization that we termed "MSC-educated macrophages." The intriguing pattern of cross-talk between macrophages, MSCs and tumor cells highlights the myeloma niche as a dynamic multi-cellular structure. Targeted reprogramming of these interactions harbors significant untapped therapeutic potential, particularly in the setting of minimal residual disease, the main obstacle toward a cure.

Randomized clinical trial of zoledronic acid in multiple myeloma patients undergoing high-dose chemotherapy and stem-cell transplantation

BACKGROUND

A growing body of evidence is demonstrating that the nitrogen-containing bisphosphonate zoledronic acid (zol) improves clinical outcomes in various cancer settings, including multiple myeloma. Those findings provided the rationale for conducting an open-label randomized controlled phase iii trial to evaluate the effect of zol on overall survival (os) and progression-free survival (pfs) in patients with previously untreated high-risk multiple myeloma.

METHODS

The trial randomly assigned 308 adult patients less than 65 years of age with previously untreated symptomatic multiple myeloma (1:1) to receive zol 4 mg intravenously once every 28 days for 24 months (n = 151) or no zol (n = 157). Before autologous stem-cell transplantation (asct), all patients received a high-dose noncytotoxic induction regimen of dexamethasone, all-trans-retinoic acid, and interferon alpha 2b.

RESULTS

After a median follow-up of 69.8 months (range: 36.5-96 months), the 10-year pfs (66% vs. 52%, p < 0.001) and os (67% vs. 48%, p < 0.001) rates were significantly higher in treated patients than in control patients. Overall response (77% zol vs. 75% control), complete response (52% vs. 46%), and very good partial response (25% vs. 29%) rates were similar between the groups. Treatment was generally well tolerated, with no reports of renal impairment or osteonecrosis of the jaw.

CONCLUSIONS

In symptomatic previously untreated multiple myeloma patients, zol combined with high-dose therapy followed by asct improved os and pfs without appreciable toxicity. These findings provide additional evidence of the meaningful anticancer activity of zol in this patient population.

PEGylation of vesicular stomatitis virus extends virus persistence in blood circulation of passively immunized mice

We are developing oncolytic vesicular stomatitis viruses (VSVs) for systemic treatment of multiple myeloma, an incurable malignancy of antibody-secreting plasma cells that are specifically localized in the bone marrow. One of the presumed advantages for using VSV as an oncolytic virus is that human infections are rare and preexisting anti-VSV immunity is typically lacking in cancer patients, which is very important for clinical success. However, our studies show that nonimmune human and mouse serum can neutralize clinical-grade VSV, reducing the titer by up to 4 log units in 60 min. In addition, we show that neutralizing anti-VSV antibodies negate the antitumor efficacy of VSV, a concern for repeat VSV administration. We have investigated the potential use of covalent modification of VSV with polyethylene glycol (PEG) or a function-spacer-lipid (FSL)-PEG construct to inhibit serum neutralization and to limit hepatosplenic sequestration of systemically delivered VSV. We report that in mice passively immunized with neutralizing anti-VSV antibodies, PEGylation of VSV improved the persistence of VSV in the blood circulation, maintaining a more than 1-log-unit increase in VSV genome copies for up to 1 h compared to the genome copy numbers for the non-PEGylated virus, which was mostly cleared within 10 min after intravenous injection. We are currently investigating if this increase in PEGylated VSV circulating half-life can translate to increased virus delivery and better efficacy in mouse models of multiple myeloma.

The PI3K inhibitor GDC-0941 combines with existing clinical regimens for superior activity in multiple myeloma

The phosphatidylinositol 3'-kinase (PI3K) pathway is dysregulated in multiple myeloma (MM); we therefore tested a highly selective class I PI3K inhibitor, GDC-0941, for anti-myeloma activity. Functional and mechanistic studies were first performed in MM cell lines, then extended to primary MM patient samples cultured in vitro. GDC-0941 was then assessed as a single agent and in various combinations in myeloma tumor xenograft models. We show p110 α and β are the predominant PI3K catalytic subunits in MM and that a highly selective class I PI3K inhibitor, GDC-0941, has robust activity as a single agent to induce cell cycle arrest and apoptosis of both MM cell lines and patient myeloma cells. Mechanistic studies revealed an induction of cell cycle arrest at G0/G1, with decreased phospho-FoxO1/3a levels, decreased cyclin D1 and c-myc expression, and an increase in the cell cycle inhibitor, p27kip. Induction of apoptosis correlated with increased expression of the pro-apoptotic BH3-only protein BIM, cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase (PARP). In vitro, GDC-0941 synergized with dexamethasone (Dex) and lenalidomide (combination index values of 0.3-0.4 and 0.4-0.8, respectively); in vivo GDC-0941 has anti-myeloma activity and significantly increases the activity of the standard of care agents in several murine xenograft tumor models (additional tumor growth inhibition of 37-53% (Dex) and 22-72% (lenalidomide)). These data provide a clear therapeutic hypothesis for the inhibition of PI3K and provide a rationale for clinical development of GDC-0941 in myeloma.

Emerging biological insights and novel treatment strategies in multiple myeloma

INTRODUCTION

Survival in multiple myeloma (MM) has improved significantly in the past 10 years due to new treatments, such as thalidomide and lenalidomide (immunomodulatory drugs or IMiDs) bortezomib and advances in supportive care. Nevertheless, almost all MM patients show disease relapse and develop drug resistance.

AREAS COVERED

The authors review the therapeutic approach for untreated MM patients. Furthermore, the prognostic stratification of patients and the proposed risk-adapted strategy are discussed. Finally, preclinical and clinical data regarding newer antimyeloma agents, currently undergoing examination such as proteasome inhibitors (PIs, carfilzomib), IMiDs (pomalidomide), epigenetic agents (histone deacetylase inhibitors vorinostat and panobinostat), humanized monoclonal antibodies (elotuzumab and MOR03087) and targeted therapies (inhibitors of NF-κB, MAPK, HSP90 and AKT) are reported.

EXPERT OPINION

MM patient outcome has remarkably improved due to the use of three to four drug combination therapies including PIs and IMiDs, which target the tumor in its bone marrow microenvironment, however MM treatment remains challenging. The use of high-throughput techniques has allowed to discover new insights into MM biology. The identification of candidate therapeutic targets and availability of respective investigative agents will allow for a substantial progress in the development and implementation of personalized medicine in MM.

Health care costs and resource utilization, including patient burden, associated with novel-agent-based treatment versus other therapies for multiple myeloma: findings using real-world claims data

BACKGROUND

. Treatment of multiple myeloma has dramatically improved with the introduction of bortezomib (BOR), thalidomide (THAL), and lenalidomide (LEN). Studies assessing health care costs, particularly economic burden on patients, are limited. We conducted a claims-based, retrospective analysis of total health care costs as well as patient burden (patient out-of-pocket costs and number of ambulatory/hospital visits) associated with BOR/THAL/LEN treatment versus other therapies (OTHER). METHODS. Treatment episodes starting between January 1, 2005 and September 30, 2010 were identified from the claims database of a large U.S. health plan. Health care costs and utilization were measured during 1 year after initiation and analyzed per treatment episode. Multivariate analyses were used to adjust for patient characteristics, comorbidities, and line of treatment.

RESULTS

A total of 4,836 treatment episodes were identified. Mean adjusted total costs were similar between BOR ($112,889) and OTHER ($111,820), but higher with THAL ($129,412) and LEN ($158,428). Mean adjusted patient out-of-pocket costs were also similar for BOR ($3,846) and OTHER ($3,900) but remained higher with THAL ($4,666) and LEN ($4,483). Mean adjusted rates of ambulatory visits were similar across therapies (BOR: 69.67; THAL: 66.31; LEN: 65.60;

OTHER

69.42).

CONCLUSIONS

Adjusted analyses of real-world claims data show that total health care costs, as well as patient out-of-pocket costs, are higher with THAL/LEN treatment episodes than with BOR/OTHER therapies. Additionally, similar rates of ambulatory visits suggest that any perceived advantage in patient convenience of the orally administered drugs THAL/LEN is not supported by these data.

Overexpression of G protein-coupled receptor 5D in the bone marrow is associated with poor prognosis in patients with multiple myeloma

BACKGROUND

G protein-coupled receptor 5D (GPRC5D) is a novel surface receptor. As this new subtype of G protein-coupled receptors was discovered, little is known about the role of this gene.

MATERIALS AND METHODS

In this retrospective study, we investigated GPRC5D mRNA expression by real-time polymerase chain reaction (RT-PCR) in bone marrow (BM) of 48 patients with multiple myeloma (MM).

RESULTS

Highly variable levels of GPRC5D (median, 288; quartiles, 17-928) were detected in patients with MM, whereas only low expression was detected in normal tissues (median, 1; quartiles, 1-23). High mRNA expression of GPRC5D correlated positively with high plasma cell count in bone marrow (r = 0·64, P < 0·001), high β(2) -microglobulin (r = 0·42, P = 0·003) and poor-risk cytogenetics: deletion 13q14 (rb-1), P = 0·003; and 14q32 translocation t(4;14)(p16;q32), P = 0·029. GPRC5D mRNA expression showed a significant correlation with overall survival (P = 0·031). The estimated overall survival of patients expressing GPRC5D above or below the median of 288 was 43·9% vs. 70·2% at 48 months. Here, we report, for the first time, the association of GPRC5D expression and cancer.

CONCLUSIONS

Overexpression in poor-risk myeloma, low expression in normal tissues and cell surface expression identify GPRC5D as a potential novel cancer antigen. Our data demonstrate that GPRC5D is a prognostic factor in MM correlating with other major risk factors.

Once- versus twice-weekly Bortezomib induction therapy with dexamethasone in newly diagnosed multiple myeloma

In this study, we administered a modified schedule of weekly intravenous Bortezomib at 1.6 mg/m(2) with dexamethasone (BD) and compared it to the standard 1.3 mg/m(2) twice-weekly BD regimen in Chinese patients with newly diagnosed multiple myeloma (MM). We assessed the difference in efficacy, safety profile and survival between the once-weekly and twice-weekly cohorts (13 vs. 24 patients). The over response rate was similar with both arms of the study, being 77% in the once-weekly schedule and 74.9% in the twice-weekly schedule (P=0.690). The median overall survival was not reached in either schedule. Also, the median progression-free survival and duration of response of the once-weekly schedule did not significantly differ from those of the twice-weekly schedule (8 months vs.10 months, P=0.545 and 6 months vs.7 months, P=0.467 respectively). Peripheral sensory neuropathy and grade 3/4 hematologic toxic effects were more frequently reported in the twice-weekly schedule than the once-weekly schedule, but there was no statistically significant difference. This preliminary experience in Chinese patients with newly diagnosed MM indicated that once-weekly infusion of Bortezomib plus dexamethasone may improve safety without affecting outcome.

Trends and outcomes of modern staging of solitary plasmacytoma of bone

Over the years, the definition of solitary plasmacytoma of bone (SPB) has shifted in part due to more modern testing capabilities. We hypothesized that outcomes data based on antiquated testing would not reflect outcomes using modern staging. To address both how widely applied adequate diagnostic staging is and what the progression rates of SPB as defined with state-of-the-art staging are, we performed a retrospective chart review of those patients with a diagnosis of SPB seen at our institution over the past decade. Two groups were studied: all patients with SPB (n = 127); and those patients referred to our institution for an indication other than progression (n = 91). The median PFS for those two groups were 26 months and 42 months, respectively. At baseline, only a minority of patients had state-of-the-art staging. The 5 patients with both modern imaging and a negative bone marrow had a 21 month PFS of 100%. Patients with plasmacytoma plus, one plasmacytoma but bone marrow consistent with monoclonal gammopathy of undetermined significance, fare worse than true SPB. The use of modern testing is imperative to characterize a patient's risk for progression. PET/CT plays an important role in the diagnostic work-up.

Melphalan 180 mg/m2 can be safely administered as conditioning regimen before an autologous stem cell transplantation (ASCT) in multiple myeloma patients with creatinine clearance 60 mL/min/1.73 m2 or lower with use of palifermin for cytoprotection: results of a phase I trial

High-dose melphalan 140 mg/m2 is the standard of care for patients with multiple myeloma (MM) with renal insufficiency (RI). Palifermin as a cytoprotective agent has demonstrated efficacy in reducing the intensity and duration of oral mucositis (OM) in patients who receive intensive chemotherapy/radiotherapy. There is no prospective data on the use of palifermin in patients with MM with RI.

ELIGIBILITY CRITERIA

creatinine clearance ≤60 mL/minute/1.73 m2, age >18 years, no dialysis, no active OM, and a suitable candidate for autologous stem cell transplant (ASCT). Melphalan dose ranged from 140 to 200 mg/m2 and escalated at the increment of 20 mg/m2. Six dosages of palifermin 60 mcg/kg/day were given intravenously between day -5 to day +3. Dose escalations were to stop if dose-limiting toxicities (DLTs) occurred at melphalan dose in ≥2 of 3 patients, with that dose declared as the maximal administered dose and the level below where ≤1 of 6 patients had DLTs was considered the maximally tolerated dose (MTD). Nineteen patients were enrolled from June 2007 to June 2011. Data on 15 evaluable patients is reported as 4 patients were removed. Median age was 59 years (range, 36-67 years). The overall incidence of OM ≥ grade 3 was 53% (8 of 15) and a median duration of ≥grade 3 OM was 6.5 days (range, 3-42 days). One patient in L2 (melphalan 160 mg/m2) developed atrial fibrillation on day +9. Two patients in L4 (melphalan 200 mg/m2) developed grade 4 OM, hence reaching DLT. No DLT was observed in 6 patients enrolled in L3 (melphalan 180 mg/m2). Palifermin has permitted safe dose escalation of melphalan up to 180 mg/m(2) in patients with RI.

TRAF6 activation in multiple myeloma: a potential therapeutic target

Multiple myeloma (MM) is an incurable B-lymphocyte malignancy. New therapeutic options have become available during the past several years; however nearly all patients acquire resistance to currently available therapeutic agents. Mechanisms contributing to the pathogenesis and chemoresistance of MM include genetic abnormalities, chromosomal translocations, gene mutations, the interaction between MM cells and the bone marrow microenvironment, and defects in the apoptotic signaling pathways. Survival signaling pathways associated with the pathogenesis of MM and bone marrow stromal cells play crucial roles in promoting growth, survival, adhesion, immortalization, angiogenesis, and drug resistance. The receptor activator of nuclear factor-kappa B/receptor activator of nuclear factor-kappa B ligand/tumor necrosis factor receptor-associated factor (RANK/RANKL-TRAF6) signal pathway mediates osteolytic bone lesions through the activation of the NF-κB and Janus kinase/signal transducer and activator of transcription (JNK) pathways in osteoclast precursor cells and thus contributes to the main clinical manifestations of bone disease. TRAF6 has also been identified as a ligase for Akt ubiquitination and membrane recruitment and its phosphorylation on growth factor stimulation. The inhibition of TRAF6 by silencing RNA or by decoy peptides decreases MM tumor cell proliferation and increases apoptosis as well as bone resorption. Some proteasome inhibitors and benzoxadiazole derivatives showed inhibitory effects on the activity and function of TRAF6. Overall, we propose that TRAF6 may be considered as a potential therapeutic target for the treatment of MM.

Quality of life assessment in multiple myeloma patients undergoing dose-reduced tandem autologous stem cell transplantation

Few studies exist that consider health-related quality of life (HR-QoL) in patients with multiple myeloma (MM) undergoing tandem autologous stem cell transplantation (TASCT). Eighteen patients with advanced MM who underwent dose-modified TASCT were enrolled in this study between March 2006 and March 2008. Patients <60 year old (10) received conditioning with melphalan 140 mg/m² and patients who were ≥60 years (8) received 100 mg/m². The median age was 57.5 years (range 35–69). We conducted the European Organization of Research and Treatment of Cancer (EORTC) QLQ-C30 and the QLQ-MY24 questionnaires via interviews at presentation, after each ASCT and thereafter every 3 months for 24 months. Mean global health measure improved from 3.44 before transplant to 4.50 (1=very poor, 7=excellent) at the second and subsequent follow-up visits (P<0.001) and the mean global quality of life score improved from 3.61 to 4.71 (P<0.001). Pain symptoms were reduced (P=0.001), and physical functioning improved (P<0.001) throughout the period of post-transplant follow-up. Our study showed that dose-reduced TASCT is well tolerated with low toxicity albeit the transient reduction in QoL during both transplants. Post-transplant follow-up showed significant improvement in overall HR-QoL that reflects positively on the overall disease-outcome. Furthermore, a sole focus on patient-survival does not adequately provide indication regarding the tolerability and effectiveness of a proposed treatment on the patient’s perceived quality of life. As clinicians, our primary concern should be toward patient-welfare as well as survival. Therefore, we should employ the tools of QoL in conjunction with overall survival in order to deliver the best possible patient outcomes. The EORTC-QLQ-MY24 is a practical tool in measuring QoL in myeloma patients.

Second autologous stem cell transplantation as salvage therapy for multiple myeloma: impact on progression-free and overall survival

The role of a second autologous stem cell transplant (ASCT) as salvage therapy is unclear, particularly with the availability of novel agents to treat progressive multiple myeloma (MM). We retrospectively reviewed all MM patients who received a second ASCT as salvage therapy at our center from March 1992 to December 2009. Eighty-one MM patients received a second ASCT for relapsed MM. The median time to relapse after first transplant was 39 months (9.83-100). All patients received reinduction therapy before the second ASCT. The high-dose regimen given before the second ASCT consisted of melphalan (MEL) alone in the majority. Complete response, very good partial response, and partial response were seen in 7.7%, 39.7%, and 50%, respectively, at day 100 post-ASCT; the median time to relapse after the second ASCT was 19 months. Early deaths occurred in 2.6%. Median progression-free survival (PFS) based on the time to myeloma relapse after first ASCT was 9.83 months (relapse ≤ 24 months) and 17.3 months (relapse ≥ 24 months) (P < .05). Median overall survival (OS) was 28.47 months (relapse ≤ 24 months) and 71.3 months (relapse >24 months) (P = .006). Second ASCT is a feasible and safe option for salvage therapy in MM. The best outcome was observed in patients whose time to progression was >24 months after first ASCT, as these patients had a subsequent PFS lasting over 1 year and an OS of almost 6 years.

A randomized phase 2 trial of a preparative regimen of bortezomib, high-dose melphalan, arsenic trioxide, and ascorbic acid

BACKGROUND

Bortezomib is active for newly diagnosed and relapsed multiple myeloma, and it has synergistic activity with melphalan. The authors of this report conducted a randomized trial to determine the safety and efficacy of adding bortezomib to a preparative regimen of arsenic trioxide (ATO), ascorbic acid (AA), and melphalan.

METHODS

Among 60 patients who enrolled between October 2006 and September 2007, 58 patients underwent autologous transplantation with a preparative regimen of melphalan 200 mg/m(2) intravenously, AA 1000 mg daily intravenously for 7 days, and ATO 0.25 mg/kg intravenously for 7 days. Patients were randomized to receive no bortezomib (Group 1), bortezomib 1 mg/m(2) × 3 doses (Group 2), and bortezomib 1.5 mg/m(2) × 3 doses (Group 3). Primary endpoints were complete response (CR), grade IV toxicity, and 90-day treatment-related mortality (TRM). Secondary endpoints were progression-free survival (PFS) and overall survival (OS).

RESULTS

The median follow-up of all surviving patients was 36 months (range, 20-43 months). The CR rates in Groups 1, 2, and 3 were 20%, 10%, and 10%, respectively. Grade 3 and 4 nonhematologic toxicities and TRM were comparable. The median OS was not reached in the groups, whereas the median PFS in Groups 1, 2, and 3 was 17.8 months, 17.4 months, and 20.7 months, respectively. PFS and OS were significantly shorter in patients who had high-risk cytogenetics (P = .016 and P = .0001, respectively) and relapsed disease (P = .0001 and P = .0001, respectively) regardless of the treatment group.

CONCLUSIONS

Adding bortezomib to a preparative regimen of ATO, AA, and high-dose melphalan was safe and well tolerated in patients with multiple myeloma. There was no significant improvement in the CR rate, PFS, or OS in the bortezomib groups.