Refractory Multiple Myeloma Patients: a Meta-Analysis and Systematic Review
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OncoTargets and Therapy Dovepress open access to scientific and medical research Open Access Full Text Article REVIEW Arsenic trioxide-based therapy in relapsed/ refractory multiple myeloma patients: a meta-analysis and systematic review Xuepeng He Abstract: Multiple myeloma (MM) is a clonal malignancy characterized by the proliferation of Kai Yang malignant plasma cells in the bone marrow and the production of monoclonal immunoglobulin. Peng Chen Although some newly approved drugs (thalidomide, lenalidomide, and bortezomib) demonstrate Bing Liu significant benefit for MM patients with improved survival, all MM patients still relapse. Arsenic Yuan Zhang trioxide (ATO) is the most active single agent in acute promyelocytic leukemia, the antitumor Fang Wang activity of which is partly dependent on the production of reactive oxygen species. Due to its multifaceted effects observed on MM cell lines and primary myeloma cells, Phase I/II trials have Zhi Guo been conducted in heavily pretreated patients with relapsed or refractory MM. Therapy regimens Xiaodong Liu varied dramatically as to the dosage of ATO and monotherapy versus combination therapy with Jinxing Lou For personal use only. other agents available for the treatment of MM. Although ATO-based combination treatment Huiren Chen was well tolerated by most patients, most trials found that ATO has limited effects on MM Department of Hematology, patients. However, since small numbers of patients were randomized to different treatment General Hospital of Beijing arms, trials have not been statistically powered to determine the differences in progression-free Military Area of PLA, Beijing, People’s Republic of China survival and overall survival among the experimental arms. Therefore, large Phase III studies of ATO-based randomized controlled trials will be needed to establish whether ATO has any potential beneficial effects in the clinical setting. Keywords: multiple myeloma, arsenic trioxide, clinical trial, therapy, meta-analysis Introduction Multiple myeloma (MM) is a clonal malignancy characterized by the proliferation OncoTargets and Therapy downloaded from https://www.dovepress.com/ by 54.191.40.80 on 09-Sep-2017 of malignant plasma cells in the bone marrow and the production of monoclonal immunoglobulin.1 MM, which is the most common primary tumor of the bone marrow, is an incurable tumor that occurs in 4.8 to eight per 1,000,000 in the US. It is estimated that 21,700 people in the US have suffered from MM, and deaths from the year 2012 numbered 6,020 people.2 The majority of MM patients will relapse or become refrac- tory to therapy after achieving complete remission.3 Over the past decade, treatment for MM patients has been greatly improved due to autologous stem cell transplantation and new drugs (thalidomide, lenalidomide, and bortezomib). These management increased rate of complete response (CR) and subsequently extended survival both in young and elderly patients with MM.3 MM patients usually achieved CR more quickly by using Correspondence: Xuepeng He the new drugs, which was associated with longer survival. However, most patients Department of Hematology, eventually relapse after CR, indicating that residual tumor cells exist. Resistance to General Hospital of Beijing Military Area of PLA, Beijing 100700, conventional therapy caused by residual diseases displays multifactorial characteris- People’s Republic of China tics, which are difficult to overcome by targeting one single mechanism.4 Alternatively, Tel +86 010 8400 8139 Email [email protected] identification of novel cellular targets or signaling pathways regulating myeloma cell submit your manuscript | www.dovepress.com OncoTargets and Therapy 2014:7 1593–1599 1593 Dovepress © 2014 He et al. This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further http://dx.doi.org/10.2147/OTT.S67165 permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php Powered by TCPDF (www.tcpdf.org) 1 / 1 He et al Dovepress growth would improve clinical outcome and survival in MM Adult patients with progressive MM who were shown patients refractory to chemotherapy. Mitochondria, which have to have chemoresistant relapse and/or refractory MM were been implied to play a crucial role in programmed cell death, eligible for the study. The response of patients with MM to apoptosis, are found to be a promising drug target that may chemotherapy was determined according to criteria raised by benefit MM patients or other tumor patients.5–7 Blade et al.13 Briefly, CR was defined as negative myeloma Arsenic trioxide (ATO) is the most active single agent used protein in serum and in urine on at least two determinations in the treatment of acute promyelocytic leukemia (APL) patients for a minimum of 6 weeks, no increase in the size of lytic (newly diagnosed and relapsed or refractory APL patients).8,9 The bone lesions, and ,5% plasma cells in the marrow. Partial rationale for ATO as a therapy for MM is that ATO inhibits cell response (PR) was defined as a$ 50% reduction in the level viability, suppresses growth, and induces apoptosis in myeloma of serum M-protein on at least two determinations 6 weeks cells in an in vitro cell culture model.10,11 Instead of affecting apart, reduction in 24-hour urinary light-chain excretion by the extrinsic (receptor-mediated) apoptotic pathway, ATO was either $90% or to ,0.2 g (if present), $50% reduction in size proposed to disrupt the intrinsic (mitochondria-mediated) apop- of soft tissue plasmacytomas, and no increase in size or num- tosis pathways by generating reactive oxygen species (ROS) ber of lytic bone lesions. Minor response (MR) was defined as and suppressing the reduced glutathione (GSH) cellular redox 25%–49% reduction in serum M-protein, 50%–89% reduc- enzymes, GSH peroxidase and thiotransferase (glutaredoxin).1,4 tion in urine M-protein (if present), 25%–49% reduction in Due to multifaceted effects of ATO on MM cell lines and pri- size of plasmacytomas, and no increase in size or number mary myeloma cells, Phase I/II trials have been conducted in of lytic bone lesions. Progressive disease (PD) was defined relapsed or refractory MM patients with heavy pretreatment. as .25% increase in serum M-protein or in 24-hour urinary However, the application of ATO has so far achieved limited light-chain excretion, an increase in size or development of success in relapsed/refractory MM,12 which could be attributed new existing lytic bone lesions, or plasmacytomas or devel- to the acquisition of resistance in MM due to changes in GSH opment of hypercalcemia. CR, PR, and MR were considered levels and apoptotic regulators or other unknown reasons.12 responses to the treatment in terms of treatment effective- For personal use only. In this study, we will review and update the published clinical ness. All publications regarding in vitro/ex vivo studies, cell studies as to the effect of ATO on MM in adults. lines, and human xenografts were excluded. There were no restrictions on the types of interventions of ATO-containing Methods therapy regimens, either as a single drug or in combination Search strategy and selection criteria with other agents. Overall response rates (CR, PR, and MR) MEDLINE, PubMed, and Web of Science were searched in and probabilities for overall survival (OS) and progression- December 2013 using the search terms “arsenic trioxide”, free survival (PFS), where applicable, will be included. “multiple myeloma”, and “clinical studies” and synonymous Data for study characteristics and clinical response were search terms such as “arsenite”, “chemical LAND21”, summarized and incorporated into table format. Heterogeneity “myeloma”, and “clinical trials”. Studies identified through of investigation was evaluated to determine whether the data OncoTargets and Therapy downloaded from https://www.dovepress.com/ by 54.191.40.80 on 09-Sep-2017 the approach as described were screened by titles first, then of the various studies could be analyzed in a meta-analysis. by abstracts of the publications. After exclusion of nonrel- The database search generated 36 articles from PubMed evant publications and identification of duplicates from the and two from the Web of Science. After initial screening different databases, the remaining papers were evaluated in of all titles, abstracts, and eligibility, ten full-text studies the full-text version for inclusion and exclusion criteria and were selected for more detailed assessment. A search of the for relevant articles in the reference lists. All clinical studies article references did not produce additional publications. except case reports were chosen: eg, randomized controlled Eventually, ten publications met the inclusion criteria for trials (RCTs), cohort studies, case control studies, and case qualitative study and two for meta-analysis. The article search series. The language of publication was restricted to English and study selection are depicted in Figure 1. and Chinese. Only the studies containing 15 or more patients were eligible for inclusion. All searched data were retrieved. Results Authors’