Phase II multicenter study of arsenic trioxide in patients with myelodysplastic syndromes

Multiple roles of arsenic compounds in phase separation and membraneless organelles formation determine their therapeutic efficacy in tumors

Arsenic compounds are widely used for the therapeutic intervention of multiple diseases. Ancient pharmacologists discovered the medicinal utility of these highly toxic substances, and modern pharmacologists have further recognized the specific active ingredients in human diseases. In particular, Arsenic trioxide (ATO), as a main component, has therapeutic effects on various tumors (including leukemia, hepatocellular carcinoma, lung cancer, etc.). However, its toxicity limits its efficacy, and controlling the toxicity has been an important issue. Interestingly, recent evidence has pointed out the pivotal roles of arsenic compounds in phase separation and membraneless organelles formation, which may determine their toxicity and therapeutic efficacy. Here, we summarize the arsenic compounds-regulating phase separation and membraneless organelles formation. We further hypothesize their potential involvement in the therapy and toxicity of arsenic compounds, highlighting potential mechanisms underlying the clinical application of arsenic compounds.

Arsenic trioxide: applications, mechanisms of action, toxicity and rescue strategies to date

Arsenical medicine has obtained its status in traditional Chinese medicine for more than 2,000 years. In the 1970s, arsenic trioxide was identified to have high efficacy and potency for the treatment of acute promyelocytic leukemia, which promoted many studies on the therapeutic effects of arsenic trioxide. Currently, arsenic trioxide is widely used to treat acute promyelocytic leukemia and various solid tumors through various mechanisms of action in clinical practice; however, it is accompanied by a series of adverse reactions, especially cardiac toxicity. This review presents a comprehensive overview of arsenic trioxide from preclinical and clinical efficacy, potential mechanisms of action, toxicities, and rescue strategies for toxicities to provide guidance or assistance for the clinical application of arsenic trioxide.

The efficacy and adverse events of arsenic trioxide for the patients with myelodysplastic syndrome: a systematic review and component network meta-analysis

BACKGROUND

Arsenic trioxide (ATO) might be effective for myelodysplastic syndrome (MDS) by apoptosis induction and demethylation. But ATO has not been widely recommended for small sample and conflicting conclusion of existing trials. This review aimed to systematically evaluate the efficacy of regimens containing ATO for the MDS and explore optimal combination.

METHOD

Randomized clinical trials (RCTs) about ATO regimens were retrieved from China National Knowledge Infrastructure, Embase and PubMed. With odds ratio (OR) as the effect size, network meta-analysis (NMA) and component network meta-analysis (CNMA) were conducted by R and 'netmeta' package, after study selection, quality assessment and data extraction.

RESULT

Thirty-night RCTs were included with a total of 2125 patients, including 1235 treated by ATO containing regimen. With support therapy alone as reference, no inconsistency and heterogeneity were observed. Although NMA did not demonstrate better efficacy of ATO alone, the result of CNMA indicated that ATO was effective in the improvement of overall remission (ORR) [OR = 2.09(1.61, 2.71)] and complete remission (CR) [OR  = 1.66(1.25, 2.21)]. Five ATO-containing regimens reported could effectively improve ORR, some of them benefit in CR or hematological improvement (HI) as well. ATO + Traditional Chinese Medicine (TCM), ATO + Thalidomide (T)+TCM, ATO + Chemotherapy (Chem)+T + TCM were regarded as the optimal combination, which improved both ORR, CR and HI in theory. ATO did not increase the risk of common adverse events compared to supportive therapy [(OR = 0.90(0.67, 1.21)].

CONCLUSION

ATO may be an effective and well-tolerant option for patients with myelodysplastic syndrome.

An overview of arsenic trioxide-involved combined treatment algorithms for leukemia: basic concepts and clinical implications

Arsenic trioxide is a first-line treatment drug for acute promyelocytic leukemia, which is also effective for other kinds of leukemia. Its side effects, however, limit its clinical application, especially for patients with complex leukemia symptoms. Combination therapy can effectively alleviate these problems. This review summarizes the research progress on the combination of arsenic trioxide with anticancer drugs, vitamin and vitamin analogs, plant products, and other kinds of drugs in the treatment of leukemia. Additionally, the new progress in arsenic trioxide-induced cardiotoxicity was summarized. This review aims to provide new insights for the rational clinical application of arsenic trioxide.

In vitro and ex vivo anti-myeloma effects of nanocomposite As4S4/ZnS/Fe3O4

Nanoparticles in medicine can integrate actively targeted imaging agents and drug delivery vehicles, and combining multiple types of therapeutics in a single particle has numerous advantages, especially in multiple myeloma. MM is an incurable hematological disorder characterized by clonal proliferation of plasma cells in the bone marrow. In this study, we evaluated the anti-myeloma activity of 3 nanocomposites (3NPs): As₄S₄/ZnS/Fe₃O₄ (1:4:1), As₄S₄/ZnS/Fe₃O₄ with folic acid (FA), and As₄S₄/ZnS/Fe₃O₄ with FA and albumin with reduced survival MM cell lines and primary MM samples by each of 3NP. Cytotoxic effects of 3NPs were associated with caspase- and mitochondria-dependent apoptosis induction and reduced c-Myc expression. Modulation of cell cycle regulators, such as p-ATM/ATM and p-ATR/ATR, and increases in p-Chk2, cyclin B1, and histones were accompanied by G₂/M arrest triggered by 3NPs. In addition, 3NPs activated several myeloma-related signaling, including JNK1/2/3, ERK1/2 and mTOR. To overcome BM microenvironment-mediated drug resistance, nanocomposites retained its anti-MM activity in the presence of stroma. 3NPs significantly decreased the stem cell-like side population in MM cells, even in the context of stroma. We observed strong synergistic effects of 3NPs combined with lenalidomide, pomalidomide, or melphalan, suggesting the potential of these combinations for future clinical studies.

Representation of therapy-related myelodysplastic syndrome in clinical trials over the past 20 years

Therapy-related myelodysplastic syndrome (t-MDS), defined as MDS occurring after previous exposure to chemotherapy or radiotherapy, constitutes 10% to 20% of all MDS diagnoses. t-MDS patients tend to have higher-risk disease and worse outcomes than de novo MDS patients and are often excluded from therapeutic clinical trials. To explore this further, we extracted clinical trials across all status types registered on ClinicalTrials.gov from 1999 to 2018 studying untreated MDS patients. Using these specific search criteria, we analyzed 317 therapeutic MDS trials based on study status, therapeutic indication, eligibility criteria, and sponsor type to examine if these factors influenced t-MDS patient inclusion. Only 18 studies (5.7%) accrued 231 t-MDS patients in total, representing 3.2% of the total accrued MDS trial patient population. Fewer t-MDS patients were accrued in therapeutic trials sponsored by pharmaceutical sponsors vs nonpharmaceutical sponsors (2.8% vs 4.0%; P = .0073). This pattern of exclusion continues in actively enrolling trials; only 5 (10%) of 49 studies specifically mention the inclusion of t-MDS patients in their eligibility criteria. Our results indicate that therapeutic MDS trials seem to exclude t-MDS patients, rendering study results less applicable to this subset of MDS patients, who often have poor outcomes. Our study emphasizes the importance of the recent focus by National Cancer Institute cooperative groups and societies to broaden eligibility criteria for all patients.

Therapeutic strategy of arsenic trioxide in the fight against cancers and other diseases

Arsenic trioxide (ATO) has been recognized as a drug for the treatment of various diseases in traditional medicine for more than two thousand years. Although ATO has recently shown excellent efficacy for the treatment of acute promyelocytic leukemia (APL), it could not provide satisfactory outcomes as a single-agent for the management of non-APL leukemia or different solid tumors. Nevertheless, combination treatment strategies, e.g., ATO with other agents, have shown promising results against different diseases. Here, we introduce in depth the latest evidence and detailed insights into ATO-mediated cures for APL by targeting PML/RARα chimeric protein, followed by the preclinical and clinical efficacy of ATO on various non-APL malignancies and solid tumors. Likewise, the antiviral activity of ATO against human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was also discussed briefly. Our review would provide a clear prospect for the combination of ATO with other agents for treatment of numerous neoplastic diseases, and open a new era in the clinically applicable range of arsenicals.

Persistent clonal cytogenetic abnormality with del(20q) from an initial diagnosis of acute promyelocytic leukemia

A 68-year-old male was diagnosed with acute promyelocytic leukemia (APL). A G-banding chromosomal analysis revealed the co-existence of two clones: one with del(20q) and t(15;17)(q22;q12) and another with del(20q) alone. During the remission of APL following treatment with all-trans-retinoic acid, del(20q) was persistently identified, indicating a diagnosis of cytogenetic abnormalities of undetermined significance (CCAUS) with isolated del(20q). Bicytopenia developed 48 months after the remission of APL. The presence of isolated del(20q) was detected in the G-banding analysis, whereas morphological dysplasia of hematopoietic cells was not confirmed. This case showed indolent progression from CCAUS after the remission of APL to clonal cytopenia of undetermined significance (CCUS). CCUS with isolated del(20q) persisted for 24 months without any finding of hematological malignancies. At the most recent follow-up, targeted capture sequencing showed the U2AF1 S34F mutation. Considerable attention needs to be paid in follow-ups for CCAUS with del(20q) after the treatment of leukemia.

Decitabine shows synergistic effects with arsenic trioxide against myelodysplastic syndrome cells via endoplasmic reticulum stress-related apoptosis

Most of the International Prognostic Scoring System (IPSS) high-risk patients with myelodysplastic syndrome partly responded to hypomethylating therapy even with transient remission, while arsenic trioxide (ATO) had partial effect in patients with MDS. Therefore, we sought to investigate the effects and possible mechanisms of the combination of ATO and decitabine (DAC) in MDS cells. In our study, the MUTZ-1 and SKM-1 cells were treated with ATO, DAC or both. Cell viability, cell apoptosis, levels of reactive oxygen species (ROS) and expressions of the endoplasmicreticulum (ER) stress-associated genes and proteins were examined. Results showed the combination of ATO and DAC synergistically inhibited the proliferation and induced apoptosis of MDS cells. Through the RNA-sequence and GSEA gene function analysis, ER stress-related pathway played an important role in apoptosis of MDS cells induced by the combination of ATO and DAC. ER stress-related genes DNA damage inducible transcript 3, GRP78, and activating transcription factor-6 were significantly highly expressed in combination group than those in single agent groups; proteins were confirmed by western blot. The levels of ROS significantly increased in the combination group. Furthermore, the apoptosis of (ATO+DAC) group MDS cells could be partially reversed by antioxidant agent N-acetylcysteine, accompanied by decreased expression of intracellular ROS and ER stress-related genes. These results suggested that the combination of ATO and DAC synergistically induced the apoptosis of MDS cells by increased ROS-related ER stress in MDS cells.

EVI-1 modulates arsenic trioxide induced apoptosis through JNK signalling pathway in leukemia cells

High expression of the oncogene ecotropic viral integration site-1 (EVI-1) is an independent negative prognostic indicator of survival in leukemia patients. This study aimed to examine the effects of arsenic trioxide (ATO) on EVI-1 in acute myeloid leukemia (AML). Mononuclear cells were isolated from the bone marrow and peripheral blood of AML patients and healthy donors. EVI-1 expression in hematopoietic cells was evaluated by RT-qPCR and Western blot analysis. EVI-1 was highly expressed in both primary AML and leukemia cell lines (THP-1 and K562). ATO down-regulated EVI-1 mRNA in zebrafish in vivo as well as in primary leukemia cells and THP-1 and K562 cells in vitro. Additionally, ATO treatment induced apoptosis, down-regulated both EVI-1 mRNA and oncoprotein expression, increased the expression of pro-apoptosis proteins, and decreased the expression of anti-apoptotic proteins in leukemia cells in vitro. EVI-1 expression in leukemia cells (THP-1 and K562) transduced with EVI-1 siRNA was significantly reduced. Silencing EVI-1 had a significant effect on the activation of the JNK pathway and the induction of leukemia cell apoptosis. ATO may downregulate EVI-1 mRNA and oncoprotein levels and block the inhibitory effects of EVI-1 on the JNK pathway, which activates the JNK apoptotic pathway, thereby leading to the apoptosis of EVI-1 in AML patients.

Combination of ATO with FLT3 TKIs eliminates FLT3/ITD+ leukemia cells through reduced expression of FLT3

Acute myeloid leukemia (AML) patients with FLT3/ITD mutations have a poor prognosis. Monotherapy with selective FLT3 tyrosine kinase inhibitors (TKIs) have shown transient and limited efficacy due to the development of resistance. Arsenic trioxide (ATO, As₂O₃) has been proven effective in treating acute promyelocytic leukemia (APL) and has shown activity in some cases of refractory and relapsed AML and other hematologic malignances. We explored the feasibility of combining FLT3 TKIs with ATO in the treatment of FLT3/ITD+ leukemias. The combination of FLT3 TKIs with ATO showed synergistic effects in reducing proliferation, viability and colony forming ability, and increased apoptosis in FLT3/ITD+ cells and primary patient samples. In contrast, no cooperativity was observed against wild-type FLT3 leukemia cells. ATO reduced expression of FLT3 RNA and its upstream transcriptional regulators (HOXA9, MEIS1), and induced poly-ubiquitination and degradation of the FLT3 protein, partly through reducing its binding with USP10. ATO also synergizes with FLT3 TKIs to inactivate FLT3 autophosphorylation and phosphorylation of its downstream signaling targets, including STAT5, AKT and ERK. Furthermore, ATO combined with sorafenib, a FLT3 TKI, in vivo reduced growth of FLT3/ITD+ leukemia cells in NSG recipients. In conclusion, these results suggest that ATO is a potential candidate to study in clinical trials in combination with FLT3 TKIs to improve the treatment of FLT3/ITD+ leukemia.

Realgar nanoparticles versus ATO arsenic compounds induce in vitro and in vivo activity against multiple myeloma

Multiple myeloma (MM), a B cell malignancy characterized by clonal proliferation of plasma cells in the bone marrow, remains incurable despite the use of novel and conventional therapies. In this study, we demonstrated MM cell cytotoxicity triggered by realgar (REA; As₄ S₄ ) nanoparticles (NREA) versus Arsenic trioxide (ATO) against MM cell lines and patient cells. Both NREA and ATO showed in vivo anti-MM activity, resulting in significantly decreased tumour burden. The anti-MM activity of NREA and ATO is associated with apoptosis, evidenced by DNA fragmentation, depletion of mitochondrial membrane potential, cleavage of caspases and anti-apoptotic proteins. NREA induced G₂ /M cell cycle arrest and modulation of cyclin B1, p53 (TP53), p21 (CDKN1A), Puma (BBC3) and Wee-1 (WEE1). Moreover, NREA induced modulation of key regulatory molecules in MM pathogenesis including JNK activation, c-Myc (MYC), BRD4, and histones. Importantly, NREA, but not ATO, significantly depleted the proportion and clonogenicity of the MM stem-like side population, even in the context of the bone marrow stromal cells. Finally, our study showed that both NREA and ATO triggered synergistic anti-MM activity when combined with lenalidomide or melphalan. Taken together, the anti-MM activity of NREA was more potent compared to ATO, providing the preclinical framework for clinical trials to improve patient outcome in MM.

Arsenic trioxide and triptolide synergistically induce apoptosis in the SKM‑1 human myelodysplastic syndrome cell line

Although certain combination therapies comprising arsenic trioxide (As₂O₃) with other agents exist for the treatment of several types of human cancer, few As₂O₃ combination therapies are clinically effective for myelodysplastic syndromes (MDS). Triptolide (TL) may be an effective therapeutic agent for the treatment of MDS. However, to date, there is no combination therapy for MDS with As₂O₃ and TL. Therefore, the aim of the present study was to investigate this combination therapy on the apoptosis of MDS SKM-1 cells. The MDS SKM-1 cells were treated with As₂O₃, TL or the two in combination at various concentrations, or were mock-treated. Cell viability, cell apoptosis, levels of reactive oxygen species (ROS) and the expression of the cell apoptosis-associated genes, B cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase-3, were determined using an MTT assay, flow cytometric analysis of annexin V-fluorescein isothiocyanate/propidium iodide double-stained cells, flow cytometic analysis of intracellular 2′,7′-dichlorodihydrofluorescein diacetate fluorescence and reverse transcription-quantitative polymerase chain reaction analysis, respectively. Combination index (CI) analysis was performed to determine whether effects were synergistic (CI<1). The combination treatment was found to synergistically inhibit MDS SKM-1 cell growth, induce cell apoptosis, increase ROS levels, upregulate the expression levels of Bax and caspase-3, and downregulate the mRNA expression of Bcl-2. In conclusion, the combination treatment of As₂O₃ and TL synergistically induced apoptosis in the MDS SKM-1 cells.

Curcumin reduces the expression of survivin, leading to enhancement of arsenic trioxide-induced apoptosis in myelodysplastic syndrome and leukemia stem-like cells

Low response, treatment-related complications and relapse due to the low sensitivity of myelodysplastic syndrome (MDS) and leukemia stem cells (LSCs) or pre-LSCs to arsenic trioxide (ATO), represent the main problems following treatment with ATO alone in patients with MDS. To solve these problems, a chemosensitization agent can be applied to increase the susceptibility of these cells to ATO. Curcumin (CUR), which possesses a wide range of anticancer activities, is a commonly used chemosensitization agent for various types of tumors, including hematopoietic malignancies. In the present study, we investigated the cytotoxic effects and potential mechanisms in MDS-SKM-1 and leukemia stem-like KG1a cells treated with CUR and ATO alone or in combination. CUR and ATO exhibited growth inhibition detected by MTT assays and apoptosis analyzed by Annexin V/PI analyses in both SKM-1 and KG1a cells. Apoptosis of SKM-1 and KG1a cells determined by Annexin V/PI was significantly enhanced in the combination groups compared with the groups treated with either agent alone. Further evaluation was performed by western blotting for two hallmark markers of apoptosis, caspase-3 and cleaved-PARP. Co-treatment of the cells with CUR and ATO resulted in significant synergistic effects. In SKM-1 and KG1a cells, 31 and 13 proteins analyzed by protein array assays were modulated, respectively. Notably, survivin protein expression levels were downregulated in both cell lines treated with CUR alone and in combination with ATO, particularly in the latter case. Susceptibility to apoptosis was significantly increased in SKM-1 and KG1a cells treated with siRNA-survivin and ATO. These results suggested that CUR increased the sensitivity of SKM-1 and KG1a cells to ATO by downregulating the expression of survivin.

Arsenic induced complete remission in a refractory T-ALL patient with a distinct T-cell clonal evolution without molecular complete remission: A case report

Currently, arsenic trioxide therapy is widely used for the treatment of acute promyelocytic leukemia (APL), relapsed and refractory adult T-cell leukemia/lymphoma and myelodysplastic syndrome. Regarding the broad antitumor activity of arsenic, certain studies have been undertaken to test its efficacy in treating acute T-cell lymphoblastic leukemia (T-ALL) cell lines and patients; however, to the best of our knowledge, no reports document that arsenic is able to induce the remission of T-ALL patients. The present study reports the case of young male patient diagnosed with T-ALL, with no significant response to common chemotherapy regimens, who finally achieved complete remission without minimal residual disease (as detected by flow cytometry) due to arsenic treatment. This result is encouraging, and the present study has shown that malignant TCRαβ⁺ cell clones can be detected at the molecular level using reverse transcription-polymerase chain reaction (PCR) combined with the GeneScan technique. The result is mainly based on the T-cell receptor (TCR) Vβ1 clone (a 190-base pair PCR product that with the same complementarity determining region 3 length can be detected for all samples collected during various statuses) and on undetectable TCR Vγ subfamily members, at the time of disease diagnosis. It is important to analyze the dynamically changing TCR pool in leukemia patients during therapy. Although the molecular mechanism through which arsenic contributes to malignant clone elimination remains unclear in the case presented, the use of arsenic is expected to be effective for clinically treating refractory and relapsed T-ALL patients.

Anti-angiogenesis in Personalized Therapy of Lung Cancer

Upregulation of angiogenesis is a frequent occurrence in lung cancer and is reported to represent a negative prognostic factor. This provides a rationale for the development and evaluation of anti-angiogenic agents. To date bevacizumab, a monoclonal antibody directed against serum VEGF, is the only anti-angiogenic agent that has demonstrated improved overall survival for patients with lung cancer. Meta-analysis of trials of bevacizumab in combination with platinum-based chemotherapy for NSCLC, show a 10% reduction in the risk of death (HR 0.90, 95% CI 0.81-0.99). However, therapy with bevacizumab is limited to NSCLC patients with non-squamous histology, good performance status, no brain metastases and the absence of bleeding or thrombotic disorders. More recently, similar survival was observed in a non bevacizumab containing regimen of carboplatin, pemetrexed and maintenance pemetrexed. Multiple oral anti-angiogenic compounds have been evaluated in NSCLC, both in first-line therapy, or upon disease progression. The majority of agents have shown some evidence of activity, but none have clearly demonstrated improvements in overall survival. Increased toxicities have been observed, including an increased risk of death for some agents, limiting their development. Promising data exist for sunitinib in patients with heavily pre-treated NSCLC, and nintedanib in combination with docetaxel, as second-line therapy for NSCLC. However, these findings require validation. Currently, there is no established role for anti-angiogenic therapy in SCLC, although there is some promise for sunitinib as maintenance therapy following platinum and etoposide chemotherapy. The challenge for anti-angiogenic therapy is to understand whether treatment effects in a subpopulation, are lost among a larger unselected population of patients. There is a need for additional translational research to identify predictive biomarkers for anti-angiogenic therapy.

Molecular and Cellular Mechanisms of Myelodysplastic Syndrome: Implications on Targeted Therapy

Myelodysplastic syndrome (MDS) is a group of heterogeneous clonal hematopoietic stem cell disorders characterized by cytopenia, ineffective hematopoiesis, and progression to secondary acute myeloid leukemia in high-risk cases. Conventional prognostication relies on clinicopathological parameters supplemented by cytogenetic information. However, recent studies have shown that genetic aberrations also have critical impacts on treatment outcome. Moreover, these genetic alterations may themselves be a target for treatment. The mutation landscape in MDS is shaped by gene aberrations involved in DNA methylation (TET2, DNMT3A, IDH1/2), histone modification (ASXL1, EZH2), the RNA splicing machinery (SF3B1, SRSF2, ZRSR2, U2AF1/2), transcription (RUNX1, TP53, BCOR, PHF6, NCOR, CEBPA, GATA2), tyrosine kinase receptor signaling (JAK2, MPL, FLT3, GNAS, KIT), RAS pathways (KRAS, NRAS, CBL, NF1, PTPN11), DNA repair (ATM, BRCC3, DLRE1C, FANCL), and cohesion complexes (STAG2, CTCF, SMC1A, RAD21). A detailed understanding of the pathogenetic mechanisms leading to transformation is critical for designing single-agent or combinatorial approaches in target therapy of MDS.

Role of endoplasmic reticulum stress in drug-induced toxicity

Drug‐induced toxicity is a key issue for public health because some side effects can be severe and life‐threatening. These adverse effects can also be a major concern for the pharmaceutical companies since significant toxicity can lead to the interruption of clinical trials, or the withdrawal of the incriminated drugs from the market. Recent studies suggested that endoplasmic reticulum (ER) stress could be an important event involved in drug liability, in addition to other key mechanisms such as mitochondrial dysfunction and oxidative stress. Indeed, drug‐induced ER stress could lead to several deleterious effects within cells and tissues including accumulation of lipids, cell death, cytolysis, and inflammation. After recalling important information regarding drug‐induced adverse reactions and ER stress in diverse pathophysiological situations, this review summarizes the main data pertaining to drug‐induced ER stress and its potential involvement in different adverse effects. Drugs presented in this review are for instance acetaminophen (APAP), arsenic trioxide and other anticancer drugs, diclofenac, and different antiretroviral compounds. We also included data on tunicamycin (an antibiotic not used in human medicine because of its toxicity) and thapsigargin (a toxic compound of the Mediterranean plant Thapsia garganica) since both molecules are commonly used as prototypical toxins to induce ER stress in cellular and animal models.

Mechanisms of Cardiotoxicity of Cancer Chemotherapeutic Agents: Cardiomyopathy and Beyond

Tremendous strides have been made in the treatment of various oncological diseases such that patients are surviving longer and are having better quality of life. However, the success has been tainted by the iatrogenic cardiac toxicities. This is especially concerning in the younger population who are facing cardiac disease such as heart failure in their 30s and 40s as the consequence of the anthracycline's side effects (used for childhood leukemia and lymphoma). This resulted in the awareness of cardiotoxic effects of anticancer drugs and emergence of a new discipline: oncocardiology. Since then, numerous anticancer drugs have been correlated to cardiomyopathy. Additionally, other cardiovascular effects have been identified, which includes but is not limited to myocardial infarction, thrombosis, hypertension, arrhythmias, and pulmonary hypertension. In this review we examine some of the anticancer agents that mitigate cardiotoxicity and present current knowledge of molecular mechanism(s). The aim of the review is to ignite awareness of emerging cardiotoxic effects as new generations of anticancer agents are being tested in clinical trials and introduced as part of the therapeutic armamentarium to our oncological patients.

The Synergistic Effects of Decitabine Combined with Arsenic Trioxide (ATO) in the Human Myelodysplastic Syndrome Cell Line SKM-1

Despite recent advances in the treatment of myelodysplastic syndrome (MDS), single-agent clinical effects remain unsatisfactory, and decitabine monotherapy is also associated with a relatively low rate of complete remission. To study the combined effects and mechanism of decitabine (DAC) and arsenic trioxide (ATO) on the human myelodysplastic cell line SKM-1,we used the MTS assay and CalcuSyn software to determine the cytotoxicity and potential synergistic effects, respectively. Furthermore, we determined apoptosis and measured the mRNA expression level of two genes that are considered main regulators of the apoptosis process. The results showed that DAC and/or ATO can inhibit the proliferation of SKM-1 cells and demonstrated significant synergy between the two agents (CI < 1). Additionally, combination of 2.5 μmol/L DAC and 5 μmol/L ATO led to a significantly higher apoptosis rate and more significantly decreased the Bcl2/Bax ratio than either compound alone (P < 0.001). Based on the observations of this study, we suggest that combined administration of these two drugs might be considered a novel therapeutic regimen for treating MDS.

The evolution of arsenic in the treatment of acute promyelocytic leukemia and other myeloid neoplasms: Moving toward an effective oral, outpatient therapy

The therapeutic potential of arsenic derivatives has long been recognized and was recently rediscovered in modern literature. Early studies demonstrated impressive activity of this compound in patients with relapsed acute promyelocytic leukemia (APL). Over the last 2 decades, intravenous arsenic trioxide has been used successfully, both alone and in combination with other agents, for the treatment of APL and, with some success, of other myeloid neoplasms. Arsenic trioxide is currently part the standard of care for patients with APL. More recently, oral formulations of this compound have been developed and are entering clinical practice. In this review, the authors discuss the evolution of arsenic in the treatment of APL and other myeloid neoplasms.

A phase II study of arsenic trioxide in patients with relapsed or refractory malignant lymphoma

Limited data have been reported regarding the use of arsenic trioxide (ATO) in the treatment of patients with relapsed or refractory malignant lymphoma; therefore, the present phase II study evaluated the efficacy and toxicity of ATO in such patients. A total of 35 patients were treated with ATO (0.25 mg/kg) infused for 1 h daily, 5 days a week, for a 6-week cycle. Patients were evaluated for the efficacy and toxicity of this regimen. The primary outcome evaluated was the overall response rate (ORR), including the complete and partial response rates. The secondary outcomes evaluated were the overall survival (OS), progression-free survival (PFS), and toxicity. Tumor response data were obtained from all 35 enrolled patients. The ORR was 43%, including complete responses in four patients (11%) and partial responses in 11 patients (31%). The median duration of response was 16 weeks (range 11-23 weeks). The median OS was 79 weeks (range 14-171 weeks), and the median PFS was 55 weeks (range 14-135 weeks). Grade I or II hematological toxicities were the most commonly reported adverse events. The results of this study appear promising for the treatment of relapsed or refractory malignant lymphoma, with well-tolerated ATO toxicity.

Adding ascorbic acid to arsenic trioxide produces limited benefit in patients with acute myeloid leukemia excluding acute promyelocytic leukemia

Arsenic trioxide (ATO) is highly effective in acute promyelocytic leukemia (APL), but despite its multiple mechanism of action, it has no activity in acute myeloid leukemia (AML) that excludes APL (non-APL AML). Ascorbic acid (AA) and ATO induces apoptosis in AML cell lines by depleting intracellular glutathione and generation of reactive oxygen species. In this study, we evaluated the effect of ATO plus AA in patients with non-APL AML. The study enrolled patient aged 18 or older with relapsed or refractory AML (non-APL) after conventional chemotherapy or previously untreated patients 55 years or older who were unfit for standard induction chemotherapy for AML. Intravenous ATO (0.25 mg/kg/day over 1-4 h) was given with intravenous AA (1 g/day over 30 min after ATO) for 5 days a week for 5 weeks (25 doses). Eleven AML patients were enrolled, including six previously untreated elderly patients aged 66-84 years in whom five had antecedent hematological disorder (ADH). Among 10 evaluable patients, one achieved a CR one a CRi and 4 patients had disappearance of blasts from peripheral blood and bone marrow. Five of the six responders were seen in previously untreated elderly patients. ATO related toxicity was mild. The combination of ATO and AA has limited clinical meaningful antileukemia activity in patients with non-APL AML.

Beyond hypomethylating agents failure in patients with myelodysplastic syndromes

PURPOSE OF REVIEW

Although hypomethylating agents (HMAs) significantly improve outcomes in myelodysplastic syndromes (MDS), only half the patients achieve objective responses, and most responders lose response within 1-2 years. Azacitidine prolongs survival by a median of only 9.5 months. Failure of HMA therapy is associated with a very dismal prognosis. Therefore, novel therapeutic approaches are clearly needed.

RECENT FINDINGS

The sequential use of the alternative HMA after failure of first line HMA is associated with modest efficacy. The improved understanding of the biologic underpinnings of the disease have opened the door to study investigational agents that target disrupted molecular pathways critical to the pathogenesis of MDS. Combination treatment strategies using an azacitidine backbone are demonstrating promising early results. Expanding the applicability of allogeneic stem cell transplantation (alloSCT), the only curative modality, by reducing toxicity and relapse rates is another area of active research.

SUMMARY

Sequential switching to the alternative HMA, clinical trials of novel targeted therapies, azacitidine-based combination therapeutic strategies, and improvements in the alloSCT platform are the main directions in improving outcomes of MDS post HMA failure.

Arsenic trioxide induces apoptosis in human platelets via C-Jun NH2-terminal kinase activation

Arsenic trioxide (ATO), one of the oldest drugs in both Western and traditional Chinese medicine, has become an effective anticancer drug, especially in the treatment of acute promyelocytic leukemia (APL). However, thrombocytopenia occurred in most of ATO-treated patients with APL or other malignant diseases, and the pathogenesis remains unclear. Here we show that ATO dose-dependently induces depolarization of mitochondrial inner transmembrane potential (ΔΨm), up-regulation of Bax and down-regulation of Bcl-2 and Bcl-X_L, caspase-3 activation, and phosphotidylserine (PS) exposure in platelets. ATO did not induce surface expression of P-selectin and PAC-1 binding, whereas, obviously reduced collagen, ADP, and thrombin induced platelet aggregation. ATO dose-dependently induced c-Jun NH₂-terminal kinase (JNK) activation, and JNK specific inhibitor dicumarol obviously reduced ATO-induced ΔΨm depolarization in platelets. Clinical therapeutic dosage of ATO was intraperitoneally injected into C57 mice, and the numbers of circulating platelets were significantly reduced after five days of continuous injection. The data demonstrate that ATO induces caspase-dependent apoptosis via JNK activation in platelets. ATO does not incur platelet activation, whereas, it not only impairs platelet function but also reduces circulating platelets in vivo, suggesting the possible pathogenesis of thrombocytopenia in patients treated with ATO.

Treatment of acute myeloid leukemia in older patients

Acute myeloid leukemia carries a dismal prognosis in patients over 60 years of age and, despite many clinical trials of both novel and conventional agents, there has been no significant improvement in overall survival during the last 30 years. Combinations of anthracyclines and cytarabine remain the cornerstone of therapy and produce complete remission in 45-55% of older patients, with a median survival of only 8-12 months. These statistics become even worse in patients over 70 years and those with unfavorable cytogenetics and/or poor performance status. Deciding which older acute myeloid leukemia patients would benefit from intensive chemotherapy is difficult and efforts are underway to improve existing risk-assessment tools. Many new agents are under development, including signal transduction inhibitors, farnesyl transferase inhibitors, antibodies and novel chemotherapeutics. To date, small-molecule inhibitors and targeted therapies have had limited single-agent efficacy and have required combination with chemotherapy. The role of hematopoietic stem cell transplantation in older patients is under investigation. All patients over 60 years of age with acute myeloid leukemia should be encouraged to participate in a clinical trial if possible.

Anticancer activity of small-molecule and nanoparticulate arsenic(III) complexes

Starting in ancient China and Greece, arsenic-containing compounds have been used in the treatment of disease for over 3000 years. They were used for a variety of diseases in the 20th century, including parasitic and sexually transmitted illnesses. A resurgence of interest in the therapeutic application of arsenicals has been driven by the discovery that low doses of a 1% aqueous solution of arsenic trioxide (i.e., arsenous acid) lead to complete remission of certain types of leukemia. Since Food and Drug Administration (FDA) approval of arsenic trioxide (As2O3) for treatment of acute promyelocytic leukemia in 2000, it has become a front-line therapy in this indication. There are currently over 100 active clinical trials involving inorganic arsenic or organoarsenic compounds registered with the FDA for the treatment of cancers. New generations of inorganic and organometallic arsenic compounds with enhanced activity or targeted cytotoxicity are being developed to overcome some of the shortcomings of arsenic therapeutics, namely, short plasma half-lives and a narrow therapeutic window.

Hypomethylating agents and chemotherapy in MDS

Until recently, the treatment of higher risk myelodysplastic syndrome was based on [1] Intensive chemotherapy using anthracycline-AraC combinations, leading to a lower complete remission rates and a shorter CR duration compared with de novo AML [2], low dose chemotherapy with limited CR rate mainly restricted to patients with normal karyotype. Azacitidine was the first drug to significantly improve survival in higher risk MDS, although it is not curative. Thus, the survival improvement obtained with azacitidine must be the starting point for combination studies, and for utilization of this drug in other situations (before allo SCT, or after chemotherapy or allo SCT as maintenance treatment).

Current therapy of myelodysplastic syndromes

After being a neglected and poorly-understood disorder for many years, there has been a recent explosion of data regarding the complex pathogenesis of myelodysplastic syndromes (MDS). On the therapeutic front, the approval of azacitidine, decitabine, and lenalidomide in the last decade was a major breakthrough. Nonetheless, the responses to these agents are limited and most patients progress within 2 years. Allogeneic stem cell transplantation remains the only potentially curative therapy, but it is associated with significant toxicity and limited efficacy. Lack or loss of response after standard therapies is associated with dismal outcomes. Many unanswered questions remain regarding the optimal use of current therapies including patient selection, response prediction, therapy sequencing and combinations, and management of resistance. It is hoped that the improved understanding of the underpinnings of the complex mechanisms of pathogenesis will be translated into novel therapeutic approaches and better prognostic/predictive tools that would facilitate accurate risk-adaptive therapy.

Arsenic trioxide and ascorbic acid interfere with the BCL2 family genes in patients with myelodysplastic syndromes: an ex-vivo study

BACKGROUND

Arsenic Trioxide (ATO) is effective in about 20% of patients with myelodysplasia (MDS); its mechanisms of action have already been evaluated in vitro, but the in vivo activity is still not fully understood. Since ATO induces apoptosis in in vitro models, we compared the expression of 93 apoptotic genes in patients' bone marrow before and after ATO treatment. For this analysis, we selected 12 patients affected by MDS who received ATO in combination with Ascorbic Acid in the context of the Italian clinical trial NCT00803530, EudracT Number 2005-001321-28.

METHODS

Real-time PCR quantitative assays for genes involved in apoptosis were performed using TaqMan® Assays in 384-Well Microfluidic Cards "TaqMan® Human Apoptosis Array".Quantitative RT-PCR for expression of EVI1 and WT1 genes was also performed. Gene expression values (Ct) were normalized to the median expression of 3 housekeeping genes present in the card (18S, ACTB and GAPDH).

RESULTS

ATO treatment induced up-regulation of some pro-apoptotic genes, such as HRK, BAK1, CASPASE-5, BAD, TNFRSF1A, and BCL2L14 and down-regulation of ICEBERG. In the majority of cases with stable disease, apoptotic gene expression profile did not change, whereas in cases with advanced MDS more frequently pro-apoptotic genes were up-regulated. Two patients achieved a major response: in the patient with refractory anemia the treatment down-regulated 69% of the pro-apoptotic genes, whereas 91% of the pro-apoptotic genes were up-regulated in the patient affected by refractory anemia with excess of blasts-1. Responsive patients showed a higher induction of BAD than those with stable disease. Finally, WT1 gene expression was down-regulated by the treatment in responsive cases.

CONCLUSIONS

These results represent the basis for a possible association of ATO with other biological compounds able to modify the apoptotic pathways, such as inhibitors of the BCL2 family.

New oral multitargeted antiangiogenics in non-small-cell lung cancer treatment

Non-small-cell lung cancer is a particularly aggressive cancer. Combination chemotherapy remains the standard therapy for patients with advanced or metastatic disease. However, despite the available treatment options for patients who progress beyond first-line therapy, prognosis remains poor. Angiogenesis is a tightly regulated process controlled by a delicate balance between pro- and antiangiogenic factors and their receptors; tumors induce angiogenesis by disrupting this balance and secreting various growth factors. Inhibition of tumor-related angiogenesis has become an attractive target for anticancer therapy. Antiangiogenic strategy includes monoclonal antibodies against VEGF and VEGF receptor and small molecule inhibitors of VEGF tyrosine kinase activity (tyrosine kinase inhibitors). Tyrosine kinase inhibitors are orally active, small molecules that represent a new class of drugs with a relatively high safety profile. They are targeted therapies that play their anticancer role interfering with specific cell signaling. This review focuses on such oral antiangiogenic agents that have been approved and are in advanced clinical development for the treatment of patients with advanced non-small-cell lung cancer.

Arsenic trioxide enhances the cytotoxic effect of cisplatin in head and neck squamous cell carcinoma cell lines

Arsenic trioxide (ATO) has been approved for the treatment of relapsed acute promyelocytic leukaemia. The aim of this study was to determine whether ATO would lead to cell death in head and neck squamous cell carcinoma (HNSCC) cell lines and whether it was able to enhance the cytotoxicity of cisplatin, a standard chemotherapeutic agent. The four HNSCC cell lines SCC9, SCC25, CAL27 and FADU were treated with ATO or cisplatin alone or with ATO and cisplatin in combination. Cytotoxicity assays, immunohistochemistry, western blot analysis and flow cytometry were carried out. Possible interactions between the two drugs were calculated using the Chou-Talalay equation. Ther results demonstrated a synergistic cytotoxic effect of the combination of ATO and cisplatin at high doses. The two agents induced apoptosis in all four HNSCC cell lines. In conclusion, this study showed that ATO is a promising therapeutic drug with cytotoxic effects in HNSCC. We demonstrated a synergistic effect in the combined treatment with cisplatin at high doses.

Combination strategies in myelodysplastic syndromes

The myelodysplastic syndromes (MDS) consist of an array of clonal hematological malignancies resulting from disorders of pluripotent hematopoietic stem cells. MDS is associated with a poor overall prognosis and patients are categorized as higher risk and lower risk on the basis of the International Prognostic Scoring System. Currently, lenalidomide, azacitidine, and decitabine are the only three FDA-approved drugs for MDS. Traditional therapies for MDS involve the administration of single agents providing either supportive measures or disease-modifying effects directed to slowing progression to acute myeloid leukemia (AML) and improving survival. Recently, however, there has been increasing evidence suggesting that the combination of drugs with different mechanisms of action offers substantial benefit in the form of diminished side effects, improved overall survival, and delayed progression to AML. Multiple studies indicate that when compared with traditional monotherapies, combining various medications with non-overlapping mechanisms of action and toxicities may result in significant benefit for patients with MDS. A variety of combination therapies with growth factors, DNA methytransferase inhibitors, histone deacetylase inhibitors, and immunosuppressant treatments provide encouraging data indicating that the successful future of MDS treatment rests in the combination of multiple treatments modalities to achieve improved clinical outcomes.

Acute promyelocytic leukemia with a smoldering course associated with therapy-related myelodysplastic syndrome

Acute promyelocytic leukemia (APL) may appear rarely as a late complication of the treatment of other primary cancers. Therapy-related APL (tAPL) differs from de novo APL in epidemiological and clinical parameters but shares common molecular signatures and does not differ in survival end- points. We describe a 67-year-old female patient who presented with an atypical course of tAPL. Atypical features in this patient's course included a preceding therapy-related myelodysplastic syndrome (MDS) with a slowly expanding pathological promyelocyte clone. Following treatment with all-trans-retinoic acid and arsenic trioxide, the patient achieved complete clinical, morphological and molecular remission. Review of the pertinent literature highlights the rarity of MDS transforming into APL, although dysplasia has been shown to be a possible feature of tAPL. MDS may be an underdiagnosed stage in tAPL leukomogenesis. This case also underscores the complexity of clinical decision-making in the context of tAPL.

From an old remedy to a magic bullet: molecular mechanisms underlying the therapeutic effects of arsenic in fighting leukemia

Arsenic had been used in treating malignancies from the 18th to mid-20th century. In the past 3 decades, arsenic was revived and shown to be able to induce complete remission and to achieve, when combined with all-trans retinoic acid and chemotherapy, a 5-year overall survival of 90% in patients with acute promyelocytic leukemia driven by the t(15;17) translocation-generated promyelocytic leukemia-retinoic acid receptor α (PML-RARα) fusion. Molecularly, arsenic binds thiol residues and induces the formation of reactive oxygen species, thus affecting numerous signaling pathways. Interestingly, arsenic directly binds the C3HC4 zinc finger motif in the RBCC domain of PML and PML-RARα, induces their homodimerization and multimerization, and enhances their interaction with the SUMO E2 conjugase Ubc9, facilitating subsequent sumoylation/ubiquitination and proteasomal degradation. Arsenic-caused intermolecular disulfide formation in PML also contributes to PML-multimerization. All-trans retinoic acid, which targets PML-RARα for degradation through its RARα moiety, synergizes with arsenic in eliminating leukemia-initiating cells. Arsenic perturbs a number of proteins involved in other hematologic malignancies, including chronic myeloid leukemia and adult T-cell leukemia/lymphoma, whereby it may bring new therapeutic benefits. The successful revival of arsenic in acute promyelocytic leukemia, together with modern mechanistic studies, has thus allowed a new paradigm to emerge in translational medicine.

A Phase 2 study of combination therapy with arsenic trioxide and gemtuzumab ozogamicin in patients with myelodysplastic syndromes or secondary acute myeloid leukemia

BACKGROUND

Higher-risk myelodysplastic syndromes (MDS) are similar pathobiologically to acute myeloid leukemia (AML), particularly in older adults. AML therapies thus may have activity in MDS. In the current study, phase 2 study data of arsenic trioxide (ATO) and gemtuzumab ozogamicin (GO) in CD33-positive patients with MDS and secondary AML (sAML) were presented.

METHODS

Between June 2004 and February 2006, 30 patients with higher-risk MDS or sAML received ATO (at a dose of 0.25 mg/kg intravenously for 5 days during Week 1, then twice weekly during Weeks 2-12) and GO (at a dose of 3 mg/m(2) on Day 8) for 1 or 2 cycles of 12 weeks each. The primary endpoint was response as per MDS or AML International Working Group (IWG) criteria. Adverse events were collected throughout treatment. Patients were followed for a minimum of 3 years for survival.

RESULTS

The median patient age was 69 years. A total of 18 patients had MDS, 12 had sAML, and 19 had been previously treated. Seventeen patients (57%) completed ≥1 cycle, and 7 patients (23%) completed 2 cycles. IWG responses occurred in 9 patients (30%) according to IWG MDS criteria (including 2 of 7 patients who failed hypomethylating agents) and 3 of 12 AML patients (25%) according to IWG AML criteria. Grade 3/4 (according to National Cancer Institute Common Toxicity Criteria [version 3.0]) thrombocytopenia occurred in 47% of patients, neutropenia in 63%, and anemia in 37% of patients. The median overall survival was 9.7 months (28.6 months in responders and 7.6 months in nonresponders; P <.001). Patients who completed 2 cycles of therapy spent a median of 13 days in the hospital.

CONCLUSIONS

Combination therapy with ATO and GO was found to have acceptable response rates and toxicity, and may be a viable treatment option to standard induction therapy, particularly for patients who fail therapy with hypomethylating agents.

Arsenic trioxide - An old drug rediscovered

Over the last 17 years, clinical trials conducted worldwide have demonstrated the efficacy of arsenic trioxide (As(2)O(3)) in the treatment of relapsed acute promyelocytic leukemia (APL). Currently, the role of As(2)O(3) in front-line therapy is under investigation. Recent trials in the US have demonstrated that the addition of As(2)O(3) to standard treatment regimens improves survival outcomes in patients with APL and may allow a reduction in cytotoxic chemotherapy exposure. As(2)O(3) has also shown efficacy in other malignancies, particularly multiple myeloma and myelodysplastic syndromes. Therapeutic doses of As(2)O(3) are well tolerated, with no evidence of long-term toxicity. Adverse events include APL differentiation syndrome, electrocardiographic abnormalities, and mild elevations in liver enzymes. This review highlights trials investigating the role of As(2)O(3) in induction and consolidation for newly diagnosed APL, as well as its role in other hematologic malignancies. The chemistry, mechanisms of action, and clinical side effects of As(2)O(3) are also discussed.

Phase III study of carboplatin and paclitaxel alone or with sorafenib in advanced non-small-cell lung cancer

PURPOSE This phase III, multicenter, randomized, placebo-controlled trial assessed the efficacy and safety of sorafenib, an oral multikinase inhibitor, in combination with carboplatin and paclitaxel in chemotherapy-naïve patients with unresectable stage IIIB or IV non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Nine hundred twenty-six patients were randomly assigned to receive up to six 21-day cycles of carboplatin area under the curve 6 and paclitaxel 200 mg/m(2) (CP) on day 1, followed by either sorafenib 400 mg twice a day (n = 464, arm A) or placebo (n = 462, arm B) on days 2 to 19. The maintenance phase after CP consisted of sorafenib 400 mg or placebo twice a day. The primary end point was overall survival (OS); secondary end points included progression-free survival and tumor response. RESULTS Overall demographics were balanced between arms; 223 patients (24%) had squamous cell histology. On the basis of a planned interim analysis, median OS was 10.7 months in arm A and 10.6 months in arm B (hazard ratio [HR] = 1.15; 95% CI, 0.94 to 1.41; P = .915). The study was terminated after the interim analysis concluded that the study was highly unlikely to meet its primary end point. A prespecified exploratory analysis revealed that patients with squamous cell histology had greater mortality in arm A than in arm B (HR = 1.85; 95% CI, 1.22 to 2.81). Main grade 3 or 4 sorafenib-related toxicities included rash (8.4%), hand-foot skin reaction (7.8%), and diarrhea (3.5%). CONCLUSION No clinical benefit was observed from adding sorafenib to CP chemotherapy as first-line treatment for NSCLC.

Optimal sequencing of treatments for patients with myelodysplastic syndromes

PURPOSE OF REVIEW

Myelodysplastic syndromes (MDS) are characterized by chronic cytopenias and a high risk of transformation to acute myeloid leukemia. To date, only allogeneic stem cell transplantation has shown curative potential in MDS. The heterogeneous nature of MDS, and the paucity of randomized studies make individual therapeutic decisions, still largely based on the international prognostic scoring system, difficult.

RECENT FINDINGS

In lower-risk MDS, recent advances include demonstration of a possible survival advantage with erythropoiesis stimulating agents, the role of lenalidomide in cases with del 5q (which lead to its approval in the treatment of lower-risk MDS with del 5q by the Food and Drug Administration), and recognition of the importance of iron overload on prognosis. In higher-risk patients, progress has come from the use of reduced intensity conditioning allogeneic SCT in elderly patients, and from results obtained with the hypomethylating agents azacytidine and decitabine, leading to their approval for the treatment of symptomatic MDS by the Food and Drug Administration. In particular, results of a phase III trial show a significant survival benefit for azacytidine over conventional treatments in higher-risk MDS. This is the first time a drug demonstrates a survival impact in higher-risk MDS.

SUMMARY

We review these recent advances in this paper.

Incorporating novel agents in the treatment of myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a group of heterogeneous clonal stem cell (SC) disorders that mainly affect the elderly population. They are characterized by ineffective hematopoiesis which results in quantitative and qualitative cellular defects and high incidence of leukemic transformation. Recent advances in MDS research have led to the development of novel agents which appears to improve remission rates and survival when compared to best supportive care. Currently azacitidine, decitabine, and lenalidomide are approved by the US FDA for the treatment of MDS, while the activity of other novel agents such as histone deacetylase inhibitors, farnesyl-transferase inhibitors, novel thrombopoietic agents, and anti-angiogenesis molecules is under evaluation. Erythropoietin-stimulating agents, iron chelating therapy and thrombopoietin receptor ligands may also improve quality of life and possibly prolong survival in MDS patients. The only treatment modality that can achieve long-term survival is the allogeneic SC transplantation which is given only in selected patients. Moreover the heterogeneity of MDS and the patient's advanced age and co-morbidity are significant factors besides cytogenetics, IPSS and WPSS that should be taken into account during the decision-making process. Therefore clinicians should treat patients with MDS on an individual basis aiming the increase of the response rates and the decrease of treatment-associated toxicities. This can only be achieved through the better understanding of the MDS subgroups. If we can better define MDS subgroups we will be able to identify patients who will benefit from the incorporation of the novel agents, as monotherapy or in combinations regimens along with supportive care.

Phase II, multicenter, uncontrolled trial of single-agent sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer

PURPOSE

Sorafenib is an oral multikinase inhibitor that targets the Ras/Raf/MEK/ERK mitogenic signaling pathway and the angiogenic receptor tyrosine kinases, vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor beta. We evaluated the antitumor response and tolerability of sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer (NSCLC), most of whom had received prior platinum-based chemotherapy.

PATIENTS AND METHODS

This was a phase II, single-arm, multicenter study. Patients with relapsed or refractory advanced NSCLC received sorafenib 400 mg orally twice daily until tumor progression or an unacceptable drug-related toxicity occurred. The primary objective was to measure response rate.

RESULTS

Of 54 patients enrolled, 52 received sorafenib. The predominant histologies were adenocarcinoma (54%) and squamous cell carcinoma (31%). No complete or partial responses were observed. Stable disease (SD) was achieved in 30 (59%) of the 51 patients who were evaluable for efficacy. Four patients with SD developed tumor cavitation. Median progression-free survival (PFS) was 2.7 months, and median overall survival was 6.7 months. Patients with SD had a median PFS of 5.5 months. Major grades 3 to 4, treatment-related toxicities included hand-foot skin reaction (10%), hypertension (4%), fatigue (2%), and diarrhea (2%). Nine patients died within a 30-day period after discontinuing sorafenib, and one patient experienced pulmonary hemorrhage that was considered drug related. CONCLUSION Continuous treatment with sorafenib 400 mg twice daily was associated with disease stabilization in patients with advanced NSCLC. The broad activity of sorafenib and its acceptable toxicity profile suggest that additional investigation of sorafenib as therapy for patients with NSCLC is warranted.

Biological responses to arsenic compounds

Arsenic is a metalloid that generates various biological effects on cells and tissues. Depending on the specific tissue exposed and the time and degree of exposure, diverse responses can be observed. In humans, prolonged and/or high dose exposure to arsenic can have a variety of outcomes, including the development of malignancies, severe gastrointestinal toxicities, diabetes, cardiac arrhythmias, and death. On the other hand, one arsenic derivative, arsenic trioxide (As(2)O(3)), has important antitumor properties. This agent is a potent inducer of antileukemic responses, and it is now approved by the Food and Drug Administration for the treatment of acute promyelocytic leukemia in humans. The promise and therapeutic potential of arsenic and its various derivatives have been exploited for hundreds of years. Remarkably, research focused on the potential use of arsenic compounds in the treatment of human diseases remains highly promising, and it is an area of active investigation. An emerging approach of interest and therapeutic potential involves efforts to target and block cellular pathways activated in a negative feedback manner during treatment of cells with As(2)O(3). Such an approach may ultimately provide the means to selectively enhance the suppressive effects of this agent on malignant cells and render normally resistant tumors sensitive to its antineoplastic properties.