Effect of renal impairment on arsenic accumulation, methylation capacity, and safety in acute promyelocytic leukemia (APL) patients treated with arsenic trioxide.

Background: Arsenic trioxide (ATO) was successfully applied to treat acute promyelocytic leukemia (APL).Methods: Inorganic arsenic (iAs), monomethylarsonic acid (MMAV) and dimethyarsinic acid (DMAV) in plasma of 143 APL patients with different renal function were determined. Arsenic methylation capacity was evaluated by iAs%, MMAV%, DMAV%, primary methylation index (PMI, MMAV/iAs), and secondary methylated index (SMI, DMAV/MMAV). Arsenic accumulation with administration frequency were explored. Moreover, safety assessments were performed.Results: Compared with normal renal function, MMAV and DMAV concentrations increased 1.5-4 fold in moderate and severe renal impairment groups, iAs increased 1.3-1.7 fold. APL patients with renal impairment showed lower iAs%, but higher DMAV% and PMI in plasma than those with normal renal function (P < 0.05). MMAV, DMAV, and tAs apparently accumulated with administration frequency in moderate and severe renal dysfunction groups. The incidence of QTc interval prolongation and liver injury increased with the increasing severity of renal impairment.Conclusion: Renal dysfunction may increase exposure to arsenic and arsenic accumulation and affect methylation capacity, then the clinical safety in APL patients treated with ATO. Arsenic-level monitoring and dosing regimen adjustment should be considered in APL patients with moderate and severe renal dysfunction.

Arsenic trioxide-loaded CalliSpheres: In vitro study of drug release and antitumor activity, and in vivo study of pharmacokinetics, treatment efficacy and safety in liver cancer.

The aim of the present study was to investigate the arsenic trioxide (ATO) loading/releasing efficiency of CalliSphere beads (CBs), as well as the in vitro anticancer activity, in vivo pharmacokinetics, treatment efficacy and safety of ATO-eluting CBs in liver cancer. The ATO loading and releasing efficiencies in CBs were evaluated. Furthermore, cell viability, invasion, apoptosis, VEGF expression and MMP9 expression were determined in liver cancer cells treated with ATO-eluting CBs or ATO solution. Rabbit liver models were established and underwent TACE with ATO-eluting CBs or ATO/lipiodol emulsion. Subsequently, their ATO pharmacokinetics were determined and macroscopic/microscopic examinations were conducted. In vitro, CB-loaded ATO increased during 40 min with an optimal loading efficiency of 23.0±2.5%, and released ATO rapidly within the first 30 min (31.40±10.0%) then slowed down within the latter 48 h (47.20±4.70%). ATO-eluting CBs exhibited decreased cell viability to some extent and similar invasive cell count, apoptosis rate, VEGF and MMP9 levels compared with ATO solution at various concentrations and time-points. In vivo, ATO concentration was lower in plasma, but higher in tumor tissues, and necrosis was more complete in tumor tissue while milder in normal liver parenchyma after rabbit liver was embolized with ATO-eluting CBs compared with ATO/lipiodol emulsion. ATO-eluting CBs may be a novel and promising therapeutic option in treating liver cancer.

Lipid/PAA-coated mesoporous silica nanoparticles for dual-pH-responsive codelivery of arsenic trioxide/paclitaxel against breast cancer cells.

Nanomedicine has attracted increasing attention and emerged as a safer and more effective modality in cancer treatment than conventional chemotherapy. In particular, the distinction of tumor microenvironment and normal tissues is often used in stimulus-responsive drug delivery systems for controlled release of therapeutic agents at target sites. In this study, we developed mesoporous silica nanoparticles (MSNs) coated with polyacrylic acid (PAA), and pH-sensitive lipid (PSL) for synergistic delivery and dual-pH-responsive sequential release of arsenic trioxide (ATO) and paclitaxel (PTX) (PL-PMSN-PTX/ATO). Tumor-targeting peptide F56 was used to modify MSNs, which conferred a target-specific delivery to cancer and endothelial cells under neoangiogenesis. PAA- and PSL-coated nanoparticles were characterized by TGA, TEM, FT-IR, and DLS. The drug-loaded nanoparticles displayed a dual-pH-responsive (pHe = 6.5, pHendo = 5.0) and sequential drug release profile. PTX within PSL was preferentially released at pH = 6.5, whereas ATO was mainly released at pH = 5.0. Drug-free carriers showed low cytotoxicity toward MCF-7 cells, but ATO and PTX co-delivered nanoparticles displayed a significant synergistic effect against MCF-7 cells, showing greater cell-cycle arrest in treated cells and more activation of apoptosis-related proteins than free drugs. Furthermore, the extracellular release of PTX caused an expansion of the interstitial space, allowing deeper penetration of the nanoparticles into the tumor mass through a tumor priming effect. As a result, FPL-PMSN-PTX/ATO exhibited improved in vivo circulation time, tumor-targeted delivery, and overall therapeutic efficacy.

Characteristics and clinical influence factors of arsenic species in plasma and their role of arsenic species as predictors for clinical efficacy in acute promyelocytic leukemia (APL) patients treated with arsenic trioxide.

Background: Arsenic trioxide (ATO) is successfully applied to treat acute promyelocytic leukemia (APL). Arsenic species levels in blood are critical to reveal metabolic mechanism and relationship between arsenic species and clinical response. Characteristics and influence factors of arsenic species in APL patients have not been studied.Methods: 305 plasma samples from APL patients treated with ATO were analyzed using HPLC-HG-AFS. Trough concentration (Ctrough), distribution, methylation levels of arsenic species were evaluated. The influence factors on arsenic species levels of plasma and association between arsenic concentrations and clinical efficacy were explored.Results: Ctrough of arsenic in effective treatment groups provide basis for defining the target range of arsenic plasma concentrations in APL patients treated with ATO. Distribution trends: DMAV > AsIII, MMAV> AsV (p < 0.0001) for continuous slow-rate (CS) infusion and DMAV > MMAV > AsIII > AsV (p < 0.0001) for conventional infusion. Infusion methods and combined medication may affect arsenic metabolism. There was a weak correlation between ATO dose and plasma Ctrough of arsenic species. Ctrough of plasma arsenic species had predictive value for treatment efficacy.Conclusion: Arsenic concentration monitoring in APL patients treated with ATO is required. These findings are critical to optimize treatment outcomes of ATO therapy.

Angiopep-2-modified calcium arsenite-loaded liposomes for targeted and pH-responsive delivery for anti-glioma therapy.

The blood-brain barrier (BBB) is the most critical obstacle in the treatment of central nervous system disorders, such as glioma, the most typical type of brain tumor. To overcome the BBB and enhance drug-penetration abilities, we used angiopep-2-modified liposomes to deliver arsenic trioxide (ATO) across the BBB, targeting the glioma. Angiopep-2-modified calcium arsenite-loaded liposomes (A2-PEG-LP@CaAs), with uniformly distributed hydrodynamic diameter (96.75 ± 0.57 nm), were prepared using the acetate gradient method with high drug-loading capacity (7.13 ± 0.72%) and entrapment efficiency (54.30 ± 9.81%). In the acid tumor microenvironment, arsenic was responsively released, thereby exerting an anti-glioma effect. The anti-glioma effect of A2-PEG-LP@CaAs was investigated both in vitro and in vivo. As a result, A2-PEG-LP@CaAs exhibited a potent, targeted anti-glioma effect mediated by the lipoprotein receptor-related (LRP) receptor, which is overexpressed in both the BBB and glioma. Therefore, A2-PEG-LP@CaAs could dramatically promote the anti-glioma effect of ATO, as a promising strategy for glioma therapy.

Prenatal arsenic exposure interferes in postnatal immunocompetence despite an absence of ongoing arsenic exposure.

Arsenic (As) readily crosses the placenta and exposure of the fetus may cause adverse consequences later in life, including immunomodulation. In the current study, the question was asked how the immune repertoire might respond in postnatal life when there is no further As exposure. Here, pregnant mice (Balb/c [H-2d]) were exposed to arsenic trioxide (As2O3) through their drinking water from time of conception until parturition. Their offspring, 4-week-old mice who had not been exposed again to As, were used for functional analyses of innate, humoral and cellular immunity. Compared to cells from non-As-exposed dam offspring, isolated peritoneal macro-phages (Mϕ) displayed no differences in T-cell stimulating ability. Levels of circulating IgG2a but not IgG1 were decreased in As-exposed dam offspring as compared to control offspring counterparts. Mixed-leukocyte reactions (MLR) indicated that CD4+ T-cells from the prenatal As-exposed mice were significantly less responsive to allogenic stimulation as evidenced by decreases in interferon (IFN)-γ and IL-2 production and in expression of CD44 and CD69 (but not CD25) activation markers. Interestingly, the Mϕ from the prenatal As-exposed mice were capable of stimulating normal allogenic T-cells, indicating that T-cells from these mice were refractory to allogenic signals. There was also a significant decrease in absolute numbers of splenic CD4+ and CD8+ T-cells due to prenatal As exposure (as compared to control). Lastly, the impaired immune function of the prenatal As-exposed mice was correlated with a very strong susceptibility to Escherichia coli infection. Taken together, the data from this study clearly show that in utero As exposure may continue to perpetuate a dampening effect on the immune repertoire of offspring, even into the early stages of postnatal life.

iRGD and TGN co-modified PAMAM for multi-targeted delivery of ATO to gliomas.

A poly(amidoamine) dendrimer (PAMAM, G5) based drug delivery system was developed for the treatment of glioma. PAMAM was modified with polyethylene glycol (PEG) to improve its in vivo stability and reduce immunogenicity. Further, the internalized RGD (iRGD) recognition ligand of the integrin αvß3 receptor and the blood-brain barrier (BBB)-targeting group TGN were introduced. Arsenic trioxide (ATO) was loaded into the internal cavity through electrostatic interactions to form iRGD/TGN-PEG-PAMAM-ATO. The drug delivery system of iRGD/TGN dual-modified PAMAM, which entrapped ATO, had a high entrapment efficiency of approximately 71.92% ± 1.17% and displayed sustainable acid-dependent drug release. Assessment of antiglioma effects revealed that survival rate was significantly higher in the iRGD/TGN comodified group than in the other groups. Overall, iRGD/TGN-based dual targeting by combining nanocarriers and targeting technology increased the amount of drug that crossed BBB, thus achieving targeted enrichment and activation of the drug in tumor tissue. This activation ultimately increased therapeutic effects and reduced side effects of ATO. This strategy using a multistep-targeted delivery system shows great promise for targeted glioma therapy.

Construction of arsenic-metal complexes loaded nanodrugs for solid tumor therapy: A mini review.

Arsenic trioxide (As2O3), a front-line therapeutic agent against acute promyelocytic leukemia, has a broad spectrum against malignancies. Unfortunately, the clinical application of As2O3 in treating hematological cancers has not been transformed to solid tumors, for its dose-limited toxicity and undesirable pharmacokinetics. The ordinary As2O3 loaded nanodrugs (such as liposomes, polymer micelles, albumin-based nanodrugs, and silica-based nanodrugs, etc.) still could not fuel up pharmaceuticals and eradicate toxicity for low delivery efficiency caused by the instability and severe drug leakage of formulations during circulation. Recently, the approach of forming and delivering arsenic-metal complexes which will dissociate in the tumoral environment caught our mind. This is the most effective strategy to reduce drug leakage in circulation and accumulate arsenite ions in tumor sites, therefore promote the anti-tumor effect and lighten the toxicity of the drug. This review aims to explain the formation mechanism of arsenic-metal nanocomposites and summarize the constructing strategies of the arsenic-metal nanocomplexes (arsenic-nickel, arsenic-manganese, arsenic-platinum, arsenic-gadolinium, arsenic-zinc, and arsenic-iron nanobins) loaded nanodrugs for solid tumor therapy. Furthermore, the expectations and challenges of arsenic-metal complexes containing nanodrugs for cancer therapy in the future were discussed.

Sustained release of arsenic trioxide benefits interventional therapy on rabbit VX2 liver tumor.

The benefit of chemotherapy as a constituent of transcatheter arterial chemoembolization (TACE) is still in debate. Recently we have developed arsenic trioxide nanoparticle prodrug (ATONP) as a new anticancer drug, but its systemic toxicity is a big issue. In this preclinical TACE study, ATONP emulsified in lipiodol behaved as drug-eluting bead manner. Sustained release of arsenic from ATONP within occluded tumor caused very low arsenic level in plasma, avoiding the "rushing out" effect as ATO did. Correspondingly, intratumoral arsenic accumulation and inorganic phosphate deprivation were simultaneously observed, and arsenic concentration was much higher as ATONP was transarterially administered than ATO, or intravenously injected. Tumor necrosis and apoptosis were remarkably more severe in ATONP group than ATO, but no significant hepatic and renal toxicity was perceived. In brief, ATONP alleviated arsenic toxicity and boosted the therapeutic effect of TACE via Pi-activated drug sustainable release.

The ability of arsenic metabolism affected the expression of lncRNA PANDAR, DNA damage, or DNA methylation in peripheral blood lymphocytes of laborers.

Arsenic has been associated with significant effects on human health. Exposure to inorganic arsenic has been associated with the changes in gene expression. Promoter of CDKN1A antisense DNA damage activated RNA (PANDAR) expression is induced by p53 protein and DNA damage response. Here, we investigated whether the ability of arsenic metabolism in individuals affected the expression of PANDAR, DNA damage, and DNA methylation. Levels of gene expression and DNA damage were examined by the quantitative polymerase chain reaction and DNA methylation was measured by the methylation-sensitive high-resolution melting curve. In our study, we demonstrated that arsenic exposure increased PANDAR expression and DNA damage among arsenic smelting plant laborers. The PANDAR expression and DNA damage were positively linked to monomethylarsonic acid % (R = 0.25, p < 0.05 and R = 0.32, p < 0.01) and negatively linked to dimethylarsinic acid % (R = -0.21, p < 0.05 and R = -0.31, p < 0.01). Subjects with low primary methylation index had increased levels of DNA damage (51.62 ± 2.96 vs. 60.93 ± 3.10, p < 0.05) and methylation (17.14 (15.88-18.51) vs. 15.83 (14.82-18.00), p < 0.05). Subjects with low secondary methylation index had increased levels of PANDAR expression (4.88 ± 0.29 vs. 4.07 ± 0.23, p < 0.01) and DNA damage (17.38 (15.88-19.29) vs. 15.83 (14.82-17.26), p < 0.01). DNA methylation of PANDAR gene was linked to the regulation of its expression in peripheral blood lymphocytes among laborers (Y = -2.08 × X + 5.64, p < 0.05). These findings suggested arsenic metabolism ability and exposure affected the expression of PANDAR, DNA damage, and DNA methylation.

Will Arsenic Trioxide Benefit Treatment of Solid Tumor by Nano- Encapsulation?

Arsenic trioxide (ATO) has remarkably enhanced therapeutic efficacy in treating both newly diagnosed and relapsed patients suffering from Acute Promyelocytic Leukemia (APL). Unfortunately, whether as a single agent, component of combined chemotherapy, or as a chemosensitizer or radiosensitizer combined with interventional therapy/radiotherapy, it did not benefit treatment of solid tumor (liver cancer, bladder cancer, glioma, breast cancer, cervical cancer, colorectal cancer, lung cancer, and melanoma) as seen from the clinical trials reported from the published journals or FDA-approved trials in the past decades. The clinical outcome failed to live up to our expectations, which was attributed to severe systemic toxicity and inappropriate pharmacokinetic such as low delivery efficiency and rapid renal elimination. Nanomedicine is designed to fuel up pharmaceuticals and polish off adverse effects by the moderation of their absorption, distribution, metabolism, and excretion. Nevertheless, quite a few nanodrugs (such as Doxil, Abraxane) were approved to be used clinically, and "from bench to bedside" it seems to be no easy way for most of them, such as nano-ATO. Encapsulating ATO into several types of nano-vehicles (liposome, polymer micelle, porous silicon, etc.), nano-TO can improve pharmacokinetic and become a prominent candidate to penetrate into tumor tissue, but so far no nano- ATO clinical trials have been approved around the world. On summarizing the clinical trials of ATO on solid tumor and preclinical study of nano-ATO, it is believed there is still a chance for ATO to play a critical co-helper in a comprehensive therapy to fight with solid tumor.

Use of a Mouse Model and Human Umbilical Vein Endothelial Cells to Investigate the Effect of Arsenic Exposure on Vascular Endothelial Function and the Associated Role of Calpains.

BACKGROUND: Arsenic (As) is a well-known environmental contaminant. Chronic exposure to As is known to increase the risk of cardiovascular diseases, including atherosclerosis, hypertension, diabetes, and stroke. However, the detailed mechanisms by which As causes vascular dysfunction involving endothelial integrity and permeability is unclear. OBJECTIVES: Our goal was to investigate how exposure to As leads to endothelial dysfunction. METHODS: Arsenic trioxide (ATO) was used to investigate the effects and mechanisms by which exposure to As leads to endothelial dysfunction using a mouse model and cultured endothelial cell monolayers. RESULTS: Compared with the controls, mice exposed chronically to As (10 ppb in drinking water supplied by ATO) exhibited greater vascular permeability to Evans blue dye and fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA). In addition, endothelial monolayers treated with ATO ([Formula: see text] As) exhibited greater intracellular gaps and permeability to low-density lipoprotein or transmigrating THP-1 cells. Furthermore, activity and protein levels of calpain-1 (CAPN-1) were significantly higher in aortas and human umbilical vein endothelial cells (HUVECs) treated with ATO. These results were consistent with effects of ATO treatment and included a rapid increase of intracellular calcium ([Formula: see text]) and higher levels of CAPN-1 in the plasma membrane. Endothelial cell dysfunction and the proteolytic disorganization of vascular endothelial cadherin (VE-cadherin) in HUVECs in response to ATO were partially mitigated by treatment with a CAPN-1 inhibitor (ALLM) but not a CAPN-2 inhibitor (Z-LLY-FMK). CONCLUSIONS: This study found that in mice and HUVEC models, exposure to ATO led to CAPN-1 activation by increasing [Formula: see text] and CAPN-1 translocation to the plasma membrane. The study also suggested that inhibitor treatment may have a role in preventing the vascular endothelial dysfunction associated with As exposure. The findings presented herein suggest that As-induced endothelial dysfunction involves the hyperactivation of the CAPN proteolytic system. https://doi.org/10.1289/EHP4538.

ZnAs@SiO2 nanoparticles as a potential anti-tumor drug for targeting stemness and epithelial-mesenchymal transition in hepatocellular carcinoma via SHP-1/JAK2/STAT3 signaling.

Rationale: Current therapies for hepatocellular carcinoma (HCC) are hampered by treatment failure and recurrence due to the remaining treatment-resistant liver cancer stem cells (CSCs). Stemness and epithelial-mesenchymal transition (EMT) are regarded as two fundamental characteristics of liver CSCs necessary for cancer progression; thus, drugs that simultaneously target both characteristics should prove effective in eliminating HCC and impeding recurrence. In this study, we developed new arsenic trioxide (ATO)-based nanoparticles (NPs), which are expected to be more effective than the current HCC therapy, and explored their potential mechanism. Methods: A "one-pot" reverse emulsification approach was employed to prepare the ZnAs@SiO2 NPs. HCC cell lines, MHCC97L and Hep3b, were used to analyze the antitumor activity of ZnAs@SiO2 NPs in vitro and in vivo by quantifying cell growth and metastasis as well as to study the effect on stemness and EMT. SHP-1 siRNA was used to validate the role of the SHP-1/JAK2/STAT3 signaling pathway in mediating inhibition of stemness and EMT by ZnAs@SiO2. Results: Compared with the current ATO treatment, ZnAs@SiO2 NPs promoted apoptosis and significantly inhibited proliferation, migration, and invasion of both MHCC97L and Hep3b cells. In the in vivo assay, ZnAs@SiO2 NPs inhibited tumor growth by 2.2-fold and metastasis by 3.5-fold as compared to ATO. The ZnAs@SiO2 NPs also inhibited tumor spheroid formation in vitro and tumor initiation in vivo and induced significant changes in the expression of stemness markers (CD133, Sox-2, and Oct-4) and EMT markers (E-cadherin, Vimentin, and Slug) both in vitro and in vivo. These effects of ZnAs@SiO2 that correlated with prognosis of HCC were mediated by the SHP-1/JAK2/STAT3 signaling. Conclusions: ZnAs@SiO2 NPs can effectively suppress tumor initiation, growth, metastasis, and inhibit stemness and EMT through regulation of SHP-1/JAK2/STAT3 signaling pathway in liver cancer cells in vitro and in vivo. Thus, ZnAs@SiO2 NPs have immense potential for HCC treatment in the future.

The simpler, the better: oral arsenic for acute promyelocytic leukemia.

Arsenic trioxide and all-trans retinoic acid have become the frontline treatments for patients with acute promyelocytic leukemia (APL). Despite the long wait for an oral arsenic drug, a commercially available agent, realgar-indigo naturalis formula (RIF), was not launched in China until 2009. Since then, over 5000 APL patients have been treated with oral RIF in China. Oral arsenic not only shows a clinical efficacy comparable to that of IV formulations but also displays a better safety profile, improved quality of life, and lower medical costs for patients. The promising results promote incorporating an outpatient postremission therapy model into clinical practice for both low-risk and high-risk APL patients in China. In this review, we discuss the evolution of oral arsenic RIF in the treatment of APL, with a special focus on how to address the related complications during induction therapy.

Time course of arsenic species in red blood cells of acute promyelocytic leukemia (APL) patients treated with single agent arsenic trioxide.

BACKGROUND: Arsenic trioxide (ATO) is widely applied to treat acute promyelocytic leukemia (APL). To elucidate metabolism and toxicity of arsenic, we analyzed time course of arsenic species in red blood cells (RBCs) of APL patients. METHODS: Nine APL patients received ATO (0.16 mg/kg/day) through 18-h infusion. Blood was collected before daily administration (days 2 to 9), and at different time points on day 8. Inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were detected by HPLC-ICP-MS. RESULTS: Arsenic species reached Cmax at 18 h on day 8. Arsenicals gradually accumulated during days 2 to 9, whereas their percentages remained almost constant. The general trend in red blood cells (RBCs) was iAs > MMA > DMA. MMA was consistently the predominant methylated arsenic metabolite in RBCs. iAs, MMA, and tAs (tAs = iAs + DMA + MMA) concentrations (P < 0.0001), MMA/DMA ratios (P = 0.0016) and iAs% (P = 0.0013) were higher in RBCs than in plasma. CONCLUSIONS: Time course of arsenic species reveal kinetic characteristic of ATO metabolites in RBCs. Arsenic species accumulated with administration frequency. Arsenic species in RBCs were remarkably different from those in plasma. Time course of arsenic species in RBCs is important in ATO clinical application.

An Overview on Arsenic Trioxide-Induced Cardiotoxicity.

Arsenic trioxide (ATO) is among the first-line chemotherapeutic drugs used in oncological practice. It has shown substantial efficacy in treating patients with relapsed or refractory acute promyelocytic leukaemia. The clinical use of ATO is hampered due to cardiotoxicity and hence many patients are precluded from receiving this highly effective treatment. An alternative to this would be to use any drug that can ameliorate the cardiotoxic effects and allow exploiting the full therapeutic potential of ATO, with considerable impact on cancer therapy. Generation of reactive oxygen species is involved in a wide range of human diseases, including cancer, cardiovascular, pulmonary and neurological disorders. Hence, agents with the ability to protect against these reactive species may be therapeutically useful. The present review focuses on the beneficial as well as harmful effects of arsenic and ATO, the mechanisms underlying ATO toxicity and the possible ways that can be adopted to circumvent ATO-induced toxicity.

Pharmacokinetic Properties of Arsenic Species after Intravenous and Intragastrical Administration of Arsenic Trioxide Solution in Cynomolgus Macaques Using HPLC-ICP-MS.

A rapid and sensitive method was established for arsenic (As) speciation based on high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). This method was validated for the quantification of four arsenic species, including arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) in cynomolgus macaque plasma. Separation was achieved in just 3.7 min with an alkyl reverse phase column and highly aqueous mobile phase containing 20 mM citric acid and 5 mM sodium hexanesulfonate (pH = 4.3). The calibration curves were linear over the range of 5⁻500 ng·mL-1 (measured as As), with r > 0.99. The above method was validated for selectivity, precision, accuracy, matrix effect, recovery, carryover effect and stability, and applied in a comparative pharmacokinetic study of arsenic species in cynomolgus macaque samples following intravenous and intragastrical administration of arsenic trioxide solution (0.80 mg·kg-1; 0.61 mg·kg-1 of arsenic); in addition, the absolute oral bioavailability of the active ingredient AsIII of arsenic trioxide in cynomolgus macaque samples was derived as 60.9 ± 16.1%.

Effect of continuous venovenous haemodialysis on outcome and pharmacokinetics of arsenic species in a patient with acute promyelocytic leukaemia and acute kidney injury.

This study presents outcome and pharmacokinetics of arsenic trioxide (ATO) metabolites in patients on continuous venovenous haemodialysis (CVVHD). Of 3 acute promyelocytic leukaemia patients receiving CVVHD in management of acute kidney injury, only 1 patient was included. The patient presented disseminated intravascular coagulation and acute kidney injury before induction therapy was conducted. CVVHD was performed and ATO was initiated. Species of ATO metabolites in plasma and effluent were analysed using high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry. Plasma concentrations of AsIII , monomethylarsonic acid and dimethylarsinic acid with CVVHD were lower than those without CVVHD. Area under the concentration-time curve from 0 to the last sample with quantifiable concentration of AsIII without CVVHD was significantly higher than that with CVVHD (292.10 ng h/mL vs 195.86 ng h/mL, P = .037), which were not observed for monomethylarsonic acid and dimethylarsinic acid. Dialysate saturation of arsenic species was remarkable, especially for AsIII . Complete remission was achieved and renal function recovered. In this study, ATO can be used safely and effectively to treat acute promyelocytic leukaemia patients undergoing CVVHD without dose adjustment.

Clinical pharmacokinetics and safety profile of single agent arsenic trioxide by continuous slow-rate infusion in patients with newly diagnosed acute promyelocytic leukemia.

PURPOSE: This study evaluated pharmacokinetics (PK) and safety profiles of single agent arsenic trioxide (ATO, As2O3) administrated as continuous slow-rate infusion in patients with newly diagnosed acute promyelocytic leukemia. PATIENTS AND METHODS: Patients received 0.16 mg/kg ATO per day. ATO was given for 40 min infusion on the first day followed by 18-20 h daily at a very slow rate with infusion speed of 8 drips/min. During the first week, plasma samples were collected immediately before next administration on each day, and 0.5, 1, 2, 4, 8, 12 h after administration, at the end of infusion (18 h) on day 7. Total arsenic was determined by ICPMS. Arsenic species, arsenious acid (AsIII) and its metabolites, monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV), were quantified by UHPLC-ICPMS. Safety assessment and PK analysis was conducted. RESULTS: Hyperleukocytosis occurred in two patients and no severe toxicity was observed. Total arsenic gradually accumulated from 15.84 to 34.12 ng/mL during the first week of therapy. MMAV/iAs increased and remained stable at value about 0.6 after day 4, while DMAV/MMAV declined under 2 after day 4. Compared with 2 h infusion, clearance (CL) of AsIII was significantly lower (0.8 ± 0.2 vs. 2.7 ± 1.7 L/kg/h, P = 0.002) while AUC0-t of AsIII was significantly increased (213.9 ± 38.6 vs. 82.6 ± 55.7 L/kg/h, P = 0.028). CONCLUSION: Continuous slow-rate ATO infusion provided an alternative administration for ATO therapy with few toxic effects. Degree of methylation from MMA to DMA is inconsistent with that from iAs to MMA. PK of arsenic species is considered important for clinical use of ATO.