Administration Of Arsenic Trioxide Research Articles

A Phase I Dose-Escalation Study of Combination Decitabine, Arsenic Trioxide and Ascorbic Acid In Patients with MDS and AML

AbstractAbstract 2148 Introduction:Myelodysplastic syndrome (MDS) and Acute Myeloid Leukemia (AML) are hematological disorders that exist on a spectrum of ineffective and malignant hematopoiesis. Hypomethylating agents have been recently shown to result in clinical response and improved survival in patients with either disease, although only in a minority of patients. Arsenic trioxide too has shown limited single agent activity in patients with MDS and AML, and ascorbic acid improves response to arsenic trioxide in patients with multiple myeloma. We therefore sought to assess the tolerability of combination decitabine, arsenic and ascorbic acid in patients with MDS and AML. Study:The primary object of this single institution, dose-escalation study was to establish the maximum tolerated dose and dose-limiting toxicities during four cycles of therapy. Arsenic trioxide was administered in three dose cohorts of 3–6 patients each: 0.1 mg/kg, 0.2 mg/kg, and 0.3 mg/kg IV on days 1–5 followed by weekly administration for 15 weeks. All patients received decitabine 20 mg/m2 IV on days 1–5 every 28 days and ascorbic acid 1000 mg IV following every administration of arsenic trioxide. Secondary objectives were to establish overall response rates and effect of therapy on bone marrow angiogenesis. Results:Thirteen patients were enrolled in three dose cohorts [9 men, 4 women; median age: 67 (range 24 – 77); 5 MDS, 7 AML; ECOG 0 (46%), 1 (38%), 2 (15%)]. Most patients were transfusion dependent [RBC dependent: MDS 4/5, AML 4/7; platelet dependent: MDS 2/5, AML 4/7]. Most patients had received prior therapy [MDS 1/5; AML 7/7]. Ten patients received at least 2 cycles with four patients completing four cycles. Dose limiting toxicities were pneumonia/infection, which occurred in the third dosing cohort. Other grade 3–4 toxicities occurring during 4 cycles of treatment were: infection (46%), hypotension (15%), hypoxia/pneumonia (20%), anemia (53%), neutropenia (38%), QTc prolongation (15% - all asymptomatic), pericardial effusion (8%), pleural effusion (8%), hyperglycemia (20%), hypokalemia (8%). According to IWG response criteria, 2/5 MDS patients achieved stable disease, 2/5 developed progressive disease, and 1/5 withdrew prior to reevaluation. Similarly, 3/7 AML patients achieved stable disease, 2/7 progressive disease, and 2/7 died without repeat bone marrow evaluation. No transfusion dependent patients achieved transfusion independence. The median overall survival of these cohorts was 207 days and four patients remain alive with a median follow-up of 490 days. We did not observe a correlation between dosing cohort and response or survival.Because arsenic trioxide has been proposed to inhibit angiogenesis, we assessed bone marrow microvessel density (MVD) using CD34 immunohistochemistry by two binded, independent reviewers. Paired bone marrow samples from eight patients surprisingly revealed an increase in the number of vessels per high powered field during therapy [pre-treatment: (ave 10.3, stdev 5.2); after cycle 2: (ave 18.0, stdev 7.0, p = 0.06); after cycle 4: (ave 17.1, stdev 3.2, p = 0.05)]. Increased MVD occurred independent of response, disease or bone marrow cellularity. Conclusions:This study demonstrates that decitabine can be safely combined with arsenic trioxide and ascorbic acid in a heavily pre-treated population of MDS and AML patients. Our maximum tolerated dose of arsenic was observed in cohort 2: 0.2 mg/kg. Combination therapy resulted in increased bone marrow microvessel density, independent of response and bone marrow cellularity. Phase 2 studies will be required to assess the efficacy of combination therapy. Disclosures:Off Label Use: Decitabine, Arsenic and Ascorbic acid for the treatment of AML. Vij: Eisai: Speakers Bureau; Cephalon: Speakers Bureau.

Nuclear Factor-κB is a Potential Therapeutic Target in Cystitis (142.9)

Abstract NF-κB has been shown to be activated in various inflammatory disorders or by physical and chemical stress. NF-κB regulates the transcriptional of genes important for chronic inflammation and drug resistance. Interstitial cystitis (IC) affects millions of women and is characterized by severe pain and chronic inflammation. Etiology and the mechanisms involved in pathogenesis of IC are still a matter of obscure. Animal models of IC and role of NF-κB as a therapeutic target in the IC have not been elucidated. Using transgenic NF-κB-Luciferase Tag female mice, we performed serial, noninvasive in vivo and ex vivo molecular imaging of NF-κB activation in the mouse body after administration of arsenic trioxide (5 mg/kg), LPS (2 mg/kg), or cyclophosphamide (CYC, 200 mg/kg) to initiate transient cystitis. Pretreatment with dexamethasone (DEX) (10 mg/kg) was used to modulate the chemical-induced NF-κB-dependent luminescence. Treatment of NF-κB-Luc mice with chemicals increased luminescence in a time- and organ-specific manner. Highest levels of bladder NF-κB-dependent luminescence were observed 4 hr after CYC administration. Pretreatment with DEX 1 hr before injection of CYC significantly down-regulated CYC-induce bladder NF-κB-dependent luminescence and gross anatomy signs of cystitis. The molecular imaging of NF-κB activity might be an attractive approach to distinguish the role of NF-κB signaling in transient cystitis and select potential candidate drugs for treatment of the IC.

Intravenous Administration of Arsenic Trioxide Encapsulated in Liposomes Inhibits the Growth of C6 Gliomas in Rat Brains

Arsenic trioxide (ATO) is a potent anti-tumor agent used to treat acute promyelocytic leukemia (APL), and more recently solid tumors including gliomas. However, the dose of ATO required to suppress gliomas is markedly higher than that used to treat APL, which leads to toxicity and undesirable side-effects, even though the local concentration of ATO in brains is relatively low after systemic administration. In an attempt to minimize the toxicity, enhance the penetrating activity across the bloodbrain barrier, and reduce enzyme degradation, we prepared ATO encapsulated in liposomes, and investigated its therapeutic effect on C6 gliomas established in rat brains. The prepared ATO liposomes were stable at room temperature for 3 days and the latency rate was over 90% within 72 h. Intravenous injection of ATO liposomes led to a much higher concentration of ATO (5- fold, compared with ATO solution) in rat brains, resulting in inhibition of C6 gliomas in brains and prolonging the survival of rats bearing brain gliomas. ATO-liposome therapy resulted in fewer side effects, compared with free ATO solution. ATO-liposome therapy inhibited tumor angiogenesis by downregulating the expression of vascular endothelial growth factor (VEGF), and inducing cell apoptosis. The results warrant future investigation of the use of ATO encapsulated in liposomes to treat gliomas.

CT Perfusion for Determination of Pharmacologically Mediated Blood Flow Changes in an Animal Tumor Model1

To prospectively compare single- and multisection computed tomographic (CT) perfusion for tumor blood flow determination in an animal model. All animal protocols and experiments were approved by the institutional animal care and use committee before the study was initiated. R3230 mammary adenocarcinoma was implanted in 11 rats. Tumors (18-20 mm) were scanned with dynamic 16-section CT at baseline and after administration of arsenic trioxide, which is known to cause acute reduction in blood flow. The concentration of arsenic was titrated (0-6 mg of arsenic per kilogram of body weight) to achieve a defined blood flow reduction (0%-75%) from baseline levels at 60 minutes, as determined with correlative laser Doppler flowmetry. The mean blood flow was calculated for each of four 5-mm sections that covered the entire tumor, as well as for the entire tumor after multiple sections were processed. Measurements obtained with both methods were correlated with laser Doppler flowmetry measurements. Interobserver agreement was determined for two blinded radiologists, who calculated the percentage of blood flow reduction for the "most representative" single sections at baseline and after arsenic administration. These results were compared with the interobserver variability of the same radiologists obtained by summing blood flow changes for the entire tumor volume. Overall correlations for acute blood flow reduction were demonstrated between laser Doppler flowmetry and the two CT perfusion approaches (single-section CT, r=0.85 and r(2)=0.73; multisection CT, r=0.93 and r(2)=0.87; pooled data, P=.01). CT perfusion disclosed marked heterogeneity of blood flow, with variations of 36% +/- 13 between adjacent 5-mm sections. Given these marked differences, interobserver agreement was much lower for single-section CT (standard deviation, 0.22) than for multisection CT (standard deviation, 0.10; P=.01). Multisection CT perfusion techniques may provide an accurate and more reproducible method of tumor perfusion surveillance than comparison of single representative tumor sections.

Arsenic Trioxide in Hematological Malignancies: The New Discovery of an Ancient Drug

Currently, Arsenic Trioxide (ATO) is considered the treatment of choice for patients with relapsed acute promyelocytic leukemia (APL). Recently, a durable remission with minimal toxicity by single agent ATO or ATO + ATRA in newly diagnosed APL was reported by different groups. These regimens have minimal toxicity and can be administered on an outpatient basis after remission induction, thus they could become a real, less toxic and more economic option to ATRA + anthracyclines in particular in low risk APL, or in patients that cannot undergo chemotherapy because of age or comorbid conditions and in patients that refuse chemotherapy. Significantly, these therapies are a successful attempt to cure a tumoral disease without chemotherapy. The results of clinical trials of ATO administration as single agent in multiple myeloma (MM) and myelodisplastic syndromes (MDS) were encouraging and showed clinical effects but they were not close to APL success. On the contrary, results of clinical trials to treat non-APL acute myeloid leukemia (AML) were disappointing. We suggest that a combination therapy with drugs targeting specific pro-survival molecules or capable to enhance pro-apoptotic pathways may lead to an improvement of ATO efficacy against hematological malignancies, in particular AML. Our pre-clinical studies showed that ATO is capable to induce cell death in acute leukemia cells but the apoptotic function is limited since it can induce also a mechanism of cell defense by activating pro-survival molecules such as MEK-ERK, Bcl-xL, Bcl-2. By combining ATO with specific MEK inhibitors, we demonstrated that the block of MEK-ERK phosphorylation, the induction of Bad de-phosphorylation, and activation of p53AIP1 apoptotic pathway interrupt the pro-survival mechanisms of ATO and kill the leukemic cells by apoptotic synergism. Our results provide an experimental basis for combined or sequential treatment with MEK inhibitors and ATO in AML. The renaissance of ATO as a drug in moderne medicine may be considered, together with ATRA success, a victory of empirical analysis, that had (and has) great impact on Chinese culture.

Recurrent Extramedullary Relapse of Acute Promyelocytic Leukemia after Allogeneic Stem Cell Transplantation: Successful Treatment by Arsenic Trioxide in Combination with Local Radiotherapy

Isolated extramedullary relapse is rare in patients with acute promyelocytic leukemia (APL) after allogeneic stem cell transplantation (SCT), and an optimal therapy for it has not been established. We describe a patient with APL who developed serially occurring extramedullary disease (EMD) after SCT. We confirmed that EMD had arisen from the recipient's APL blasts by detecting t(15;17) and PML/RARalpha from the tumor cell suspension. The patient displayed EMD 4 times at different sites. Administration of all-trans retinoic acid with local radiotherapy and with chemotherapy for the first to third EMDs resulted in regression of the tumors. However, these regimens did not prevent the subsequent occurrence of new EMD. For the fourth EMD, intravenous administration of arsenic trioxide followed by local radiotherapy resulted in the disappearance of EMD, and no further EMD has developed to date. In the present case, the bone marrow was in morphologic and molecular remission during the course of recurrent EMD. The accumulation of detailed cases is needed to elucidate the pathogenesis, predisposing factors, and optimal therapy for EMD in APL after SCT.

Perfusion and diffusion MRI in the assessment of the antivascular effect of arsenic trioxide combined with radiotherapy for glioblastoma multiforme: NABTT phase I study

1538 Background: Significant tumor control and prolongation of survival have been demonstrated by combined use of radiosurgery and antivascular agent, Arsenic Trioxide (ATO), in rodent gliosarcoma model in rats. This agent is now undergoing clinical evaluation in the NABTT Brain Tumor Consortium in a Phase I trial with ATO dose escalation in combination with fractionated radiation therapy. Since this agent showed rapid effect on the tumor vasculature in the animal studies, MRI perfusion and diffusion studies were performed shortly following ATO administration. Methods: The patients were treated with external beam radiotherapy 60 Gy in 6 weeks with ATO at a starting dose of 0.25 mg/kg once a week during the course radiotherapy. ATO dose was escalated by 0.05 mg. The perfusion images were acquired using a Echo Planar Image (EPI) sequence. Perfusion parameters were Mean Transit Time (MTT), relative Cerebral Blood Volume (rCBV), and relative Cerebral Blood Flow (rCBF). The perfusion parameter values under regions of interest (ROI) from the enhancing and non-enhancing portions of the lesion were then followed serially during treatment. Results: There was a delay on mean transit time (MTT) and relative cerebral flow (rCBF) by ATO and radiotherapy, compared to counterpart normal brain. This effect was apparent within 24 hours of ATO infusion. The extent and duration of these changes will be correlated with conventional measures of outcome, such as lesion volumes, response, and time to tumor progression (TTP). There were no dose limiting toxicities with doses of ATO as high as 0.35 mg/kg once a week. Conclusions: A total of 12 patients were treated with this phase I trial. At the doses studied thus far, ATO combined with radiotherapy appears safe in the treatment of glioblastoma multiforme. ATO induced a differential delay of blood flow in the tumor compared to the normal brain. ATO showed the immediate effects and serial evaluation highlights the dynamic nature of the intratumoral vasculature in response to ATO, antivascular agent. No significant financial relationships to disclose.

On-line coupling of microdialysis sampling with high performance liquid chromatography and hydride generation atomic absorption spectrometry for continuous in vivo monitoring of arsenic species in the blood of living rabbits

An automated on-line method has been developed for the continuous in vivo monitoring of arsenic species, including arsenite (AsIII), arsenate (AsV), monomethvlarsonic acid (MMA) and dimethvlarsinic acid (DMA), in the blood of living rabbits. The method is based on microdialysis sampling, high performance liquid chromatography (HPLC) separation and hydride generation atomic absorption spectrometry (HGAAS) detection. Dialysates perfused through an implanted microdialysis probe were collected in the sample loop of an on-line injector for direct and automated injection into an HPLC system hyphenated with HGAAS. Operating under optimal conditions, the detection limit was found to be 2.0, 2.9, 2.4 and 4.2 ng/ml for AsIII, MMA, DMA and AsV, respectively. Typical precision values of 7.0% (AsIII), 7.0% (MMA), 5.1% (DMA) and 8.7% (AsV) were obtained, respectively at a concentration level of 10 ng/ml. Spike recoveries close to 100%, relative to an aqueous standard, were obtained for each species. The average in vivo recoveries of AsIII, MMA, DMA and AsV in the blood of living rabbits were 5.7, 12.4, 8.9, and 11.0%, respectively. The use of an on-line microdialysis–HPLC–HGAAS system permitted the continuous monitoring, with a temporal resolution of 20 min sampling, of four arsenic species in the blood of living rabbits treated with arsenic trioxide. Based on our results, we present here the first finding, to the best of our knowledge of the distribution of arsenite in the blood of a living organism after administration of arsenic trioxide.

三酸化二砒素とHyperthermiaの併用する処理順番の違いによる腫瘍成長抑制効果の比較

三酸化二砒素とHyperthermiaの併用する処理順番の違いによる腫瘍成長抑制効果の比較

Antibody binding capacity for evaluation of MDR-related proteins in acute promyelocytic leukemia: Onset versus relapse expression.

Multidrug resistance (MDR) remains a major obstacle for successful treatment in cancer, in particular in acute leukemia. In acute promyelocytic leukemia (APL), the high sensitivity to anthracyclines appears to be attributable to the low frequency of MDR proteins overexpression at onset even if 30% of patients still relapse and become resistant to therapy. In attempt to explain different blast cell sensitivity, we studied the expression of PGP, MRP1, MRP2, and LRP in 45 cases of APL, comparing onset of disease with relapse. PGP, LRP, and MRP on bone marrow or peripheral blood blast cells were evaluated by flow cytometry using the MRK-16, LRP-56, MRP-m6, and MRP2 antibodies and results expressed by the mean fluorescence index (MFI). The antibody binding capacity (ABC) for each MDR protein was also calculated. At diagnosis, only 2 of 45 patients overexpressed PGP and 1 overexpressed LRP. PGP and LRP overexpressing cases significantly grew up during disease progression and at second relapse mean PGP MFI and mean LRP MFI were significantly higher than at onset (P = 0.001 and P = 0.008, respectively). By analyzing ABC, the same trend was more evident because a significant increment of PGP and LRP was observed at second (P = 0.002 and P = 0.002, respectively), but even at first relapse (P = 0.018 and P = 0.002, respectively). No changes were demonstrated in MRP1 and MRP2 expression in any phase of disease considered. Our data confirm the low expression at diagnosis of proteins related to development of drug resistance in APL. The evidence of a relative easy induction of PGP and LRP, but not of MRP, can be useful in choosing drugs to employ for consolidation or rescue therapy.

In vivo genotoxicity evaluation of dimethylarsinic acid in Muta™Mouse

Dimethylarsinic acid (DMA) induces DNA damage in the lung by formation of various peroxyl radical species. The present study was conducted to evaluate whether arsenite or its metabolite, DMA, could initiate carcinogenesis via mutagenic DNA lesions in vivo that can be attributed to oxidative damage. A transgenic mouse model, Muta™Mouse, was used in this study and mutations in the lacZ transgene and in the endogenous cII gene were assessed. When DMA was intraperitoneally injected into Muta™Mice at a dose of 10.6 mg/kg per day for 5 consecutive days, it caused only a weak increase in the mutant frequency (MF) of the lacZ gene in the lung, which was at most 1.3-fold higher than in the untreated control animals. DMA did not appreciably raise the MF in the bladder or bone marrow. Further analysis of the cII gene in the lung, the organ in which DMA induced the DNA damage, revealed only a marginal increase in the MF. Following DMA administration, no change in the cII mutation spectra was observed, except for a slight increase in the G:C to T:A transversion. Administration of arsenic trioxide (arsenite) at a dose of 7.6 mg/kg per day did not result in any increase in the MF of the lacZ gene in the lung, kidney, bone marrow, or bladder. Micronucleus formation was also evaluated in peripheral blood reticulocytes (RETs). The assay for micronuclei gave marginally positive results with arsenite, but not with DMA. These results suggest that the mutagenicity of DMA and arsenite might be too low to be detected in the Muta™Mouse.

The alteration of mitochondria is an early event of arsenic trioxide induced apoptosis in esophageal carcinoma cells.

It is accepted that inorganic arsenic trioxide is an inducer of apoptosis for many types of cancer. Our previous studies have demonstrated that arsenic trioxide induces apoptosis of esophageal carcinoma cells. Administration of arsenic trioxide results in the inhibition of growth and survival of tumor cells. Esophageal carcinoma cells treated with arsenic trioxide for 3 days demonstrated a typical morphological appearance of apoptosis. To further examine molecular mechanism of arsenic trioxide induced apoptosis of esophageal carcinoma cells, we have investigated the early changes of the apoptotic cell induced by arsenic trioxide. Our results indicated that arsenic trioxide induced apoptosis of esophageal carcinoma cells occurs as early as 2 h after treatment. Annexin-v staining has further proved that the phosphatidylserine is exposed at 2 h. The early morphological change of arsenic trioxide treated cells was in the mitochondria. Arsenic trioxide treated cells displayed aggregated mitochondria. It induces accumulation of high electron-density amorphous substances, swollen and disruption of mitochondria in oesophageal carcinoma cells after 2 h treatment. The alteration of mitochondria induced by arsenic trioxide seems to occur before the condensation of chromatin. Thus, our data demonstrated that the primary target of arsenic trioxide induced apoptosis of esophageal carcinoma cells may be the mitochondria. It is possible that arsenic trioxide is a mitochondriotoxic agent.

Effect of S-adenosylmethionine on methylation of inorganic arsenic.

We studied the role of S-adenosylmethionine (SAM) as a methyl group donor in the methylation of inorganic arsenic in mammalians. The SAM and S-adenosylhomocysteine (SAH) levels in the livers of untreated hamsters were 74.3 +/- 8.2 and 40.0 +/- 6.4 nmol/g, respectively. The SAM level was 63.9 +/- 6.5 nmol/g following oral administration of 1.5 mg/kg of arsenic trioxide, which was 14% lower than the control level (t-test, p less than 0.05). This fall of the SAM level in the liver presumably derived from the SAM having acted as a methyl group donor. Oral administration of 1.5 mg/kg of arsenic trioxide once only to hamsters pretreated intraperitoneally with 2.0 mg/kg of SAM once only gave the following arsenic levels in the liver and urine. The dimethylated arsenic (DMA) levels in the livers of hamsters treated with SAM plus arsenic trioxide were significantly high, that is, 2 times as high as the control value at 6 hours, and 1.5 times as high as the control value at 24 hours after the administration of arsenic trioxide. The urinary DMA excretion rate was significantly higher, that is, higher by 36%, than the control value. The urinary DMA excretion rate following pretreatment with SAM was not dose-dependent. Pretreatment with methionine failed to exert any significant acceleratory effect on the methylation of arsenic trioxide. The decreasing pattern of the SAM level in the liver following administration of arsenic trioxide and the DMA behavior in the liver and urine following administration of SAM and arsenic trioxide revealed that SAM accelerated the methylation of inorganic arsenic. In other words, it appeared that SAM could be a very potent methyl group donor to inorganic arsenic.

On the Tissue Distribution and the Excretion of Arsenic in Rats and Rabbits of Administration with Arsenical Compounds

Distribution of arsenic in blood and tissues, and excretion of arsenic in feces and urine after an oral administration of arsenic trioxide (29 mg/kg) or methylarsine sulfide (36 mg/kg) were examined in rats and rabbits. Blood level of arsenic in rats reached the maximum 3 days after a single administration of arsenic trioxide, and decreased at a slow biological half-life of 60 days, but blood concentration of arsenic in rabbits was about 1/80 of that in rats 24 hr after dosing. Distribution of arsenic in rat tissues attained the maximum 2 days, but its content was only 1% of the administered dose. Excretion of arsenic in rat feces was 68.6% during the first 4 days and a trace amount of arsenic was detected in bile. Fecal excretion of arsenic in rabbits was 62.9% and 36.2% during 7 days, respectively, when arsenic trioxide and methylarsine sulfide were given. On the other hand, urinary excretion of arsenic in the rat was only 1.8% of the dose during 30 days after arsenic trioxide administration, but the level of arsenic in rabbit urine was 5.5% and 18.2%, respectively, during 7 days after arsenic trioxide and methylarsine sulfide treatment.