Simultaneous determination of cytosine arabinoside, daunorubicin and etoposide in human plasma

DeSUMOylation of chromatin-bound proteins limits the rapid transcriptional reprogramming induced by daunorubicin in acute myeloid leukemias

Genotoxicants have been used for decades as front-line therapies against cancer on the basis of their DNA-damaging actions. However, some of their non-DNA-damaging effects are also instrumental for killing dividing cells. We report here that the anthracycline Daunorubicin (DNR), one of the main drugs used to treat Acute Myeloid Leukemia (AML), induces rapid (3 h) and broad transcriptional changes in AML cells. The regulated genes are particularly enriched in genes controlling cell proliferation and death, as well as inflammation and immunity. These transcriptional changes are preceded by DNR-dependent deSUMOylation of chromatin proteins, in particular at active promoters and enhancers. Surprisingly, inhibition of SUMOylation with ML-792 (SUMO E1 inhibitor), dampens DNR-induced transcriptional reprogramming. Quantitative proteomics shows that the proteins deSUMOylated in response to DNR are mostly transcription factors, transcriptional co-regulators and chromatin organizers. Among them, the CCCTC-binding factor CTCF is highly enriched at SUMO-binding sites found in cis-regulatory regions. This is notably the case at the promoter of the DNR-induced NFKB2 gene. DNR leads to a reconfiguration of chromatin loops engaging CTCF- and SUMO-bound NFKB2 promoter with a distal cis-regulatory region and inhibition of SUMOylation with ML-792 prevents these changes.

Metabolomics as an Important Tool for Determining the Mechanisms of Human Skeletal Muscle Deconditioning

Muscle deconditioning impairs both locomotor function and metabolic health, and is associated with reduced quality life and increased mortality rates. Despite an appreciation of the existence of phenomena such as muscle anabolic resistance, mitophagy, and insulin resistance with age and disease in humans, little is known about the mechanisms responsible for these negative traits. With the complexities surrounding these unknowns and the lack of progress to date in development of effective interventions, there is a need for alternative approaches. Metabolomics is the study of the full array of metabolites within cells or tissues, which collectively constitute the metabolome. As metabolomics allows for the assessment of the cellular metabolic state in response to physiological stimuli, any chronic change in the metabolome is likely to reflect adaptation in the physiological phenotype of an organism. This, therefore, provides a holistic and unbiased approach that could be applied to potentially uncover important novel facets in the pathophysiology of muscle decline in ageing and disease, as well as identifying prognostic markers of those at risk of decline. This review will aim to highlight the current knowledge and potential impact of metabolomics in the study of muscle mass loss and deconditioning in humans and will highlight key areas for future research.

Pharmacokinetics and pharmacogenetics of liposomal cytarabine in AML patients treated with CPX-351

CPX-351 is a liposome encapsulating cytarabine and daunorubicin for treating Acute Myeloid Leukemia (AML) patients. To what extent differences in cytidine deaminase (CDA) activity, the enzyme that catabolizes free cytarabine in the liver, can affect the pharmacokinetics of liposomal cytarabine as well, is unknown. We have studied the pharmacokinetics (PK) of released, liposomal and total cytarabine using a population-modeling approach in 9 adult AML patients treated with liposomal CPX-351. Exposure levels and PK parameters were compared with respect to the patient's CDA status (i.e., Poor Metabolizer (PM) vs. Extensive Metabolizer (EM)). Overall response rate was 75%, and 56% of patients had non-hematological severe toxicities, including one lethal toxicity. All patients had febrile neutropenia. A large (>60%) inter-individual variability was observed on pharmacokinetics parameters and subsequent drug levels. A trend towards severe toxicities was observed in patients with higher exposure of cytarabine. Results showed that liposomal CPX-351 led to sustained exposure with reduced clearance (Cl = 0.16 L/h) and prolonged half-life (T_1/2 = 28 h). Liposomal nanoparticles were observed transiently in bone marrow with cytarabine levels 2.3-time higher than in plasma. Seven out of 9 patients were PM with a strong impact on the PK parameters, i.e., PM patients showing higher cytarabine levels as compared with EM patients (AUC: 5536 vs. 1784 ng/mL.h), sustained plasma exposure (T_1/2: 33.9 vs. 13.7 h), and reduced clearance (Cl: 0.12 vs. 0.29 L/h). This proof-of-concept study suggests that CDA status has a major impact on cytarabine PK and possibly safety in AML patients even when administered as a liposome.

HPLC methods for quantifying anticancer drugs in human samples: A systematic review

Pharmacokinetic (PK) study of anticancer drugs in cancer patients is highly crucial for dose selection and dosing intervals in clinical applications. Once an anticancer drug is administered, it undergoes various metabolic pathways; to determine these pathways, it is necessary to follow the administered drug in biological samples via different analytical methods. In addition, multi-drug quantification methods in patients undergoing multi-drug regimens of cancer therapy can have several benefits, such as reduced sampling time and analysis costs. In order to collect and categorize these studies, we conducted a systematic review of HPLC methods reported for the analysis of anticancer drugs in biological samples. A systematic search was performed on PubMed Medline, Scopus, and Web of Science databases, and 116 studies were included. In summary of included studies, when the objective of a method was to quantify a single drug, MS, or UV detectors were utilized equivalently. On the other hand, in methods with the aim of quantifying drug and metabolite(s) in a single run, MS detectors were the most utilized. This review can provide a comprehensive insight for researchers prior to developing a quantification method and selecting a detector.

Analysis of daunorubicin and its metabolite daunorubicinol in plasma and urine with application in the evaluation of total, renal and metabolic formation clearances in patients with acute myeloid leukemia

This report presents improved analysis methods of daunorubicin (DAUN) and its metabolite daunorubicinol (DAUNOL) in small volumes of plasma, as total and unbound concentrations, as well as in urine. This study also presents the pharmacokinetics of DAUN and DAUNOL in patients (n = 12) diagnosed with acute myeloid leukemia treated with intravenous DAUN (60 mg/m²/day, for three days). Serial blood and urine samples were collected up to 144 h after the beginning of the first infusion. The analytical methods presented no significant matrix effect. The linear ranges were 0.1-1000 ng/mL in plasma, 0.05-40 ng/mL in ultrafiltrate and 0.5-3000 ng/ml in urine. The precision and accuracy presented coefficients of variation and standard errors lower than 15 % in the three matrices. The methods allowed for the quantification of samples up to 144 h after the beginning of the first infusion. Unbound fractions for DAUN and DAUNOL were 23.91 % (17.33-32.99) and 29.23 % (25.84-33.07), respectively. The fraction recovered in urine was 4.40 % (3.87-5.03) for DAUN and 7.91 % (6.86-9.19) for DAUNOL. Total 292.96 L/h (261.74-327.90), renal 13.01 L/h (11.44-14.88), and hepatic 280.26 L/h (248.40-317.91) clearances of DAUN, as well as the DAUNOL formation clearance 23.41 L/h (19.09-28.97), were evaluated.

Electromembrane extraction of anthracyclines from plasma: Comparison with conventional extraction techniques

Electromembrane extraction (EME) of the polar zwitterionic drugs, anthracyclines (ANT, doxorubicin, daunorubicin and its metabolite daunorubicinol), from rabbit plasma was investigated. The optimized EME was compared to conventional sample pretreatment techniques such as protein precipitation (PP) and liquid-liquid extraction (LLE), mainly in terms of extraction reliability, recovery and matrix effect. In addition, phospholipids profile in the individual extracts was evaluated. The extracted samples were analyzed using UHPLC-MS/MS with electrospray ionization in positive ion mode. The method was validated within the concentration range of 0.25-1000 ng/mL for all tested ANT. Compared with PP and LLE, the EME provided high extraction recovery (more than 80% for all ANT) and excellent sample clean-up (matrix effect were 100 ± 10% with RSD values lower than 4% for all ANT). Furthermore, only negligible amounts of phospholipids were detected in the EME samples. Finally, practical applicability of EME was proved by analysis of plasma samples taken from a pilot in vivo study in rabbits. Consistent results were obtained when using both EME and LLE to extract the plasma prior to the analysis, which further confirmed high reliability of EME. This study clearly showed that EME is a simple, rapid, repeatable technique for extraction of ANT from plasma and it is an up to date alternative to routine conventional extraction techniques.

Slower degradation rate of cytarabine in blood samples from acute myeloid leukemia by comparison with control samples

PURPOSE

Cytarabine, a key chemotherapy agent for acute myeloid leukemia (AML) treatment, is deaminated into inactive uracil-arabinoside by cytidine deaminase. This deamination leads to samples stability issues with respect to clinical pharmacokinetic trials. The aim of our study was to study in vitro cytarabine stability in blood samples obtained from AML patients.

METHODS

Cytarabine quantification was performed using a fully validated LC/MS/MS method. In vitro cytarabine stability was assessed at room temperature over 24 h in samples coming from 14 AML patients and 7 control patients (CTRL) with no hematological malignancy. In vitro concentrations versus time data were analyzed using a noncompartmental approach.

RESULTS

Cytarabine in vitro area under the curve (AUC_IVlast) was 22-fold higher in AML samples as compared to CTRL samples (AML mean (standard deviation (SD)), 51,829 (27,004) h ng/mL; CTRL mean (SD), 2356 (1250) h ng/mL, p = 0.00019). This increase was associated with a prolonged in vitro degradation half-life (t_1/2IVdeg AML mean (SD), 15 (11.8) h; CTRL mean (SD), 0.36 (0.37) h, p = 0.0033). Multiple linear regression analysis showed that AML diagnosis significantly influenced t_1/2IVdeg and AUC_IVlas relationship.

CONCLUSION

Cytarabine stability is higher in AML than in CTRL samples. The absence of correlation between t_1/2IVdeg and AUC_IVlast in AML samples suggests that in vitro cytarabine degradation in AML is complex. These results open perspectives including the evaluation of the clinical relevance and the involved molecular mechanisms.

Simultaneous determination of cytosine arabinoside and its metabolite uracil arabinoside in human plasma by LC-MS/MS: Application to pharmacokinetics-pharmacogenetics pilot study in AML patients

Purine analogs like aracytine (AraC) are a mainstay for treating acute myeloid leukemia (AML). There are marked differences in drug dosing and scheduling depending on the protocols when treating AML patients with AraC. Large inter-patient pharmacokinetics variability has been reported, and genetic polymorphisms affecting cytidine deaminase (CDA), the liver enzyme responsible for the conversion of Ara-C to inactive uracil arabinoside (AraU) could be a culprit for either life-threatening toxicities or poor efficacy related to substantial changes in plasma exposure levels among patients. The quantitative determination of Ara-C in plasma is challenging due the required sensitivity because of the short half-life of this drug (i.e., <10 min) and the metabolic instability in biological matrix upon sampling possibly resulting in erratic values. We developed and validated a liquid chromatography tandem mass spectrometry method (UPLC-MS/MS) for the simultaneous determination of Ara-C and Ara-U metabolite in human plasma. After simple and rapid precipitation, analytes were successfully separated and quantitated over a 1-500 ng/ml range for Ara-C and 250-7500 ng/ml range for AraU. The performance and reliability of this method was tested as part of an investigational study in AML patients treated with low dose cytarabine and confirmed marked differences in drug exposure levels and metabolic ratio, depending on the CDA status of the patients. Overall, this new method meets the requirements of current bioanalytical guidelines and could be used to monitor drug levels in AML patients with respect to their CDA phenotypes.

Antineoplastic drugs and their analysis: a state of the art review

We provide an overview of the analytical methods available for the quantification of antineoplastic drugs in pharmaceutical formulations, biological and environmental samples.

Simultaneous determination of clofarabine and cytarabine in human plasma by LC-MS/MS

Combination of cytostatic agents is a basic principle in the treatment of cancer. For the treatment of acute myeloid leukemia (AML), purine analogs, like clofarabine and cytarabine act synergistically. Little is known, however, on their interaction in vivo. We developed a method for the simultaneous determination of clofarabine and cytarabine in human plasma. The substances were extracted from plasma samples by protein precipitation with acetonitrile. Cladribine was the internal standard (IS). The analytes were separated on Synergi HydroRP column (150mm×2.0mm, 4μm) and a triple-quadrupole mass spectrometry with an electrospray ionisation (ESI) source was applied for detection. The mobile phase consisted of acetonitrile, ammonium acetate 2mM and 0.5% formic acid in a gradient mode at a flow rate of 0.5ml/min. The injection volume was 10μl and the total run time was 6.0min. Retention times were 2.46min for clofarabine, 0.97min for cytarabine and 2.43min for the IS. Calibration ranges were 8-1000ng/ml for clofarabine and 20-2500ng/ml for cytarabine. The intra-day and inter-day precision was less than 15% and the relative standard deviation was all within ±15%. This new method allows a rapid and simple determination of both clofarabine and cytarabine in human plasma. It was applied to a pharmacokinetic investigation within a hematological trial in adult patients with AML.

Nanotherapeutics With Anthracyclines: Methods of Determination and Quantification of Anthracyclines in Biological Samples

Anthracyclines, e.g. doxorubicin, pirarubicin, are widely used as cytostatic agents in the polymer nanotherapeutics designed for the highly effective antitumor therapy with reduced side effects. However, their precise dosage scheme needs to be optimized, which requires an accurate method for their quantification on the cellular level in vitro during nanocarrier development and in body fluids and tissues during testing in vivo. Various methods detecting the anthracycline content in biological samples have already been designed. Most of them are highly demanding and they differ in exactness and reproducibility. The cellular uptake and localization is predominantly observed and determined by microscopy techniques, the anthracycline content is usually quantified by chromatographic analysis using fluorescence detection. We reviewed and compared published methods concerning the detection of anthracycline nanocarriers.

Febrile neutropenia in chemotherapy treated small-cell lung cancer patients

Background.

Chemotherapy with platinum agent and etoposide for small-cell lung cancer (SCLC) is supposed to be associated with intermediate risk (10–20%) of febrile neutropenia. Primary prophylaxis with granulocyte colony-stimulating factors (G-CSFs) is not routinely recommended by the treatment guidelines. However, in clinical practice febrile neutropenia is often observed with standard etoposide/platinum regimen. The aim of this analysis was to evaluate the frequency of neutropenia and febrile neutropenia in advanced SCLC patients in the first cycle of standard chemotherapy. Furthermore, we explored the association between severe neutropenia and etoposide peak plasma levels in the same patients.

Methods.

The case series based analysis of 17 patients with advanced SCLC treated with standard platinum/etoposide chemotherapy, already included in the pharmacokinetics study with etoposide, was performed. Grade 3/4 neutropenia and febrile neutropenia, observed after the first cycle are reported. The neutrophil counts were determined on day one of the second cycle unless symptoms potentially related to neutropenia occurred. Adverse events were classified according to Common Toxicity Criteria 4.0. Additionally, association between severe neutropenia and etoposide peak plasma concentrations, which were measured in the scope of pharmacokinetic study, was explored.

Results.

Two out of 17 patients received primary GCS-F prophylaxis. In 15 patient who did not receive primary prophylaxis the rates of both grade 3/4 neutropenia and febrile neutropenia were high (8/15 (53.3%) and 2/15 (13.3%), respectively), already in the first cycle of chemotherapy. One patient died due to febrile neutropenia related pneumonia. Neutropenic events are assumed to be related to increased etoposide plasma concentrations after a standard etoposide and cisplatin dose. While the mean etoposide peak plasma concentration in the first cycle of chemotherapy was 17.6 mg/l, the highest levels of 27.07 and 27.49 mg/l were determined in two patients with febrile neutropenia.

Conclusions.

Our study indicates that there is a need to reduce the risk of neutropenic events in chemotherapy treated advanced SCLC, starting in the first cycle. Mandatory use of primary G-CSF prophylaxis might be considered. Alternatively, use of improved risk models for identification of patients with increased risk for neutropenia and individualization of primary prophylaxis based on not only clinical characteristics but also on etoposide plasma concentration measurement, could be a new, promising options that deserves further evaluation.

The ROS/SUMO axis contributes to the response of acute myeloid leukemia cells to chemotherapeutic drugs

Chemotherapeutic drugs used in the treatment of acute myeloid leukemias (AMLs) are thought to induce cancer cell death through the generation of DNA double-strand breaks. Here, we report that one of their early effects is the loss of conjugation of the ubiquitin-like protein SUMO from its targets via reactive oxygen species (ROS)-dependent inhibition of the SUMO-conjugating enzymes. Desumoylation regulates the expression of specific genes, such as the proapoptotic gene DDIT3, and helps induce apoptosis in chemosensitive AMLs. In contrast, chemotherapeutics do not activate the ROS/SUMO axis in chemoresistant cells. However, pro-oxidants or inhibition of the SUMO pathway by anacardic acid restores DDIT3 expression and apoptosis in chemoresistant cell lines and patient samples, including leukemic stem cells. Finally, inhibition of the SUMO pathway decreases tumor growth in mice xenografted with AML cells. Thus, targeting the ROS/SUMO axis might constitute a therapeutic strategy for AML patients resistant to conventional chemotherapies.

Analysis of anticancer drugs: a review

In the last decades, the number of patients receiving chemotherapy has considerably increased. Given the toxicity of cytotoxic agents to humans (not only for patients but also for healthcare professionals), the development of reliable analytical methods to analyse these compounds became necessary. From the discovery of new substances to patient administration, all pharmaceutical fields are concerned with the analysis of cytotoxic drugs. In this review, the use of methods to analyse cytotoxic agents in various matrices, such as pharmaceutical formulations and biological and environmental samples, is discussed. Thus, an overview of reported analytical methods for the determination of the most commonly used anticancer drugs is given.

Quantitative liquid chromatographic analysis of anthracyclines in biological fluids

Anthracyclines are amongst the most widely used drugs in oncology, being part of the treatment regimen in most patients receiving systemic chemotherapy. This review provides a comprehensive summary of the sample preparation techniques and chromatographic methods that have been developed during the last two decades for the analysis of the 4 most administered anthracyclines, doxorubicin, epirubicin, daunorubicin and idarubicin in plasma, serum, saliva or urine, within the context of clinical and pharmacokinetic studies or for assessing occupational exposure. Following deproteinization, liquid-liquid extraction, solid phase extraction or a combination of these techniques, the vast majority of methods utilizes reversed-phase C18 stationary phases for liquid chromatographic separation, followed by fluorescence detection, or, more recently, tandem mass spectrometric detection. Some pros and cons of the different techniques are addressed, in addition to potential pitfalls that may be encountered in the analysis of this class of compounds.