scholarly journals Quantification of Plasma and Urine Thymidine and 2’-Deoxyuridine by LC-MS/MS for the Pharmacodynamic Evaluation of Erythrocyte Encapsulated Thymidine Phosphorylase in Patients with Mitochondrial Neurogastrointestinal Encephalomyopathy

2020 ◽  
Vol 9 (3) ◽  
pp. 788 ◽  
Author(s):  
Karin Kipper ◽  
Max Hecht ◽  
Natalicia J. Antunes ◽  
Lynette D. Fairbanks ◽  
Michelle Levene ◽  
...  

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an ultra-rare disorder caused by mutations in TYMP, leading to a deficiency in thymidine phosphorylase and a subsequent systemic accumulation of thymidine and 2’-deoxyuridine. Erythrocyte-encapsulated thymidine phosphorylase (EE-TP) is under clinical development as an enzyme replacement therapy for MNGIE. Bioanalytical methods were developed according to regulatory guidelines for the quantification of thymidine and 2’-deoxyuridine in plasma and urine using liquid chromatography-tandem mass spectrometry (LC–MS/MS) for supporting the pharmacodynamic evaluation of EE-TP. Samples were deproteinized with 5% perchloric acid (v/v) and the supernatants analyzed using a Hypercarb column (30 × 2.1 mm, 3 µm), with mobile phases of 0.1% formic acid in methanol and 0.1% formic acid in deionized water. Detection was conducted using an ion-spray interface running in positive mode. Isotopically labelled thymidine and 2’-deoxyuridine were used as internal standards. Calibration curves for both metabolites showed linearity (r > 0.99) in the concentration ranges of 10–10,000 ng/mL for plasma, and 1–50 µg/mL for urine, with method analytical performances within the acceptable criteria for quality control samples. The plasma method was successfully applied to the diagnosis of two patients with MNGIE and the quantification of plasma metabolites in three patients treated with EE-TP.

2019 ◽  
Vol 8 (4) ◽  
pp. 457 ◽  
Author(s):  
Michelle Levene ◽  
Murray Bain ◽  
Nicholas Moran ◽  
Niranjanan Nirmalananthan ◽  
Joanna Poulton ◽  
...  

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an ultra-rare autosomal recessive disorder of nucleoside metabolism that is caused by mutations in the nuclear thymidine phosphorylase gene (TYMP) gene, encoding for the enzyme thymidine phosphorylase. There are currently no approved treatments for MNGIE. The aim of this study was to investigate the safety, tolerability, and efficacy of an enzyme replacement therapy for the treatment of MNGIE. In this single centre study, three adult patients with MNGIE received intravenous escalating doses of erythrocyte encapsulated thymidine phosphorylase (EE-TP; dose range: 4 to 108 U/kg/4 weeks). EE-TP was well tolerated and reductions in the disease-associated plasma metabolites, thymidine, and deoxyuridine were observed in all three patients. Clinical improvements, including weight gain and improved disease scores, were observed in two patients, suggesting that EE-TP is able to reverse some aspects of the disease pathology. Transient, non-serious adverse events were observed in two of the three patients; these did not lead to therapy discontinuation and they were managed with pre-medication prior to infusion of EE-TP. To conclude, enzyme replacement therapy with EE-TP demonstrated biochemical and clinical therapeutic efficacy with an acceptable clinical safety profile.


Author(s):  
Maria Rincon Nigro ◽  
Jing Ma ◽  
Ololade Tosin Awosemo ◽  
Huan Xie ◽  
Omonike Arike Olaleye ◽  
...  

OJT007 is a methionine aminopeptidase 1 (MetAP1) inhibitor with potent anti-proliferative effects against Leishmania Major. In order to study its pharmacokinetics as a part of the drug development process, a sensitive, specific, and reproducible ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated. Voriconazole was used as the internal standard to generate standard curves ranging from 5 to 1000 ng/mL. The separation was achieved using a UPLC system equipped with an Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 μm) with 0.1% formic acid in acetonitrile and 0.1% formic acid in water as the mobile phase under gradient elution at a flow rate of 0.4 mL/min. The mass analysis was performed with a 4000 QTRAP® mass spectrometer using multiple-ion reaction monitoring (MRM) in the positive mode, with the transition of m/z 325 → m/z 205 for OJT007 and m/z 350 → m/z 101 for voriconazole. The intra- and inter-day precision and accuracy were within ±15%. The mean extraction recovery and the matrix effect were 95.1% and 7.96%, respectively, suggesting no significant matrix interfering with the quantification of the drug in rat plasma. This study was successfully used for the pharmacokinetic evaluation of OJT007 using the rat as an animal model.


2019 ◽  
Vol 8 (8) ◽  
pp. 1096 ◽  
Author(s):  
Bax ◽  
Levene ◽  
Bain ◽  
Fairbanks ◽  
Filosto ◽  
...  

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive disorder which primarily affects the gastrointestinal and nervous systems. This disease is caused by mutations in the nuclear TYMP gene, which encodes for thymidine phosphorylase, an enzyme required for the normal metabolism of deoxynucleosides, thymidine, and deoxyuridine. The subsequent elevated systemic concentrations of deoxynucleosides lead to increased intracellular concentrations of their corresponding triphosphates, and ultimately mitochondrial failure due to progressive accumulation of mitochondrial DNA (mtDNA) defects and mtDNA depletion. Currently, there are no treatments for MNGIE where effectiveness has been evidenced in clinical trials. This Phase 2, multi-centre, multiple dose, open label trial without a control will investigate the application of erythrocyte-encapsulated thymidine phosphorylase (EE-TP) as an enzyme replacement therapy for MNGIE. Three EE-TP dose levels are planned with patients receiving the dose level that achieves metabolic correction. The study duration is 31 months, comprising 28 days of screening, 90 days of run-in, 24 months of treatment and 90 days of post-dose follow-up. The primary objectives are to determine the safety, tolerability, pharmacodynamics, and efficacy of multiple doses of EE-TP. The secondary objectives are to assess EE-TP immunogenicity after multiple dose administrations and changes in clinical assessments, and the pharmacodynamics effect of EE-TP on clinical assessments.


2021 ◽  
Vol 3 (1) ◽  
pp. 169-175
Author(s):  
Xinghua Zhao ◽  
◽  
Jiaojiao Zhang ◽  
Yutong Liang ◽  
Jie Li ◽  
...  

Purpose: A simple, sensitive and specific HPLC–MS/MS method was established to analysis the pharmacokinetics of CB1107 in mouses. Methods: A simple, selective, and sensitive high-throughput liquid chromatography-tandem mass spectrometry (LC-MS-MS) method has been developed and validated for quantitative determination of CB1107 in rat serum.Chromatographic separation was achieved on a Zorbax Extend C18 Rapid Resolution HD column (4.6 mm × 50 mm, 1.8 μm). The column temperature was maintained at 35℃ and at flow rate of 0.6 mL/min. Injection volume was 20 μL. The mobile phases consisted of 0.1% formic acid in water (mobile phase A)and 0.1% formic acid in acetonitrile (mobile phase B), and total run time was 30min. MS-MS detection was performed in the selected monitoring mode of electrospray positive ionization reaction. Results: The pharmacokinetic characteristics of CB1107 in mice belong to the two-compartment model.When the doses were 400 mg/kg, 600 mg/kg and 800 mg/kg, corresponding area under the plasma concentration-time curve (AUC) respectively were 20.011±1.24 mg/h/L, 26.778±2.19 mg/h/L, 38.82±1.44 mg/h/L, suggesting that CB1107 have a good absorption in the body.And the AUC of three doses are proportional, indicating that CB1107 conforms to linear pharmacokinetics in vivo. Conclusion: This method was successfully applied to study the pharmacokinetics at three different doses of CB1107 after oral administration in mouses. In this study, the bioactivity mechanism of CB1107, by the pharmacokinetic investigation of CB1107 in vivo.


Gene Therapy ◽  
2014 ◽  
Vol 21 (7) ◽  
pp. 673-681 ◽  
Author(s):  
S López-Estévez ◽  
G Ferrer ◽  
J Torres-Torronteras ◽  
M J Mansilla ◽  
S Casacuberta-Serra ◽  
...  

Author(s):  
Srikanth I ◽  
Prameela Rani A

Objective: This study was to develop and validate a liquid chromatography–tandem mass spectrometry (LC–MS/MS) for the quantification of lenvatinib (LT) in human plasma.Methods: A simple, sensitive and specific LC–MS/MS method was developed for quantification of LT in human plasma using LTD4 as internal standard (IS). The analytical method consists of liquid–liquid extraction of plasma sample followed by the determination of LT by a LC–MS/MS. The analyte was separated on a Zorbax Eclipse XDB-C18 (150×4.6 mm, 5 μ) column with an isocratic mobile phase of acetontrile:0.1% formic acid (80:20 v/v) at a flow rate of 0.6 mL/minutes. The protonated ions were formed by a turbolon spray in a positive mode were used to detect analyte and IS. The MS/MS detection was made by monitoring the fragmentation of m/z 427.10→370.10 for LT and m/z 430.30→370.10 for IS on a MS.Result: The method was validated with the correlation coefficients of (r2) ≥0.995 over a linear concentration range of 10.20-501.60 pg/mL. This method demonstrated intra- and inter-day precision within 1.06-2.42% and 0.03-0.55% and accuracy within 95.64-100.08% and 97.16-100.07%.Conclusion: This method is suitable and convenient to pharmacokinetics and bioavailability studies for estimation of LT in biological samples by LC–MS/MS.


Author(s):  
Katherine A. Birchenall ◽  
Gavin I. Welsh ◽  
Andrés López Bernal

The mechanism of human labour remains poorly understood, limiting our ability to manage complications of parturition such as preterm labour and induction of labour. In this study we have investigated the effect of labour on plasma metabolites immediately following delivery, comparing cord and maternal plasma taken from women who laboured spontaneously and delivered vaginally with women who were delivered via elective caesarean section and did not labour. Samples were analysed using ultra high-performance liquid chromatography-tandem mass spectrometry. Welch’s two-sample t-test was used to identify any significant differences. Of 826 metabolites measured, 26.9% (222/826) were significantly altered in maternal plasma and 21.1% (174/826) in cord plasma. Labour involves changes in many maternal organs and poses acute metabolic demands in the uterus and in the fetus and these are reflected in our results. While a proportion of these differences are likely to be secondary to the physiological demands of labour itself, these results present a comprehensive picture of the metabolome in the maternal and fetal circulations at the time of delivery and can be used to guide future studies. We discuss potential causal pathways for labour including endocannabinoids, ceramides, sphingolipids and steroids. Further work is necessary to confirm the specific pathways involved in the spontaneous onset of labour.


Author(s):  
BAITHA PALANGGATAN MAGGADANI ◽  
YAHDIANA HARAHAP ◽  
HARMITA ◽  
SAMUEL J. HARYONO ◽  
TESANIKA RIBKA JOULIN SITORUS

Objective: Tamoxifen (TAM) is a hormonal therapy that is clinically proven to reduce breast cancer recurrence by blocking estrogen receptor, mainly through its active metabolites, 4-hydroxytamoxifen (4HT) and endoxifen (END), which have a higher affinity to ER than TAM itself. The objective of the present study was to develop and validate simple and rapid LC-MS/MS method for analysis TAM and its metabolites simultaneously in dried blood spot (DBS) sample for monitoring studies purposes. Methods: Optimization was done by evaluating several parameters that affect the efficiency of DBS preparation, such as blood spot volume, drying time and extraction method from the DBS paper. The effectiveness of chromatographic conditions was also optimized by varying flow rate, mobile phase combination and gradient. Clomiphene was used as the internal standard. Results: The result showed that preparation of 20 µl blood spot volume with 120 min of drying time and 25 min of extraction time using 1 ml methanol was the most efficient condition and also fulfilled recovery and matrix effect requirement according to FDA and EMA guidelines. The separation was performed on UPLC Class BEH C18 using formic acid 0.1%-formic acid 0.1% in acetonitrile (35:65) as the mobile phase in isocratic mode at 0.25 ml/min with a total analysis time of 4 min. Conclusion: This method has successfully fulfilled all validation requirements referring to EMA and FDA guidelines.


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