scholarly journals Relationship between plasma and intracellular concentrations of bedaquiline and its M2 metabolite in South African patients with rifampin-resistant TB

2021 ◽  
Author(s):  
Precious Ngwalero ◽  
James C.M. Brust ◽  
Stijn W. van Beek ◽  
Sean Wasserman ◽  
Gary Maartens ◽  
...  
Keyword(s):  
High Performance ◽  
Mononuclear Cells ◽  
Plasma Concentrations ◽  
Maximum Effect ◽  
Population Pharmacokinetic ◽  
Primary Metabolite ◽  
Peripheral Blood Mononuclear ◽  
Plasma Ratio ◽  
Intracellular Concentrations

Bedaquiline is recommended for the treatment of all patients with rifampin-resistant tuberculosis (RR-TB). Bedaquiline accumulates within cells, but its intracellular pharmacokinetics have not been characterized, which may have implications for dose optimization. We developed a novel assay using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure the intracellular concentrations of bedaquiline and its primary metabolite M2 in patients with RR-TB in South Africa. Twenty-one participants were enrolled and underwent sparse sampling of plasma and peripheral blood mononuclear cells (PBMCs) at months 1, 2 and 6 of treatment and at 3 and 6 months after bedaquiline treatment completion. Intensive sampling was performed at month 2. We used non-compartmental analysis to describe plasma and intracellular exposures and a population pharmacokinetic model to explore the relationship between plasma and intracellular pharmacokinetics and the effects of key covariates. Bedaquiline concentrations from month 1 to month 6 of treatment ranged from 94.7 – 2540 ng/mL in plasma and 16.2 – 5478 ng/mL in PBMCs and concentrations of M2 over the six-month treatment period ranged from 34.3 – 496 ng/mL in plasma and 109.2 – 16764 ng/mL in PBMCs. Plasma concentrations of bedaquiline were higher than M2, but intracellular concentrations of M2 were considerably higher than bedaquiline. In the pharmacokinetic modeling, we estimated a linear increase in the intracellular-plasma accumulation ratio for bedaquiline and M2, reaching maximum effect after 2 months of treatment. The typical intracellular-plasma ratio 1 and 2 months after start of treatment was 0.61 (95%CI: 0.42-0.92) and 1.10 (95%CI: 0.74-1.63) for bedaquiline and 12.4 (95%CI: 8.8-17.8) and 22.2 (95%CI: 15.6-32.3) for M2. The intracellular-plasma ratio for both bedaquiline and M2 was decreased by 54% (95%CI: 24-72%) in HIV-positive patients compared to HIV-negative patients. Bedaquiline and M2 were detectable in PBMCs 6 months after treatment discontinuation. M2 accumulated at higher concentrations intracellularly than bedaquiline, supporting in vitro evidence that M2 is the main inducer of phospholipidosis.

scholarly journals Population Pharmacokinetic Modeling of Plasma and Intracellular Ribavirin Concentrations in Patients with Chronic Hepatitis C Virus Infection

2015 ◽  
Vol 59 (4) ◽  
pp. 2179-2188 ◽  
Author(s):  
Liviawati S. Wu ◽  
Joseph E. Rower ◽  
James R. Burton ◽  
Peter L. Anderson ◽  
Kyle P. Hammond ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Mononuclear Cells ◽  
Formation Rate ◽  
Plasma Concentrations ◽  
Compartment Model ◽  
Population Pharmacokinetic ◽  
Peripheral Blood Mononuclear ◽  
First Order

ABSTRACTRibavirin, a guanosine analog, is a broad-spectrum antiviral agent. Ribavirin has been a fundamental component of the treatment of hepatitis C virus (HCV) infection for decades, but there is a very limited understanding of the clinical pharmacology of this drug. Furthermore, it is associated with a major dose-limiting toxicity, hemolytic anemia. Ribavirin undergoes intracellular phosphorylation by host enzymes to ribavirin monophosphate (RMP), ribavirin diphosphate (RDP), and ribavirin triphosphate (RTP). The intracellular forms have been associated with antiviral and toxic effectsin vitro, but the kinetics of these phosphorylated moieties have not been fully elucidatedin vivo. We developed a model to characterize the plasma pharmacokinetics of ribavirin and the difference between intracellular phosphorylation kinetics in red cells (nonnucleated) and in peripheral blood mononuclear cells (nucleated). A time-independent two-compartment model with first-order absorption described the plasma data well. The cellular phosphorylation kinetics was described by a one-compartment model for RMP, with the formation rate driven by plasma concentrations and the first-order degradation rate. RDP and RTP rapidly reached equilibrium with RMP. Concomitant telaprevir use, inosine triphosphatase genetics, creatinine clearance, weight, and sex were significant covariates. The terminal ribavirin half-life in plasma and phosphorylated anabolites in cells was approximately 224 h. We found no evidence of time-dependent kinetics. These data provide a foundation for uncovering concentration-effect associations for ribavirin and determining the optimal dose and duration of this drug for use in combination with newer direct-acting HCV agents. (This study has been registered at ClinicalTrials.gov under registration no. NCT01097395.)

scholarly journals In Vitro Interactions between Apricitabine and Other Deoxycytidine Analogues

2007 ◽  
Vol 51 (8) ◽  
pp. 2948-2953 ◽  
Author(s):  
R. Bethell ◽  
J. De Muys ◽  
J. Lippens ◽  
A. Richard ◽  
B. Hamelin ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
High Performance ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Transcriptase Inhibitor ◽  
Reverse Transcriptase Activity ◽  
Peripheral Blood Mononuclear ◽  
Reverse Transcriptase Inhibitor ◽  
Hiv 1

ABSTRACT Apricitabine is a novel deoxycytidine analogue reverse transcriptase inhibitor that is under development for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. Apricitabine is phosphorylated to its active triphosphate by deoxycytidine kinase, which is also responsible for the intracellular phosphorylation of lamivudine (3TC) and emtricitabine (FTC); hence, in vitro studies were performed to investigate possible interactions between apricitabine and these agents. Human peripheral blood mononuclear cells (PBMC) were incubated for 24 h with various concentrations of 3H-labeled or unlabeled apricitabine, 3TC, or FTC. Intracellular concentrations of parent compounds and their phosphorylated derivatives were measured by high-performance liquid chromatography. In other experiments, viral reverse transcriptase activity was measured in PBMC infected with HIV-1 bearing M184V in the presence of various concentrations of apricitabine and 3TC. [3H]apricitabine and [3H]3TC were metabolized intracellularly to form mono-, di-, and triphosphates. 3TC and FTC (1 to 10 μM) produced concentration-dependent decreases in apricitabine phosphorylation; in contrast, apricitabine at concentrations of up to 30 μM had no effect on the phosphorylation of 3TC or FTC. The combination of apricitabine and 3TC reduced the antiviral activity of apricitabine against HIV-1: apricitabine concentrations producing 50% inhibition of viral reverse transcriptase were increased two- to fivefold in the presence of 3TC. These findings suggest that nucleoside reverse transcriptase inhibitors with similar modes of action may show biochemical interactions that affect their antiviral efficacy. It is therefore essential that potential interactions between combinations of new and existing agents be thoroughly investigated before such combinations are introduced into clinical practice.

Phase I and Pharmacologic Study of 17-(Allylamino)-17-Demethoxygeldanamycin in Adult Patients With Solid Tumors

2005 ◽  
Vol 23 (9) ◽  
pp. 1885-1893 ◽  
Author(s):  
Jean L. Grem ◽  
Geraldine Morrison ◽  
Xiao-Du Guo ◽  
Elizabeth Agnew ◽  
Chris H. Takimoto ◽  
...  
Keyword(s):  
Protein Content ◽  
High Performance ◽  
Mononuclear Cells ◽  
Plasma Concentrations ◽  
Immunoblot Analysis ◽  
Maximum Plasma ◽  
Peripheral Blood Mononuclear ◽  
Biologic Effects ◽  
Grade 3 ◽  
Dose Levels

Purpose To determine the clinical toxicities of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) given as a 1-hour infusion daily for 5 days every 3 weeks. Patients and Methods Nineteen patients received 17-AAG over six dose levels (10 to 56 mg/m2) using an accelerated titration scheme. Drug levels of 17-AAG were determined by high-performance liquid chromatography. Biologic effects of 17-AAG were monitored by changes in the content of target proteins by immunoblot analysis of lysates prepared from peripheral-blood mononuclear cells. Results Toxicity was acceptable at doses up to 28 mg/m2. The cohort was expanded to three patients at 40 mg/m2 because a second occurrence of grade 2 hepatic transaminitis occurred. Two of six assessable patients who received 56 mg/m2 had reversible, grade 3 hepatic transaminitis. Five additional patients were enrolled at 40 mg/m2; none had dose-limiting toxicity. The maximum plasma concentrations (Cmax) of 17-AAG at 40 and 56 mg/m2 were 1,724 and 2,046 ng/mL, respectively; the average plasma exposures (AUC) were 2,809 and 6,708 hours·ng/mL, respectively. Less than 3% of the daily dose was excreted into the urine. Clearance did not correlate with body-surface area. Possible biologic activity was suggested by apparent increased protein content of either glucose-related 78 kd protein or heat shock protein 70 with ≥ 14 mg/m2 and decreased protein content of either Lck or Raf1 with ≥ 28 mg/m2 of 17-AAG. Conclusion 17-AAG 40 mg/m2 (median dose, 70 mg) was well tolerated when given daily for 5 days every 3 weeks.

scholarly journals Intracellular Concentrations of Posaconazole in Different Compartments of Peripheral Blood

2010 ◽  
Vol 54 (7) ◽  
pp. 2928-2931 ◽  
Author(s):  
Fedja Farowski ◽  
Oliver A. Cornely ◽  
Jörg J. Vehreschild ◽  
Pia Hartmann ◽  
Tim Bauer ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Fungal Infections ◽  
Gradient Centrifugation ◽  
Plasma Concentrations ◽  
Therapeutic Drug ◽  
Peripheral Blood Mononuclear ◽  
Liquid Chromatography Tandem Mass ◽  
Intracellular Concentrations ◽  
High Concentrations

ABSTRACT Therapeutic drug monitoring (TDM) of antifungal plasma concentrations is increasingly recommended. However, data on antifungal concentrations in the other compartments of the peripheral blood are limited. Hence, we collected 23 blood samples from 14 patients receiving posaconazole for prophylaxis of fungal infections. These samples were separated by double-discontinuous Ficoll-Hypaque density gradient centrifugation. The intracellular posaconazole concentrations of the obtained cells, i.e., the peripheral blood mononuclear cells (PBMCs), polymorphonuclear leukocytes (PMNs), and red blood cells (RBCs), were determined by liquid chromatography-tandem mass spectrometry. The intracellular concentrations of the PBMCs and PMNs were significantly higher than those of surrounding media (P < 0.001). The ratios between the intracellular and extracellular concentrations (C/E) were 22.5 ± 21.2, 7.66 ± 6.50, and 0.09 ± 0.05 for the PBMCs, PMNs, and RBCs, respectively. Posaconazole reaches high concentrations within human PBMCs and PMNs and is, to a lesser extent, present in RBCs. The high intracellular concentrations might contribute to posaconazole efficacy and distribution.

Phase I trial of panobinostat (P) and imatinib (IM) in patients with treatment-refractory gastrointestinal stromal tumors (GIST).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 10032-10032
Author(s):  
Sebastian Bauer ◽  
Ralf A. Hilger ◽  
Florian Grabellus ◽  
James Nagarajah ◽  
Mathias Hoiczyk ◽  
...  
Keyword(s):  
Phase I ◽  
Mononuclear Cells ◽  
Metabolic Response ◽  
Combined Treatment ◽  
Plasma Concentrations ◽  
Maximum Tolerated Dose ◽  
Clinical Activity ◽  
Peripheral Blood Mononuclear

10032^ Background: Panobinostat (LBH589; P) is a pan-deacetylase-inhibitor that has preclinical activity in combination with IM in GIST models in vitro and in vivo. Aim of this study was to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of escalating doses of P in combination with IM in patients with GIST who have failed IM and sunitinib treatment. Methods: This was a two-center phase I study using a 3+3 design with a prespecified expansion of the MTD cohort. IM was administered at a dose of 400mg qd. Following a 7 day run-in phase, escalating doses of P were added. The starting dose for P was 20 mg given as a three-times-per-week (MWF schedule) oral dose for 3 out of 4 weeks. Doses were increased by 10 mg if no dose limiting toxicities emerged. Blood samples were drawn for PK and biomarker assessments of IM, its main metabolite N-desmethyl-IM, and P using a validated RP-HPLC method. Acetylation of histone A3 was evaluated in peripheral blood mononuclear cells (PBMNC) as pharmacodynamic marker for P activity. Metabolic response using PET (EORTC-PET study criteria) was assessed on day 7 of IM run-in and after 3 weeks of combined treatment with IM and P. Results: In total 12 extensively pretreated (median 5 pretreatments) pts (4 f, 8 m; median age 56 y, 34-75 y) received study treatment at 2 dose levels (DL). 2 dose-limiting toxicities (grade 4 thrombocytopenia) occurred at DL 2 (30 mg). Most common AEs were thrombocytopenia, anemia, fatigue, nausea, emesis, diarrhea, creatinine elevation, abdominal cramping, and weight loss. DL 1 (20mg) was declared MTD, and 5 additional pts were enrolled at DL1. Analysis of P and IM PK revealed mean peak concentration of 14.8 +/- 9.5 ng/ml for P (20 mg). IM plasma concentrations with 400 mg once-daily administration were 2.8 ± 1.1 μg/mL at peak and 1.2 ± 0.4 μg/mL at trough. Histone A3 acetylation was demonstrated in PBMNC from pts treated at DL 1. 11 pts were evaluable for PET response: 1 had mPR, 7 had mSD and 3 had mPD. Longest treatment duration was 17 weeks (median: 6wks). Conclusions: P in combination with IM is moderately tolerated. Evidence of target inhibition at the MTD was associated with limited clinical activity in heavily pretreated pts with GIST.

scholarly journals High Intracellular Concentrations of Posaconazole Do Not Impact on Functional Capacities of Human Polymorphonuclear Neutrophils and Monocyte-Derived MacrophagesIn Vitro

2016 ◽  
Vol 60 (6) ◽  
pp. 3533-3539 ◽  
Author(s):  
Fedja Farowski ◽  
Oliver A. Cornely ◽  
Pia Hartmann
Keyword(s):  
Mononuclear Cells ◽  
Fungal Infections ◽  
Polymorphonuclear Neutrophils ◽  
Oxygen Species ◽  
Peripheral Blood Mononuclear ◽  
Content Type ◽  
Tissue Integrity ◽  
Intracellular Concentrations ◽  
Functional Capacities

Posaconazole is a commonly used antifungal for the prophylaxis and treatment of invasive fungal infections. We previously demonstrated that the intracellular concentration of posaconazole in peripheral blood mononuclear cells (PBMCs) and polymorphonuclear neutrophils (PMNs) was greatly increased compared to the plasma concentration. As these professional phagocytes are crucial to combat fungal infections, we set out to investigate if and how, beneficial or deleterious, this high loading of intracellular posaconazole impacts the functional capacities of these cells. Here, we show that high intracellular concentrations of posaconazole do not significantly impact PMN and monocyte-derived macrophage functionin vitro. In particular, killing capacity and cytoskeletal features of PMN, such as migration, are not affected, indicating that these cells serve as vehicles for posaconazole to the site of infection. Moreover, since posaconazole as such slowed the germination ofAspergillus fumigatusconidia, infected neutrophils released less reactive oxygen species (ROS). Based on these findings, we propose that the delivery of posaconazole by neutrophils to the site ofAspergillusspecies infection warrants control of the pathogen and preservation of tissue integrity at the same time.

scholarly journals Effects of drugs on 2',3'-dideoxy-2',3'-didehydrothymidine phosphorylation in vitro.

1997 ◽  
Vol 41 (6) ◽  
pp. 1231-1236 ◽  
Author(s):  
P G Hoggard ◽  
S Kewn ◽  
M G Barry ◽  
S H Khoo ◽  
D J Back
Keyword(s):  
High Performance ◽  
Additional Data ◽  
Mononuclear Cells ◽  
U937 Cells ◽  
Small Reduction ◽  
Peripheral Blood Mononuclear ◽  
Immunodeficiency Virus ◽  
Diphenyl Tetrazolium Bromide ◽  
Anti Hiv

Drugs commonly administered to patients infected with the human immunodeficiency virus (HIV) have been studied for their propensity to alter the intracellular phosphorylation of the anti-HIV nucleoside analog stavudine (2',3'-dideoxy-2',3'-didehydrothymidine; d4T) in peripheral blood mononuclear cells (PBMCs) and U937 cells in vitro. PBMCs isolated from the blood of healthy volunteers were stimulated by the mitogen phytohemagglutinin (10 microg/ml) for 72 h. Stimulated PBMCs (3 x 10(6) cells/plate) were then incubated with [3H]d4T (0.65 microCi; 3 microM) and either acyclovir, dapsone, ddC, ddI, fluconazole, foscarnet, ganciclovir, itraconazole, lobucavir, ranitidine, ribavirin, rifampin, sorivudine, sulfamethoxazole, trimethoprim, lamivudine (3TC), zidovudine, or thymidine (30 and 300 microM) for 24 h. Doxorubicin and drugs showing some evidence of inhibition were also studied at 0.3 and 3 microM. Cells were extracted overnight with 60% methanol prior to analysis by radiometric high-performance liquid chromatography. Additional data for nine of the drugs were obtained by incubation with [3H]d4T in U937 cells for 24 h. The effect of d4T (0.2 to 20 microM) on zidovudine (0.65 microCi; 0.018 microCi) phosphorylation was also studied. Zidovudine significantly reduced d4T total phosphates in PBMCs and U937 cells (in PBMCs to 33% [P < 0.001] and 17% [P < 0.001] of that in control cells at 3 and 30 microM, respectively). A small reduction in zidovudine phosphorylation was seen with d4T but only at d4T:zidovudine ratios of 100 and 1,000. Of the other compounds screened, only thymidine, ribavirin, and doxorubicin produced inhibition of d4T phosphorylation in both PBMCs and U937 cells. However, doxorubicin was cytotoxic at 3 microM. The decrease in d4T phosphorylation in the presence of ribavirin is consistent with previous findings with zidovudine. Although ddC significantly inhibited the phosphorylation of d4T in PBMCs, this was not seen in U937 cells, and it is probable that the findings in PBMCs are related to mitochondrial toxicity [based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide cytotoxicity assay]. The only drugs screened which may interfere with d4T phosphorylation at clinically relevant concentrations were zidovudine, ribavirin, and doxorubicin.

Phase I Trial of Histone Deacetylase Inhibition by Valproic Acid Followed by the Topoisomerase II Inhibitor Epirubicin in Advanced Solid Tumors: A Clinical and Translational Study

2007 ◽  
Vol 25 (15) ◽  
pp. 1979-1985 ◽  
Author(s):  
Pamela Münster ◽  
Douglas Marchion ◽  
Elona Bicaku ◽  
Morgen Schmitt ◽  
Ji Hyun Lee ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Histone Deacetylase ◽  
Topoisomerase Ii ◽  
Mononuclear Cells ◽  
Plasma Concentrations ◽  
Median Number ◽  
Maximum Tolerated Dose ◽  
Peripheral Blood Mononuclear ◽  
Histone Deacetylase Inhibition

Purpose To determine the safety, toxicity, and maximum-tolerated dose of a sequence-specific combination of the histone deacetylase inhibitor (HDACi), valproic acid (VPA), and epirubicin in solid tumor malignancies and to define the clinical feasibility of VPA as an HDACi. Patients and Methods Patients were treated with increasing doses of VPA (days 1 through 3) followed by epirubicin (day 3) in 3-week cycles. The study evaluated pharmacokinetic and pharmacodynamic end points, toxicities, and tumor response. Results Forty-eight patients were enrolled, and 44 received at least one cycle of therapy. Patients (median age, 54 years; range, 39 to 78 years) received the following doses of VPA: 15, 30, 45, 60, 75, 90, 100, 120, 140, and 160 mg/kg/d. Dose-limiting toxicities were somnolence (n = 1), confusion (n = 3), and febrile neutropenia (n = 1). No exacerbation of epirubicin-related toxicities was observed. Partial responses were seen across different tumor types in nine patients (22%), and stable disease/minor responses were seen in 16 patients (39%), despite a median number of three prior regimens (range, zero to 10 prior regimens). Patients received a median number of four treatment cycles (range, one to 10 cycles), and treatment was stopped after reaching maximal epirubicin doses rather than progression in 13 (32%) of 41 patients patients. Total and free VPA plasma concentrations increased linearly with dose and correlated with histone acetylation in peripheral-blood mononuclear cells. Conclusion The maximum-tolerated dose and recommended phase II dose was VPA 140 mg/kg/d for 48 hours followed by epirubicin 100 mg/m2. Sustained plasma concentrations of VPA exceeding those required for in vitro synergy were achieved with acceptable toxicity. Noteworthy antitumor activity was observed in heavily pretreated patients and historically anthracycline-resistant tumors.

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