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70 result(s) for "Decosterd, Laurent A."
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The Steps to Therapeutic Drug Monitoring: A Structured Approach Illustrated With Imatinib
Pharmacometric methods have hugely benefited from progress in analytical and computer sciences during the past decades, and play nowadays a central role in the clinical development of new medicinal drugs. It is time that these methods translate into patient care through therapeutic drug monitoring (TDM), due to become a mainstay of precision medicine no less than genomic approaches to control variability in drug response and improve the efficacy and safety of treatments. In this review, we make the case for structuring TDM development along five generic questions: 1) Is the concerned drug a candidate to TDM? 2) What is the normal range for the drug's concentration? 3) What is the therapeutic target for the drug's concentration? 4) How to adjust the dosage of the drug to drive concentrations close to target? 5) Does evidence support the usefulness of TDM for this drug? We exemplify this approach through an overview of our development of the TDM of imatinib, the very first targeted anticancer agent. We express our position that a similar story shall apply to other drugs in this class, as well as to a wide range of treatments critical for the control of various life-threatening conditions. Despite hurdles that still jeopardize progress in TDM, there is no doubt that upcoming technological advances will shape and foster many innovative therapeutic monitoring methods.
Towards a new combination therapy for tuberculosis with next generation benzothiazinones
The benzothiazinone lead compound, BTZ043, kills Mycobacterium tuberculosis by inhibiting the essential flavo‐enzyme DprE1, decaprenylphosphoryl‐beta‐D‐ribose 2‐epimerase. Here, we synthesized a new series of piperazine‐containing benzothiazinones (PBTZ) and show that, like BTZ043, the preclinical candidate PBTZ169 binds covalently to DprE1. The crystal structure of the DprE1‐PBTZ169 complex reveals formation of a semimercaptal adduct with Cys387 in the active site and explains the irreversible inactivation of the enzyme. Compared to BTZ043, PBTZ169 has improved potency, safety and efficacy in zebrafish and mouse models of tuberculosis (TB). When combined with other TB drugs, PBTZ169 showed additive activity against M. tuberculosis in vitro except with bedaquiline (BDQ) where synergy was observed. A new regimen comprising PBTZ169, BDQ and pyrazinamide was found to be more efficacious than the standard three drug treatment in a murine model of chronic disease. PBTZ169 is thus an attractive drug candidate to treat TB in humans. Synopsis Tuberculosis (TB) drug resistance is still spreading worldwide, emphasizing the need for new efficient drug combinations. PBTZ169 is here presented as an optimized, potent and synergistic preclinical drug candidate for the treatment of TB in humans. The development of a new candidate drug, PBTZ169, for the treatment of tuberculosis is described. Atomic level understanding of the action of PBTZ169 against its target DprE1 is available. A new PBTZ169 combination therapy has been tested in a murine model and shown to be superior to the existing standard of care. Graphical Abstract Tuberculosis (TB) drug resistance is still spreading worldwide, emphasizing the need for new efficient drug combinations. PBTZ169 is here presented as an optimized, potent and synergistic preclinical drug candidate for the treatment of TB in humans.
Precision Oncology by Point-of-Care Therapeutic Drug Monitoring and Dosage Adjustment of Conventional Cytotoxic Chemotherapies: A Perspective
Therapeutic drug monitoring (TDM) of conventional cytotoxic chemotherapies is strongly supported yet poorly implemented in daily practice in hospitals. Analytical methods for the quantification of cytotoxic drugs are instead widely presented in the scientific literature, while the use of these therapeutics is expected to keep going for longer. There are two main issues hindering the implementation of TDM: turnaround time, which is incompatible with the dosage profiles of these drugs, and exposure surrogate marker, namely total area under the curve (AUC). Therefore, this perspective article aims to define the adjustment needed from current to efficient TDM practice for cytotoxics, namely point-of-care (POC) TDM. For real-time dose adjustment, which is required for chemotherapies, such POC TDM is only achievable with analytical methods that match the sensitivity and selectivity of current methods, such as chromatography, as well as model-informed precision dosing platforms to assist the oncologist with dose fine-tuning based on quantification results and targeted intervals.
Anticancer Activities of Novel Nicotinamide Phosphoribosyltransferase Inhibitors in Hematological Malignancies
Targeting cancer cells that are highly dependent on the nicotinamide adenine dinucleotide (NAD+) metabolite is a promising therapeutic strategy. Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme catalyzing NAD+ production. Despite the high efficacy of several developed NAMPT inhibitors (i.e., FK866 (APO866)) in preclinical studies, their clinical activity was proven to be limited. Here, we report the synthesis of new NAMPT Inhibitors, JJ08, FEI191 and FEI199, which exhibit a broad anticancer activity in vitro. Results show that these compounds are potent NAMPT inhibitors that deplete NAD+ and NADP(H) after 24 h of drug treatment, followed by an increase in reactive oxygen species (ROS) accumulation. The latter event leads to ATP loss and mitochondrial depolarization with induction of apoptosis and necrosis. Supplementation with exogenous NAD+ precursors or catalase (ROS scavenger) abrogates the cell death induced by the new compounds. Finally, in vivo administration of the new NAMPT inhibitors in a mouse xenograft model of human Burkitt lymphoma delays tumor growth and significantly prolongs mouse survival. The most promising results are collected with JJ08, which completely eradicates tumor growth. Collectively, our findings demonstrate the efficient anticancer activity of the new NAMPT inhibitor JJ08 and highlight a strong interest for further evaluation of this compound in hematological malignancies.
Tamoxifen prolongs survival and alleviates symptoms in mice with fatal X-linked myotubular myopathy
X-linked myotubular myopathy (XLMTM, also known as XLCNM) is a severe congenital muscular disorder due to mutations in the myotubularin gene, MTM1 . It is characterized by generalized hypotonia, leading to neonatal death of most patients. No specific treatment exists. Here, we show that tamoxifen, a well-known drug used against breast cancer, rescues the phenotype of Mtm1 -deficient mice. Tamoxifen increases lifespan several-fold while improving overall motor function and preventing disease progression including lower limb paralysis. Tamoxifen corrects functional, histological and molecular hallmarks of XLMTM, with improved force output, myonuclei positioning, myofibrillar structure, triad number, and excitation-contraction coupling. Tamoxifen normalizes the expression level of the XLMTM disease modifiers DNM2 and PI3KC2B, likely contributing to the phenotypic rescue. Our findings demonstrate that tamoxifen is a promising candidate for clinical evaluation in XLMTM patients. X-linked myotubular myopathy (XLMTM) is a severe muscle disease with no effective treatment. Here, the authors show that tamoxifen, a drug used to treat breast cancer, rescues the pathology in a mouse model of the disease, at least in part by normalizing expression of the disease modifier proteins DNM2 and BIN1
Inhibition of vascular calcification by inositol phosphates derivatized with ethylene glycol oligomers
Myo -inositol hexakisphosphate (IP6) is a natural product known to inhibit vascular calcification (VC), but with limited potency and low plasma exposure following bolus administration. Here we report the design of a series of inositol phosphate analogs as crystallization inhibitors, among which 4,6-di- O -(methoxy-diethyleneglycol)- myo -inositol-1,2,3,5-tetrakis(phosphate), (OEG 2 ) 2 -IP4, displays increased in vitro activity, as well as more favorable pharmacokinetic and safety profiles than IP6 after subcutaneous injection. (OEG 2 ) 2 -IP4 potently stabilizes calciprotein particle (CPP) growth, consistently demonstrates low micromolar activity in different in vitro models of VC (i.e., human serum, primary cell cultures, and tissue explants), and largely abolishes the development of VC in rodent models, while not causing toxicity related to serum calcium chelation. The data suggest a mechanism of action independent of the etiology of VC, whereby (OEG 2 ) 2 -IP4 disrupts the nucleation and growth of pathological calcification. Cardiovascular calcification is a serious pathology for which effective pharmacological treatments are lacking. Here the authors show that an optimized oligo(ethylene glycol) derivative of inositol phosphate interferes with calcium phosphate crystallization and inhibits soft tissue calcification in vivo following subcutaneous injection.
Efficacy and safety of dolutegravir plus emtricitabine versus standard ART for the maintenance of HIV-1 suppression: 48-week results of the factorial, randomized, non-inferiority SIMPL’HIV trial
Dolutegravir (DTG)-based dual therapy is becoming a new paradigm for both the initiation and maintenance of HIV treatment. The SIMPL'HIV study investigated the outcomes of virologically suppressed patients on standard combination antiretroviral therapy (cART) switching to DTG + emtricitabine (FTC). We present the 48-week efficacy and safety data on DTG + FTC versus cART. SIMPL'HIV was a multicenter, open-label, non-inferiority randomized trial with a factorial design among treatment-experienced people with HIV in Switzerland. Participants were enrolled between 12 May 2017 and 30 May 2018. Patients virologically suppressed for at least 24 weeks on standard cART were randomized 1:1 to switching to DTG + FTC or to continuing cART, and 1:1 to simplified patient-centered monitoring versus standard monitoring. The primary endpoint was the proportion of patients virologically suppressed with <100 copies/ml through 48 weeks. The secondary endpoints included virological suppression at 48 weeks according to the US Food and Drug Administration (FDA) snapshot analysis. Non-inferiority of DTG + FTC versus cART for viral suppression was assessed using a stratified Mantel-Haenszel risk difference, with non-inferiority declared if the lower bound of the 95% confidence interval was greater than -12%. Adverse events were monitored to assess safety. Quality of life was evaluated using the PROQOL-HIV questionnaire. Ninety-three participants were randomized to DTG + FTC, and 94 individuals to cART. Median nadir CD4 count was 246 cells/mm3; median age was 48 years; 17% of participants were female. DTG + FTC was non-inferior to cART. The proportion of patients with viral suppression (<100 copies/ml) through 48 weeks was 93.5% in the DTG + FTC arm and 94.7% in the cART arm in the intention-to-treat population (risk difference -1.2%; 95% CI -7.8% to 5.6%). Per-protocol analysis showed similar results, with viral suppression in 96.5% of patients in both arms (risk difference 0.0%; 95% CI -5.6% to 5.5%). There was no relevant interaction between the type of treatment and monitoring (interaction ratio 0.98; 95% CI 0.85 to 1.13; p = 0.81). Using the FDA snapshot algorithm, 84/93 (90.3%) participants in the DTG + FTC arm had an HIV-1 RNA viral load of <50 copies/ml compared to 86/94 (91.5%) participants on standard cART (risk difference -1.1%; 95% CI -9.3% to 7.1%; p = 0.791). The overall proportion of patients with adverse events and discontinuations did not differ by randomization arm. The proportion of patients with serious adverse events was higher in the cART arm (16%) compared to the DTG + FTC arm (6.5%) (p = 0.041), but none was considered to be related to the study medication. Quality of life improved more between baseline and week 48 in the DTG + FTC compared to the cART arm (adjusted difference +2.6; 95% CI +0.4 to +4.7). The study's main limitations included a rather small proportion of women included, the open label design, and its short duration. In this study, DTG + FTC as maintenance therapy was non-inferior to cART in terms of efficacy, with a similar safety profile and a greater improvement in quality of life, thus expanding the offer of 2-drug simplification options among virologically suppressed individuals. ClinicalTrials.gov NCT03160105.
Development and validation of a multiplex UHPLC-MS/MS method for the determination of the investigational antibiotic against multi-resistant tuberculosis macozinone (PBTZ169) and five active metabolites in human plasma
The emergence of Mycobacterium tuberculosis strains resistant to current first-line antibiotic regimens constitutes a major global health threat. New treatments against multidrug-resistant tuberculosis (MDR-TB) are thus eagerly needed in particular in countries with a high MDR-TB prevalence. In this context, macozinone (PBTZ169), a promising drug candidate with an unique mode of action and highly potent in vitro tuberculocidal properties against MDR Mycobacterium strains, has now reached the clinical phase and has been notably tested in healthy male volunteers in Switzerland. To that endeavor, a multiplex UHPLC-MS/MS method has been developed for the sensitive and accurate human plasma levels determination of PBTZ169 along with five metabolites retaining in vitro anti-TB activity. Plasma protein precipitation with methanol was carried out as a simplified sample clean-up procedure followed by direct injection of the undiluted supernatant for the bioanalysis of the six analytes within 5 min, using 1.8 μm reversed-phase chromatography coupled to triple quadrupole mass spectrometry employing electrospray ionization in the positive mode. Stable isotopically-labelled PBTZ169 was used as internal standard (ISTD), while metabolites could be reliably quantified using two unlabeled chemical analogues selected as ISTD from a large in-house analogous compounds library. The overall methodology was fully validated according to current recommendations (FDA, EMEA) for bioanalytical methods, which include selectivity, carryover, qualitative and quantitative matrix effect, extraction recovery, process efficiency, trueness, precision, accuracy profiles, method and instrument detection limits, integrity to dilution, anticoagulant comparison and short- and long-term stabilities. Stability studies on the reduced metabolite H2-PBTZ169 have shown no significant impact on the actual PBTZ169 concentrations determined with the proposed assay. This simplified, rapid, sensitive and robust methodology has been applied to the bioanalysis of human plasma samples collected within the frame of a phase I clinical study in healthy volunteers receiving PBTZ169.
Population pharmacokinetics and pharmacodynamics of the artesunate–mefloquine fixed dose combination for the treatment of uncomplicated falciparum malaria in African children
Background The World Health Organization (WHO) recommends combinations of an artemisinin derivative plus an anti-malarial drug of longer half-life as treatment options for uncomplicated Plasmodium falciparum infections. In Africa, artesunate–mefloquine (ASMQ) is an infrequently used artemisinin-based combination therapy (ACT) because of perceived poor tolerance to mefloquine. However, the WHO has recommended reconsideration of the use of ASMQ in Africa. In this large clinical study, the pharmacokinetics (PK) of a fixed dose combination of ASMQ was investigated in an African paediatric population to support dosing recommendations used in Southeast Asia and South America. Methods Among the 472 paediatric patients aged 6–59 months from six African centres included in the large clinical trial, a subset of 50 Kenyan children underwent intensive sampling to develop AS, its metabolite dihydroartemisinin (DHA) and MQ PK models. The final MQ PK model was validated using sparse data collected in the remaining participants (NONMEM ® ). The doses were one or two tablets containing 25/55 mg AS/MQ administered once a day for 3 days according to patients’ age. A sensitive LC–MS/MS method was used to quantify AS, DHA and MQ concentrations in plasma. An attempt was made to investigate the relationship between the absence/presence of malaria recrudescence and MQ area under the curve (AUC) using logistic regression. Results AS/DHA concentration–time profiles were best described using a one-compartment model for both compounds with irreversible AS conversion into DHA. AS/DHA PK were characterized by a significant degree of variability. Body weight affected DHA PK parameters. MQ PK was characterized by a two-compartment model and a large degree of variability. Allometric scaling of MQ clearances and volumes of distribution was used to depict the relationship between MQ PK and body weight. No association was found between the model predicted AUC and appearance of recrudescence. Conclusions The population pharmacokinetic models developed for both AS/DHA and MQ showed a large variability in drug exposure in the investigated African paediatric population. The largest contributor to this variability was body weight, which is accommodated for by the ASMQ fixed dose combination (FDC) dosing recommendation. Besides body weight considerations, there is no indication that the dosage should be modified in children with malaria compared to adults. Trial registration Pan African Clinical Trials Registry PACTR201202000278282 registration date 2011/02/16
Real-Life Therapeutic Concentration Monitoring of Long-Acting Cabotegravir and Rilpivirine: Preliminary Results of an Ongoing Prospective Observational Study in Switzerland
SHCS#879 is an ongoing Switzerland-wide multicenter observational study conducted within the Swiss HIV Cohort Study (SHCS) for the prospective follow-up of people living with HIV (PLWH) receiving long-acting injectable cabotegravir-rilpivirine (LAI-CAB/RPV). All adults under LAI-CAB/RPV and part of SHCS are enrolled in the project. The study addresses an integrated strategy of treatment monitoring outside the stringent frame of controlled clinical trials, based on relevant patient characteristics, clinical factors, potential drug-drug interactions, and measurement of circulating blood concentrations. So far, 91 blood samples from 46 PLWH have been collected. Most individuals are less than 50 years old, with relatively few comorbidities and comedications. The observed concentrations are globally in accordance with the available values reported in the randomized clinical trials. Yet, low RPV concentrations not exceeding twice the reported protein-adjusted 90% inhibitory concentration have been observed. Data available at present confirm a considerable between-patient variability overall. Based on the growing amount of PK data accumulated during this ongoing study, population pharmacokinetic analysis will characterize individual concentration-time profiles of LAI-CAB/RPV along with their variability in a real-life setting and their association with treatment response and tolerability, thus bringing key data for therapeutic monitoring and precision dosage adjustment of this novel long-acting therapy.