Comparison of pharmacokinetics and bioavailability of bedaquiline fumarate, benzoate and maleate in dogs.

BACKGROUND: Bedaquiline (BDQ) as a fumarate salt is indicated as part of a regimen to treat multidrug-resistant TB (MDR-TB). BDQ benzoate and maleate have been identified as promising alternatives that will encourage generic pharmaceutical houses to manufacture this drug. Our study compared the pharmacokinetics (PK) of BDQ fumarate vs. the maleate and benzoate salts in dogs.METHODS: The PK of BDQ and its active N-desmethyl metabolite M2 following intravenous administration of 1 mg/kg BDQ (as fumarate) and oral administration of 10 mg/kg BDQ as fumarate, benzoate, or maleate salts in suspension to fasted male beagle dogs was evaluated in a parallel-group and crossover study with N = 4 per group. BDQ and M2 plasma concentrations were determined up to 168 h post-dose. T-tests were conducted to compare the area under the curve, AUC0-t among groups.RESULTS: Orally administered fumarate, benzoate, and maleate salts, in parallel-group design, resulted in mean BDQ AUC0-t of 9,267 ± SD 10,182, 19,258 ± SD 11,803, and 15,396 ± SD 9,170 ng.h/ml, respectively; and in a crossover design of 9,267 ± SD 10,182, 17,441 ± SD 24,049, and 18,087 ± SD 19,758 ng.h/ml, respectively. P values were >0.05.CONCLUSION: There was no statistically significant difference in BDQ and M2 AUC0-t following oral administration of fumarate, benzoate and maleate salts in dogs.

Safety and Tolerability of Tecarfarin (ATI-5923) in Healthy Chinese Volunteers: Multiple Oral Dose-Escalation Phase I Trial.

BACKGROUND: Tecarfarin (ATI-5923), a structural analog of warfarin, was designed to provide more uniform and stable anticoagulation. OBJECTIVE: We aimed to evaluate the safety, tolerability, pharmacokinetic and pharmacodynamic profile of tecarfarin when administered in multiple ascending doses (MADs) to healthy Chinese volunteers. METHODS: Forty healthy Chinese volunteers were enrolled into four sequential cohorts (10, 20, 30, and 40 mg), with 10 subjects in each cohort. Participants in the MAD study for each sequential cohort were dose-titrated to achieve the target international normalized ratio (INR 1.7-2.0) for 14 days. Safety and tolerability were assessed throughout the study. RESULTS: The pharmacokinetic and pharmacodynamic profile of tecarfarin was investigated in a healthy Chinese population. Dose titration of tecarfarin was necessary to keep the INR in the target range in all subjects in the 20, 30 and 40 mg cohorts and a few subjects (n = 3) in the 10 mg cohort. Tecarfarin was well tolerated without serious adverse events. Only one treatment-related adverse event (hematochezia) resulted in early withdrawal from the MAD 40 mg cohort. CONCLUSION: Tecarfarin was well-tolerated by Chinese volunteers. Dose titration was needed for tecarfarin doses larger than 20 mg to keep the INR in the target range. REGISTRATION: ClinicalTrials.gov identifier: NCT04627116.

Targeted Delivery of Soluble Guanylate Cyclase (sGC) Activator Cinaciguat to Renal Mesangial Cells via Virus-Mimetic Nanoparticles Potentiates Anti-Fibrotic Effects by cGMP-Mediated Suppression of the TGF-ß Pathway.

Diabetic nephropathy (DN) ranks among the most detrimental long-term effects of diabetes, affecting more than 30% of all patients. Within the diseased kidney, intraglomerular mesangial cells play a key role in facilitating the pro-fibrotic turnover of extracellular matrix components and a progredient glomerular hyperproliferation. These pathological effects are in part caused by an impaired functionality of soluble guanylate cyclase (sGC) and a consequentially reduced synthesis of anti-fibrotic messenger 3',5'-cyclic guanosine monophosphate (cGMP). Bay 58-2667 (cinaciguat) is able to re-activate defective sGC; however, the drug suffers from poor bioavailability and its systemic administration is linked to adverse events such as severe hypotension, which can hamper the therapeutic effect. In this study, cinaciguat was therefore efficiently encapsulated into virus-mimetic nanoparticles (NPs) that are able to specifically target renal mesangial cells and therefore increase the intracellular drug accumulation. NP-assisted drug delivery thereby increased in vitro potency of cinaciguat-induced sGC stabilization and activation, as well as the related downstream signaling 4- to 5-fold. Additionally, administration of drug-loaded NPs provided a considerable suppression of the non-canonical transforming growth factor ß (TGF-ß) signaling pathway and the resulting pro-fibrotic remodeling by 50-100%, making the system a promising tool for a more refined therapy of DN and other related kidney pathologies.

Phase I study of tamibarotene monotherapy in pediatric and young adult patients with recurrent/refractory solid tumors.

PURPOSE: Tamibarotene is a synthetic retinoid that inhibits proliferation and induces differentiation of malignant cells by binding to the retinoic acid receptor α/ß. Previous in vitro studies have shown that some pediatric solid tumors with retinoic acid receptors differentiate in response to retinoic acid. We conducted a phase I dose-escalation study to determine the recommended dose of tamibarotene for further study in pediatric and young adult patients with recurrent/refractory solid tumors. METHODS: Pediatric and young adult patients with recurrent/refractory solid tumors were administered tamibarotene at 4, 6, 8, 10, and 12 mg/m2/day for 14 or 21 days of a 28 day cycle. Safety, efficacy, and pharmacokinetics of tamibarotene were evaluated. RESULTS: Twenty-two patients (median age 8 years) were enrolled in this study. No dose-limiting toxicity (DLT) was encountered, and tamibarotene was generally well tolerated. Two patients experienced severe adverse events (AEs), leading to discontinuation of the treatment. One grade 4 venous thrombosis and one grade 2 erythema multiforme were observed, which promptly resolved after tamibarotene discontinuance. The grade 4 venous thrombosis was a severe AE but not DLT because it occurred after the evaluation period. Pharmacokinetic analyses showed a dose-dependent increase in the maximum drug concentration (Cmax) and area under the concentration-time curve (AUC). None of the patients achieved a complete response or partial response. Seven patients had stable disease lasting longer than 18 weeks. CONCLUSIONS: The recommended dose for phase II study of tamibarotene in pediatric and young adult patients with refractory solid tumors is 12 mg/m2/day for 21 days in a 28 day cycle.

Pharmacokinetics of Eltrombopag in Healthy Chinese Subjects and Effect of Sex and Genetic Polymorphism on its Pharmacokinetic and Pharmacodynamic Variability.

BACKGROUND AND OBJECTIVE: Eltrombopag is the first oral, small-molecule, non-peptide thrombopoietin receptor agonist for the treatment of idiopathic thrombocytopenic purpura. This study investigated the pharmacokinetics of eltrombopag in healthy Chinese subjects and evaluated the effect of sex and genetic polymorphisms on its variability. METHODS: Forty-eight healthy subjects were administered a single dose of eltrombopag (25 mg). Plasma concentrations of eltrombopag were determined using a validated liquid chromatography-tandem mass spectrometry method, and platelet counts were determined by blood tests. CYP1A2 rs762551, CYP2C8*3 rs10509681, CYP2C8*3 rs11572080, UGT1A1 rs887829, UGT1A3 rs3806596, and BCRP rs2231142 polymorphisms were genotyped by Sanger sequencing. A back-propagation artificial neural network (BP-ANN) model was constructed to predict pharmacokinetics based on physiological factors and genetic polymorphism data. RESULTS: Compared with male subjects, female subjects who received a single 25-mg dose of eltrombopag exhibited a significantly increased mean maximum plasma concentration (Cmax) and significantly decreased apparent clearance. Additionally, CYP1A2 rs762551 C>A single nucleotide polymorphism influenced distribution and elimination. C-allele carriers exhibited 30% higher systemic exposure and 20% lower apparent clearance compared with homozygous A-allele carriers. Mean percentage increases in platelet counts from baseline to Day 5 were 9.38% and 17.06% in male and female subjects, respectively. The BP-ANN model had a high goodness-of-fit index and good coherence between predicted and measured concentrations (R = 0.98979). CONCLUSION: Sex and CYP1A2 rs762551 C>A were associated with the pharmacokinetic variability of eltrombopag in healthy Chinese subjects. Females exhibited a better platelet-elevating effect compared with males administered the same dosage. The developed BP-ANN model based on physiological factors and genetic polymorphism data could be promising for applications in pharmacokinetic studies. TRIAL REGISTRATIONS: https://www.Chinadrugtrials.org.cn CTR20190898.

Discovery of a novel series of guanidinebenzoates as gut-restricted enteropeptidase and trypsin dual inhibitors for the treatment of metabolic syndrome.

A novel series of guanidinebenzoate enteropeptidase and trypsin dual inhibitors has been discovered and SAR studies were conducted. Optimization was focused on improving properties for gut restriction, including increased aqueous solubility, lower cellular permeability, and reduced oral bioavailability. Lead compounds were identified with efficacy in a mouse fecal protein excretion study.

Pilot Study of Corneal Clearance With the Use of a Rho-Kinase Inhibitor After Descemetorhexis Without Endothelial Keratoplasty for Fuchs Endothelial Corneal Dystrophy.

PURPOSE: To investigate corneal clearance time using a topical rho-kinase inhibitor, netarsudil, after descemetorhexis without endothelial keratoplasty (DWEK). METHODS: Twenty eyes from 10 patients with Fuchs endothelial corneal dystrophy had DWEK with cataract surgery. For the first eye of each participant, netarsudil was administered immediately after surgery until corneal clearance. For the second eye, netarsudil was withheld 2 weeks beyond the time for corneal clearance of the first eye and then administered only if corneal edema was still present. Interpatient and intrapatient comparisons were made for pachymetry, endothelial cell count, intraocular pressure, and time to corneal clearance. RESULTS: Intrapatient comparison demonstrated no significant difference in preoperative pachymetry (P value 0.58), endothelial cell counts (P value 0.97), and intraocular pressure (P value 0.46) between eyes treated with netarsudil immediately after DWEK and those with delayed netarsudil use. Average time for corneal clearance in eyes treated with netarsudil immediately after surgery was 4.6 ± 1.7 weeks, which was significantly shorter than eyes not treated with netarsudil immediately at 8 ± 1.9 weeks (P < 0.01). Corneal clearance occurred in eyes between 1 and 2 weeks after addition of netarsudil as a "rescue" drop. Interpatient comparison demonstrated significantly greater endothelial cell counts in eyes treated with netarsudil immediately compared with eyes with a delay in netarsudil use (P = 0.05). CONCLUSIONS: Netarsudil significantly reduces the time to corneal clearance after DWEK. Furthermore, increased endothelial cell counts in eyes with immediate netarsudil use versus delayed netarsudil use suggests that the immediate perioperative period is crucial in cell regeneration and migration.

Pharmacokinetics and metabolism of LNP023 in rats by liquid chromatography combined with electrospray ionization-tandem mass spectrometry.

In this study, a simple and sensitive LC-tandem mass spectrometric method was developed and validated for the determination of LNP023 in rat plasma. The plasma sample was precipitated with acetonitrile and then separated on an ACQUITY HSS T3 column (50 mm × 2.1 mm, 1.8 µm) using 0.1% formic acid in water and acetonitrile as the mobile phase. The MS detection was performed in positive multiple-reaction monitoring mode with precursor-to-product ion transitions of m/z 423.3 → 174.1 and m/z 435.3 → 367.1 for LNP023 and olaparib (internal standard), respectively. The developed assay was validated in the linear range of 0.1-1000 ng/mL with correlation coefficient (r) greater than 0.9992. The validation parameters were all within the acceptable limits. The validated method has been successfully used to investigate the pharmacokinetics of LNP023 in rat plasma, and our results indicated that LNP023 showed low clearance and high bioavailability (62.2%). Furthermore, four minor metabolites from rat plasma were detected and identified by LC combined with high-resolution mass spectrometry. The metabolic pathways were O-deethylation (M1), hydroxylation (M4), oxidation (M3), and acyl-glucuronidation (M2).

Nine absorbed components pharmacokinetic of raw and processed Moutan Cortex in normal and blood-heat and hemorrhage syndrome model rats.

Raw Moutan Cortex (RMC) and Processed Moutan Cortex (PMC) have a long history of use in China and other Asian countries. In this study, a rapid and accurate ultra-high-pressure liquid chromatography coupled with diode array detector (UHPLC-DAD) method was developed and validated for the simultaneous determination of nine absorbed compounds of RMC/PMC. After extraction by protein precipitation with methanol from plasma, the analytes were separated on an Acquity UPLC® BEH Shield RP18 column (2.1 × 100 mm, 1.7 µm, Waters, USA). Acetonitrile (A) and 0.1% (v/v) formic acid in water (B) were selected as the mobile phase to perform gradient elution. The linearity of nine analytes was >0.9915. The intra- and inter-assay precision (RSD) values were within 11.18%, and accuracy ranged from 91.32 to 101.29%. Suitable stability, matrix effect and extraction recoveries were also obtained. The validated method was applied to compare the pharmacokinetics of RMC and PMC in Blood-Heat and Hemorrhage Syndrome Model and normal rats. The results revealed that processing and the pathological state could influence the pharmacokinetic characteristics of compounds in RMC/PMC. The study willbe useful for further studies on pharmacokinetics and clinical application of raw and processed Moutan Cortex.

First-in-human phase I study of immunomodulatory E7046, an antagonist of PGE2-receptor E-type 4 (EP4), in patients with advanced cancers.

BACKGROUND: E7046 is a highly selective, small-molecule antagonist of the E-type prostanoid receptor 4 (EP4) for prostaglandin E2, an immunosuppressive mediator of the tumor immune microenvironment. This first-in-human phase 1 study assessed the safety, tolerability, pharmacokinetics, pharmacodynamics, maximum tolerated dose (MTD) and recommended phase 2 dose of E7046. METHODS: This first-in-human study enrolled 30 patients with advanced tumors of cancer types associated with high levels of myeloid infiltrates. E7046 was administered orally once-daily in sequential escalating dose cohorts (125, 250, 500, and 750 mg) with ≥6 patients per cohort. Tumor assessments were performed every 6 weeks. Paired tumor biopsies and blood samples, before and on treatment, were collected for pharmacokinetic and pharmacodynamic characterization of the treatment. RESULTS: No dose-limiting toxicities were observed, and the MTD was not reached. E7046 had an elimination half-life (t1/2) of 12 hours, and drug exposure increased dose-dependently from 125 to 500 mg. Target modulation by E7046 was supported by changes in genes downstream of EP4 with concurrent enhanced antitumoral immune responses. A best response of stable disease (per irRECIST) was reported in 23% of patients treated with E7046 (n=30) (125 mg: n=2; 250 mg: n=2; 750 mg: n=3). Over half (4/7) of the patients with stable disease had treatment duration of 18 weeks or more, and three patients (3/15; 20%) achieved metabolic responses. CONCLUSIONS: In this first-in-human study, E7046 administered orally once daily demonstrated manageable tolerability, immunomodulatory effects, and a best response of stable disease (≥18 weeks) in several heavily pretreated patients with advanced malignancies. The 250 and 500 mg doses are proposed for further development in the combination setting. TRIAL REGISTRATION NUMBER: NCT02540291.

Prediction of Clinical Transporter-Mediated Drug-Drug Interactions via Comeasurement of Pitavastatin and Eltrombopag in Human Hepatocyte Models.

A structurally identifiable micro-rate constant mechanistic model was used to describe the interaction between pitavastatin and eltrombopag, with improved goodness-of-fit values through comeasurement of pitavastatin and eltrombopag. Transporter association and dissociation rate constants and passive rates out of the cell were similar between pitavastatin and eltrombopag. Translocation into the cell through transporter-mediated uptake was six times greater for pitavastatin, leading to pronounced inhibition of pitavastatin uptake by eltrombopag. The passive rate into the cell was 91 times smaller for pitavastatin compared with eltrombopag. A semimechanistic physiologically-based pharmacokinetic (PBPK) model was developed to evaluate the potential for clinical drug-drug interactions (DDIs). The PBPK model predicted a twofold increase in the pitavastatin peak blood concentration and area under the concentration-time curve in the presence of eltrombopag in simulated healthy volunteers. The use of structural identifiability supporting experimental design combined with robust micro-rate constant parameter estimates and a semimechanistic PBPK model gave more informed predictions of transporter-mediated DDIs.

First-in-Human Study of AG10, a Novel, Oral, Specific, Selective, and Potent Transthyretin Stabilizer for the Treatment of Transthyretin Amyloidosis: A Phase 1 Safety, Tolerability, Pharmacokinetic, and Pharmacodynamic Study in Healthy Adult Volunteers.

AG10 is a novel, potent, and selective oral transthyretin (TTR) stabilizer being developed to treat TTR amyloidosis (ATTR). This randomized, double-blind, placebo-controlled study evaluated safety, tolerability, pharmacokinetics, and pharmacodynamics (ex vivo stabilization) of orally administered AG10 in healthy adult volunteers. Both mutant and wild-type ATTR are underdiagnosed diseases with limited therapeutic options. As TTR amyloidogenesis is initiated by dissociation of TTR tetramers destabilized due to inherited mutations or aging, AG10 is designed to treat the disease at its source. Four single and three multiple ascending dose levels of AG10 or matching placebo were orally administered. Safety and tolerability were assessed by vital signs, electrocardiogram, adverse events, and clinical laboratory tests. Pharmacokinetics were measured using a validated bioanalytical assay. Pharmacodynamics were assessed via three pharmacodynamic assays of TTR stabilization. AG10 was uniformly well tolerated, and no safety signals of clinical concern were observed. Pharmacokinetic observations included time to maximum concentration <1 hour, dose-dependent maximum concentration and area under the plasma concentration-time curve, low intersubject variability, and half-life ∼25 hr. Complete (>90%) stabilization of TTR was observed across the entire dosing interval at steady state on the highest dose tested. Serum TTR levels, an in vivo reflection of TTR stabilization by AG10, increased from baseline following 12 days of dosing. AG10 appears to be safe and well tolerated in healthy adult volunteers and can completely stabilize TTR across the dosing interval, establishing clinical proof of concept. Based on these data, AG10 has the potential to be a safe and effective treatment for patients with either mutant or wild-type ATTR.

Safety, Tolerability, and Pharmacokinetics of the Mineralocorticoid Receptor Modulator AZD9977 in Healthy Men: A Phase I Multiple Ascending Dose Study.

Excessive activation of the mineralocorticoid receptor (MR) underlies the pathophysiology of heart failure and chronic kidney disease. Hyperkalemia risk limits the therapeutic use of conventional MR antagonists. AZD9977 is a nonsteroidal, selective MR modulator that may protect nonepithelial tissues without disturbing electrolyte balance. This phase I study investigated the safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple oral doses of AZD9977 in healthy volunteers. Twenty-seven male participants aged 23-45 years were randomized 3:1 to receive oral AZD9977 or placebo for 8 days (with twice-daily dosing on days 2-7), in dose cohorts of 50, 150, and 300 mg (AZD9977, n = 6 per cohort; placebo, n = 3 per cohort). Adverse events occurred in 4 of 18 participants receiving AZD9977 (22.2%) and 6 of 9 receiving placebo (66.7%), all of mild or moderate severity; none were serious or led to withdrawal. AZD9977 was rapidly absorbed, with median time of maximum concentration of 0.50-0.84 hours across dose groups. Area under the curve and maximum concentration were approximately dose proportional but elimination and accumulation terminal half-life increased with dose. Steady-state was reached after 3-4 days, with dose-dependent accumulation of 1.2-1.7-fold. Renal clearance was 5.9-6.5 L/hour and 24-37% of AZD9977 was excreted in the urine. Serum aldosterone levels increased dose dependently from days -1 to 7 in participants receiving AZD9977, but serum potassium levels and urinary electrolyte excretion were unchanged. AZD9977 was generally well-tolerated with no safety concerns. Exploratory outcomes suggested reduced hyperkalemia risk compared with MR antagonists. These findings support further clinical development of AZD9977.

Comprehensive characterization and resolution of discrepant spectrophotometric bilirubin results in patients on eltrombopag therapy.

Background Eltrombopag is a thrombopoietin receptor agonist used for the treatment of thrombocytopenic conditions. It can cause pH-dependent discoloration of plasma/serum. Eltrombopag is potentially hepatotoxic. It can affect the assessment of hyperbilirubinemia because of its (i) absorbance at ~450 nm (bilirubin), (ii) absorbance at ~550 nm (diazo-bilirubin) and (iii) it can cause yellowish discoloration of the eyes at normal circulating bilirubin levels. Methods We collected 66 samples from patients on a range of eltrombopag dosages up to 150 mg daily. Bilirubin was measured using multiple routine spectrophotometric analyzers, the Doumas reference method and high-performance liquid chromatography (HPLC). Plasma/serum eltrombopag concentrations were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Spike-in and admixture experiments delineated the effects of eltrombopag and its metabolites. Results Forty-nine of 52 samples from patients on ≥50 mg daily eltrombopag therapy showed significantly discrepant inter-analyzer total bilirubin results, a difference up to 64 µmol/L (3.7 mg/dL). In one sample, total bilirubin varied from 8 to 65 µmol/L (0.4-3.8 mg/dL) by different routine analyzers, with direct bilirubin ≤4 µmol/L (0.2 mg/dL). There was a positive correlation between total bilirubin difference and plasma eltrombopag concentration (r = 0.679), and spike-in experiments demonstrated that Beckman AU and Doumas reference methods were susceptible to positive interference. HPLC can quantify bilirubin after separating eltrombopag, and results suggest different analyzers are affected to varying degrees by eltrombopag and its metabolites. Conclusions Eltrombopag and its metabolites can cause positive interference to the spectrophotometric measurements of total bilirubin. Accurate measurements of total bilirubin may improve our understanding of the prevalence of hyperbilirubinemia in patients on eltrombopag therapy.

Insights From Liver-Humanized Mice on Cholesterol Lipoprotein Metabolism and LXR-Agonist Pharmacodynamics in Humans.

BACKGROUND AND AIMS: Genetically modified mice have been used extensively to study human disease. However, the data gained are not always translatable to humans because of major species differences. Liver-humanized mice (LHM) are considered a promising model to study human hepatic and systemic metabolism. Therefore, we aimed to further explore their lipoprotein metabolism and to characterize key hepatic species-related, physiological differences. APPROACH AND RESULTS: Fah-/- , Rag2-/- , and Il2rg-/- knockout mice on the nonobese diabetic (FRGN) background were repopulated with primary human hepatocytes from different donors. Cholesterol lipoprotein profiles of LHM showed a human-like pattern, characterized by a high ratio of low-density lipoprotein to high-density lipoprotein, and dependency on the human donor. This pattern was determined by a higher level of apolipoprotein B100 in circulation, as a result of lower hepatic mRNA editing and low-density lipoprotein receptor expression, and higher levels of circulating proprotein convertase subtilisin/kexin type 9. As a consequence, LHM lipoproteins bind to human aortic proteoglycans in a pattern similar to human lipoproteins. Unexpectedly, cholesteryl ester transfer protein was not required to determine the human-like cholesterol lipoprotein profile. Moreover, LHM treated with GW3965 mimicked the negative lipid outcomes of the first human trial of liver X receptor stimulation (i.e., a dramatic increase of cholesterol and triglycerides in circulation). Innovatively, LHM allowed the characterization of these effects at a molecular level. CONCLUSIONS: LHM represent an interesting translatable model of human hepatic and lipoprotein metabolism. Because several metabolic parameters displayed donor dependency, LHM may also be used in studies for personalized medicine.

Novel spectrofluorimetric quantification of alogliptin benzoate in biofluids exploiting its interaction with 4-chloro-7-nitrobenzofurazan.

The direct determination of alogliptin benzoate (ALO) using fluorescence has not yet been accomplished because ALO cannot fluoresce naturally. Accordingly, it should be derivatized first with a fluorogenic reagent to enhance the sensitivity required for its bioanalysis. This method is the first spectrofluorimetric assay for ALO quantification exploiting the nucleophilic nature of its amino group to react with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in borate buffer at pH 8.5 to produce a strong fluorescent compound that is excited at and emits at wavelengths 470 and 527 nm, respectively. Experimental variables concerning the conditions of reaction and fluorogenic intensity were carefully investigated and optimized. Linearity was from 1-250 ng ml-1 with a lower detection limit of 0.29 ng ml-1 and a lower quantification limit of 0.88 ng ml-1 . Validation of the current study was accomplished with mean per cent recovery of 100.62 ± 1.59 in tablets and 99.86 ± 0.82 in human plasma. Furthermore, the current method has been utilized in the bioanalysis of ALO in real rat plasma after oral administration with a simple specimen preparation. The developed method has proven to be a promising alternative method for ALO analysis in bioequivalence studies.

Quantification of urinary derivatives of Phenylbutyric and Benzoic acids by LC-MS/MS as treatment compliance biomarkers in Urea Cycle disorders.

PURPOSE: Salts of phenylacetic acid (PAA) and phenylbutyric acid (PBA) have been used for nitrogen elimination as a treatment for hyperammonaemia caused by urea cycle disorders (UCD). A new analytical method for PBA measurement in urine which helps to evaluate the drug adherence has been implemented. METHODS: Urine specimens from UCD patients receiving PBA were analysed by tandem mass spectrometry to measure urine phenylacetylglutamine (PAGln). Some clinical and biochemical data for each patient were collected. RESULTS: Our study included 87 samples from 40 UCD patients. The PAGln levels did not correlate with height, weight or age. However, the PAGln values showed correlation with PBA dose (r = 0.383, P = 0.015). Plasma glutamine and ammonia levels presented a positive correlation (r = 0.537, P < 0.001). The stability for PAGln in urine was determined at different storage temperatures. CONCLUSIONS: We have developed a simple method for the determination of PAGln in urine, which acts as useful biomarker of effective drug delivery. PAGln in urine is stable at room temperature at least for 15 days, and for several months when frozen at -20 °C. This procedure is useful for the optimization and monitorization of the drug dose allowing the use of spot urine samples.

Phase I, Open-Label, Dose-Escalation Study of the Safety, Pharmacokinetics, Pharmacodynamics, and Efficacy of GSK2879552 in Relapsed/Refractory SCLC.

INTRODUCTION: This first-time-in-humans study assessed the safety, pharmacokinetics (PK), pharmacodynamics (PD), and clinical activity of GSK2879552 in patients with relapsed or refractory SCLC. METHODS: This phase I, multicenter, open-label study (NCT02034123) enrolled patients (≥18 years old) with relapsed or refractory SCLC (after ≥1 platinum-containing chemotherapy or refusal of standard therapy). Part 1 was a dose-escalation study; Part 2 was a dose-expansion study. Dose escalations were based on safety, PK, and PD. The primary end point (Part 1) was to determine the safety, tolerability, and recommended dose and regimen of GSK2879552. Secondary end points were to characterize PK and PD parameters and measure disease control rate at week 16. Part 2 was not conducted. RESULTS: Between February 4, 2014, and April 18, 2017, a total of 29 patients were allocated to one of nine dose cohorts (0.25 mg-3 mg once daily and 3-mg or 4-mg intermittent dosing). In all, 22 patients completed the study; 7 withdrew, primarily owing to adverse events (AEs). Most patients (24 of 29 [83%]) had at least one treatment-related AE, most commonly thrombocytopenia (12 of 29 [41%]). Twelve serious AEs (SAEs) were reported by nine patients; six were considered treatment related, the most common of which was encephalopathy (four SAEs). Three patients died; one death was related to SAEs. PK was characterized by rapid absorption, slow elimination, and a dose-proportional increase in exposure. CONCLUSIONS: GSK2879552 is a potent, selective inhibitor of lysine demethylase 1A and has demonstrated favorable PK properties but provided poor disease control and a high AE rate in patients with SCLC. The study was terminated, as the risk-benefit profile did not favor continuation.

Romiplostim for the management of pediatric immune thrombocytopenia: drug development and current practice.

Since successful cloning of thrombopoietin (TPO) in 1994, significant advances have been made in the development of recombinant TPO receptor agonists. The US Food and Drug Administration (FDA) has approved 2 agents for use in patients with immune thrombocytopenia (ITP): eltrombopag and romiplostim. Romiplostim is a once-weekly subcutaneous injection that has been shown to increase the platelet count, lessen bleeding, and reduce concurrent medication use in adults with ITP. In December 2018, the US FDA approved romiplostim for use in pediatric patients ≥1 year of age with ITP of >6 months' duration and insufficient response to corticosteroids, immunoglobulins, or splenectomy, based on similarly favorable clinical trial data. In addition, romiplostim is well tolerated, making it an attractive option for the treatment of children. Expansion of off-label romiplostim use is being reported in children for ITP <6 months, neonatal thrombocytopenia, hereditary thrombocytopenias, and chemotherapy- and bone marrow transplant-associated thrombocytopenia. We review here the development of romiplostim with a focus on pediatric use.

Experimental and Computational Evaluation of Piperonylic Acid Derived Hydrazones Bearing Isatin Moieties as Dual Inhibitors of Cholinesterases and Monoamine Oxidases.

A set of piperonylic acid derived hydrazones with variable isatin moieties was synthesized and evaluated for their inhibitory activity against the enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and monoamine oxidases A and B (MAO-A/B). The results of in vitro studies revealed IC50 values in the micromolar range, with the majority of the compounds showing selectivity for the MAO-B isoform. N-[2-Oxo-1-(prop-2-ynyl)indolin-3-ylidene]benzo[d][1,3]dioxole-5-carbohydrazide (3) was identified as a lead AChE inhibitor with IC50 =0.052±0.006 µm. N-[(3E)-5-chloro-2-oxo-2,3-dihydro-1H-indol-3-ylidene]-2H-1,3-benzodioxole-5-carbohydrazide (2) was the lead MAO-B inhibitor with IC50 =0.034±0.007 µm, and showed 50 times greater selectivity for MAO-B over MAO-A. The kinetic studies revealed that compounds 2 and 3 displayed competitive and reversible inhibition of AChE and MAO-B, respectively. The molecular docking studies revealed the significance of hydrophobic interactions in the active site pocket of the enzymes under investigation. Further optimization studies might lead to the development of potential neurotherapeutic agents.