Disposition and Mass Balance of Etrasimod in Healthy Subjects and In Vitro Determination of the Enzymes Responsible for Its Oxidative Metabolism

Etrasimod (APD334) is an investigational, once-daily, oral, selective sphingosine 1-phosphate receptor 1,4,5 modulator (S1P_1,4,5 ) in development for treatment of various immune-mediated inflammatory disorders. The disposition and mass balance of a single 2-mg [¹⁴ C]etrasimod dose were evaluated in 8 healthy males. An in vitro study was also conducted to identify etrasimod's oxidative metabolizing enzymes. Peak concentrations of etrasimod and total radioactivity in plasma and whole blood were typically reached 4-7 hours postdose. Etrasimod constituted 49.3% of total radioactivity plasma exposure, with multiple minor/trace metabolites making up the remainder. Etrasimod was slowly cleared mainly via biotransformation, predominantly by oxidative metabolism, with unchanged etrasimod recovered in feces accounting for only 11.2% of the dose and none in urine. The mean apparent terminal half-lives of etrasimod and total radioactivity in plasma were 37.8 and 89.0 hours, respectively. Mean cumulative recovery of radioactivity in excreta over 336 hours was 86.9% of the dose, mostly in feces. The prevalent metabolites eliminated in feces were M3 (hydroxy-etrasimod) and M36 (oxy-etrasimod sulfate), accounting for 22.1% and 18.9% of the dose, respectively. From in vitro reaction phenotyping, the predominant enzymes involved in the oxidation of etrasimod were CYP2C8, CYP2C9, and CYP3A4, with minor contributions from CYP2C19 and CYP2J2.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Absolute Bioavailability, Mass Balance, and Metabolic Profiling Assessment of [14 C]-Belumosudil in Healthy Men: A Phase 1, Open-Label, 2-Part Study

Belumosudil is a selective Rho-associated coiled-coil containing protein kinase 2 (ROCK2) inhibitor. ROCK2 has been shown to drive proinflammatory response and fibrosis that occurs with chronic graft-versus-host disease; therefore, inhibition of ROCK2 has emerged as a therapeutic target for chronic graft-versus-host disease. In this phase 1 two-part study, the pharmacokinetics, mass balance, and metabolic profile of belumosudil were evaluated after single doses of unlabeled belumosudil oral tablets (200 mg), radiolabeled belumosudil intravenous (IV) microtracer infusions (100 μg), and radiolabeled oral capsules (200 mg). Absolute bioavailability based on area under the plasma concentration-time curve from time 0 to infinity for the oral dose/area under the plasma concentration-time curve from time 0 to infinity for the IV dose was calculated as 63.7%. Radiolabeled IV microtracer dosing demonstrated a low extraction ratio and distribution of belumosudil into tissues. The majority of total radioactivity was recovered in feces, with minimal amounts recovered in urine, suggesting minimal renal elimination of belumosudil. In addition to parent and main metabolite KD025m2, metabolites identified in plasma included the phase 2 metabolites O-dealkylated belumosudil sulfate and belumosudil glucuronide. These metabolites (with the exception of the glucuronide) in addition to monohydroxy-belumosudil, and belumosudil diol were identified in feces. No metabolites in urine accounted for >10% of the radioactive dose.

Metabolism of the Dual Orexin Receptor Antagonist ACT-541468, Based on Microtracer/ Accelerator Mass Spectrometry

Background:

As part of an integrated and innovative approach to accelerate the clinical development of the dual receptor antagonist ACT-541468, 6 healthy subjects in one cohort in a first-in-humans (FIH) study received an oral dose of 50 mg non-labeled ACT-541468 together with a microtracer amount of 250 nCi of 14C-labeled ACT- 541468 to investigate its absorption, distribution, metabolism, and excretion (ADME).

Methods:

Using accelerator mass spectrometry (AMS), radiochromatograms were constructed for fractionated plasma, urine, and feces samples. Subsequently, the structures of the metabolites were elucidated using high performance liquid chromatography (HPLC) coupled with high resolution mass spectrometry.

Results:

In total 77 metabolites have been identified of which 30, 28, and 60 were present in plasma, urine, and feces, respectively. In plasma, the major metabolites were the mono-oxidized benzylic alcohol M3, the ACT-541468 aldehyde M1, formed by further oxidation of M3 in the benzylic position, and the doubly oxidized M10, formed by (1) benzylic oxidation of M3 (loss of one molecule of water and one molecule of ammonia) and (2) additional loss of water from the oxidized pyrrolidine ring of M5. Transformation of the pyrrolidine to a 6-membered ring was detected. Metabolites that accounted for more than 5% of total radioactivity in excreta were M2, which is also formed by oxidation at the benzylic position, M4, formed by demethylation of the methoxy-group, M7 and A6, both formed by oxidation of M4, and M10, the only major metabolite detected in urine.

Conclusion:

In conclusion, ACT-541468 is extensively metabolized predominantly by oxidative transformations.

Tumor necrosis factor family member LIGHT acts with IL-1β and TGF-β to promote airway remodeling during rhinovirus infection

BACKGROUND

Rhinovirus (RV) can exacerbate allergen-driven asthma. However, it has been suggested that serial infections with RV may also lead to asthma-like features in childhood without prior allergen exposure.

AIM

We sought to test the effects of RV infection in the absence of allergen challenge on lung tissue remodeling and to understand whether RV induced factors in common with allergen that promote remodeling.

METHODS

We infected C57BL/6 mice multiple times with RV in the absence or presence of allergen to assess airway remodeling. We used knockout mice and blocking reagents to determine the participation of LIGHT (TNFSF14), as well as IL-1β and TGF-β, each previously shown to contribute to lung remodeling driven by allergen.

RESULTS

Recurrent RV infection without allergen challenge induced an increase in peribronchial smooth muscle mass and subepithelial fibrosis. Rhinovirus (RV) induced LIGHT expression in mouse lungs after infection, and alveolar epithelial cells and neutrophils were found to be potential sources of LIGHT. Accordingly, LIGHT-deficient mice, or mice where LIGHT was neutralized, displayed reduced smooth muscle mass and lung fibrosis. Recurrent RV infection also exacerbated the airway remodeling response to house dust mite allergen, and this was significantly reduced in LIGHT-deficient mice. Furthermore, neutralizing IL-1β or TGF-β also limited subepithelial fibrosis and/or smooth muscle thickness induced by RV.

CONCLUSION

Rhinovirus can promote airway remodeling in the absence of allergen through upregulating common factors that also contribute to allergen-associated airway remodeling.

Pharmacokinetics, absorption, and excretion of radiolabeled revexepride: a Phase I clinical trial using a microtracer and accelerator mass spectrometry-based approach

Purpose

Gastroesophageal reflux disease involves the reflux of gastric and/or duodenal content into the esophagus. Prokinetic therapies, such as the selective 5-hydroxytryptamine receptor 4 agonist revexepride, may aid gastric emptying. This Phase I study evaluated the pharmacokinetics and excretion pathways of [¹⁴C]revexepride in healthy individuals using a microtracer approach with accelerator mass spectrometry.

Participants and methods

Six healthy men received a single oral dose of 2 mg [¹⁴C]revexepride containing ~200 nCi of radioactivity; blood, urine, and fecal samples were collected over a 10-day period.

Results

Almost 100% of ¹⁴C was recovered: 38.2%±10.3% (mean ± standard deviation) was recovered in urine, and 57.3%±0.4% was recovered in feces. Blood cell uptake was low, based on the blood plasma total radioactivity ratio of 0.8. The mean revexepride renal clearance was 8.6 L/h, which was slightly higher than the typical glomerular filtration rate in healthy individuals. Time to reach maximal concentration was 1.75±1.17 hours (mean ± standard deviation). No safety signals were identified.

Conclusion

This study demonstrated that revexepride had rapid and moderate-to-good oral absorption. Excretion of radioactivity was completed with significant amounts in feces and urine. Renal clearance slightly exceeded the typical glomerular filtration rate, suggesting the involvement of active transportation in the renal tubules.

Pharmacokinetics and metabolism of [14C]-tozadenant (SYN-115), a novel A2a receptor antagonist ligand, in healthy volunteers

1. This phase-I study (NCT02240290) was designed to investigate the human absorption, disposition and mass balance of ¹⁴C-tozadenant, a novel A2a receptor antagonist in clinical development for Parkinson s disease. 2. Six healthy male subjects received a single oral dose of tozadenant (240 mg containing 81.47 KBq of [¹⁴C]-tozadenant). Blood, urine and feces were collected over 14 days. Radioactivity was determined by liquid scintillation counting or accelerator mass spectrometry (AMS). Tozadenant and metabolites were characterized using HPLC-MS/MS and HPLC-AMS with fraction collection. 3. At 4 h, the C_max of tozadenant was 1.74 μg/mL and AUC_(0-t) 35.0 h μg/mL, t_1/2 15 h, Vz/F 1.82 L/kg and CL/F 1.40 mL/min/kg. For total [¹⁴C] radioactivity, the C_max was 2.29 μg eq/mL at 5 h post-dose and AUC_(0-t) 43.9 h μg eq/mL. Unchanged tozadenant amounted to 93% of the radiocarbon AUC_(0-48h). At 312 h post-dose, cumulative urinary and fecal excretion of radiocarbon reached 30.5% and 55.1% of the dose, respectively. Unchanged tozadenant reached 11% in urine and 12% of the dose in feces. Tozadenant was excreted as metabolites, including di-and mono-hydroxylated metabolites, N/O dealkylated metabolites, hydrated metabolites. 4. The only identified species circulating in plasma was unchanged tozadenant. Tozadenant was primarily excreted in urine and feces in the form of metabolites.

A life course perspective on familial and environmental risks for schizophrenia using a western Australian E-cohort

Introduction

Familial risk for psychosis may interact with environmental risk factors.

Objectives

We are studying a large birth cohort of children of mothers with psychotic disorders, themselves at high risk of developing a psychotic illness, to understand the developmental aetiology of psychotic illness.

Aims

Our aim is to examine whether exposure to environmental stressors in childhood, including timing of exposure, is a risk factor for psychotic illness, independent of familial liability. Specificity to maternal schizophrenia is explored.

Methods

We used record-linkage across state-wide registers (midwives, psychiatric, child protection and mortality, among others) to identify 15,486 offspring born in Western Australia 1980–2001 to mothers with a lifetime history of psychotic illness (case children) and compared them with 452,459 offspring born in the same period to mothers with no known psychiatric history (comparison children).

Results

A total of 4.1% of case children had developed a psychotic illness compared to 1.1% of comparison children. Exposure to environmental risk factors including obstetric complications, aboriginality, lower socioeconomic status, discontinuity in parenting and childhood abuse significantly increased risk of psychotic illness in offspring. Length and age at time of discontinuity in parenting impacted on risk. At the same time, case children were also significantly more likely than comparison children to be at risk of experiencing these adverse life events.

Conclusions

Exposure to environmental stressors is associated with psychotic illness, and timing of exposure is important. However, children already at increased familial risk for psychotic illness are also at increased risk of experiencing these environmental stressors.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Human mass balance study of TAS-102 using (14)C analyzed by accelerator mass spectrometry

BACKGROUND

TAS-102 is an oral fluoropyrimidine prodrug composed of trifluridine (FTD) and tipiracil hydrochloride (TPI) in a 1:0.5 ratio. FTD is a thymidine analog, and it is degraded by thymidine phosphorylase (TP) to the inactive trifluoromethyluracil (FTY) metabolite. TPI inhibits degradation of FTD by TP, increasing systemic exposure to FTD.

METHODS

Patients with advanced solid tumors (6 M/2 F; median age 58 years; PS 0-1) were enrolled on this study. Patients in group A (N = 4) received 60 mg TAS-102 with 200 nCi [(14)C]-FTD, while patients in group B (N = 4) received 60 mg TAS-102 with 1000 nCi [(14)C]-TPI orally. Plasma, blood, urine, feces, and expired air (group A only) were collected up to 168 h and were analyzed for (14)C by accelerator mass spectrometry and analytes by LC-MS/MS.

RESULTS

FTD: 59.8% of the (14)C dose was recovered: 54.8% in urine mostly as FTY and FTD glucuronide isomers. The extractable radioactivity in the pooled plasma consisted of 52.7% FTD and 33.2% FTY. TPI: 76.8% of the (14)C dose was recovered: 27.0% in urine mostly as TPI and 49.7% in feces. The extractable radioactivity in the pooled plasma consisted of 53.1% TPI and 30.9% 6-HMU, the major metabolite of TPI.

CONCLUSION

Absorbed (14)C-FTD was metabolized and mostly excreted in urine. The majority of (14)C-TPI was recovered in feces, and the majority of absorbed TPI was excreted in urine. The current data with the ongoing hepatic and renal dysfunction studies will provide an enhanced understanding of the TAS-102 elimination profile.

Polar and magnetic layered A-site and rock salt B-site-ordered NaLnFeWO6 (Ln = La, Nd) perovskites

We have expanded the double perovskite family of materials with the unusual combination of layered order in the A sublattice and rock salt order over the B sublattice to compounds NaLaFeWO6 and NaNdFeWO6. The materials have been synthesized and studied by powder X-ray diffraction, neutron diffraction, electron diffraction, magnetic measurements, X-ray absorption spectroscopy, dielectric measurements, and second harmonic generation. At room temperature, the crystal structures of both compounds can be defined in the noncentrosymmetric monoclinic P2(1) space group resulting from the combination of ordering both in the A and B sublattices, the distortion of the cell due to tilting of the octahedra, and the displacement of certain cations. The magnetic studies show that both compounds are ordered antiferromagnetically below T(N) ≈ 25 K for NaLaFeWO6 and at ∼21 K for NaNdFeWO6. The magnetic structure of NaNdFeWO6 has been solved with a propagation vector k = ((1/2) 0 (1/2)) as an antiferromagnetic arrangement of Fe and Nd moments. Although the samples are potential multiferroics, the dielectric measurements do not show a ferroelectric response.

Phenotype of autosomal dominant cone–rod dystrophy due to the R838C mutation of the GUCY2D gene encoding retinal guanylate cyclase-1

AIMS

To describe the phenotype of members of a large Caucasian British family affected by autosomal dominant cone-rod dystrophy due to an R838C mutation in the guanylate cyclase 2D (GUCY2D) gene encoding retinal guanylate cyclase-1 (RETGC-1).

METHODS

Retrospective review of 29 patients from four generations of the same family.

RESULTS

Visual symptoms usually commenced in childhood. Only two patients, aged 14 and 25 years, had visual acuity compatible with driving. Of the 12 patients aged over 40 years, eight (66%) had vision of counting fingers or worse and were eligible for blind registration in the UK. Of the 29 patients, 18 (62%) had myopia greater than 5 D in at least one eye. Most had discernible macular changes on biomicroscopy, which varied from subtle RPE change to gross macular atrophy. All patients who underwent computerised perimetry exhibited a central or paracentral scotoma with normal peripheral field of vision. Of the 21 patients who underwent electrodiagnostic testing, all exhibited decreased cone function, but rod function was normal in 12 (57%) patients.

CONCLUSION

We believe this report highlights the importance of phenotype-genotype correlation in cone and cone-rod dystrophies. Increased understanding of the varying phenotypes associated with different genetic mutations allows appropriate counselling of patients. In addition, the phenotypic characterisation of the natural history of these conditions may prove valuable in the future should therapeutic interventions become available.

Australian survey of acrylamide in carbohydrate-based foods

A method was developed and validated for the determination of acrylamide in carbohydrate-based foods. Solid-phase extraction employing a mixed-bed anion and cation exchange cartridge in series with a C18 extraction disk was used to clean-up water extracts of food samples before analysis by liquid chromatography coupled with tandem mass spectrometry detection. The limit of detection was calculated as approximately 25 microg kg(-1) and the limit of reporting was 50 microg kg(-1). The average method recovery for 84 samples from a range of matrices reporting was 99% with a relative standard deviation of 11.2%. A survey was conducted of 112 samples of carbohydrate-based foods composited from 547 products available in the Australian market. The analytical results were used in conjunction with Australian food consumption data derived from the 1995 National Nutrition Survey (NNS) to prepare preliminary dietary exposure estimates of Australians to acrylamide through only the food groups examined. Mean dietary exposure to acrylamide resulting from consumption of the foods tested, for Australians aged 2 years and above, was estimated as 22-29 microg day(-1) (equivalent to 0.4-0.5 microg kg(-1) bodyweight day(-1)) and between 73 and 80 microg day(-1) (1.4 and 1.5 microg kg(-1) bodyweight day(-1)) for 95th percentile consumers. Young children (2-6 years) consuming acrylamide-containing foods had a higher acrylamide exposure on a per kilogram bodyweight basis (mean 1.0-1.3 microg kg(-1) bodyweight day(-1)). The estimated exposure of Australians to acrylamide is similar to that estimated for other countries.