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In this report, the European Bioanalysis Forum shares the proposals for harmonized implementation of the ICH M10 guideline on bioanalytical method validation and study sample analysis from the ICH M10 workshop. The focus of the discussions was to understand new, changed or still ambiguous regulatory expectations in the guideline, as identified in feedback from the pre-workshop surveys or during the workshop. The proposals from the workshop aim at stimulating and helping a harmonized implementation of the guideline, and using our community as a sounding board during and after implementation to highlight areas of misalignment and to create a platform for continued sharing with the regulatory authorities in an effort to contribute to industry and regulators developing similar interpretations on guideline expectations.

Aim: Capillary microsampling of 15 μl whole blood from fingersticks or heelsticks was used to collect pharmacokinetic (PK) samples from pediatric subjects in two projects. Results: In a mebendazole multisite study in Ethiopia and Rwanda in subjects between 1 and 16 years old, complete PK profiles (7 timepoints) could be obtained, although some of the fingerstick samples were contaminated by the dosing formulation. In a multisite study with a respiratory syncytial virus drug in children between 1 and 24 months old, sparse PK sampling was done (2 samples). All samples were successfully analyzed even though some capillaries were not properly filled. Conclusion: CMS shows potential for PK sampling in pediatrics but may need further optimization.

The neglected tropical disease onchocerciasis, or river blindness, is caused by infection with the filarial nematode Onchocerca volvulus. Current estimates indicate that 17 million people are infected worldwide, the majority of them living in Africa. Today there are no non-invasive tests available that can detect ongoing infection, and that can be used for effective monitoring of elimination programs. In addition, to enable pharmacodynamic studies with novel macrofilaricide drug candidates, surrogate endpoints and efficacy biomarkers are needed but are non-existent. We describe the use of a multimodal untargeted mass spectrometry-based approach (metabolomics and lipidomics) to identify onchocerciasis-associated metabolites in urine and plasma, and of specific lipid features in plasma of infected individuals (O. volvulus infected cases: 68 individuals with palpable nodules; lymphatic filariasis cases: 8 individuals; non-endemic controls: 20 individuals). This work resulted in the identification of elevated concentrations of the plasma metabolites inosine and hypoxanthine as biomarkers for filarial infection, and of the urine metabolite cis-cinnamoylglycine (CCG) as biomarker for O. volvulus. During the targeted validation study, metabolite-specific cutoffs were determined (inosine: 34.2 ng/ml; hypoxanthine: 1380 ng/ml; CCG: 29.7 ng/ml) and sensitivity and specificity profiles were established. Subsequent evaluation of these biomarkers in a non-endemic population from a different geographical region invalidated the urine metabolite CCG as biomarker for O. volvulus. The plasma metabolites inosine and hypoxanthine were confirmed as biomarkers for filarial infection. With the availability of targeted LC-MS procedures, the full potential of these 2 biomarkers in macrofilaricide clinical trials, MDA efficacy surveys, and epidemiological transmission studies can be investigated., Author summary Today’s diagnosis of infection with the filarial parasite Onchocerca volvulus mainly depends on the microscopic analysis of skin biopsies and serological testing. The work presented here describes the use of multiple mass spectrometry-based screening methods (metabolomics and lipidomics) to search for biomarkers indicative of infection with Onchocerca volvulus. This resulted in the identification of elevated concentrations of the plasma metabolites inosine and hypoxanthine as biomarkers for filarial infection, and of the urine metabolite cis-cinnamoylglycine as biomarker for O. volvulus. Further evaluation of these biomarkers in a geographically distinct non-endemic population however invalidated the use of urine cis-cinnamoylglycine. These findings are of utmost importance as it not only opens new avenues in the development of non-invasive diagnostic tools for filarial infections, but also emphasizes the need for evaluation and validation of newly discovered biomarkers in different populations from different geographies.

Once released, the ICH M10 Guideline on bioanalytical method validation will become one of the most important milestones in the history of regulated bioanalysis, closing a chapter on intense discussions among the industry and health authorities started in Crystal City in 2001. In this manuscript, the European Bioanalysis Forum community reports back on their feedback on the ICH M10 draft guideline gathered during the public consultation period. The comments given are intended to contribute to a guideline that combines several decades of experience and current scientific vision. They should provide future generations of bioanalytical scientist a regulatory framework so their bioanalytical work can contribute to safe, effective and high-quality medicines, which can be developed and registered in the most resource-efficient manner.

The 2018 12th Workshop on Recent Issues in Bioanalysis (12th WRIB) took place in Philadelphia, PA, USA on April 9–13, 2018 with an attendance of over 900 representatives from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day full immersion in bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule bioanalysis involving LC–MS, hybrid ligand binding assay (LBA)/LC–MS and LBA/cell-based assays approaches. This 2018 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2018 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1) covers the recommendations for LC–MS for small molecules, peptides, oligonucleotides and small molecule biomarkers. Part 2 (hybrid LBA/LC–MS for biotherapeutics and regulatory agencies’ inputs) and Part 3 (large molecule bioanalysis, biomarkers and immunogenicity using LBA and cell-based assays) are published in volume 10 of Bioanalysis, issues 23 and 24 (2018), respectively.

Within our company, incurred sample reproducibility (ISR) was implemented a decade ago. Only 11 studies (

Aim: Imetelstat, a 13-mer oligonucleotide with a lipid tail is being evaluated for treating hematologic myeloid malignancies. This report describes the development of extraction and quantification methods for imetelstat. Methodology & results: Imetelstat was extracted using SPE (rat plasma) or by hybridization using a biotinylated capture probe (human plasma) and was quantified by LC–MS/MS. Calibration curves were established (0.1–50 μg/ml). Stability of imetelstat in plasma was demonstrated. Concentrations of imetelstat extracted using either of the methods and quantified with LC–MS/MS were comparable with a validated ELISA. Conclusion: Two extraction methods (solid phase and hybridization) were developed for quantifying imetelstat in plasma using LC–MS/MS. The hybridization extraction in combination with LC–MS/MS is a novel extraction approach.

The strategy of outsourcing bioanalytical services at Janssen has been evolving over the last years and an update will be given on the recent changes in our processes. In 2016, all internal GLP-related activities were phased out and this decision lead to the re-orientation of the in-house bioanalytical activities. As a consequence, in-depth experience with the validated bioanalytical assays for new drug candidates is currently gained together with the external partner, since development and validation of the assay and execution of GLP preclinical studies are now transferred to the CRO. The evolution to externalize more bioanalytical support has created opportunities to build even stronger partnerships with the CROs and to refocus internal resources. Case studies are presented illustrating challenges encountered during method development and validation at preferred partners when limited internal experience is obtained or with introduction of new technology.

Aim: Quantitative LC–MS analysis of oligonucleotides (OGNs) in biological matrices is needed to support candidate selection of new therapeutic OGNs. Methodology & results: A set of 20 single stranded antisense oligonucleotides (ASO) and five siRNAs were extracted from plasma and tissue homogenates. Anion Exchange (AEX) SPE was selected as generic extraction approach, resulting in recoveries from plasma >70%. Extraction from tissue homogenates showed often more variation and lower recoveries. A proof of concept of a novel tailored hybridization extraction is demonstrated for two 16-mer reference OGNs. Conclusion: Two methods for extraction of OGNs were investigated and applied for quantitative analysis. The AEX-SPE is considered a more generic approach preferred when multiple compounds are evaluated. Hybridization extraction has great potential but critical reagents per analyte are needed.

Two case studies are presented of validated assays where the internal standard showed high variability, and there was a clear response difference between study samples and standards and quality controls. In the first case a co-eluting peak boosted the stable isotope labeled internal standard response in samples from hepatically impaired subjects. In the second case the blank plasma matrix suppressed the structural analog internal standard response. For both assays the issue could be resolved by adapting the chromatographic conditions and re-validating the assay (case 1) or by diluting the study samples with blank plasma (case 2).

Aim: To evaluate alternative analytical strategies to extend the dynamic range in quantitative LC–MS/MS. Methods & results: Two approaches based on prior or no prior knowledge of expected exposure levels were evaluated. These approaches make use of two analytical strategies, which include the use of more than one injection volume or dilution of sample extract with solvents or solvent mixtures. A total of 16 compounds with varying logP values were classified into polar and nonpolar groups and used in this evaluation. From the two analytical strategies, three workflows were derived. Conclusion: All three workflows were successfully evaluated and resulted in good accuracy (80–120%) for all the compound groups.

Introduction The Belgian Health Care Reform: “Integrated Care for a better health” was approved by all responsible ministers in 2015 (federal level and federated entities). This plan aims to provide high quality care and support to all patients, at the best cost, and to improve the health status of the population (Triple Aim). In order to achieve this goal, local pilot projects were implemented all across the country following a ‘guided bottom-up approach’. In this approach, actors were given the initiative to create a project based on the local needs and context with the government acting as facilitating partner. After a conceptualization phase, 12 projects have started in January 2018 with the deployment of a specific action plan in order to achieve integrated care in their region. On the basis of the experiences during the first 18 months of implementation, some lessons learned and recommendations can already be formulated. Policy Context And Objective Belgium has an accessible health care with a national, compulsory health insurance (covering 99% of the population). Fee for Service, fragmented services and lack of coordination and communication lead to inefficiencies and make the system unsustainable for dealing with the future societal challenges (e.g. multimorbidity). A legislative basis was created to allow pilot regions to test new, integrated models of care. Target Population The Plan targets the whole Belgian population with a focus on people with a chronic disease. In total, the 12 projects cover a region of 2.52 million people (about a quarter of the Belgian population). Highlights The first stage of implementation already highlighted different key lessons for the future design and implementation of integrated care policies in Belgium, such as: - The underlying vision and key components of integrated care as put forward in the national plan are widely supported by all stakeholders - The guided bottom-up approach in order to create and sustain support at the local level is valuable, but building these relationships of trust takes time - Integration at the policy level is a key determinant for a successful change towards integrated care - To be able to test new practices, a sufficient amount of legal flexibility is highly desirable - Some key aspects of integrated care systems are difficult to develop through bottom-up pilot projects; e.g. sustainable multidisciplinary and transmural communication tools - To be able to evaluate such complex system changes, extensive data are needed that are not always available yet in current practice - Within a co-creative approach between government and field, the aspect of trust is essential: o Clarity in the role of the government (partner and evaluator) o Clear expectations between both parties Conclusion The early implementation stage of integrated care in Belgium highlighted different good practices as well as some strategic challenges. Also, these first experiences demonstrated the enormous support and willingness to change at the local level. Clear policy choices now need to be made in order to overcome these challenges so that the 12 pilot regions can grow to reach their full potential.

Polyphenols display a number of interesting properties but their low solubility limits practical applications. In that respect, glycosylation offers a solution for which sucrose phosphorylase has been proposed as a cost-effective biocatalyst. However, its activity on alternative acceptor substrates is too low for synthetic purposes and typically requires the addition of organic (co-)solvents. Here, we describe the engineering of the enzyme from Thermoanaerobacterium thermosaccharolyticum to enable glycosylation of resveratrol as test case. Based on docking and modeling studies, an active-site loop was predicted to hinder binding. Indeed, the unbolted loop variant R134A showed useful affinity for resveratrol (K(m)=185 mM) and could be used for the quantitative production of resveratrol 3-α-glucoside in an aqueous system. Improved activity was also shown for other acceptors, introducing variant R134A as promising new biocatalyst for glycosylation reactions on bulky phenolic acceptors.

Tapentadol is a novel, centrally acting analgesic with 2 mechanisms of action, MOR agonism and noradrenaline (NA) reuptake inhibition in a single molecule. It is the first member of a new therapeutic class, MOR-NRI. A high throughput liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay was developed and validated for the quantitative analysis of tapentadol and its O-glucuronide metabolite in human serum. Simultaneous quantification was deemed to be challenging because of the large difference in concentrations between tapentadol and its O-glucuronide metabolite in clinical samples. Therefore, a method was established using a common processed sample, but with different injection volumes and chromatographic conditions for each analyte. Tapentadol and tapentadol-O-glucuronide were determined by protein precipitation of 0.100ml of the samples with acetonitrile. The internal standards used are D₆-tapentadol and D₆-tapentadol-O-glucuronide. The validated concentration range was 0.200-200 ng/ml (tapentadol) and 10.0-10,000 ng/ml (tapentadol-O-glucuronide). Chromatographic separation was achieved by gradient elution on a Waters Acquity UPLC BEH C18 (1.7 μm, 2.1 × 50 mm) column, with mobile phase consisting of 0.01 M ammonium formate (adjusted to pH 4 using formic acid) (A) and methanol (B). A separate injection was done for measurement of each analyte, with a different gradient and run time. The analytes were detected by using an electrospray ion source on a triple quadrupole mass spectrometer operating in positive ionization mode. The run time was 1.6 min for tapentadol and 1.5 min for tapentadol-O-glucuronide. The high sensitivity and acceptable performance of the assay allowed its application to the analysis of serum samples in clinical trials. The validated method was used for analysis of tapentadol in over 17,000 samples.

The 2017 11th Workshop on Recent Issues in Bioanalysis (11th WRIB) took place in Los Angeles/Universal City, California from 3 April 2017 to 7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, weeklong event – A Full Immersion Week of Bioanalysis, Biomarkers and Immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small and large molecule analysis involving LCMS, hybrid LBA/LCMS and ligand-binding assay (LBA) approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1) covers the recommendations for Small Molecules, Peptides and Small Molecule Biomarkers using LCMS. Part 2 (Biotherapeutics, Biomarkers and Immunogenicity Assays using Hybrid LBA/LCMS and Regulatory Agencies’ Inputs) and Part 3 (LBA: Immunogenicity, Biomarkers and PK Assays) are published in volume 9 of Bioanalysis, issues 23 and 24 (2017), respectively.

Coproporphyrins are proposed as endogenous biomarkers of hepatic Organic Anion Transporting Polypeptide (OATP)1B functional activity. In this study, a new sample extraction method based on a mixed-mode anion exchange sorbent (SPE clean-up using Oasis 30mg Max 96 well plates) was developed for absolute quantification of coproporphyrin I and III (CP-I and CP-III) in human plasma. Chromatographic separation was performed with an Ace Excel 2 C18 PFP, 3μm, 2.1×150mm, maintained at 60°C. A 10mM ammonium formate containing 0.1% HCOOH and acetonitrile (100%) was used as mobile phase A and B, respectively. Mass transition, m/z 655.3→596.3 was selected to monitor CP-I and CP-III, while m/z 659.3→600.3 transition was used for the stable isotope labelled internal standard. Optimization of the liquid chromatography tandem mass spectrometry method ensured a lower limit of quantification (LLOQ) of 20pg/mL. Both CP-I and CP-III had extraction recoveries of 70%. The calibration range was 0.02-100ng/mL for both CP-I and CP-III, yielding calibration curves with correlation coefficients greater than 0.988. Inter day precision (CV9%) and accuracy (84.3-103.9%) complied with the recommendation of the European Bioanalytical Forum. The optimized method was used to analyse plasma samples originating from three independent clinical studies. Obtained CP-I and CP-III plasma baseline levels in healthy volunteers were in good agreement with previously published data. Moreover, CP-I and CP-III plasma levels in human subjects dosed with a clinically confirmed OATP inhibitor were significantly increased compared to their baseline levels. These data demonstrate the potential of CP-I and CP-III as endogenous biomarkers to predict the drug-drug interaction (DDI) related to hepatic OATP1B inhibition. Stability of CP-I and CP-III in plasma and solvents under different processing and storage conditions was also evaluated.

Bedaquiline (BDQ) is an antibiotic to treat pulmonary multidrug-resistant tuberculosis (MDR-TB). Studies up to 39 weeks were conducted orally in dogs to assess the toxicity and pharmacokinetics of BDQ and its N-desmethyl metabolite (D-BDQ). Phospholipidosis (PLD) seen in the monocytic phagocytic system was considered an adaptive change. Skeletal muscle, heart, stomach, liver, and pancreas toxicities with D-BDQ as the main contributor were associated with a less-than-dose-proportional increase in plasma exposure and an overproportional tissue uptake of BDQ and D-BDQ at high-dose levels. Tissue concentrations of BDQ and D-BDQ slowly decreased after lowering the dose, contributing to the recovery of the pathological findings. Treatment was better tolerated at mid-dose levels, characterized by a dose-proportional increase in plasma and tissue exposures. Treatment at a low dose, reaching exposures approximating therapeutic exposures, was without adverse effects and not associated with PLD. There was no evidence of delayed toxicities after treatment cessation. Intermittent dosing was better tolerated at high doses. Since MDR-TB patients are dosed within the linear plasma exposure range and plasma levels of BDQ and D-BDQ are similar or lower than in dogs, PLD and adverse findings related to tissue accumulation that occurred at high doses in dogs are unlikely to occur in humans.

The 2014 8th Workshop on Recent Issues in Bioanalysis (8th WRIB), a 5-day full immersion in the evolving field of bioanalysis, took place in Universal City, California, USA. Close to 500 professionals from pharmaceutical and biopharmaceutical companies, contract research organizations and regulatory agencies worldwide convened to share, review, discuss and agree on approaches to address current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches and immunogenicity. From the prolific discussions held during the workshop, specific recommendations are presented in this 2014 White Paper. As with the previous years’ editions, this paper acts as a practical tool to help the bioanalytical community continue advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2014 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1) covers the recommendations for small molecule bioanalysis using LCMS. Part 2 (Hybrid LBA/LCMS, Electronic Laboratory Notebook and Regulatory Agencies’ input) and Part 3 (Large molecules bioanalysis using LBA and Immunogenicity) will be published in the upcoming issues of Bioanalysis.

Drug-drug interactions between canagliflozin, a sodium glucose co-transporter 2 inhibitor, and glyburide, metformin, and simvastatin were evaluated in three phase-1 studies in healthy participants. In these open-label, fixed sequence studies, participants received: Study 1-glyburide 1.25 mg/day (Day 1), canagliflozin 200 mg/day (Days 4-8), canagliflozin with glyburide (Day 9); Study 2-metformin 2,000 mg/day (Day 1), canagliflozin 300 mg/day (Days 4-7), metformin with canagliflozin (Day 8); Study 3-simvastatin 40 mg/day (Day 1), canagliflozin 300 mg/day (Days 2-6), simvastatin with canagliflozin (Day 7). Pharmacokinetic parameters were assessed at prespecified intervals. Co-administration of canagliflozin and glyburide did not affect the overall exposure (maximum plasma concentration [Cmax ] and area under the plasma concentration-time curve [AUC]) of glyburide and its metabolites (4-trans-hydroxy-glyburide and 3-cis-hydroxy-glyburide). Canagliflozin did not affect the peak concentration of metformin; however, AUC increased by 20%. Though Cmax and AUC were slightly increased for simvastatin (9% and 12%) and simvastatin acid (26% and 18%) following coadministration with canagliflozin, compared with simvastatin administration alone; however, no effect on active 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibitory activity was observed. There were no serious adverse events or hypoglycemic episodes. No drug-drug interactions were observed between canagliflozin and glyburide, metformin, or simvastatin. All treatments were well-tolerated in healthy participants.

The N-terminal domain of the Epa1p adhesin from Candida glabrata (N-Epa1p) is a calcium-dependent lectin, which confers the opportunistic yeast the ability to adhere to human epithelial cells. This lectin domain is able to interact with galactosides and, more precisely, with glycan molecules containing the Gal beta-1,3-GalNAc disaccharide, also known as the T-antigen. Based on the crystallographic structure of the N-Epa1p domain and the role of the variable loop CBL2 in glycan binding, saturation mutagenesis on some residues of the CBL2 loop was used to increase the binding affinity of N-Epa1p for fibronectin, which was selected as a model of a human glycoprotein. Two adhesin mutants, E227A and Y228W, with improved binding features were obtained. More importantly, a glycan array screening revealed that single-point mutations in the CBL2 could produce significant changes in the carbohydrate specificity of the protein. In particular, lectin molecules were generated with a high affinity for sulfated glycans, which may find an application as molecular probes for the identification of 6-sulfogalactose containing glycans and glycoconjugates.

Simeprevir (also known as TMC435 or TMC435350) is a novel hepatitis C protease inhibitor. A validated high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the sensitive and selective quantification of simeprevir in human EDTA plasma is described. During assay development, special attention was given to light instability of the drug in plasma and blood. The method consisted of precipitation of plasma proteins with acetonitrile after which the supernatant was analyzed using electrospray LC–MS/MS. The linearity was confirmed in the concentration range from 2.00 to 2000 ng/mL, with 50-fold dilution extending to 100,000 ng/mL. The precision of this assay, expressed as CV, ranged between 4.4% and 8.5% over the entire concentration range with assay accuracy between −0.3% and 8.5%. The method was applied successfully in many clinical studies to document the pharmacokinetics of simeprevir in plasma from healthy volunteers and patients.

Despite the growing importance of prebiotics in nutrition and gastroenterology, their structural variety is currently still very limited. The lack of straightforward procedures to gain new products in sufficient amounts often hampers application testing and further development. Although the enzyme sucrose phosphorylase can be used to produce the rare disaccharide kojibiose (α-1,2-glucobiose) from the bulk sugars sucrose and glucose, the target compound is only a side product that is difficult to isolate. Accordingly, for this biocatalyst to become economically attractive, the formation of other glucobioses should be avoided and therefore we applied semi-rational mutagenesis and low-throughput screening, which resulted in a double mutant (L341I_Q345S) with a selectivity of 95% for kojibiose. That way, an efficient and scalable production process with a yield of 74% could be established, and with a simple yeast treatment and crystallization step over a hundred grams of highly pure kojibiose (>99.5%) was obtained.

Sucrose phosphorylase is a promising biocatalyst for the glycosylation of a wide range of compounds, but its industrial application has been hampered by the low thermostability of known representatives. Hence, in this study, the putative sucrose phosphorylase from the thermophile Thermoanaerobacterium thermosaccharolyticum was recombinantly expressed and fully characterised. The enzyme showed significant activity on sucrose (optimum at 55 °C), and with a melting temperature of 79 °C and a half-life of 60 h at the industrially relevant temperature of 60 °C, it is far more stable than known sucrose phosphorylases. Substrate screening and detailed kinetic characterisation revealed however a preference for sucrose 6'-phosphate over sucrose. The enzyme can thus be considered as a sucrose 6'-phosphate phosphorylase, a specificity not yet reported to date. Homology modelling and mutagenesis pointed out particular residues (Arg134 and His344) accounting for the difference in specificity. Moreover, phylogenetic and sequence analysis suggest that glycoside hydrolase 13 subfamily 18 might harbour even more specificities. In addition, the second gene residing in the same operon as sucrose 6'-phosphate phosphorylase was identified as well, and found to be a phosphofructokinase. The concerted action of both these enzymes implies a new pathway for the breakdown of sucrose, in which the reaction products end up at different stages of the glycolysis.

Thanks to its broad acceptor specificity, sucrose phosphorylase (SP) has been exploited for the transfer of glucose to a wide variety of acceptor molecules. Unfortunately, the low affinity (K-m > 1 M) of SP towards these acceptors typically urges the addition of cosolvents, which often either fail to dissolve sufficient substrate or progressively give rise to enzyme inhibition and denaturation. In this work, a buffer/ethyl acetate ratio of 5:3 was identified to be the optimal solvent system, allowing the use of SP in biphasic systems. Careful optimization of the reaction conditions enabled the synthesis of a range of alpha-D-glucosides, such as cinnamyl alpha-D-glucopyranoside, geranyl alpha-D-glucopyranoside, 2-O-alpha-D-glucopyranosyl pyrogallol, and series of alkyl gallyl 4-O-alpha-D-glucopyranosides. The usefulness of biphasic catalysis was further illustrated by comparing the glucosylation of pyrogallol in a cosolvent and biphasic reaction system. The acceptor yield for the former reached only 17.4%, whereas roughly 60% of the initial pyrogallol was converted when using biphasic catalysis.

Sucrose phosphorylase (SP) is a promising biocatalyst for the production of special sugars and glycoconjugates, but its transglycosylation activity rarely exceeds the competing hydrolytic reaction. Knowing how specificity is controlled, would allow to optimise this activity in an efficient way by means of enzyme engineering. Therefore, in this study, a map of the acceptor site of the SP from Bifidobacterium adolescentis was created by substituting each residue by alanine and analysing the influence on the affinity for both the natural (inorganic phosphate and fructose) and alternative acceptors ( d -arabitol and pyridoxine). All residues examined were found to contribute to the specificity for phosphate (Arg135, Leu343, Tyr344), fructose (Tyr132, Asp342) or both (Pro134, Tyr196, His234, Gln345). Alternative acceptors that are glycosylated rather efficiently (e.g. d -arabitol) were found to interact with the same residues as fructose, whereas poor acceptors like pyridoxine do not seem to make any specific interactions with the enzyme. Furthermore, it is shown here that SP is already optimised to outcompete water as an acceptor substrate, meaning that it will be very difficult to lower its hydrolytic activity any further. Consequently, increasing the transglycosylation activity towards alternative acceptors seems to be the best strategy, although that would probably require a drastic remodelling of the acceptor site in most cases.

Background: In the framework of wider exploration of the application of dried blood spots (DBS) in bioanalysis, by the DBS consortium of the European Bioanalytical Forum, one team of five laboratories investigated the merits of the various ways of IS addition prior to LC–MS/MS analysis. A set of 22 pharmaceutical compounds with log P in the range of 0–10 was selected for this purpose. Assessments were made of precision, recovery, and of the effects of prolonged storage. Results: Assay precision was not significantly different for 3 month-aged samples as compared with ‘fresh’ samples stored for 7–22 days. Extraction recovery from 3 month-aged spots decreased for some of the analytes; the most widely employed addition of IS in the extraction solvent does not compensate for recovery in such cases. Conclusion: From the overall results, it is clear that there is no ‘one size fits all’ approach to IS addition in DBS bioanalysis.

Consensus engineering, which is replacing amino acids by the most frequently occurring one at their positions in a multiple sequence alignment (MSA), is a known strategy to increase the stability of a protein. The application of this concept to the entire sequence of an enzyme, however, has been tried only a few times mainly because of the problems determining the consensus in highly variable regions. We show that this problem can be solved by replacing such problematic regions by the corresponding sequence of the natural homologue closest to the consensus. When one or a few sub-families are overrepresented in the MSA the consensus sequence is a biased representation of the sequence space. We examine the influence of this bias by constructing three consensus sequences using different MSAs of sucrose phosphorylase (SP). Each consensus enzyme contained about 70 mutations compared to its closest natural homologue and folded correctly and displayed activity on sucrose. Correlation analysis revealed that the family's co-evolution network was kept intact, which is one of the main advantages of full-length consensus design. The consensus enzymes displayed an "average" thermostability, that is, one that is higher than some but not all known representatives. We cautiously present practical rules for the design of consensus sequences, but warn that the measure of success depends on which natural enzyme is used as point of comparison.

Aim: Capillary microsampling (CMS) to collect microplasma volumes is gradually replacing traditional, larger volume sampling from rats in GLP toxicology studies. Methodology: About 32 µl of blood is collected with a capillary, processed to plasma and stored in a 10- or 4-µl capillary which is washed out further downstream in the laboratory. CMS has been standardized with respect to materials, assay validation experiments and application for sample analysis. Conclusion: The implementation of CMS has resulted in blood volume reductions in the rat from 300 to 32 µl per time point and the elimination of toxicokinetic satellite groups in the majority of the rat GLP toxicology studies. The technique has been successfully applied in 26 GLP studies for 12 different projects thus far.

Glycosylation is a crucial modification of many secondary metabolites, but is a challenging reaction to perform at a larger scale. In this chapter, an engineering pipeline will be discussed that was used to develop sucrose phosphorylase as a practical biocatalyst for glycoside synthesis. By addressing both enzyme and process engineering in a systematic fashion, we were able to establish a technology with proven industrial value. First, various homologs were compared to identify the most suitable starting point for further optimization. The stability of the best enzyme was then increased by semirational mutagenesis, after which its active site was rationally engineered to enable the binding of polyphenolic acceptors. Finally, the enzyme’s glycosylation activity was further improved by developing an appropriate solvent system, which enabled the cost-effective production of 1 kg of phenolic glucosides.

2-(4-Chloro-2-cyano-2-phenylbutyl)aziridines were employed for the one-step stereoselective construction of both endo- and exo-2-aminomethyl-4-phenyl-1-azabicyclo[2.2.1]heptanes as new azaheterobicyclic scaffolds via a double LiAlH(4)-induced reductive cyclization protocol. Antiplasmodial assessment of these 1-azabicyclo[2.2.1]heptanes revealed moderate to good activities in the micromolar range, with the exo-isomers being the most promising structures. Furthermore, the proposed mode of action was supported by ligand docking studies, pointing to a strong binding interaction with the enzyme plasmepsin II.

Aim: A procedure was developed for the assessment of photochemical stability of drugs in blood and plasma under standardized conditions. The procedure avoids a variable outcome of photochemical stability experiments and tests relevant worst case conditions so that unnecessary light protection is avoided. Results/methodology: Blood and plasma were spiked with a mixture of drugs and incubated in a Suntest CPS+, in the laboratory on the bench and near the window on a sunny summer day. The results were compared. Discussion/conclusion: No protection from light, limited protection from light and full protection from light are advised for drugs that are stable in plasma in the Suntest CPS+ at 250 W/m2 for at least 30 min, for 5–30 min and for

Statistical analysis of a protein multiple sequence alignment can reveal groups of positions that undergo interdependent mutations throughout evolution. At these so-called correlated positions, only certain combinations of amino acids appear to be viable for maintaining proper folding, stability, catalytic activity or specificity. Therefore, it is often speculated that they could be interesting guides for semi-rational protein engineering purposes. Because they are a fingerprint from protein evolution, their analysis may provide valuable insight into a protein’s structure or function and furthermore, they may also be suitable target positions for mutagenesis. Unfortunately, little is currently known about the properties of these correlation networks and how they should be used in practice. This review summarises the recent findings, opportunities and pitfalls of the concept.

Background: Many patients with chronic pain, including those with chronic whiplash-associated disorders (WAD), show features of central sensitization. Randomized trials examining whether treatments are able to influence the process of central sensitization in patients with chronic WAD are emerging. Therefore, the present study aimed at examining whether acupuncture results in activation of endogenous analgesia and relief in symptoms in patients with chronic WAD. Methods: In this randomized crossover pilot trial with blinded assessors, each patient (n = 39) received two treatment sessions of identical duration, with acupuncture and relaxation therapy randomly crossed over in visit 2. Primary outcome measurement included immediate activation of endogenous analgesia i.e., pressure pain sensitivity and conditioned pain modulation. Secondary outcome measurements included pain relief and reduced disability level. Results: Local pressure pain sensitivity at baseline and during conditioned pain modulation decreased significantly more following acupuncture compared with relaxation (time ¥ group interactions: p 0.05). Conclusion: It was shown that one session of acupuncture treatment results in acute improvements in pressure pain sensitivity in the neck and calf of patients with chronic WAD. Acupuncture had no effect on conditioned pain modulation or temporal summation of pressure pain. Both acupuncture and relaxation appear to be well-tolerated treatments for people with chronic WAD. These findings suggest that acupuncture treatment activates endogenous analgesia in patients with chronic WAD.

This open-label, parallel-group study was designed to characterize the pharmacokinetics (PK) of carisbamate in participants with mild or moderate hepatic impairment versus those with normal hepatic function. Healthy (n = 10) and hepatic-impaired (n = 20) participants received a single 200-mg oral dose of carisbamate. Serial PK blood samples were collected up to 120 hours postdose. A modest increase in mean area under the plasma concentration-time curve from 0 to infinity (AUC(∞)) was observed for the mild impairment group compared with the normal group (ratio of geometric means ~116%), while mean maximum plasma concentration (C(max)) values were similar (ratio of geometric means ~94%). The AUC(∞) value for the moderate hepatic-impaired group was approximately 207% that of the normal group, while there was a smaller increase in C(max) (~118%) compared with the normal group. Mean half-life (t(1/2)) values were prolonged in the moderate impairment group (21 hours) relative to the normal group (11 hours). There was a decrease in apparent clearance (CL/F) and an increase in AUC(∞u) (AUC(∞) × % drug unbound). The percentage of carisbamate unbound to proteins did not change across the groups, suggesting the increases in AUC(∞) were due to decreased intrinsic hepatic clearance. Carisbamate 200 mg was well tolerated.

The plasma kinetics and tissue distribution of galantamine hydrobromide [4aS-(4aa,6s,8aR*)] -4a,5,9,10,11,12-hexahy-dro-3- methoxy-11 – methyl- 6H- benzo -furo-[3a,3,2-ef] [2]benzazepin-6-ol hydro-bromide, CAS-1953-04-4], a reversible acetylcholinesterase inhibitor, were studied in male and female non-pregnant and pregnant SPF Wistar rats and in male Fisher x Copenhagen pigmented rats. Most studies were performed using 3H-labelled galantamine hydrobromide, measuring unchanged drug (UD) and non-volatile radioactivity (NVR) in plasma and tissues by high-performance liquid chromatography (HPLC), liquid scintillation counting and quantitative whole-body autoradiography (QWBA). Plasma levels after single intravenous administration of UD (1.25–2.5 mg/kg) declined bi- or triphasically, with an elimination half-life of 3.5 h in male, and 5.1 h in female rats. The plasma clearance (Cl) averaged 1.9 l/kg/h (male rats) and 0.9 1/kg/h (female rats), and the volume of distribution (Vdss) was about 51/kg for both male and female rats. Following oral administration (2.5–10 mg /kg), galantamine was rapidly absorbed in both sexes, with an absolute oral bioavailability of 77 %. Distribution studies after oral administration of 3H-galantamine showed an almost immediate equilibrium between plasma and tissues, with highest tissue levels of NVR and UD in liver, kidney, salivary glands, adrenal glands and, for the female rat, spleen, and lowest in white fat. To most tissues and especially to brain, the distribution of UD was more pronounced than that of its metabolites. Tissue concentrations of UD and NVR declined at a similar rate as plasma, showing no undue retention. QWBA in the pigmented rat showed the same distribution and elimination pattern of NVR. Only in hair follicles and choroid some retention of NVR was seen, but the calculated half-life was less than one day. In the female pregnant SPF Wistar rat, maternal tissue distribution of NVR was similar to that of the non-pregnant rat. NVR tissue levels in the foetus were similar to those found in maternal blood during the whole experiment, indicating a rapid equilibrium without accumulation.

To reduce the amount of consumables and number of pipetting steps in high-throughput screening, a constitutive expression system was developed that comprises four different promoters of varying strength. The system was validated by the expression of different sucrose phosphorylase enzymes from Leuconostoc mesenteroides, Lactobacillus acidophilus and Bifidobacterium adolescentis in 96-deep-and low-well plates at three temperatures. Drastically improved soluble expression in mini-cultures was observed for the enzymes from L. mesenteroides strains by reducing the promoter strength from strong to intermediate and by expressing the proteins at lower temperatures. In contrast, the enzymes from B. adolescentis and L. acidophilus were expressed most efficiently with a strong promoter. The constitutive expression of sucrose phosphorylases in low-well plates resulted in a level of activity that is equal or even better than what was achieved by inducible expression. Therefore, our plasmid set with varying constitutive promoters will be an indispensable tool to optimize enzyme expression for high-throughput screening.

Background: Knowledge of antipsychotic drug levels at point of care (POC) may significantly aid therapeutic decision-making. To support the development of future POC devices and to validate the use of fingerstick capillary blood sampling, two robust hydrophilic interaction LC–ESI/MS/MS methods were developed and validated. Two PK studies were completed evaluating the correlation between fingerstick blood and plasma concentrations with corresponding venous blood and plasma concentrations for several commonly prescribed atypical antipsychotics and selected metabolites. Sensitive and reliable LC–MS/MS bioanalytical assays were developed to support these studies. Results: Three methods, requiring only 25-μl matrix volumes, were developed using supported liquid extraction with hydrophilic interaction LC–MS/MS detection and validated according to regulatory guidance. Conclusion: Robust and efficient LC–MS/MS assays were established and were effective in providing antipsychotic drug matrix comparator results in the intended clinical studies.

The synthesis of novel isoform-selective HDAC inhibitors is considered to be an important, emerging field in medicinal chemistry. In this paper, the preparation and assessment of thirteen selective HDAC6 inhibitors is disclosed, elaborating on a previously developed thiaheterocyclic Tubathian series. All compounds were evaluated in vitro for their ability to inhibit HDAC6, and a selection of five potent compounds was further screened toward all HDAC isoforms (HDAC1-11). The capability of these Tubathian analogs to inhibit α-tubulin deacetylation was assessed as well, and ADME/Tox data were collected. This thorough SAR evaluation revealed that the oxidized, para-substituted hydroxamic acids can be recognized as valuable lead structures in the pursuit of novel potent and selective HDAC6 inhibitors. crosscheck: This document is CrossCheck deposited related_data: Supplementary Information copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal history: Received 21 December 2015; Accepted 5 January 2016; Accepted Manuscript published 5 January 2016; Advance Article published 29 January 2016; Version of Record published 16 February 2016 ispartof: Organic & Biomolecular Chemistry vol:14 issue:8 pages:2537-49 ispartof: location:England status: published

Summary: Purpose: To characterize possible pharmacokinetic interactions between the new antiepileptic drug carisbamate (RWJ-333369) and valproic acid (VPA) or lamotrigine (LTG) following multiple dosing in healthy subjects. Methods: Two open-label, sequential-design studies were conducted in 24 healthy adults. In Study 1, subjects received carisbamate alone (5 days 250 mg q12h; 5 days 500 mg q12h), then VPA alone (7 days 300 mg q12h; 7 days 500 mg q12h), and then a combination of VPA (500 mg q12h) and carisbamate (5 days 250 mg q12h; 5 days 500 mg q12h). In Study 2, subjects received carisbamate alone as in Study 1, then LTG alone (14 days 25 mg q12h; 14 days 50 mg q12h), and then combination of LTG (50 mg q12h) and carisbamate (3 days 250 mg q12h; 14 days 500 mg q12h). Results: Coadministration of VPA or LTG had minimal effect on carisbamate mean Cmax and AUCss values. Mean VPA-Cmax and AUCss values were ∼15% lower when given concomitantly with carisbamate. However, the 90% confidence intervals (CIs) for the Cmax and AUCss ratio with/without carisbamate were within the 80–125% equivalence range, Cmax 82–89%; AUCss 81–88%. Mean LTG Cmax and AUCss values were ∼20% lower when given concomitantly with carisbamate. The 90% CIs with and without carisbamate for LTG Cmax and AUCss were 79–86% and 75–81%, respectively. This modest change is not considered clinically significant. Conclusions: There were no clinically significant interactions between carisbamate and VPA or LTG. Concomitant administration of carisbamate with VPA or LTG was generally safe and well tolerated.

The body distribution of total radioactivity (TR) and bortezomib was investigated in male Sprague-Dawley rats after single and repeated i.v. (bolus) administration with (14)C-labelled bortezomib (VELCADE) (0.2 mg/kg; 0.28 MBq./kg).Bortezomib was dosed on days 1, 4, 8, and 11 (i.e. a clinical dosing cycle) and the animals were sacrificed at selected time points following single and repeated dose administration for the quantification of TR in blood, plasma, and various tissues by liquid scintillation counting following organ dissection or by quantitative whole body autoradiography. In selected tissues, bortezomib levels were determined by LC-MS/MS.In general, plasma TR levels were less than 10% of the corresponding blood concentrations. TR was rapidly and widely distributed to the tissues with only limited penetration into the central nervous system (CNS). In the tissues, highest levels of TR were measured in bortezomib-eliminating organs (liver and kidney), lymphoid tissues, and regions of rapidly dividing cells (e.g. the bone marrow, intestinal mucosa). Low TR concentrations were found in the CNS (tissue-to-blood ratio of approximately 0.05 after repeated dosing). With the exception of the liver, TR consisted almost exclusively of the parent drug. Tissue concentrations of TR and bortezomib increased up to about threefold from the first to the third dose administration, after which they remained constant.No undue tissue accumulation of TR and of bortezomib was observed in rats following a full clinical dosing cycle of bortezomib.

An acupuncture treatment can reduce pain sensitivity in patients with chronic whiplash associated disorders (WAD). But it has been hypothesized that many of the experimental results in acupuncture research could be interpreted as stress-induced analgesia.The present study aimed at examining whether acupuncture has an effect on the autonomic nervous system response in patients with chronic WAD and if this response is related to the pain inhibition after an acupuncture session.Randomized crossover trial with blinded assessor.Two private practices.Thirty-nine patients with chronic WAD received 2 treatment sessions of identical duration, with acupuncture and relaxation therapy randomly crossed over in the 2 visits. The primary outcome measurement was the registration of autonomic nervous system parameters (heart rate, skin conductance, and heart rate variability parameters) during the administration of experimental pain. Endogenous analgesia was the secondary outcome.Following one acupuncture treatment session, there was a significant change for 2 parameters: the heart rate was slightly reduced and the skin conductance was raised. Comparing the effects of acupuncture and relaxation, no differences were found with respect to the change in any of the autonomic parameters. Further, the reduction in pain sensitivity in response to acupuncture treatment was unrelated to any of the changes in autonomic measurements.The results were observed after only one session of acupuncture.In patients with chronic WAD, in response to a single treatment session, no acupuncture specific effects on the autonomic response to pain assessment were present and the analgesia after one session of acupuncture is not caused by stress-induced analgesia but is more likely the result of an acupuncture specific reaction.

The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of over 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. It is once again a 5-day week long event – a full immersion bioanalytical week – specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches including the focus on biomarkers and immunogenicity. This 2015 White Paper encompasses recommendations that emerged from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to advance scientific excellence, improve quality and deliver better regulatory compliance. Due to its length, the 2015 edition of this comprehensive White Paper has been divided into three parts. Part 1 covers the recommendations for small molecule bioanalysis using LCMS. Part 2 (hybrid LBA/LCMS and regulatory agencies’ inputs) and Part 3 (large molecule bioanalysis using LBA, biomarkers and immunogenicity) will also be published in volume 7 of Bioanalysis, issues 23 and 24, respectively.

Ronald de Vries graduated in Organic and Analytical Chemistry at the Free University of Amsterdam, The Netherlands. After working in a Contract Laboratory (CRO) for 7 years, he joined Janssen R&D in 1998. At Janssen R&D, Belgium, Ronald worked in the bioanalytical department that supports both clinical and nonclinical bioanalysis. In this department he had several roles, such as providing the bioanalytical support for various drug development programs and leading the method establishment group. He has done numerous global assay transfers to/from Janssen from/to other laboratories and plays an important role in the introduction and application of new technologies and applied innovation in the department. In 2014 he started in the drug metabolism and pharmacokinetics department of Janssen R&D, where his main tasks are in vivo and in vitro metabolite identification using high resolution MS and Radiodetection.

In recent years, carbohydrate epimerases have attracted a lot of attention as efficient biocatalysts that can convert abundant sugars (e.g.d-fructose) directly into rare counterparts (e.g.d-psicose). Despite increased research activities, no review about these enzymes has been published in more than a decade, meaning that their full potential is hard to appreciate. Here, we present an overview of all known carbohydrate epimerases based on a classification in structural families, which links every substrate specificity to a well-defined reaction mechanism. The mechanism can even be predicted for enzymes that have not yet been characterized or that lack structural information. In this review, the different families are discussed in detail, both structurally and mechanistically, with special reference to recent examples in the literature. Furthermore, the value of understanding the reaction mechanism will be illustrated by making the link to possible application and engineering targets.

Improving potencies through concomitant blockage of multiple epitopes and avid binding by fusing multiple (different) monovalent Nanobody building blocks via linker sequences into one multivalent polypeptide chain is an elegant alternative to affinity maturation. We explored a large and random formatting library of bivalent (combinations of two identical) and biparatopic (combinations of two different) Nanobodies for functional blockade of Pseudomonas aeruginosa PcrV. PcrV is an essential part of the P. aeruginosa type III secretion system (T3SS), and its oligomeric nature allows for multiple complex binding and blocking options. The library screening yielded a large number of promising biparatopic lead candidates, revealing significant (and non-trivial) preferences in terms of Nanobody building block and epitope bin combinations and orientations. Excellent potencies were confirmed upon further characterization in two different P. aeruginosa T3SS-mediated cytotoxicity assays. Three biparatopic Nanobodies were evaluated in a lethal mouse P. aeruginosa challenge pneumonia model, conferring 100% survival upon prophylactic administration and reducing lung P. aeruginosa burden by up to 2 logs. At very low doses, they protected the mice from P. aeruginosa infection-related changes in lung histology, myeloperoxidase production, and lung weight. Importantly, the most potent Nanobody still conferred protection after therapeutic administration up to 24 h post-infection. The concept of screening such formatting libraries for potency improvement is applicable to other targets and biological therapeutic platforms.