Metabolite Bioanalysis in Drug Development: Recommendations from the IQ Consortium Metabolite Bioanalysis Working Group

The intent of this perspective is to share the recommendations of the International Consortium for Innovation and Quality in Pharmaceutical Development Metabolite Bioanalysis Working Group on the fit-for-purpose metabolite bioanalysis in support of drug development and registration. This report summarizes the considerations for the trigger, timing, and rigor of bioanalysis in the various assessments to address unique challenges due to metabolites, with respect to efficacy and safety, which may arise during drug development from investigational new drug (IND) enabling studies, and phase I, phase II, and phase III clinical trials to regulatory submission. The recommended approaches ensure that important drug metabolites are identified in a timely manner and properly characterized for efficient drug development.

Cross-Validation of Metabolic Phenotypes in SARS-CoV-2 Infected Subpopulations Using Targeted Liquid Chromatography-Mass Spectrometry (LC-MS)

To ensure biological validity in metabolic phenotyping, findings must be replicated in independent sample sets. Targeted workflows have long been heralded as ideal platforms for such validation due to their robust quantitative capability. We evaluated the capability of liquid chromatography-mass spectrometry (LC-MS) assays targeting organic acids and bile acids to validate metabolic phenotypes of SARS-CoV-2 infection. Two independent sample sets were collected: (1) Australia: plasma, SARS-CoV-2 positive (n = 20), noninfected healthy controls (n = 22) and COVID-19 disease-like symptoms but negative for SARS-CoV-2 infection (n = 22). (2) Spain: serum, SARS-CoV-2 positive (n = 33) and noninfected healthy controls (n = 39). Multivariate modeling using orthogonal projections to latent structures discriminant analyses (OPLS-DA) classified healthy controls from SARS-CoV-2 positive (Australia; R2 = 0.17, ROC-AUC = 1; Spain R2 = 0.20, ROC-AUC = 1). Univariate analyses revealed 23 significantly different (p < 0.05) metabolites between healthy controls and SARS-CoV-2 positive individuals across both cohorts. Significant metabolites revealed consistent perturbations in cellular energy metabolism (pyruvic acid, and 2-oxoglutaric acid), oxidative stress (lactic acid, 2-hydroxybutyric acid), hypoxia (2-hydroxyglutaric acid, 5-aminolevulinic acid), liver activity (primary bile acids), and host-gut microbial cometabolism (hippuric acid, phenylpropionic acid, indole-3-propionic acid). These data support targeted LC-MS metabolic phenotyping workflows for biological validation in independent sample sets.

Recommendations and feedback from the European Bioanalysis Forum Workshop: 1 year into ICH M10 - keeping our finger on the pulse

The ICH M10 guideline on bioanalytical method validation and sample analysis is being adopted since 2023. However, and inevitably, some paragraphs or requirements remain ambiguous and are open for different interpretations. In support of a harmonized interpretation by the industry and health authorities, the European Bioanalysis Forum organized a workshop on 14 November 2023 in Barcelona, Spain, to discuss unclear and/or ambiguous paragraphs which were identified by the European Bioanalysis Forum community and delegates of the workshop prior to the workshop. This manuscript reports back from the workshop with recommendations and aims at continuing an open scientific discussion within the industry and with regulators in support of a science-driven guideline for the bioanalytical community and in line with the ICH mission - that is, achieve greater harmonization worldwide to ensure that safe, effective and high-quality medicines are developed and registered in the most resource-efficient manner.

Set up and validation of a sensitive method to quantify prostaglandins, prostaglandin-glycerol esters and prostaglandin-ethanolamides, as well as their respective precursors

Arachidonic acid-derived prostaglandins are widely studied for their role in inflammation. However, besides arachidonic acid, other arachidonic moiety-containing lipids can be metabolized by COX-2. Indeed, the endocannabinoids 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (anandamide, AEA) can follow the same biochemical pathways than arachidonic acid leading to the formation of prostaglandin-glycerol esters (PG-G) and prostaglandin-ethanolamides (or prostamides, PG-EA), respectively. The data reported so far support the interest of these bioactive lipids in inflammatory conditions. However, there is only a handful of methods described for their quantification in biological matrices. Moreover, given the shared biochemical pathways for arachidonic acid, 2-AG and AEA, a method allowing for the quantification of these precursors and the corresponding prostaglandin derivatives appears as largely needed. Thus, we report here the development and validation of a single run UPLC-MS/MS quantification method allowing the quantification of these endocannabinoids-derived mediators together with the classical prostaglandin. Moreover, we applied the method to the quantification of these lipids in vitro (using lipopolysaccharides-activated J774 macrophage cells) and in vivo in several tissues from DSS-induced colitis mice. This femtomole-range method should improve the understanding of the interaction between these lipid mediators and inflammation.

In Vivo Efficacy and Toxicity of an Antimicrobial Peptide in a Model of Endotoxin-Induced Pulmonary Inflammation

SET-M33 is a synthetic peptide that is being developed as a new antibiotic against major Gram-negative bacteria. Here we report two in vivo studies to assess the toxicity and efficacy of the peptide in a murine model of pulmonary inflammation. First, we present the toxicity study in which SET-M33 was administered to CD-1 mice by snout inhalation exposure for 1 h/day for 7 days at doses of 5 and 20 mg/kg/day. The results showed adverse clinical signs and effects on body weight at the higher dose, as well as some treatment-related histopathology findings (lungs and bronchi, nose/turbinates, larynx and tracheal bifurcation). On this basis, the no observable adverse effect level (NOAEL) was considered to be 5 mg/kg/day. We then report an efficacy study of the peptide in an endotoxin (LPS)-induced pulmonary inflammation model. Intratracheal administration of SET-M33 at 0.5, 2 and 5 mg/kg significantly inhibited BAL neutrophil cell counts after an LPS challenge. A significant reduction in pro-inflammatory cytokines, KC, MIP-1α, IP-10, MCP-1 and TNF-α was also recorded after SET-M33 administration.

A proposed framework to evaluate the quality and reliability of targeted metabolomics assays from the UK Consortium on Metabolic Phenotyping (MAP/UK)

Targeted metabolite assays that measure tens or hundreds of pre-selected metabolites, typically using liquid chromatography-mass spectrometry, are increasingly being developed and applied to metabolic phenotyping studies. These are used both as standalone phenotyping methods and for the validation of putative metabolic biomarkers obtained from untargeted metabolomics studies. However, there are no widely accepted standards in the scientific community for ensuring reliability of the development and validation of targeted metabolite assays (referred to here as 'targeted metabolomics'). Most current practices attempt to adopt, with modifications, the strict guidance provided by drug regulatory authorities for analytical methods designed largely for measuring drugs and other xenobiotic analytes. Here, the regulatory guidance provided by the European Medicines Agency, US Food and Drug Administration and International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use are summarized. In this Perspective, we have adapted these guidelines and propose a less onerous 'tiered' approach to evaluate the reliability of a wide range of metabolomics analyses, addressing the need for community-accepted, harmonized guidelines for tiers other than full validation. This 'fit-for-purpose' tiered approach comprises four levels-discovery, screening, qualification and validation-and is discussed in the context of a range of targeted and untargeted metabolomics assays. Issues arising with targeted multiplexed metabolomics assays, and how these might be addressed, are considered. Furthermore, guidance is provided to assist the community with selecting the appropriate degree of reliability for a series of well-defined applications of metabolomics.

Intact Protein Mass Spectrometry for Therapeutic Protein Quantitation, Pharmacokinetics, and Biotransformation in Preclinical and Clinical Studies: An Industry Perspective

Recent advancements in immunocapture methods and mass spectrometer technology have enabled intact protein mass spectrometry to be applied for the characterization of antibodies and other large biotherapeutics from in-life studies. Protein molecules have not been traditionally studied by intact mass or screened for catabolites in the same manner as small molecules, but the landscape has changed. Researchers have presented methods that can be applied to the drug discovery and development stages, and others are exploring the possibilities of the new approaches. However, a wide variety of options for assay development exists without clear recommendation on best practice, and data processing workflows may have limitations depending on the vendor. In this perspective, we share experiences and recommendations for current and future application of mass spectrometry for biotherapeutic molecule monitoring from preclinical and clinical studies.

Passive immunotherapy with a novel antibody against 3pE-modified Aβ demonstrates potential for enhanced efficacy and favorable safety in combination with BACE inhibitor treatment in plaque-depositing mice

The imbalance between production and clearance of amyloid β (Aβ) peptides and their resulting accumulation in the brain is an early and crucial step in the pathogenesis of Alzheimer's disease (AD). Therefore, Aβ is strongly positioned as a promising and extensively validated therapeutic target for AD. Investigational disease-modifying approaches aiming at reducing cerebral Aβ concentrations include prevention of de novo production of Aβ through inhibition of β-site amyloid precursor protein cleaving enzyme 1 (BACE1), and clearance of Aβ deposits via passive Aβ immunotherapy. We have developed a novel, high affinity antibody against Aβ peptides bearing a pyroglutamate residue at amino acid position 3 (3pE), an Aβ species abundantly present in plaque deposits in AD brains. Here, we describe the preclinical characterization of this antibody, and demonstrate a significant reduction in amyloid burden in the absence of microhemorrhages in different mouse models with established plaque deposition. Moreover, we combined antibody treatment with chronic BACE1 inhibitor treatment and demonstrate significant clearance of pre-existing amyloid deposits in transgenic mouse brain, without induction of microhemorrhages and other histopathological findings. Together, these data confirm significant potential for the 3pE-specific antibody to be developed as a passive immunotherapy approach that balances efficacy and safety. Moreover, our studies suggest further enhanced treatment efficacy and favorable safety after combination of the 3pE-specific antibody with BACE1 inhibitor treatment.

A targeted ultra performance liquid chromatography - Tandem mass spectrometric assay for tyrosine and metabolites in urine and plasma: Application to the effects of antibiotics on mice

Tyrosine plays a key role in mammalian biochemistry and defects in its metabolism (e.g., tyrosinemia, alkaptonuria etc.) have significant adverse consequences for those affected if left untreated. In addition, gut bacterially-derived p-cresol and its metabolites are of interest as a result of various effects on host xenobiotic metabolism. A fit-for-purpose quantitative ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) assay was developed to target and quantify tyrosine and eleven metabolites in urine and plasma. Dansylation, using dansyl chloride, was used to improve chromatographic and mass spectral properties for tyrosine and nine phenolic metabolites, with detection using positive electrospray ionisation (ESI). The sulfate and glucuronide conjugates of p-cresol, where the phenol group was blocked, were quantified intact, using negative ESI via polarity switching during the same run. Sample preparation for urine and plasma involved deproteinization by solvent precipitation (of acetonitrile:isopropyl alcohol (1:1 v/v)) followed by in situ dansylation in 96 well plates. To minimize sample and solvent usage, and maximize sensitivity, analysis was performed using microbore reversed-phase gradient UPLC on a C8 phase with a 7.5 min. cycle time. The coefficients of variation obtained were <15%, with lower limits of quantification ranging from 5 to 250 nM depending upon the analyte. The method was applied to plasma and urine samples obtained from mice placed on a high tyrosine diet with one subgroup of animals subsequently receiving antibiotics to suppress the gut microbiota. Whilst plasma profiles were largely unaffected by antibiotic treatment clear reductions in the amount of p-cresol sulfate and p-cresol glucuronide excreted in the urine were observed for these mice.

In vitro testing of the hemaPEN microsampling device for the quantification of acetaminophen in human blood

Background: The hemaPEN is a liquid microsampling device for the reproducible collection and storage of blood samples as dried blood spots, for subsequent quantitative analysis. Materials & methods: We examined the device’s ability to collect accurate and precise blood volumes, at different hematocrit levels, via in vitro studies using acetaminophen in human blood. We also investigated the impact of different user training approaches on device performance. Results: The hemaPEN demonstrated acceptable volumetric accuracy and precision, regardless of the training medium used. Issues with apparent hematocrit-dependent bias were found to be associated with the extraction process, rather than the volumetric performance of the device. Conclusion: The hemaPEN is capable of readily producing high quality blood microsamples for reproducible and accurate quantitative bioanalysis.

Strategies and analytical workflows to extend the dynamic range in quantitative LC–MS/MS analysis

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.

Clinical pharmacokinetics, pharmacodynamics, safety, and tolerability of JNJ-54175446, a brain permeable P2X7 antagonist, in a randomised single-ascending dose study in healthy participants

BACKGROUND

Central nervous system-derived interleukin-1β plays a role in mood disorders. P2X7 receptor activation by adenosine-triphosphate leads to the release of interleukin-1β.

AIMS

This first-in-human study evaluated safety, tolerability, pharmacokinetics and pharmacodynamics of a novel central nervous system-penetrant P2X7 receptor antagonist, JNJ-54175446, in healthy participants.

METHODS

The study had three parts: an ascending-dose study in fasted participants (0.5-300 mg JNJ-54175446); an ascending-dose study in fed participants (50-600 mg); and a cerebrospinal fluid study (300 mg). Target plasma concentrations were based on estimated plasma effective concentration (EC)₅₀ (105 ng/mL) and EC₉₀ (900 ng/mL) values for central nervous system P2X7 receptor binding.

RESULTS

Seventy-seven participants received a single oral dose of JNJ-54175446 ( n=59) or placebo ( n=18). Area under the curve of concentration time extrapolated to infinity (AUC_∞) increased dose-proportionally; maximum concentration (C_max) of plasma (C_max,plasma) increased less than dose-proportionally following single doses of JNJ-54175446. Because food increases bioavailability of JNJ-54175446, higher doses were given with food to evaluate safety at higher exposures. The highest C_max,plasma reached (600 mg, fed) was 1475±163 ng/mL. JNJ-54175446 C_max in cerebrospinal fluid, a proxy for brain penetration, was seven times lower than in total plasma; unbound C_max,plasma and C_max,CSF were comparable (88.3±35.7 vs 114±39 ng/mL). JNJ-54175446 inhibited lipopolysaccharide/3'-O-(4-benzoylbenzoyl)-ATP-induced interleukin-1β release from peripheral blood in a dose-dependent manner (inhibitory concentration (IC)₅₀:82 ng/mL; 95% confidence interval: 48-94). Thirty-three of 59 (55.9%) participants reported at least one treatment-emergent adverse event; the most common adverse event being headache (11/59, 18.6%).

CONCLUSION

Plasma exposure of JNJ-54175446 was dose-dependent. No serious adverse events occurred. Single-dose administration of JNJ-54175446>10 mg attenuated ex-vivo lipopolysaccharide-induced interleukin-1β release in peripheral blood. Passive brain penetration of JNJ-54175446 was confirmed.

Incurred sample reproducibility: 10 years of experiences: views and recommendations from the European Bioanalysis Forum

With 10 years of experiences on incurred sample reanalysis (ISR) as an integrated part of regulated bioanalysis, the European Bioanalysis Forum has reflected on the implementation and the use of ISR. Three surveys were conducted in 2016 and 2017 as a revisit of the ISR experiences within European pharmaceutical industry and contract research organizations: has ISR become a tool for postvalidation and process check of a bioanalytical method performance and has ISR become a routine in our laboratories? Do we agree on the interpretation of guidelines/guidance and are we aligned in our approach – among others?

Pharmacodynamics of atabecestat (JNJ-54861911), an oral BACE1 inhibitor in patients with early Alzheimer's disease: randomized, double-blind, placebo-controlled study

BACKGROUND

β-Secretase enzyme (BACE) inhibition has been proposed as a priority treatment mechanism for Alzheimer's disease (AD), but treatment initiation may need to be very early. We present proof of mechanism of atabecestat (also known as JNJ-54861911), an oral BACE inhibitor for the treatment of AD, in Caucasian and Japanese populations with early AD who do not show signs of dementia.

METHODS

In two similarly designed phase I studies, a sample of amyloid-positive elderly patients comprising 45 Caucasian patients with early AD diagnosed as preclinical AD (n = 15, Clinical Dementia Rating [CDR] = 0) or with mild cognitive impairment due to AD (n = 30, CDR = 0.5) and 18 Japanese patients diagnosed as preclinical AD (CDR-J = 0) were randomized 1:1:1 to atabecestat 10 or 50 mg or placebo (n = 6-8/treatment) daily for 4 weeks. Safety, pharmacokinetics (PK), and pharmacodynamics (PD) (i.e., reduction of cerebrospinal fluid [CSF] amyloid beta 1-40 [Aβ_1-40] levels [primary endpoint] and effect on other AD biomarkers) of atabecestat were evaluated.

RESULTS

In both populations, atabecestat was well tolerated and characterized by linear PK and high central nervous system penetrance of unbound drug. Atabecestat significantly reduced CSF Aβ_1-40 levels from baseline at day 28 in both the 10-mg (67-68%) and 50-mg (87-90%) dose groups compared with placebo. For Caucasians with early AD, the least squares mean differences (95% CI) were - 69.37 (- 72.25; - 61.50) and - 92.74 (- 100.08; - 85.39), and for Japanese with preclinical AD, they were - 62.48 (- 78.32; - 46.64) and - 80.81 (- 96.13; - 65.49), respectively. PK/PD model simulations confirmed that once-daily 10 mg and 50 mg atabecestat can attain 60-70% and 90% Aβ_1-40 reductions, respectively. The trend of the reduction was similar across the Aβ_1-37, Aβ_1-38, and Aβ_1-42 fragments in both atabecestat dose groups, consistent with Aβ_1-40. CSF amyloid precursor protein fragment (sAPPβ) levels declined from baseline, regardless of patient population, whereas CSF sAPPα levels increased compared with placebo. There were no relevant changes in either CSF total tau or phosphorylated tau 181P over a 4-week treatment period.

CONCLUSIONS

JNJ-54861911 at 10 and 50 mg daily doses after 4 weeks resulted in mean CSF Aβ_1-40 reductions of 67% and up to 90% in both Caucasian and Japanese patients with early stage AD, confirming results in healthy elderly adults.

TRIAL REGISTRATION

ALZ1005: ClinicalTrials.gov, NCT01978548. Registered on 7 November 2013. ALZ1008: ClinicalTrials.gov, NCT02360657. Registered on 10 February 2015.

Quantitative analysis of imetelstat in plasma with LC-MS/MS using solid-phase or hybridization extraction

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 application of control charts in regulated bioanalysis for monitoring long-term reproducibility

In regulated bioanalysis, the acceptance of results is batch-wise. When during clinical development derived pharmacokinetic or pharmacodynamic results from different studies will be combined or compared, it is recommendable to monitor the long-term reproducibility of bioanalytical assays. Long-term reproducibility can be evaluated by control charts generated from control samples included in each batch. We present a methodology for the implementation, construction and evaluation of control charts next to the regular batch acceptance of bioanalytical results. Decision rules can be set up for a statistical evaluation of the results. Violation of a decision rule may lead to a root-cause investigation and corrective actions to improve assay robustness. Three examples of control charts, for pharmacokinetic and pharmacodynamic analytes are presented.

Ocular bioanalysis: challenges and advancements in recent years for these rare matrices

There are many ocular diseases still presenting unmet medical needs. Therefore, new ophthalmologic drugs are being developed. Bioanalysis of eye compartments (along with plasma and other tissues) is important to determine exposure of the target organ to the drug and to help interpret local pharmacological or toxic effects. This review article identifies several challenges that occur within ocular bioanalysis. They include sample collection and preparation, analytical issues, sourcing control matrix, data interpretation and regulatory requirements. It summarizes how these challenges have been recently addressed, how research has advanced and which questions remain unanswered. Recommendations are made based on the literature and our practical experience within ocular bioanalysis and future perspectives are discussed.

The 8th Japan Bioanalysis Forum symposium

The 8th Japan Bioanalysis Forum symposium, the Tower Hall Funabori, Tokyo, Japan, 8-9 February 2017 The 8th Japan Bioanalysis Forum (JBF) symposium was successfully held between 8 and 9 February 2017 at the Tower Hall Funabori, Tokyo, Japan. In total, 24 speakers from Japan, USA and Europe gave presentations regarding the immunogenicity of biopharmaceuticals, ICH S3A Q&A microsampling, ICH M10 bioanalytical method validation, large molecule analysis through LC-MS, auditing activities for bioanalysis and biomarker bioanalysis. Achievements regarding eight diverse themes were also shared by Japan Bioanalysis Forum discussion groups. Over 300 scientists from regulatory agencies, industry and academia actively took part in discussions during the symposium. This article provides the highlights of all the topics discussed in this symposium.

Implementing a tiered approach to bioanalytical method validation for large-molecule ligand-binding assay methods in pharmacokinetic assessments

Bioanalytical methods must enable the delivery of data that meet sound, scientifically justified, fit-for-purpose criteria. At early phases of biotherapeutic drug development, suitable criteria of a ligand-binding assay could be met for pharmacokinetic (PK) in-study sample testing without a full validation defined by regulatory guidelines. To ensure fit-for-purpose methods support PK testing through all phases of biotherapeutic development, three tiers of method validation - regulatory, scientific and research validations - are proposed. The three-tiered framework for method validation outlines the differences in the parameters that should be assessed, the acceptance criteria that may be applied, and the documentation necessary at each level. The criteria for selecting the appropriate application of each of these PK method validation workflows are discussed.

From patient to tube: the importance of physiologically relevant quantitative bioanalytical assays

Circulating drug concentrations (clinical or preclinical) underly many interactions between industry and regulators; expressing safety coverage, pharmacokinetic-pharmacodynamic relationships or defining bioequivalence and dosing regimens. Accurate and precise measurement of these circulating concentrations is pivotal to the evolution and validation of any bioanalytical method that supports regulatory interactions. Since the bioanalyst is presented with a sub-aliquot of sampled biological matrix, how do they ensure this aliquot reflects the concentration in the subject at the time of collection? Here we share experiences from project support (internal and at CROs) that suggests we need to be ever vigilant translating the needs of bioanalysis with those of project teams. The simple mantra is for bioanalytical measurements to be physiologically relevant to the patient.

7th Japan Bioanalysis Forum symposium: regulated bioanalysis, to a new stage

Tower Hall Funabori, Tokyo, Japan, 9-10 March 2016 At the 7th Japan Bioanalysis Forum symposium, bioanalytical methods and processes were discussed with authorities after the issuing of bioanalytical method validation guidelines (EMA and Japanese Ministry of Health, Labour and Welfare) and draft guidance (US FDA). Method establishment and bioanalysis of biomarkers were discussed with a focus on scientific validation. Bioanalytical methods for antibody-drug conjugates, the potential of MS imaging and microsampling activity in drug development were introduced. Discussion groups presented and openly discussed their results with about 300 attendees. This manuscript provides an overview of the highlights of the symposium.

Profiling the dynamics of CSF and plasma Aβ reduction after treatment with JNJ-54861911, a potent oral BACE inhibitor

OBJECTIVES

Safety, tolerability, pharmacokinetics, and pharmacodynamics of a novel β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor, JNJ-54861911, were assessed after single and multiple dosing in healthy participants.

METHODS

Two randomized, placebo-controlled, double-blind studies were performed using single and multiple ascending JNJ-54861911 doses (up to 14 days) in young and elderly healthy participants. Regular blood samples and frequent CSF samples, up to 36 hours after last dose, were collected to assess the pharmacokinetic and pharmacodynamic (Aβ, sAPPα,β,total levels) profiles of JNJ-54861911.

RESULTS

JNJ-54861911 was well-tolerated, adverse events were uncommon and unrelated to JNJ-54861911. JNJ-54861911 showed dose-proportional CSF and plasma pharmacokinetic profiles. Plasma- and CSF-Aβ and CSF-sAPPβ were reduced in a dose-dependent manner. Aβ reductions (up to 95%) outlasted exposure to JNJ-54861911. APOE ε4 carrier status and baseline Aβ levels did not influence Aβ/sAPPβ reductions.

CONCLUSION

JNJ-54861911, a potent brain-penetrant BACE1 inhibitor, achieved high and stable Aβ reductions after single and multiple dosing in healthy participants.

Best practices for metabolite quantification in drug development: updated recommendation from the European Bioanalysis Forum

Metabolite quantification and profiling continues to grow in importance in today's drug development. The guidance provided by the 2008 FDA Metabolites in Safety Testing Guidance and the subsequent ICH M3(R2) Guidance (2009) has led to a more streamlined process to assess metabolite exposures in preclinical and clinical studies in industry. In addition, the European Bioanalysis Forum (EBF) identified an opportunity to refine the strategies on metabolite quantification considering the experience to date with their recommendation paper on the subject dating from 2010 and integrating the recent discussions on the tiered approach to bioanalytical method validation with focus on metabolite quantification. The current manuscript summarizes the discussion and recommendations from a recent EBF Focus Workshop into an updated recommendation for metabolite quantification in drug development.

Analysis of aluminium in rat following administration of allergen immunotherapy using either aluminium or microcrystalline-tyrosine-based adjuvants

Background: Investigation into the absorption, distribution and elimination of aluminium in rat after subcutaneous aluminium adjuvant formulation administration using ICP-MS is described. Method & results: Assays were verified under the principles of a tiered approach. There was no evidence of systemic exposure of aluminium, in brain or in kidney. Extensive and persistent retention of aluminium at the dose site was observed for at least 180 days after administration. Conclusion: This is the first published work that has quantified aluminium adjuvant retention based on the quantity of aluminium delivered in a typical allergy immunotherapy course. The results indicate that the repeated administration of aluminium-containing adjuvants will likely contribute directly and significantly to an individual's body burden of aluminium.