Bioanalytical Considerations Research Articles

Therapeutic Drug Monitoring of Low Methotrexate Doses for Drug Exposure and Adherence Assessment-Pre-Analytical Variables, Bioanalytical Issues, and Current Clinical Applications.

Methotrexate (MTX) is an antifolic agent used in the first line of anti-inflammatory disease treatment and some oncologic issues. The metabolism of MTX is rapid, and the MTX concentration in the blood is not significant 24 h after administration. Unlike this, methotrexate polyglutamates (MTXPGs) can be informative biomarkers of drug exposure. It is widely concluded that MTXPG retention in red blood cells (RBCs) is related to appropriate efficacy, drug exposure, and toxicity during treatment. Therefore, the mentioned biomarker may be appropriately used for the PK/PD monitoring of low-dose MTX (LDMTX) treatment. The presented review study aimed to review published studies about MTX determination in clinical practice, including pre-analytical variability, bioanalytical considerations, and clinical applications of the methods for pharmacotherapy supporting target populations. In total, 14 papers from the field of bioanalytics have been included in the main review. For each phase of an analytical process, the best practises and main findings were defined as guidelines for proper analytical method optimisation, validation, and standard operation procedure implementation in clinical practice. The presented study is the first comprehensive review of MTX and its methods of metabolite determination to account for pre-analytical, analytical, and post-analytical phases concerning the TDM process.

PK/PD and Bioanalytical Considerations of AAV-Based Gene Therapies: an IQ Consortium Industry Position Paper.

Interest and efforts to use recombinant adeno-associated viruses (AAV) as gene therapy delivery tools to treat disease have grown exponentially. However, gaps in understanding of the pharmacokinetics/pharmacodynamics (PK/PD) and disposition of this modality exist. This position paper comes from the Novel Modalities Working Group (WG), part of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ). The pan-industry WG effort focuses on the nonclinical PK and clinical pharmacology aspects of AAV gene therapy and related bioanalytical considerations.Traditional PK concepts are generally not applicable to AAV-based therapies due to the inherent complexity of a transgene-carrying viral vector, and the multiple steps and analytes involved in cell transduction and transgene-derived protein expression. Therefore, we explain PK concepts of biodistribution of AAV-based therapies and place key terminologies related to drug exposure and PD in the proper context. Factors affecting biodistribution are presented in detail, and guidelines are provided to design nonclinical studies to enable a stage-gated progression to Phase 1 testing. The nonclinical and clinical utility of transgene DNA, mRNA, and protein analytes are discussed with bioanalytical strategies to measure these analytes. The pros and cons of qPCR vs. ddPCR technologies for DNA/RNA measurement and qualitative vs. quantitative methods for transgene-derived protein are also presented. Last, best practices and recommendations for use of clinical and nonclinical data to project human dose and response are discussed. Together, the manuscript provides a holistic framework to discuss evolving concepts of PK/PD modeling, bioanalytical technologies, and clinical dose selection in gene therapy.

Bioanalytical Methods and Strategic Perspectives Addressing the Rising Complexity of Novel Bioconjugates and Delivery Routes for Biotherapeutics.

In recent years, an increase in the discovery and development of biotherapeutics employing new modalities, such as bioconjugates or novel routes of delivery, has created bioanalytical challenges. The inherent complexity of conjugated molecular structures means that quantification of the bioconjugate and its multiple components is critical for preclinical/clinical studies to inform drug discovery and development. Moreover, bioconjugates involve additional multifactorial complexity because of the potential for in vivo catabolism and biotransformation, which may require thorough investigations in multiple biological matrices. Furthermore, excipients that enhance absorption are frequently evaluated and employed for the development of oral and inhaled biotherapeutics. Risk-benefit assessments are required for novel or existing excipients that utilize dosages above previously approved levels. Bioanalytical methods that can measure both excipients and potential drug metabolites in biological matrices are highly relevant to these emerging bioanalysis challenges. We discuss the bioanalytical strategies for analyzing bioconjugates such as antibody–drug conjugates and antibody–oligonucleotide conjugates and review recent advances in bioanalytical methods for the quantification and characterization of novel bioconjugates. We also discuss bioanalytical considerations for both biotherapeutics and excipients through novel administration routes and review analyses in various biological matrices, from the extensively studied serum or plasma to tissue biopsy in the context of preclinical and clinical studies from both technical and regulatory perspectives.

Special Focus Issue - COVID-19: bioanalytical considerations, contributions and lessons - part 2.

Special Focus Issue - COVID-19: bioanalytical considerations, contributions and lessons - part 2.

COVID-19: Bioanalytical Considerations, Contributions and Lessons–Part 1

COVID-19: Bioanalytical Considerations, Contributions and Lessons–Part 1

Technical bioanalytical considerations for detection and quantification of cytokines in ELISA assays

Enzyme-linked Immunosorbent Assays (ELISAs) techniques are widely known for the robust signal amplification with high sensitivity and specificity for the quantitation of antibodies and antigens in complex biological fluids. However, strict caution in the pre-analytical, analytical, and post-analytical phases is crucial to warrant an immunoassay quality. Since analytical errors are commonly seen in papers, this study aimed to discuss the main principles and guidelines to guarantee the specificity and sensitivity in the post-analytical phase of the ELISA method. Briefly, we highlighted the relevance of the analytical noise, as well as the limit of detection and quantitation, in the sensitivity of an immunoassay. Moreover, strategies involving the use of reverse pipetting and the spike-and-recovery test can decrease the inter-assay variance, while the linearity-of-dilution assay may protect against the prozone (or hook) effect. Addressed to researchers from different fields, we offer recommendations to limit variability and increase the usefulness of the ELISA assay in a practical way that will assist scientists to prevent future analytical errors.

Critical reagent screening and characterization: benefits and approaches for protein biomarker assays by hybrid LC-MS.

In recent years, hybrid ligand-binding assays (LBAs)/LC-MS assays have been increasingly used for quantitation of protein biomarkers in biological matrices. However, unlike in LBAs where the importance of critical reagent screening and characterization is well understood and widely reported, benefits of well-characterized hybrid LC-MS assay reagents are frequently underestimated. Two groups of analyte-specific reagents, binding reagents and assay calibrators, are considered the critical reagents for biomarker assays. In this article, we summarize the similarities and differences of critical reagents used in LBAs and hybrid LC-MS assays, overview the benefits and approaches of critical reagent screening, characterization, antibody conjugation and discuss bioanalytical considerations in hybrid LC-MS assay development for robust measurements of protein biomarkers in biological matrices.

Quantification below the LLOQ in regulated LC-MS/MS assays: a review of bioanalytical considerations and cautions.

In response to an earlier workshop covering the pros and cons of quantification below the LLOQ (BLQ) the author reviews the topics discussed from the bioanalytical standpoint. Important considerations for estimating concentrations below the LLOQ include: method signal-to-noise, baseline shape and condition, close lying interference peaks (especially for protein methods), matrix effect, adsorption and stability of the analyte at low concentrations and carryover. These methodological issues are discussed as possible contributors to inaccuracy in BLQ estimations, and appropriate cautions are provided via examples. A proposed method for the evaluation of BLQ estimations utilizes extended incurred sample reanalysis analysis where BLQ samples or spiked simulated samples are analyzed with quality controls and standards in addition to those in the original study. Generally, BLQ estimations are discouraged, with the recommendation that any extrapolations should be done in close collaboration between the pharmacokinetic (PK) and bioanalytical scientists in consultation with the regulatory agency.

An Overall Comparison of Small Molecules and Large Biologics in ADME Testing

<p class="ADMETabstracttext">Biologics mainly monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs) as new therapeutics are becoming increasingly important biotherapeutics. This review is intended to provide an overall comparison between small molecules (SMs) and biologics or large molecules (LMs) concerning drug metabolism and pharmacokinetic (DMPK) or associated with absorption, distribution, metabolism and elimination (ADME) testing from pharmaceutical industry drug discovery and development points of view, which will help design and conduct relevant ADME testing for biologics such as mAbs and ADCs. Recent advancements in the ADME for testing biologics and related bioanalytical methods are discussed with an emphasis on ADC drug development as an example to understand its complexity and challenges from extensive in vitro characterization to in vivo animal PK studies. General non-clinical safety evaluations of biologics in particular for ADC drugs are outlined including drug-drug interaction (DDI) and metabolite/catabolite assessments. Regulatory guidance on the ADME testing and safety evaluations including immunogenicity as well as bioanalytical considerations are addressed for LMs. In addition, the preclinical and human PK data of two marked ADC drugs (ADCETRIS, SGN-35 and KADCYLA, T-DM1) as examples are briefly discussed with regard to PK considerations and PK/PD perspectives.</p>

Boston Society's 11th Annual Applied Pharmaceutical Analysis conference.

Boston Society's 11th Annual Applied Pharmaceutical Analysis conference, Hyatt Regency Hotel, Cambridge, MA, USA, 14-16 September 2015 The Boston Society's 11th Annual Applied Pharmaceutical Analysis (APA) conference took place at the Hyatt Regency hotel in Cambridge, MA, on 14-16 September 2015. The 3-day conference affords pharmaceutical professionals, academic researchers and industry regulators the opportunity to collectively participate in meaningful and relevant discussions impacting the areas of pharmaceutical drug development. The APA conference was organized in three workshops encompassing the disciplines of regulated bioanalysis, discovery bioanalysis (encompassing new and emerging technologies) and biotransformation. The conference included a short course titled 'Bioanalytical considerations for the clinical development of antibody-drug conjugates (ADCs)', an engaging poster session, several panel and round table discussions and over 50 diverse talks from leading industry and academic scientists.

Statistical and Bioanalytical Considerations for Establishing a Depletion Criterion for Specificity Testing During Immunogenicity Assessment of a Biotherapeutic

Immunogenicity assessment of fully human monoclonal antibody-based biotherapeutics requires sensitive and specific ligand binding assays. One of the components of specificity is the depletion of signal by a relevant biotherapeutic that is commonly based on an arbitrary depletion criterion of inhibition of the original response or reduction of the signal below the screening assay cut point (ACP). Hence, there is a need to develop a statistically derived physiologically relevant specificity criterion. We illustrate an optimization approach to determine the concentration of biotherapeutic required for the specificity evaluation. Naïve donor sample sets with and without circulating drug and antitherapeutic/drug antibody (ADA) were prepared. Next, a depletion cut point (DCP) using naïve and ADA-containing donor sets with the optimized biotherapeutic concentration was evaluated. A statistically derived design of experiment was used to establish a validated DCP. A reliable DCP requires naïve (no ADA) donors treated only with an optimized concentration of biotherapeutic. The additional DCPs generated using two distinct concentrations of ADA-spiked sample sets led to a physiologically irrelevant criterion that was not necessarily representative of real-time samples. This increased the risk of false positives or negatives. In this study, well-defined bioanalytical and statistical methods were employed to validate a DCP to confirm the presence of biotherapeutic specific ADA in human serum samples. A physiologically relevant and effective strategy to confirm specificity in immune reactive samples, especially those that are close to the ACP, is proposed through this study.

Assessing Immunogenicity of Biosimilar Therapeutic Monoclonal Antibodies: Regulatory and Bioanalytical Considerations

This article reflects on methodological limitations for interpretation of relative immunogenicity of biosimilar and reference therapeutic monoclonal antibodies, in emphasizing the relevance of correlation of bioanalytical signals with appropriate clinical end points, and the possible need for post-marketing observational studies to indicate the impact of detected differences in anti-drug antibody incidence and magnitude on sustainability of treatment benefit. Given the current uncertainty regarding the longer term clinical impact of undesirable immunogenicity for reference products, there can be no predefined margin for an acceptable difference based on incidence and magnitude of detected anti-drug antibodies. Any detected differences should be assessed in relation to clinical parameters; and the designation of biosimilarity made with reference to the similarity demonstrated in the directly comparative quality, nonclinical and clinical evaluations. Application of this 'totality of evidence' approach is illustrated for infliximab and adalimumab.

A Wide Angle View of Biosimilars from A Bioanalytical Perspective

BioanalysisVol. 5, No. 5 OpinionA wide angle view of biosimilars from a bioanalytical perspectivePhilip OldfieldPhilip OldfieldPhilip Oldfield Bioanalytical Consulting, 400 Bellerive, Hudson, Quebec, J0P 1H0 Canada. Search for more papers by this authorEmail the corresponding author at philip.oldfield@poldfieldbc.comPublished Online:20 Feb 2013https://doi.org/10.4155/bio.12.316AboutSectionsView ArticleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinkedInRedditEmail View articleKeywords: biosimilarimmunoassayimmunogenicityimmunoreactivityinnovatorReferences1 Yallow R, Berson S. Immunoassay of endogenous plasma insulin in man. J. Clin. Investig.39(7),1157–1175 (1960).Crossref, Medline, Google Scholar2 Owen WE, Roberts WL. Cross-reactivity of three recombinant insulin analogs with five commercial insulin immunoassays. Clin. Chem.50(1),257–259 (2004).Crossref, Medline, CAS, Google Scholar3 Glenn C, Armston A. Cross-reactivity of 12 recombinant insulin preparations in the Beckman Unicel Dxl 800 insulin assay. Ann. Clin. Biochem.47(Pt 3),264–266 (2010).Crossref, Medline, CAS, Google Scholar4 Kuhlmann M, Marre M. Lessons learned from biosimilar epoetins and insulins. Br. J. Diabetes Vasc. Dis.10(2),90–97 (2010).Crossref, CAS, Google Scholar5 Oldfield PR. Differences in bioanalytical method validation for biologically derived macromolecules (biosimilars) compared with small molecules (generics). Bioanalysis3(14),1551–1553 (2011).Link, CAS, Google Scholar6 Sola RJ, Griebenow K. Glycosylation of therapeutic proteins: an effective strategy to optimize efficacy. BioDrugs24(1),9–21 (2010).Crossref, Medline, CAS, Google Scholar7 Oortwijn BD, Roos A, Royle L et al. Differential glycosylation of polymeric and monoeric IgA: a possible role in glomerular inflammation in IgA nephropathy. J. Am. Soc. Nephrol.17(12),3529–3539, (2006).Crossref, Medline, CAS, Google Scholar8 Heinemann L, Hompesch M. Biosimilar insulin’s: how similar is similar?J. Diabetes Sci. Technol.5(3),741–754 (2011).Crossref, Medline, Google Scholar9 European Medicines Agency. Question and Answers on Withdrawal of the Marketing Authorisation Application for Insulin Human Rapid Marvel, Insulin Human Long Marvel, Insulin Human 30/70 Mix Marvel. European Medicines Agency, London, UK (2008).Google Scholar10 Kuhlmann M, Covic A. The protein science of biosimilars. Nephrol. Dial. Transplant.21(Suppl. 5),4–8 (2006).Crossref, Medline, CAS, Google Scholar11 Lee JW, Wang Y-M, Moxness M, DeSilva B. Perspective bioanalytical considerations in the comparability assessment of biotherapeutics. Bioanalysis3(6),613–622 (2011).Link, CAS, Google Scholar101 The discovery and manufacture of insulin. www.lillyindia.co.in/pdf/insulindiscovery.pdfGoogle Scholar102 The Nobel Prize in Physiology or Medicine 1923, Frederick G Banting Nobel lecture ‘Diabetes and Insulin’. www.nobelprize.org/nobel_prizes/medicine/laureates/1923/banting-lecture.htmlGoogle Scholar103 Novo nordisk history. www.novonordisk.com/images/about_us/history/history_uk.pdfGoogle ScholarFiguresReferencesRelatedDetailsCited ByBiosimilarity tetrahedron2 December 2015Highly sensitive ligand-binding assays in pre-clinical and clinical applications: immuno-PCR and other emerging techniques1 January 2015 | The Analyst, Vol. 140, No. 18Bioanalytical strategy used in development of pharmacokinetic (PK) methods that support biosimilar programs1 November 2014 | mAbs, Vol. 6, No. 5Advances in the quantitation of therapeutic insulin analogues by LC–MS/MSMichael Blackburn3 December 2013 | Bioanalysis, Vol. 5, No. 23 Vol. 5, No. 5 Follow us on social media for the latest updates Metrics Downloaded 547 times History Published online 20 February 2013 Published in print March 2013 Information© Future Science LtdKeywordsbiosimilarimmunoassayimmunogenicityimmunoreactivityinnovatorFinancial & competing interests disclosureThe author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.No writing assistance was utilized in the production of this manuscript.PDF download

Bioanalytical Considerations in The Comparability Assessment of Biotherapeutics

Comparison of biotherapeutic products before and after manufacturing changes is required to show that the products are highly similar. Besides in vitro assessment on the critical quality attributes and potency, biocomparability studies are sometimes required to demonstrate similarities in pharmacokinetic and pharmacodynamic characteristics. The complex and diverse nature of biotherapeutics requires multifaceted considerations in the biocomparability study design, bioanalytical measurements of drug concentrations and/or pharmacodynamic responses, immunogenicity analysis, data interpretation and decision making. A major perspective is to understand the structure and biological functions of the biotherapeutics in relation to the indication. Issues of a common standard and the importance of the use of ligand-binding assays that are sensitive to structural changes are discussed. It would not be possible to use the same process and one-size-fit-all criteria for biocomparability studies of all biologics. Previous examples from industry and our experience of the bioanalytical considerations for fit-for-purpose pharmacokinetic support and immunogenicity assessments are presented.

Early Human ADME Using Microdoses and Microtracers: Bioanalytical Considerations

Quantitative assessment of metabolites of drug candidates in early-phase clinical development presents an analytical challenge when methods, standards and assays are not yet available. Radioisotopic labeling, principally with radiocarbon ((14)C), is the preferred method for discovering and quantifying the absolute yields of metabolites in the absence of reference material or a priori knowledge of the human metabolism. However, the detection of (14)C is inefficient by decay counting methods and, as a result, high radiological human (14)C-doses had been needed to assure sensitive detection of metabolites over time. High radiological doses and the associated costs have been a major obstacle to the routine (and early) use of (14)C despite the recognized advantages of a (14)C-tracer for quantifying drug metabolism and disposition. Accelerator mass spectrometry eliminates this long-standing problem by reducing radioactivity levels while delivering matrix-independent quantitation to attomole levels of sensitivity in small samples or fractionated isolates. Accelerator mass spectrometry and trace (14)C-labeled drugs are now used to obtain early insights into the human metabolism of a drug candidate in ways that were not previously practical. With this article we describe some of our empirically based approaches for regualted bioanalysis and offer perspectives on current applications and opportunities for the future.

Bioanalytical considerations for compounds containing free sulfhydryl groups.

Thiol-containing compounds pose bioanalytical challenge in several dimensions due to extreme reactivity of the sulfhydryl group. The development of robust bioanalytical methodology for thiol groups should address the aspects of adequate stabilization in the biological matrix and selectivity considerations. In this context, availability of plethora of thiol reagents provides ample opportunity to achieve the above goals. However, several considerations need to be factored into the decision-making of a suitable scheme for the thiol drugs under investigation. This review provides some critical insights to many such considerations that may be vital for development and validation of methods for thiol-containing drugs.

Metabolism of aromatic and heterocyclic amine bladder carcinogens: bioanalytical considerations

Aromatic and heterocyclic amines are environmental chemicals which can cause bladder cancer in man. Because these chemicals cause carcinomas at a site distal to their portals of entry, metabolic processes are involved in initiation of their carcinogenic effects. N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) and its deformylated analogue, ANFT, were used as model compounds to assess metabolism. Electrochemical properties of ANFT made liquid chromatography with electrochemical detection a specific and sensitive method for analysis. Peroxidatic metabolism of ANFT by prostaglandin H synthase (PHS) in the presence of N-acetylcysteine resulted in the formation of 2-amino-4-(5-nitro-2-furyl)-5-(N-acetylcystein-S-yl)thiazole (ANFT-MA). This thioether product has an oxidation potential significantly lower than ANFT. Rat urinary excretion of ANFT-MA was significantly decreased with peroxidase inhibitors, 6-n-propyl-2-thiouracil and methimazole. Inhibitors did not alter excretion of ANFT or prostaglandin E2, a PHS product of arachidonic acid metabolism. 1H and 13C-NMR were selected to explore potential structural differences between ANFT and FANFT which might explain preferential PHS metabolism of ANFT. Evidence for a "zwitterion" configuration for ANFT but not FANFT was observed. ANFT in the "zwitterion" configuration would be a better reducing co-substrate. Chemical synthesis and GC-MS fragmentation patterns identified 3-(2,3-dihydro-1-methyl-2-pyrrolyl)pyridine as a peroxidatic product of nicotine metabolism. This peroxidatic product was found in urine from a cigarette smoker in an amount approximately 6% that observed for continine. Thus, a potential rôle for peroxidative metabolism was demonstrated in man.