Search

Aim: Ivosidenib is a potent and selective small molecule inhibitor of mutant isocitrate dehydrogenase 1. Accurate measurement of ivosidenib is the key to ivosidenib pharmacokinetics in clinical trials. Materials & methods: Quantitation of ivosidenib was conducted by using a stable isotope labeled compound (ivosidenib-d4) as the internal standard. Results: This assay was validated and successfully applied to support multiple clinical trials. Selected clinical samples were also tested by a chiral LC–MS/MS method against four ivosidenib isomer standards to exclude the possibility of in vivo racemization of ivosidenib. Conclusion: A robust LC–MS/MS method was validated for ivosidenib in human plasma. This is the first time for ivosidenib bioanalytical method in any human matrix to be reported.

Aim: 2-Hydroxyglutarate (2-HG) is a target engagement biomarker in patients after treatment with inhibitors of mutated isocitrate dehydrogenase (mIDH). Accurate measurement of 2-HG is critical for monitoring the inhibition effectiveness of the inhibitors. Materials & methods: Human plasma samples were spiked with stable isotope labelled internal standard, processed by protein precipitation, and analyzed using LC–MS/MS. This method was validated following regulatory guidance and has been successfully applied in a clinical study for mIDH inhibition. Results: An LC–MS/MS method with a surrogate analyte approach was developed and validated to measure 2-HG in human plasma with acceptable intra- and inter-assay accuracy and precision. Conclusion: A sensitive and robust LC–MS/MS method was developed and validated for measuring 2-HG in human plasma.

The use of quality control (QC) samples in bioanalysis is well established and consistent with regulatory guidance. However, a systematic evaluation of whether QC samples serve the intended purpose of improving data quality has not been undertaken. The Translational and ADME Sciences Leadership Group (TALG) of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ) conducted an evaluation to assess whether closer agreement is observed when comparing pharmacokinetic data from two passed runs, than when comparing data from failed and passed (retest) runs. Analysis of data collected across organizations, molecular types and analytical platforms, revealed that bioanalytical methods are very reproducible; and that QC samples improve the overall quality of pharmacokinetic concentration data and justifies their continued use.

Aim: Recombinant FGF21 analogs are under wide ranging investigations as a potential therapeutic agent for Type 2 diabetes, as well as other metabolic disorders. The endogenous FGF21 is often used as a surrogate pharmacodynamic(PD) biomarker to assess drug efficacy and safety. Results & methodology: Immunocapture was performed using a monoclonal antibody which had been generated to bind to specific domain of native FGF21 as the capture reagent. After immunocapture, enzymatic digestion was performed and a native FGF21-specific tryptic peptide was monitored using LC–MS/MS by selective reaction monitoring. Conclusion: We have successfully developed and validated a bioanalytical assay which provides the specificity to differentiate the endogenous FGF21 from the recombinant therapeutic agent which has nearly identical sequence to the endogenous molecule.

Background: Creatinine is an endogenous compound generated from creatine by normal muscular metabolism. It is an important indicator of renal function and the serum level is routinely monitored in clinical labs. Results & methodology: Surrogate analyte (d3-creatinine) was used for calibration standard and quality control preparation and the relative instrument response ratio between creatinine and d3-creatinine was used to calculate the endogenous creatinine concentrations. Conclusion: A fit-for-purpose strategy of using a surrogate analyte and authentic matrix was adopted for this validation. The assay was the first human plasma assay using such strategy and was successfully applied to a clinical study to confirm a transient elevation of creatinine observed using an existing clinical assay.

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.

A consistent calibration curve slope is a positive indication of assay performance in a validated bioanalytical method using LC–MS/MS. It is one of the quality indicators utilized by bioanalytical scientists during the data review process. However, it is not uncommon that a calibration curve slope varies significantly across different analytical runs during sample analysis. The causes for such variation and their potential impacts on the assay ruggedness have been discussed on multiple occasions [1,2]. Although there is no specific requirements for the acceptability of calibration curve slope in regulatory guidelines, a scientific understanding of what is behind the observed deviation is valuable during method development, validation and sample analysis. Large variance in curve slope often indicates potential issues associated with a method. We advocate always assessing and understanding root cause for such variance and this paper tries to illustrate possible causes for the calibration curve slope variation (including the linearity change) and assess their impacts on the analysis results.

In the last several years, dried blood spot (DBS) sampling has re-emerged and attracted a great interest in the pharmaceutical industry as a microsampling technology for drug discovery and development studies. Although significant progress has been made to understand strengths and weaknesses of the technique, many organizations are still at the evaluation stage and experimental observations have resulted in more questions being raised as to whether there is a real future for this technology in pharmaceutical research, especially in support of pharmacokinetic studies. This article summarizes recently gained knowledge against the originally projected advantages of this technique, discusses some practical challenges that need to be overcome before DBS can be widely applied in drug development studies, and highlights some specific study types where DBS can be applied with a good benefit:risk ratio. The authors hope this article can stimulate further discussions about what are the next steps for DBS.