2023 White Paper on Recent Issues in Bioanalysis: ISR for ADA Assays, the Rise of dPCR vs qPCR, International Reference Standards for Vaccine Assays, Anti-AAV TAb Post-Dose Assessment, NanoString Validation, ELISpot as Gold Standard (Part 3 - Recommendations on Gene Therapy, Cell Therapy, Vaccines Immunogenicity & Technologies; Biotherapeutics Immunogenicity & Risk Assessment; ADA/NAb Assay/Reporting Harmonization)

The 17th Workshop on Recent Issues in Bioanalysis (17th WRIB) took place in Orlando, FL, USA on June 19-23, 2023. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 17th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week to allow an exhaustive and thorough coverage of all major issues in bioanalysis of biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on "EU IVDR 2017/746 Implementation and impact for the Global Biomarker Community: How to Comply with these NEW Regulations" and on "US FDA/OSIS Remote Regulatory Assessments (RRAs)" were the special features of the 17th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2023 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 2023 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations on Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity. Part 1A (Mass Spectrometry Assays and Regulated Bioanalysis/BMV), P1B (Regulatory Inputs) and Part 2 (Biomarkers, IVD/CDx, LBA and Cell-Based Assays) are published in volume 16 of Bioanalysis, issues 8 and 9 (2024), respectively.

2022 White Paper on Recent Issues in Bioanalysis: Enzyme Assay Validation, BAV for Primary End Points, Vaccine Functional Assays, Cytometry in Tissue, LBA in Rare Matrices, Complex NAb Assays, Spectral Cytometry, Endogenous Analytes, Extracellular Vesicles Part 2 - Recommendations on Biomarkers/CDx, Flow Cytometry, Ligand-Binding Assays Development & Validation; Emerging Technologies; Critical Reagents Deep Characterization

The 16th Workshop on Recent Issues in Bioanalysis (16th WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 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 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations on LBA, Biomarkers/CDx and Cytometry. Part 1 (Mass Spectrometry and ICH M10) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 15 of Bioanalysis, issues 16 and 14 (2023), respectively.

2022 White Paper on Recent Issues in Bioanalysis: ICH M10 BMV Guideline & Global Harmonization; Hybrid Assays; Oligonucleotides & ADC; Non-Liquid & Rare Matrices; Regulatory Inputs (Part 1A - Recommendations on Mass Spectrometry, Chromatography and Sample Preparation, Novel Technologies, Novel Modalities, and Novel Challenges, ICH M10 BMV Guideline & Global Harmonization Part 1B - Regulatory Agencies' Inputs on Regulated Bioanalysis/BMV, Biomarkers/CDx/BAV, Immunogenicity, Gene & Cell Therapy and Vaccine)

The 16th Workshop on Recent Issues in Bioanalysis (16th WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on the ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 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 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1A) covers the recommendations on Mass Spectrometry and ICH M10. Part 1B covers the Regulatory Agencies' Inputs on Bioanalysis, Biomarkers, Immunogenicity, Gene & Cell Therapy and Vaccine. Part 2 (LBA, Biomarkers/CDx and Cytometry) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 15 of Bioanalysis, issues 15 and 14 (2023), respectively.

2022 White Paper on Recent Issues in Bioanalysis: FDA Draft Guidance on Immunogenicity Information in Prescription Drug Labeling, LNP & Viral Vectors Therapeutics/Vaccines Immunogenicity, Prolongation Effect, ADA Affinity, Risk-based Approaches, NGS, qPCR, ddPCR Assays (Part 3 - Recommendations on Gene Therapy, Cell Therapy, Vaccines Immunogenicity & Technologies; Immunogenicity & Risk Assessment of Biotherapeutics and Novel Modalities; NAb Assays Integrated Approach)

The 2022 16th Workshop on Recent Issues in Bioanalysis (WRIB) took place in Atlanta, GA, USA on September 26-30, 2022. Over 1000 professionals representing pharma/biotech companies, CROs, and multiple regulatory agencies convened to actively discuss the most current topics of interest in bioanalysis. The 16th WRIB included 3 Main Workshops and 7 Specialized Workshops that together spanned 1 week in order to allow exhaustive and thorough coverage of all major issues in bioanalysis, biomarkers, immunogenicity, gene therapy, cell therapy and vaccines. Moreover, in-depth workshops on ICH M10 BMV final guideline (focused on this guideline training, interpretation, adoption and transition); mass spectrometry innovation (focused on novel technologies, novel modalities, and novel challenges); and flow cytometry bioanalysis (rising of the 3rd most common/important technology in bioanalytical labs) were the special features of the 16th edition. As in previous years, WRIB continued to gather a wide diversity of international, industry opinion leaders and regulatory authority experts working on both small and large molecules as well as gene, cell therapies and vaccines to facilitate sharing and discussions focused on improving quality, increasing regulatory compliance, and achieving scientific excellence on bioanalytical issues. This 2022 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 2022 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations on Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity. Part 1 (Mass Spectrometry and ICH M10) and Part 2 (LBA, Biomarkers/CDx and Cytometry) are published in volume 15 of Bioanalysis, issues 16 and 15 (2023), respectively.

Biomarker Assay Validation by Mass Spectrometry

Decades of discussion and publication have gone into the guidance from the scientific community and the regulatory agencies on the use and validation of pharmacokinetic and toxicokinetic assays by chromatographic and ligand binding assays for the measurement of drugs and metabolites. These assay validations are well described in the FDA Guidance on Bioanalytical Methods Validation (BMV, 2018). While the BMV included biomarker assay validation, the focus was on understanding the challenges posed in validating biomarker assays and the importance of having reliable biomarker assays when used for regulatory submissions, rather than definition of the appropriate experiments to be performed. Different from PK bioanalysis, analysis of biomarkers can be challenging due to the presence of target analyte(s) in the control matrices used for calibrator and quality control sample preparation, and greater difficulty in procuring appropriate reference standards representative of the endogenous molecule. Several papers have been published offering recommendations for biomarker assay validation. The situational nature of biomarker applications necessitates fit-for-purpose (FFP) assay validation. A unifying theme for FFP analysis is that method validation requirements be consistent with the proposed context of use (COU) for any given biomarker. This communication provides specific recommendations for biomarker assay validation (BAV) by LC-MS, for both small and large molecule biomarkers. The consensus recommendations include creation of a validation plan that contains definition of the COU of the assay, use of the PK assay validation elements that support the COU, and definition of assay validation elements adapted to fit biomarker assays and the acceptance criteria for both.

Protein Biomarker Quantification by Immunoaffinity Liquid Chromatography–Tandem Mass Spectrometry: Current State and Future Vision

Immunoaffinity–mass spectrometry (IA-MS) is an emerging analytical genre with several advantages for profiling and determination of protein biomarkers. Because IA-MS combines affinity capture, analogous to ligand binding assays (LBAs), with mass spectrometry (MS) detection, this platform is often described using the term hybrid methods. The purpose of this report is to provide an overview of the principles of IA-MS and to demonstrate, through application, the unique power and potential of this technology. By combining target immunoaffinity enrichment with the use of stable isotope-labeled internal standards and MS detection, IA-MS achieves high sensitivity while providing unparalleled specificity for the quantification of protein biomarkers in fluids and tissues. In recent years, significant uptake of IA-MS has occurred in the pharmaceutical industry, particularly in the early stages of clinical development, enabling biomarker measurement previously considered unattainable. By comparison, IA-MS adoption by CLIA laboratories has occurred more slowly. Current barriers to IA-MS use and opportunities for expanded adoption are discussed. The path forward involves identifying applications for which IA-MS is the best option compared with LBA or MS technologies alone. IA-MS will continue to benefit from advances in reagent generation, more sensitive and higher throughput MS technologies, and continued growth in use by the broader analytical community. Collectively, the pursuit of these opportunities will secure expanded long-term use of IA-MS for clinical applications.

Estimation of an Appropriate Dose of Trazodone for Pediatric Insomnia and the Potential for a Trazodone-Atomoxetine Interaction

There is a paucity of clinical trials for the treatment of pediatric insomnia. This study was designed to predict the doses of trazodone to guide dosing in a clinical trial for pediatric insomnia using physiologically‐based pharmacokinetic (PBPK) modeling. Data on the pharmacokinetics of trazodone in children are currently lacking. The interaction potential between trazodone and atomoxetine was also predicted. Doses predicted in the following age groups, with exposures corresponding to adult dosages of 30, 75, and 150 mg once a day (q.d.), respectively, were: (i) 2‐ to 6‐year‐old group, doses of 0.35, 0.8, and 1.6 mg/kg q.d.; (ii) >6‐ to 12‐year‐old group, doses of 0.4, 1.0, and 1.9 mg/kg q.d.; (iii) >12‐ to 17‐year‐old group, doses of 0.4, 1.1, and 2.1 mg/kg q.d. An interaction between trazodone and atomoxetine was predicted to be unlikely. Clinical trials based on the aforementioned predicted dosing are currently in progress, and pharmacokinetic data obtained will enable further refinement of the PBPK models.

New Insights on the Pharmacokinetics of Ulifloxacin After Administration of Prulifloxacin in Patients with Mild, Moderate and Severe Renal Impairment

Background

The antibacterial agent prulifloxacin, a prodrug of ulifloxacin, is indicated in the treatment of acute lower urinary tract infections, acute exacerbation of chronic bronchitis and acute bacterial rhinosinusitis.

Objective

We aimed to provide new insights on the pharmacokinetics (PK) of ulifloxacin in patients with different degrees of renal impairment.

Methods

A two-site, international, open-label, parallel-group, single- and repeated-dose study was performed. The drug was administered as a single dose of 600 mg to subjects with normal renal function and patients with mild, moderate and severe renal impairment. Subsequently, the same dose was administered daily for 7 days to subjects with normal renal function and patients with mild and moderate renal impairment, while a dose of 300 mg was administered daily for 7 days to patients with severe renal impairment. Plasma and urine ulifloxacin levels were measured. Complete safety evaluation was performed.

Results

Exposure to ulifloxacin increased as renal function decreased due to a lower ulifloxacin clearance. Ulifloxacin PK were significantly changed only in patients with severe renal impairment. The amount of ulifloxacin excreted in urine over a 24-h dosing period was similar in subjects with normal renal function and patients with mild impaired renal function, but lower in those with moderate and severe renal impairment.

Conclusion

Our data show that prulifloxacin is a safe quinolone and is well tolerated in both subjects with normal renal function and patients with impaired renal function, requiring a minimal dosage adjustment only in patients with severe renal impairment.

Recommendations for validation of LC-MS/MS bioanalytical methods for protein biotherapeutics

This paper represents the consensus views of a cross-section of companies and organizations from the USA and Canada regarding the validation and application of liquid chromatography tandem mass spectrometry (LC-MS/MS) methods for bioanalysis of protein biotherapeutics in regulated studies. It was prepared under the auspices of the AAPS Bioanalytical Focus Group's Protein LC-MS Bioanalysis Subteam and is intended to serve as a guide to drive harmonization of best practices within the bioanalytical community and provide regulators with an overview of current industry thinking on applying LC-MS/MS technology for protein bioanalysis. For simplicity, the scope was limited to the most common current approach in which the protein is indirectly quantified using LC-MS/MS measurement of one or more of its surrogate peptide(s) produced by proteolytic digestion. Within this context, we considered a range of sample preparation approaches from simple in-matrix protein denaturation and digestion to complex procedures involving affinity capture enrichment. Consideration was given to the method validation experiments normally associated with traditional LC-MS/MS and ligand-binding assays. Our collective experience, thus far, is that LC-MS/MS methods for protein bioanalysis require different development and validation considerations than those used for small molecules. The method development and validation plans need to be tailored to the particular assay format being established, taking into account a number of important factors: the intended use of the assay, the test species or study population, the characteristics of the protein biotherapeutic and its similarity to endogenous proteins, potential interferences, as well as the nature, quality, and availability of reference and internal standard materials.

Elimination of isobaric interference and signal-to-noise ratio enhancement using on-line mobile phase filtration in liquid chromatography/tandem mass spectrometry

RATIONALE

Liquid chromatography/tandem mass spectrometry (LC/MS/MS) instruments are selective and sensitive but can still be affected by isobaric interference or chemical noise arising from multiple sources such as the mobile phase. In this study, a high-performance liquid chromatography (HPLC) on-line mobile phase filtration setup is described and used to remove interference to allow better detection of the analyte of interest.

METHODS

For instance, a filtration device containing a chemical sorbent is installed at the HPLC outlet of the aqueous solvent pump A or the organic solvent pump B. This manuscript reports different case scenarios under reversed-phase and HILIC separations either in positive (ESI(+)) or negative electrospray ionization (ESI(-)) mode using selected reaction monitoring (SRM) scans as well as additional Q1 MS scans.

RESULTS

The filtration of the aqueous effluent of the mobile phase using a porous graphitic carbon filter eliminated the isobaric interferences and improved the detectability of gestodene and perindopril-D4. Also, a strong cation-exchange guard column installed at the acetonitrile outlet pump was found helpful on reducing the baseline intensity and improving significantly the signal-to-noise ratio (S/N) of methenamine. Moreover, the on-line mobile phase filtration was efficient at removing chemical background ions in full scan mode.

CONCLUSIONS

This strategy demonstrated its usefulness by removing co-eluting isobaric interference, and reducing chemical background ions from the mobile phase, while drastically improving S/N.

Pre-cut dried blood spot (PCDBS): an alternative to dried blood spot (DBS) technique to overcome hematocrit impact

Quantification of analytes by Dried Blood Spots (DBS) on different paper cards has been extensively reported in the past several years. However, some factors limit the robustness of the precision and accuracy of DBS such as: hematocrit level, blood viscosity, analyte nature, spotting technique and spotting conditions. As such, the paper material used for DBS must meet strict quality control criteria to produce reliable quantification of drugs: uniformity, no chemical leaching and no chromatographic effect. To overcome these variables, especially the hematocrit impact, a modification of the traditional DBS, named Pre-Cut Dried Blood Spot (PCDBS), is presented. In contrast to the classical DBS technique, the new PCDBS procedure demonstrates no variation in response, within ±3%, independently of the hematocrit level or of the type of card used. The impact of the hematocrit level on the analyte recovery is discussed for both DBS and PCDBS approaches. Moreover, for quantification of naproxen by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS), the PCDBS technique was demonstrated to be as precise (%CV ≤3.1%) and accurate (%nominal between 95.4 and 104.4%) as the classical DBS procedure.

Importance of using highly pure internal standards for successful liquid chromatography/tandem mass spectrometric bioanalytical assays

Internal standards (IS) with similar physicochemical properties to the analyte provide multiple advantages in liquid chromatography/tandem mass spectrometric (LC/MS/MS) bioanalytical methods such as: reduction of the analysis run time, improvement in the intra-injection reproducibility, impact reduction of matrix and ionization effects. However, it is important to evaluate the purity of the IS prior to their use. Indeed, a minor impurity in the IS may lead to an important issue during bioanalytical method development. Stable labelled internal standards are usually appropriate IS for bioanalysis. The use of oxycodone-D3, ursodiol-D5 and atovaquone-D4 as internal standards in three different bioanalytical methods was evaluated. During oxycodone, oxymorphone and noroxycodone simultaneous quantification method development, oxymorphone was identified as a contaminant in oxycodone-D3. Since the limit of quantification for oxymorphone was very low (10 pg/mL), the presence of an even low percentage of oxymorphone in oxycodone-D3 leads to the change of the stable labelled IS for an analogue, ethylmorphine. 23-Nordeoxycholic acid was preferred to ursodiol-D5 as internal standard for the ursodiol, tauroursodiol and glycoursodiol simultaneous quantification method. Indeed, more than 7% of ursodiol was identified in the ursodiol-D5 which could not be bypassed by decreasing the IS concentration without compromising the linearity. An atovaquone-D4 reference standard revealed the non-negligible presence of atovaquone-D5 to atovaquone-D8 that has a large impact on the method validation. Therefore, atovaquone-D4 was sent for recertification since its isotopic purity was found to be much less than the isotopic purity mentioned on its certificate of analysis. Consequently, during bioanalytical method development, the purity of the IS should be scrutinized.

Determination of the active and inactive metabolites of prasugrel in human plasma by liquid chromatography/tandem mass spectrometry

Two fast and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS)-based bioanalytical assays were developed and validated to quantify the active and three inactive metabolites of prasugrel. Prasugrel is a novel thienopyridine prodrug that is metabolized to the pharmacologically active metabolite in addition to three inactive metabolites, which directly relate to the formation and elimination of the active metabolite. After extraction and separation, the analytes were detected and quantified using a triple quadrupole mass spectrometer using positive electrospray ionization. The validated concentration range for the inactive metabolites assay was from 1 to 500 ng/mL for each of the three analytes. Additionally, a 5x dilution factor was validated. The interday accuracy ranged from -10.5% to 12.5% and the precision ranged from 2.4% to 6.6% for all three analytes. All results showed accuracy and precision within +/-20% at the lower limit of quantification and +/-15% at other levels. The validated concentration range for the active metabolite assay was from 0.5 to 250 ng/mL. Additionally, a 10x dilution factor was validated. The interbatch accuracy ranged from -7.00% to 5.98%, while the precision ranged from 0.98% to 3.39%. Derivatization of the active metabolite in blood with 2-bromo-3'-methoxyacetophenone immediately after collection was essential to ensure the stability of the metabolite during sample processing and storage. These methods have been applied to determine the concentrations of the active and inactive metabolites of prasugrel in human plasma.

What medical staffs need to know about recruiting physicians

Hospital medical staffs involved in physician recruiting face an enormously complex task. The "old boy network" is probably not the most effective way to find physicians.