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: 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.

Approaches to improve drug tolerance and target tolerance in the assessment of neutralizing anti-drug antibodies.

Aim: Neutralizing anti-drug antibody (NAb) assays are inherently prone to the interference from drug and its soluble target, potentially resulting in erroneous results. An effective approach to improve drug tolerance of an NAb assay is pretreatment of samples with acid to dissociate immune complexes of NAb and drug, followed by separating NAbs from circulating drug before testing them in the assay. Methods and Results: The acid pretreatment conditions were optimized to improve drug tolerance of cell-based and non-cell-based NAb assays. NAbs were further separated from circulating drug either through direct drug removal or purification of NAb from the sample. In addition, an integrated experimental strategy was implemented to simultaneously improve drug and its soluble target tolerance for reliable NAb assessment. Conclusion: The approaches described herein would enable the development of reliable NAb assays that overcome drug and its target interference for more precise and sensitive NAb assessment.

Strategies to Determine Assay Format for the Assessment of Neutralizing Antibody Responses to Biotherapeutics.

Most biotherapeutics can elicit immune responses in dosed recipients generating anti-drug antibodies (ADAs). Neutralizing antibodies (NAbs) are a subpopulation of ADAs that can potentially impact patient safety and directly mediate loss of drug efficacy by blocking the biological activity of a therapeutic product. Therefore, NAb detection is an important aspect of immunogenicity assessment, requiring sensitive and reliable methods reflective of the therapeutic mechanism of action (MoA). Both cell-based and non cell-based assays are viable options for NAb assessment. However, the scientific approach for the selection of a suitable assay format (cell-based or non cell-based) for NAb assessment is not currently well defined. In this manuscript, the authors summarize the design and utility of cell-based and non cell-based NAb assays and recommend a NAb assay format selection approach that relies on a combination of three factors. These include (i) the therapeutic MoA, (ii) the evidence of desirable assay performance characteristics, and (iii) risk of immunogenicity. The utility of correlating NAb response with pharmacodynamic data is also discussed. The aim of this paper is to provide a consistent strategy that will guide the selection of scientifically justified assay formats capable of detecting clinically relevant NAbs for biotherapeutics with varying MoAs and diverse complexity.