2021 White Paper on Recent Issues in Bioanalysis: TAb/NAb, Viral Vector CDx, Shedding Assays; CRISPR/Cas9 & CAR-T Immunogenicity; PCR & Vaccine Assay Performance; ADA Assay Comparability & Cut Point Appropriateness (Part 3 - Recommendations on Gene Therapy, Cell Therapy, Vaccine Assays; Immunogenicity of Biotherapeutics and Novel Modalities; Integrated Summary of Immunogenicity Harmonization)

A roadmap towards a human-centric safety assessment of advanced therapy medicinal products

Advanced therapy medicinal products (ATMPs) are among the most complex pharmaceuticals with high human specificity. Species differences severely limit the clinical relevance of in vivo data. We conducted interviews with stakeholders involved in ATMP development about their perspective on the use of in vivo studies, the perceived hurdles and associated potential solutions regarding non-clinical development of ATMPs. In total, 17 stakeholders from 9 different countries were interviewed. A workshop was held with key stakeholders to further discuss major topics identified from the interviews. Conducting in vivo studies remains the status quo for ATMPs development. The hurdles identified included determining the amount of information required before clinical entry and effective use of limited human samples to understand a treatment or for clinical monitoring. A number of key points defined the need for future in vivo studies as well as improved application and implementation of New Approach Methodology (NAM)-based approach for products within a well-known modality or technology platform. These included data transparency, understanding of the added value of in vivo studies, and continuous advancement, evaluation, and qualification of NAMs. Based on the outcome of the discussions, a roadmap with practical steps towards a human-centric safety assessment of ATMPs was established.

2023 White Paper on Recent Issues in Bioanalysis: EU IVDR 2017/746 Implementation/Impact, IVD/CDx/CLIA Approved Assays, High Dimensional Cytometry, Multiplexing Technologies, LBA Tissue Analysis, Vaccine Study Endpoints, Cell-Based Assays for Biomarkers, Cell Therapy and Vaccines (PART 2 - Recommendations on Development & Validation of Biomarkers, IVD, CDx, Cell-Based, Flow Cytometry, Ligand-Binding and Enzyme Assays; Advanced Critical Reagents Strategies)

The 17th Workshop on Recent Issues in Bioanalysis (17th WRIB) took place in Orlando, FL, USA on 19-23 June 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 2) covers the recommendations on Biomarkers, IVD/CDx, LBA and Cell-Based Assays. Part 1A (Mass Spectrometry Assays and Regulated Bioanalysis/BMV), P1B (Regulatory Inputs) and Part 3 (Gene Therapy, Cell therapy, Vaccines and Biotherapeutics Immunogenicity) are published in volume 16 of Bioanalysis, issues 9 and 7 (2024), respectively.

Immunogenicity Risk Assessment of Process-Related Impurities in An Engineered T Cell Receptor Cellular Product

Cell therapies such as genetically modified T cells have emerged as a promising and viable treatment for hematologic cancers and are being aggressively pursued for a wide range of diseases and conditions that were previously difficult to treat or had no cure. The process development requires genetic modifications to T cells to express a receptor (engineered T cell receptor (eTCR)) of specific binding qualities to the desired target. Protein reagents utilized during the cell therapy manufacturing process, to facilitate these genetic modifications, are often present as process-related impurities at residual levels in the final drug product and can represent a potential immunogenicity risk upon infusion. This manuscript presents a framework for the qualification of an assay for assessing the immunogenicity risk of AA6 and Cas9 residuals. The same framework applies for other residuals; however, AAV6 and Cas9 were selected as they were residuals from the manufacturing of an engineered T cell receptor cellular product in development. The manuscript: 1) elucidates theoretical risks, 2) summarizes analytical data collected during process development, 3) describes the qualification of an in vitro human PBMC cytokine release assay to assess immunogenicity risk from cellular product associated process residuals; 4) identifies a multiplexed inflammatory innate and adaptive cytokine panel with pre-defined criteria using relevant positive controls; and 5) discusses qualification challenges and potential solutions for establishing meaningful thresholds. The assessment is not only relevant to establishing safe exposure levels of these residuals but also in guiding risk assessment and CMC strategy during the conduct of clinical trials.

Engineered IgM and IgG cleaving enzymes for mitigating antibody neutralization and complement activation in AAV gene transfer

Systemic dosing of adeno-associated viral (AAV) vectors poses potential risk of adverse side effects including complement activation triggered by anti-capsid immunity. Due to the multifactorial nature of toxicities observed in this setting, a wide spectrum of immune modulatory regimens are being investigated in the clinic. Here, we discover an IgM cleaving enzyme (IceM) that degrades human IgM, a key trigger in the anti-AAV immune cascade. We then engineer a fusion enzyme (IceMG) with dual proteolytic activity against human IgM and IgG. IceMG cleaves B cell surface antigen receptors and inactivates phospholipase gamma signaling in vitro. Importantly, IceMG is more effective at inhibiting complement activation compared with an IgG cleaving enzyme alone. Upon IV dosing, IceMG rapidly and reversibly clears circulating IgM and IgG in macaques. Antisera from these animals treated with IceMG shows decreased ability to neutralize AAV and activate complement. Consistently, pre-conditioning with IceMG restores AAV transduction in mice passively immunized with human antisera. Thus, IgM cleaving enzymes show promise in simultaneously addressing multiple aspects of anti-AAV immunity mediated by B cells, circulating antibodies and complement. These studies have implications for improving safety of AAV gene therapies and possibly broader applications including organ transplantation and autoimmune diseases.

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.

Risk-based approach of bioanalytical methods for clinical immunogenicity assessment of multidomain biotherapeutics

Tweetable abstract Risk-based bioanalytical method development for clinical antidrug antibody detection and characterization of multidomain biotherapeutics.

Recommendations for Method Development and Validation of qPCR and dPCR Assays in Support of Cell and Gene Therapy Drug Development

The emerging use of qPCR and dPCR in regulated bioanalysis and absence of regulatory guidance on assay validations for these platforms has resulted in discussions on lack of harmonization on assay design and appropriate acceptance criteria for these assays. Both qPCR and dPCR are extensively used to answer bioanalytical questions for novel modalities such as cell and gene therapies. Following cross-industry conversations on the lack of information and guidelines for these assays, an American Association of Pharmaceutical Scientists working group was formed to address these gaps by bringing together 37 industry experts from 24 organizations to discuss best practices to gain a better understanding in the industry and facilitate filings to health authorities. Herein, this team provides considerations on assay design, development, and validation testing for PCR assays that are used in cell and gene therapies including (1) biodistribution; (2) transgene expression; (3) viral shedding; (4) and persistence or cellular kinetics of cell therapies.

Thrombotic microangiopathy following systemic AAV administration is dependent on anti-capsid antibodies

BACKGROUNDSystemic administration of adeno-associated virus (AAV) can trigger life-threatening inflammatory responses, including thrombotic microangiopathy (TMA), acute kidney injury due to atypical hemolytic uremic syndrome-like complement activation, immune-mediated myocardial inflammation, and hepatic toxicity.METHODSWe describe the kinetics of immune activation following systemic AAV serotype 9 (AAV9) administration in 38 individuals following 2 distinct prophylactic immunomodulation regimens. Group 1 received corticosteroids and Group 2 received rituximab plus sirolimus in addition to steroids to prevent anti-AAV antibody formation.RESULTSGroup 1 participants had a rapid increase in immunoglobulin M (IgM) and IgG. Increase in D-dimer, decline in platelet count, and complement activation are indicative of TMA. All Group 1 participants demonstrated activation of both classical and alternative complement pathways, as indicated by depleted C4 and elevated soluble C5b-9, Ba, and Bb antigens. Group 2 patients did not have a significant change in IgM or IgG and had minimal complement activation.CONCLUSIONSThis study demonstrates that TMA in the setting of AAV gene therapy is antibody dependent (classical pathway) and amplified by the alternative complement pathway. Critical time points and interventions are identified to allow for management of immune-mediated events that impact the safety and efficacy of systemic gene therapy.

Emerging approaches to induce immune tolerance to therapeutic proteins

Immunogenicity affects the safety and efficacy of therapeutic proteins. This review is focused on approaches for inducing immunological tolerance to circumvent the immunogenicity of therapeutic proteins in the clinic. The few immune tolerance strategies that are used in the clinic tend to be inefficient and expensive and typically involve global immunosuppression, putting patients at risk of infections. The hallmark of a desirable immune tolerance regimen is the specific alleviation of immune responses to the therapeutic protein. In the past decade, proof-of-principle studies have demonstrated that emerging technologies, including nanoparticle-based delivery of immunomodulators, cellular targeting and depletion, cellular engineering, gene therapy, and gene editing, can be leveraged to promote tolerance to therapeutic proteins. We discuss the potential of these novel approaches and the barriers that need to be overcome for translation into the clinic.

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.

Multifaceted Approach for Quantification and Enzymatic Activity of Iduronate-2-Sulfatase to Support Developing Gene Therapy for Hunter Syndrome

Mucopolysaccharidosis type II, commonly called Hunter syndrome, is a rare X-linked recessive disease caused by the deficiency of the lysosomal enzyme iduronate-2-sulphatase (I2S). A deficiency of I2S causes an abnormal glycosaminoglycans accumulation in the body's cells. Although enzyme replacement therapy is the standard therapy, adeno-associated viruses (AAV)-based gene therapy could provide a single-dose solution to achieve a prolonged and constant enzyme level to improve patient's quality of life. Currently, there is no integrated regulatory guidance to describe the bioanalytical assay strategy to support gene therapy products. Herein, we describe the streamlined strategy to validate/qualify the transgene protein and its enzymatic activity assays. The method validation for the I2S quantification in serum and method qualification in tissues was performed to support the mouse GLP toxicological study. Standard curves for I2S quantification ranged from 2.00 to 50.0 μg/mL in serum and 6.25 to 400 ng/mL in the surrogate matrix. Acceptable precision, accuracy, and parallelism in the tissues were demonstrated. To assess the function of the transgene protein, fit-for-purpose method qualification for the I2S enzyme activity in serum was performed. The observed data indicated that the enzymatic activity in serum increased dose-dependently in the lower I2S concentration range. The highest I2S transgene protein was observed in the liver among tissue measured, and its expression level was maintained up to 91 days after the administration of rAAV8 with a codon-optimized human I2S. In conclusion, the multifaceted bioanalytical method for I2S and its enzymatic activity were established to assess gene therapy products in Hunter syndrome.

Statistical Approaches for Establishing Appropriate Immunogenicity Assay Cut Points: Impact of Sample Distribution, Sample Size, and Outlier Removal

The statistical assessments needed to establish anti-drug antibody (ADA) assay cut points (CPs) can be challenging for bioanalytical scientists. Poorly established CPs that are too high could potentially miss treatment emergent ADA or, when set too low, result in detection of responses that may have no clinical relevance. We evaluated 16 validation CP datasets generated with ADA assays at Regeneron's bioanalytical laboratory and compared results obtained from different CP calculation tools. We systematically evaluated the impact of various factors on CP determination including biological and analytical variability, number of samples for capturing biological variability, outlier removal methods, and the use of parametric vs. non-parametric CP determination. In every study, biological factors were the major component of assay response variability, far outweighing the contribution from analytical variability. Non-parametric CP estimations resulted in screening positivity in drug-naïve samples closer to the targeted rate (5%) and were less impacted by skewness. Outlier removal using the boxplot method with an interquartile range (IQR) factor of 3.0 resulted in screening positivity close to the 5% targeted rate when applied to entire drug-naïve dataset. In silico analysis of CPs calculated using different sample sizes showed that using larger numbers of individuals resulted in CP estimates closer to the CP of the entire population, indicating a larger sample size (~ 150) for CP determination better represents the diversity of the study population. Finally, simpler CP calculations, such as the boxplot method performed in Excel, resulted in CPs similar to those determined using complex methods, such as random-effects ANOVA.

Immunogenicity of CRISPR therapeutics-Critical considerations for clinical translation

CRISPR offers new hope for many patients and promises to transform the way we think of future therapies. Ensuring safety of CRISPR therapeutics is a top priority for clinical translation and specific recommendations have been recently released by the FDA. Rapid progress in the preclinical and clinical development of CRISPR therapeutics leverages years of experience with gene therapy successes and failures. Adverse events due to immunogenicity have been a major setback that has impacted the field of gene therapy. As several in vivo CRISPR clinical trials make progress, the challenge of immunogenicity remains a significant roadblock to the clinical availability and utility of CRISPR therapeutics. In this review, we examine what is currently known about the immunogenicity of CRISPR therapeutics and discuss several considerations to mitigate immunogenicity for the design of safe and clinically translatable CRISPR therapeutics.