Immunomodulation in the enzyme replacement therapy (ERT)-naïve setting has prolonged survival and improved clinical outcomes in patients with cross-reactive immunologic material (CRIM)-negative infantile Pompe disease (IPD). We have previously demonstrated that immunomodulation with a short-course of rituximab, methotrexate, and IVIG is successful in achieving immune tolerance in a large cohort of IPD patients from various treatment centers. Data presented will support this carefully planned short-course of prophylactic immunomodulation is safe and efficacious in inducing immune tolerance to ERT.

Pegvaliase, a PEGylated bacterially-derived enzyme substitution therapy received approval from the Food and Drug Administration (FDA) for maintenance dosages up to 40 mg/day in adult patients with PKU. We will provide comprehensive immunogenicity analyses in subjects receiving 60 mg/day maintenance doses including antibody responses, circulating immune complex levels, and complement (C3 & C4) levels to support the inclusion of doses up to 60 mg/day of pegvaliase.

This presentation describes the clinical immunogenicity profile for Valoctocogene roxaparvovec, an AAV5 mediated gene therapy encoding FVIII for the treatment of Hemophilia A. The development and characterization of assays used to detect pre-existing AAV5 immunogenicity, and to characterize the post-dosing humoral and cellular immune responses will be discussed.

The assessment of the immunogenicity is a pivotal aspect of the development of AAV-based gene therapies. The humoral and cellular immune responses can have an impact on the efficacy and/or safety of these gene therapies. This presentation will illustrate the challenges that the immune response poses to the safe and effective development of gene therapies and strategies to mitigate the impact of the immune response.

There are several options in developing anti-drug antibody assay to assess the immunogenicity of therapeutics. Each approach have limitations, in the quest for an assay that balance’s sensitivity and drug tolerance. This case study will describe one approach. Once the assay was developed validated, the study results did not correlate with PK profiles and suggested some type of assay interference. Considering more information about the target that was collected during the study, the ADA assay was re-development. With the improved ADA assay and re-analyses of study samples, the results provided a more focused assessment of immunogenicity for the study.

Immunogenicity Bioanalytical Report Harmonization committee has organized to align reporting strategies for clinical immunogenicity studies across industry and regulatory authorities. To comply with regulatory recommendations on anti-drug antibody and neutralizing antibody validations, this team is working to standardize the  presentation of bioanalytical immunogenicity data to facilitate filings to health authorities. This AAPS sponsored effort is supported by ~50 industry representatives.

Bispecific mAbs (bsmAbs) are a novel class of mAbs that aim to improve drug efficacy by simultaneously working on two targets. This is a relatively new approach with limited experiences in clinical development. This presentation will use case studies to discusses our strategy for assessing the anti-drug antibody (ADA) responses to the bsmAb and summarizes the characterization results as well as the clinical impact of ADAs on drug exposure and safety.

We developed a new quantitative bio-immunoassay to determine ADA levels and their neutralizing capacity. Utilising NGS and proteomics we found that the B-cell response following mAb administration is a vaccine-like response that may be induced by immunocomplexes and that the response is diverted to the marginal zone rather to the germinal centers. The data obtained in the study will help to assess the immunogenicity of biologics under development and help to revise treatment strategies that may result in increased drug efficacy. Moreover, the methods developed in the study can be readily used in the clinic and facilitate decision making during treatment with biologics.

As therapeutic antibodies become increasingly complex, the potential for anti-drug antibody (ADA) responses become more common, making in vitro immunogenicity prediction assays an important tool for drug development.  A key component of the immune response is the uptake of antibody by antigen presenting cells (APCs) such as dendritic cells.  This presentation will highlight the development of a dendritic cell (DC) loading assay that measures antibody internalization and shows that highly immunogenic antibodies are internalized to a higher degree than antibodies with low immunogenicity.

The use of immune modulatory biologics to augment functionality of immune cells can also augment the risk of immunogenicity. The quality of such an immune response and its clinical relevance will be explored through this talk. Whether the activation of immune cells can break tolerance to otherwise tolerant sequences will also be explored.

This talk will describe the drug development workflow and tools to identify and engineer lead therapeutic biologics with reduced immunogenicity risk. Novel biological modalities can have multiple pathways to an anti-therapeutic immune response and that require modification of tools and assays.

This talk will focus on the assessment of pre-existing antibodies to the viral capsid and the implications for their impact on the successful dosing of gene therapy drug candidates. Case studies will show how the thought process about pre-existing antibodies is evolving. There will be a focus on the tools used to measure pre-existing antibodies against the viral capsid and their utilization as exclusion criteria for entry into clinical studies.

In this study, we use ADA assays to measure pre-existing reactivity, i.e. the ability of a molecule to produce an ADA-like response in normal human serum. The magnitude of pre-existing reactivity correlates with clinical immunogenicity. Furthermore, the domain specificity was the same in pre-existing ADA as in TE-ADA. Based on this, magnitude and domain specificity of pre-existing reactivity can be a powerful tool to understand the immunogenic potential of biotherapeutics.