A single point mutation on FLT3L-Fc protein increases the risk of immunogenicity.

INTRODUCTION

As a crucial asset for human health and modern medicine, an increasing number of biotherapeutics are entering the clinic. However, due to their complexity, these drugs have a higher potential to be immunogenic, leading to the generation of anti-drug antibodies (ADAs). Clinically significant ADAs have an impact on pharmacokinetics (PK), pharmacodynamics (PD), effectiveness, and/or safety. Thus, it is crucial to understand, manage and minimize the immunogenicity potential during drug development, ideally starting from the molecule design stage.

METHODS

In this study, we utilized various immunogenicity risk assessment methods, including prediction, dendritic cell internalization, MHC-associated peptide proteomics, HLA peptide binding, and T cell proliferation, to assess the immunogenicity risk of FLT3L-Fc variants.

RESULTS

We identified a single point mutation in the human FLT3L-Fc protein that introduced highly immunogenic T cell epitopes, leading to the induction of T cell responses and thereby increasing the immunogenicity risk in clinical settings. Consequently, the variant with this point mutation was removed from further consideration as a clinical candidate.

DISCUSSION

This finding underscores the necessity for careful evaluation of mutations during the engineering of protein therapeutics. The integration of multiple immunogenicity risk assessment tools offers critical insights for informed decision-making in candidate sequence design and therapeutic lead selection.