Immunogenicity Risk Assessment for Multi-specific Therapeutics

Abstract

The objective of this manuscript is to provide the reader with a hypothetical case study to present an immunogenicity risk assessment for a multi-specific therapeutic as part of Investigational New Drug (IND) application. In order to provide context for the bioanalytical strategies used to support the multi-specific therapeutic presented herein, the introduction focuses on known immunogenicity risk factors. The subsequent hypothetical case study applies these principles to a specific example HC-12, based loosely on anti-TNFα and anti-IL-17A bispecific molecules previously in development, structured as an example immunogenicity risk assessment for submission to health authorities. The risk of higher incidence and safety impact of anti-drug antibodies (ADA) due to large protein complexes is explored in the context of multi-specificity and multi-valency of the therapeutic in combination with the oligomeric forms of the targets.

RUBY® – a tetravalent (2+2) bispecific antibody format with excellent functionality and IgG-like stability, pharmacology and developability properties

“…Some general aspects were nevertheless considered in the generation of the RUBY bsAb format concerning immunogenicity and safety. Bispecific antibodies have been shown to cause immunogenicity and anti-drug antibodies in clinical studies, 47 , 48 which can limit their therapeutic use. 49 When engineering RUBY we sought to minimize the sequenced-based format attribute-related immunogenic risk.…”

A humanized minipig model for the toxicological testing of therapeutic recombinant antibodies

“…It is well known that the pharmacology of therapeutic antibodies upon binding to their targets is a major driver of toxicity and influences the immunogenicity profile 32 , 33 . Consequently, a lack of cross-reactivity would limit the usefulness of the hIgG transgenic animal models.…”

Pre-Clinical In-Vitro Studies on Parameters Governing Immune Complex Formation

“…In-vitro assessments are able to shed light on factors modulating IC formation. These factors are clearly not of generic applicability, but are dependent on the class of the biotherapeutic [14], and sometimes even on the specific biotherapeutic candidate. Therapeutic mAbs trigger mainly anti-idiotopic immune responses, with the ADAs being mainly directed against the CDR regions and not against the human framework of IgGs [21,31].…”

“…As indicated by healthcare agencies [4,5], the complexity of the immunological response is driven primarily by drug product-related factors and further impacted by patient and disease-related factors. Drug product-related factors include the presence of neoepitopes like non-human amino acid sequence stretches in the biotherapeutic and artificial protein constructs formed by protein engineering [14]; physical and chemical degradation and herewith associated stability of the drug material in biofluids [15]; the multimerization state of the biotherapeutic and its pharmacologic target in the body; "high" concentration of the biotherapeutic; especially in the case of mimicking a low-concentration endogenous protein; and many more [16].…”

“…Predictive in silico [11,45] and other immunogenicity-potential assessment tools like the MAPPs assay [12] can provide valuable insights for the required immunogenicity risk assessments [14] and the selection process to define lead candidates with the lowest immunogenic potential during developability assessment phases [10]. The analytical toolbox presented in this manuscript, designed to shed light on factors influencing IC formation, is a well suited state-of-the-art screening and prediction instrument, which can be used in research organizations to obtain additional insights into the behavior of biotherapeutic lead candidates in a simulated scenario of immunogenicity.…”