ISV C-Terminal Truncation to Reduce ADA Assay Protein Interference

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for detecting anti-drug antibodies (ADA) in assays involving immunoglobulin single variable domains (ISVs) fail to account for aspecific protein interference, leading to inaccurate results.

Innovation Solution

Develop methods and assays to predict and modify ISVs by adding a limited number of amino acid residues to the C-terminal end, reducing or eliminating protein interference in ADA assays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If ISV is used in ADA assays, then detection of anti-drug antibodies is enabled, but aspecific protein interference occurs leading to inaccurate results

Engineering Contradiction:

Improvedetection accuracyVSAvoidproteins

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent removes the problematic C-terminal region of the ISV that causes asspecific protein binding. By truncating the ISV to remove residues 107-113 (the C-terminal tail including the hydrophobic patch), the interfering protein-binding capability is extracted while preserving the antigen-binding function of the variable domain.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent modifies the physical-chemical parameters of the ISV by altering its amino acid sequence at the C-terminus. Specifically, it changes the hydrophobicity and charge characteristics of the C-terminal region through truncation or mutation, thereby reducing asspecific protein interactions while maintaining immunogenicity and antigen binding.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If C-terminal region of ISV is modified to reduce protein interference, then assay accuracy improves, but immunogenicity may be affected

Engineering Contradiction:

Improveassay accuracyVSAvoidimmunogenicity

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies local modification only to the C-terminal region (residues 107-113) of the ISV, leaving the rest of the variable domain structure intact. This localized change reduces protein interference at the problematic C-terminal end while preserving the immunogenic determinants located in the variable region framework and CDRs.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent performs partial modification by truncating only a small portion (7 residues) from the C-terminus rather than extensively modifying the entire ISV structure. This partial action is sufficient to eliminate the hydrophobic patch responsible for interference while maintaining overall immunogenicity.

Inventive Principle:

Principle #16Partial or excessive action

3Object-affected harmful factors

If truncated ISV is used, then protein interference is reduced, but detection sensitivity may decrease

Engineering Contradiction:

ImproveproteinsVSAvoiddetection sensitivity

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent uses feedback from binding assays to optimize the truncated ISV design. By testing different truncation variants and measuring both their antigen-binding capability and interference levels, the optimal truncation point is identified that balances sensitivity maintenance with interference reduction.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate prediction and reduction of aspecific protein interference, ensuring reliable detection of ADA in ISV-based treatments, facilitating clinical development and treatment monitoring.

Implementation Method 1

contacting said ISV with an analytical agent, wherein said analytical agent is an antibody that has been obtained from a human subject and that has been selected, generated and/or isolated based on its ability to recognise and/or bind to the C-terminal end of an ISV

Methodology Applied

Scientific EffectAntigen-antibody binding:

Data Source

PatentUS12516105B2Techniques for predicting, detecting and reducing aspecific protein interference in assays involving immunoglobulin single variable domains

Publication Date: 2026.01.06 SANOFI SA(FR)

AI summary

This invention provides, and in certain specific but non-limiting aspects relates to: assays that can be used to predict whether a given ISV will be subject to protein interference as described herein and/or give rise to an (aspecific) signal in such an assay (such as for example in an ADA immunoassay). Such predictive assays could for example be used to test whether a given ISV could have a tendency to give rise to such protein interference and/or such a signal; to select ISV's that are not or less prone to such protein interference or to giving such a signal; as an assay or test that can be used to test whether certain modification(s) to an ISV will (fully or partially) reduce its tendency to give rise to such interference or such a signal; and/or as an assay or test that can be used to guide modification or improvement of an ISV so as to reduce its tendency to give rise to such protein interference or signal; methods for modifying and/or improving ISV's to as to remove or reduce their tendency to give rise to such protein interference or such a signal; modifications that can be introduced into an ISV that remove or reduce its tendency to give rise to such protein interference or such a signal; ISV's that have been specifically selected (for example, using the assay(s) described herein) to have no or low(er)/reduced tendency to give rise to such protein interference or such a signal; modified and/or improved ISV's that have no or a low(er)/reduced tendency to give rise to such protein interference or such a signal.