Fusion Antibody Delivery of Iduronate 2-Sulfatase Across the BBB

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Solution Overview

Problem

Current treatments for Type II mucopolysaccharidosis (Hunter's syndrome) are hindered by the inability of systemically administered recombinant iduronate 2-sulfatase (IDS) to cross the blood-brain barrier, limiting its effectiveness in addressing CNS-related symptoms.

Innovation Solution

Development of fusion antibodies, such as HIR Ab-IDS, which fuse IDS to a structure capable of crossing the blood-brain barrier, specifically binding to the extracellular domain of the human insulin receptor, allowing IDS to be delivered to the CNS.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If systemically administered recombinant IDS is used, then enzyme replacement therapy is provided, but the IDS cannot cross the blood-brain barrier to treat CNS symptoms

Engineering Contradiction:

Improveeffectiveness of IDS in treating CNS symptomsVSAvoidblood-brain barrier blocking IDS delivery

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a fusion antibody as an intermediary carrier that binds to IDS and facilitates its transport across the blood-brain barrier. The fusion antibody comprises an IDS-binding domain and a BBB-crossing domain, acting as a mediator to deliver IDS into the CNS where it can degrade glycosaminoglycans and treat Hunter syndrome symptoms.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite therapeutic molecule by fusing IDS with a BBB-crossing antibody structure. This composite fusion antibody combines the enzymatic activity of IDS with the BBB-penetrating capability of the antibody, enabling simultaneous enzyme replacement and barrier penetration that neither component could achieve alone.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If fusion antibody structure is created to cross BBB, then IDS delivery to CNS is enabled, but the complexity of the therapeutic composition increases

Engineering Contradiction:

Improveability to deliver IDS to CNSVSAvoidcomplexity of fusion antibody structure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The fusion antibody is segmented into distinct functional domains: an IDS-binding domain (comprising IDS or IDS-binding fragment) and a BBB-crossing domain (comprising BBB-crossing antibody or antibody fragment). This segmentation allows each domain to be optimized independently for its specific function while maintaining overall structural integrity and facilitating production.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fusion antibody is designed with multi-functionality, simultaneously performing IDS binding, BBB penetration, and enzymatic activity. This universal design consolidates multiple functions into a single therapeutic molecule, simplifying the treatment approach compared to using separate agents for each function.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Quantity of substance

If IDS is fused to BBB-crossing structure, then CNS penetration is achieved, but the retention of IDS enzymatic activity must be maintained

Engineering Contradiction:

Improveamount of IDS activity delivered to CNSVSAvoidretention of IDS enzymatic activity

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The fusion antibody employs local quality differentiation where the IDS-binding domain maintains high enzymatic activity for glycosaminoglycan degradation, while the BBB-crossing domain is optimized for barrier penetration. This spatial separation of functions within the single molecule ensures that IDS activity is preserved while achieving CNS delivery.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention optimizes parameters of the fusion antibody including molecular weight, charge distribution, and structural conformation to balance BBB penetration with IDS activity retention. By adjusting these parameters, the fusion antibody achieves efficient CNS delivery while maintaining enzymatic functionality for treating Hunter syndrome.

Inventive Principle:

Principle #35Parameter changes

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

The fusion antibodies maintain significant IDS activity post-delivery, effectively reducing pathological glycosaminoglycan accumulation in the CNS, thereby ameliorating neurodegeneration and mental retardation symptoms.

Implementation Method 1

the HIR Ab-IDS fusion antibody binds to the extracellular domain of the insulin receptor and is transported across the blood brain barrier ('BBB') into the CNS

Methodology Applied

Scientific EffectReceptor-mediated transport:

Implementation Method 2

iduronate 2-sulfatase activity... which functions to degrade mucopolysaccharides... catalyzes hydrolysis of the 2-sulfate groups of the L-iduronate 2-sulfate units

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentUS20260078178A1Methods and compositions for increasing iduronate 2-sulfatase activity in the CNS

Publication Date: 2026.03.19 ARMAGEN INC

AI summary

Provided herein are methods and compositions for treating a subject suffering from a deficiency in iduronate 2-sulfatase in the CNS. The methods include systemic administration of a bifunctional fusion antibody comprising an antibody that crosses the blood brain barrier (BBB) and an iduronate 2-sulfatase.