OR4-Modified Amatoxin Conjugates for Solid Tumor Potency
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Solution Overview
Problem
Current antibody drug conjugates (ATACs) are less effective in treating solid tumors compared to liquid tumors, necessitating improved treatment options and efficacy for solid tumors.
Innovation Solution
Development of amatoxin-linker constructs with a specific —OR4 substituent on position 4 of the indole ring, conjugated to target-binding moieties like antibodies, which are cleavable or self-immolative linkers, enhancing potency against solid tumors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional amatoxin conjugates are used, then liquid tumors (hematologic malignancies) show good efficacy, but solid tumors exhibit reduced treatment effectiveness
Solution Approach 1:
The patent modifies the amatoxin molecule at a specific local position (position 4 of the indole ring) by introducing an —OR4 substituent. This localized chemical modification enhances the conjugate's potency specifically against solid tumors while maintaining effectiveness against liquid tumors, thereby resolving the contradiction between general efficacy and tumor type adaptability.
Solution Approach 2:
The patent changes the chemical parameter of the amatoxin conjugate by introducing an —OR4 substituent at position 4 of the indole ring. This parameter change (chemical structure modification) results in improved cytotoxic potential and tumor growth inhibition against solid tumors, addressing the effectiveness gap between liquid and solid tumor treatments.
2Reliability
If amatoxin conjugates are designed with standard linkers, then manufacturing is straightforward, but potency against solid tumors is insufficient
Solution Approach 1:
The patent modifies the linker structure by introducing a cleavable or self-immolative linker with specific chemical properties. This parameter change in the linker structure enhances the release of active amatoxin upon tumor cell internalization, thereby increasing potency against solid tumors while maintaining reasonable manufacturing complexity.
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 amatoxin-linker constructs demonstrate superior cytotoxic potential against solid tumors, as evidenced by increased cell viability reduction and tumor volume inhibition in xenograft models, compared to constructs lacking the —OR4 substituent.
Implementation Method 1
Amatoxins bind to RNA polymerase II with very high affinity resulting in a dramatic decrease in protein synthesis and ultimately in apoptosis
Implementation Method 2
When bound to RNA polymerase II, amanitins inhibit the translocation of the enzyme on the RNA and DNA and thus transcription rate is slowed down by over 1000fold finally resulting in apoptosis of the cell
Implementation Method 3
The linker is a PAB Val Ala Linker... conjugated, via amino acid 1 and a cleavable linker conjugated thereto, to an anti BCMA-binding antibody
Data Source
AI summary
The present invention relates to an amatoxin-linker construct comprising an amatoxin according to formula (I) wherein: R1 and R2 are each —OH, R3 is NH2, or a linker which carries a reactive group Y for linking said amatoxin to a target-binding moiety, R4 is H or a linker which carries a reactive group Y for linking said amatoxin to a target-binding moiety, R5 is absent or ═O, wherein R3 and R4 cannot be the same, for use in the manufacture of a binding moiety-toxin conjugate for the treatment of a solid tumor, and a respective binding moiety-toxin conjugate for the treatment of a solid tumor.