Fully-Human Anti-FRalpha Antibodies With Sub-Nanomolar CDR Binding
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Solution Overview
Problem
Existing anti-FRalpha monoclonal antibodies, such as farletuzumab, have failed to meet clinical trial endpoints for treating cancers like ovarian and lung cancer, highlighting the need for improved therapeutic agents with high affinity and broad cross-reactivity for FRalpha.
Innovation Solution
Development of a novel anti-FRalpha Fab with nanomolar affinity, derived from CDRs, which can be used in IgG formats, cross-reacts with cynomolgus FRalpha, and is compatible with various immunotherapeutic strategies, including antibody conjugates and CAR-T therapies, offering high specificity and efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing anti-FRalpha monoclonal antibodies (e.g., farletuzumab) are used, then therapeutic development can proceed, but clinical trial endpoints are not met due to insufficient affinity and efficacy
Solution Approach 1:
The patent applies parameter changes by optimizing the CDR sequences to achieve sub-nanomolar affinity (KD < 1 nM) for human FRalpha. The engineered antibody maintains high binding affinity while showing cross-reactivity with cynomolgus FRalpha, thereby improving both therapeutic reliability and manufacturing precision through precise molecular parameter optimization.
Solution Approach 2:
The patent creates a composite therapeutic approach by developing an engineered monoclonal antibody that combines optimized CDR regions with full IgG format. This composite structure integrates the high-affinity binding characteristics of the engineered Fab with the therapeutic capabilities of complete IgG molecules, enabling both diagnostic and therapeutic applications.
2Reliability
If high affinity binding is achieved, then therapeutic efficacy improves, but cross-reactivity with non-human FRalpha may be reduced
Solution Approach 1:
The patent applies local quality by specifically optimizing the CDR regions (particularly CDR-H3 and CDR-L3) to achieve high affinity for human FRalpha while maintaining key residues that accommodate cynomolgus FRalpha. This localized optimization in the binding regions allows differential affinity: sub-nanomolar for human FRalpha and nanomolar for cynomolgus FRalpha, enabling both therapeutic efficacy and preclinical model validation.
3Manufacturing precision
If novel CDRs are engineered for high affinity, then binding strength increases, but development time and complexity increase
Solution Approach 1:
The patent applies preliminary action by performing in silico CDR optimization and in vitro affinity maturation before entering clinical trials. The engineered CDRs were developed and validated in preclinical studies, demonstrating sub-nanomolar affinity and cross-reactivity, thereby preparing the therapeutic candidate in advance to accelerate subsequent clinical development and reduce overall development time.
Data Source
AI summary
This disclosure describes proteins that specifically bind human folate receptor alpha (FRalpha) with high affinity. These proteins include a recombinant human anti-FRalpha IgG1 that is suitable for use as a therapeutic antibody to treat cancers that express FRalpha. Other FRalpha-binding proteins are also described including antibody fragments, antibody conjugates, and fusion proteins.