Antibody Species Conversion

At Fusion, we specialize in grafting antigen-binding regions (CDRs) onto native frameworks from the target species. Our approach preserves specificity while improving safety, tolerability, and downstream performance in veterinary and cross-species applications.

Applications

• Conversion of antibodies from mouse and rabbit discovery programs for veterinary use
• Adaptation of human clinical-stage antibodies for animal health and diagnostics

Common Species Conversions

Key Challenges in Species Conversion

• Framework-CDR mismatch can lead to loss of affinity or structural instability
• Canonical loop differences, especially in CDR-H1 and H2, may disrupt antigen binding
• Cattle-specific constraints: ultralong CDR-H3 loops are structurally incompatible with conventional grafts
• Immunogenicity risks from foreign sequences in veterinary hosts
• Sparse germline databases complicate framework selection
• Limited structural data hinders accurate modelling
• Backmutation complexity due to poorly annotated framework residues

Fusion’s Unique Approach

• Proven framework selection and grafting strategy, built on >290 successful humanization projects
• Expertise in atypical architectures, including non-canonical loops and species-specific frameworks
• Deep structural insight into donor and acceptor antibodies of different species for optimal pairing
• Feasibility modelling to assess project success before initiation
• Liability and CDR sequence screening to flag developability and immunogenicity risks early

Integrated Services to Accelerate Success

• Scalable antibody production (mg to g levels) for rapid prototyping and testing
• Stable cell line development for consistent, high-yield expression
• Purification strategies matched to veterinary isotypes, delivering clean, reliable antibody preparations for downstream use.
• Binding analysis to confirm functional retention post-conversion
• Thermal stability profiling to assess folding robustness and guide framework selection
• Aggregation and solubility testing to identify risks and optimize manufacturability

Ready to explore species conversion for your antibody program? Partner with Fusion to unlock veterinary compatibility with precision and confidence.