RAMP® Rational Affinity Maturation Platform
Fusion’s affinity maturation platform combines natural somatic hypermutation with advanced structural modelling to introduce targeted mutations and evaluate molecular interactions, resulting in antibody variants with enhanced binding affinity and improved stability.
RAMP® Rational Affinity Maturation Platform
Fusion’s affinity maturation platform combines natural somatic hypermutation with advanced structural modelling to introduce targeted mutations and evaluate molecular interactions, resulting in antibody variants with enhanced binding affinity and improved stability.

Using our Rational Affinity Maturation Platform: RAMP®
We don’t use phage display in our approach. We do something different.
The RAMP® Process
Rational Library Design
RAMP® employs a proprietary, cutting-edge approach to library design that explores the natural somatic hypermutation landscape of antibody sequences.
This method introduces carefully selected substitutions across both the framework and CDR regions, while applying strict filters to avoid safety and manufacturing liabilities. By mimicking natural mutation patterns, RAMP® can uncover unexpected improvements in antibody performance, including enhanced affinity, stability, and developability.
In Silico Selection
We analyze the antibody library using advanced in silico modelling and molecular docking to identify variants with predicted enhancements in both binding affinity and structural stability.
This data-driven selection process ensures a careful balance between functional performance and developability - an essential principle at the core of the RAMP® platform.
This rapid selection approach enables us to focus a large virtual library of variants down to a micro-library of approximately 100 sequences for in vitro expression and characterization.
Micro Library Expression and Characterization
A key advantage of our Affinity Maturation approach is the elimination of the need to express large physical libraries of variants.
With RAMP®, we generate a focused micro-library of carefully selected variants, expressed directly in CHO cells in full-length IgG format. This avoids biases associated with scFv or Fab formats and bypasses stability constraints linked to bacterial expression systems. Each variant is thoroughly characterized in vitro for binding kinetics and biophysical properties.
A high proportion of the expressed monoclonal antibodies demonstrate enhanced affinity compared to the parental antibody, providing a rich pool of candidates for lead selection or further rounds of RAMP® optimization.
Applications:
- Affinity Enhancement RAMP® enables improvements in both association (on-rate) and dissociation (off-rate) kinetics, resulting in significantly increased binding affinity compared to the parental antibody.
- Affinity Fine-Tuning For applications such as ADCs, bispecifics, and T-cell engagers, a slow off-rate may not be optimal due to potential cytotoxicity or reduced cell recruitment. RAMP® generates a diverse panel of variants with tailored binding kinetics to meet specific functional requirements.
- Developability Optimization The platform can produce backup candidates with improved developability profiles, offering greater flexibility and risk mitigation during lead selection.
- Extended IP Protection Clients have successfully broadened their intellectual property coverage by leveraging the extensive sequence diversity introduced through the RAMP® process.
What Set Us Apart from Other Affinity Maturation Methods?
- Affinity Enhancement Achieves >10-fold improvement in binding affinity per round, with success in generating picomolar (pM) binders.
- Optimized Expression Through targeted mutagenesis, RAMP® avoids introducing liability motifs and atypical antibody structure. Selected monoclonal antibodies often show enhanced developability, including reduced aggregation, greater stability, and higher expression yields.
- Manufacturability Advantage No reliance on scFv formats or bacterial expression systems, as required in phage display - ensuring compatibility with full-length IgG expression in CHO cells.
- Specificity Assurance Unlike some affinity maturation methods that introduce residues causing non-specific or off-target binding, RAMP® maintains high specificity, avoiding "sticky" antibodies that compromise therapeutic utility.
- Rapid Turnaround Each round of RAMP® is completed in under 12 weeks, enabling fast progression through development stages.
For more information about affinity maturation
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