High potency alone does not make a viable biologic drug. Many promising candidates fail in development due to poor manufacturability, instability, aggregation, or chemical liabilities. Integrating developability assessment from the earliest stages of discovery is essential.
Pillar 1: Manufacturability and Expression
The candidate must be producible at viable commercial titers in standard expression systems like CHO cells. Target titers of >1 g/L are the benchmark for commercial feasibility.
Pillar 2: Stability (Thermodynamic and Colloidal)
Thermodynamic stability is assessed via melting temperature (Tm) using differential scanning calorimetry (DSC) or differential scanning fluorimetry (DSF). Colloidal stability (the propensity for protein-protein interactions in solution) is measured by dynamic light scattering (DLS) or self-interaction nanoparticle spectroscopy (SINS).
Pillar 3: High Solubility and Low Aggregation Propensity
Surface hydrophobicity analysis identifies patches that drive aggregation. Size-exclusion chromatography (SEC) testing quantifies the fraction of monomer vs. aggregate species. High monomer percentage at target formulation concentrations is essential.
Pillar 4: Chemical Stability and Lack of Post-Translational “Hotspots”
Sequence liabilities that drive chemical degradation must be identified and eliminated early:
- Deamidation: Asparagine residues, particularly at N-G and N-S motifs
- Isomerization: Aspartate residues converting to isoaspartate
- Oxidation: Methionine and tryptophan residues
- Unpaired cysteines: Leading to disulfide scrambling and aggregation
- Unwanted glycosylation sites: N-X-S/T sequons in binding regions
Conclusion: Integrating Developability from Day One
The most efficient path to a viable biologic is to assess developability in parallel with affinity and specificity screening, not as a late-stage gate. Surface display platforms enable simultaneous selection for function and expression, making early developability assessment practical at library scale.
Related Ranomics services
- Antibody engineering: Developability screening integrated into antibody discovery.
- Mammalian display: Developability-focused screening on a mammalian display platform.
Frequently asked questions
What is protein developability?
Protein developability is the set of properties that determine whether a biologic candidate can be manufactured and formulated into a viable drug, separate from its potency. A candidate with high affinity can still fail development due to poor expression, instability, aggregation, or chemical liabilities. Developability rests on four pillars: manufacturability, thermodynamic and colloidal stability, solubility, and chemical stability.
What are the four pillars of protein developability?
The four pillars are manufacturability and expression, measured against commercial titer benchmarks above 1 g/L in CHO cells; stability, both thermodynamic, assessed by melting temperature, and colloidal; solubility and low aggregation propensity, assessed by surface hydrophobicity and size-exclusion chromatography; and chemical stability, the absence of sequence liabilities that drive degradation.
What sequence liabilities affect protein developability?
Key chemical liabilities include deamidation at asparagine residues, particularly N-G and N-S motifs; isomerization of aspartate to isoaspartate; oxidation of methionine and tryptophan; unpaired cysteines that cause disulfide scrambling and aggregation; and unwanted N-X-S/T glycosylation sequons in binding regions. These hotspots should be identified and eliminated early in discovery.
When should developability be assessed in antibody discovery?
Developability should be assessed in parallel with affinity and specificity screening from the earliest discovery stages, not as a late-stage gate. Surface display platforms allow simultaneous selection for function and expression, making early developability assessment practical at library scale. Catching liabilities early moves expensive late-stage failures to a phase where they cost orders of magnitude less to fix.