Biosimilar Higher-Order Structure Testing
Structural comparability data for your biosimilar regulatory submissions. Demonstrate HOS similarity to reference products using native solution analysis.
Why Higher-Order Structure Matters for Biosimilars
Regulatory expectation: FDA and EMA require demonstration that biosimilars are "highly similar" to reference products — including at the level of higher-order structure (HOS).
Primary sequence identity is not enough. Regulators expect evidence that your biosimilar maintains the same:
- Tertiary structure — overall 3D molecular shape
- Quaternary structure — oligomeric state and subunit arrangement
- Conformational behavior — flexibility and domain organization
- Aggregation profile — absence of unwanted aggregates
Our analysis provides structural fingerprints that complement other HOS methods (CD, FTIR, HDX-MS) with unique insights from solution scattering.
HOS Parameters We Determine
Molecular Envelope
- Ab-initio shape reconstruction
- Radius of gyration (Rg)
- Maximum dimension (Dmax)
- Molecular weight estimation
Oligomeric State
- Monomer/dimer/oligomer distribution
- Aggregation detection
- Concentration-dependent behavior
- Self-association assessment
Conformational Analysis
- Domain organization
- Flexibility assessment
- Pair distance distribution P(r)
- Comparison to reference
Supporting Regulatory Submissions
FDA 351(k) Biosimilar Applications
Structural comparability data meeting FDA expectations for biosimilar BLA submissions. HOS fingerprinting to demonstrate "highly similar" structure.
- Side-by-side comparison with reference product
- Statistical analysis of structural parameters
- Lot-to-lot consistency data
EMA Biosimilar Dossiers
Structural characterization supporting European biosimilar marketing authorizations. Comparability studies aligned with EMA guidelines.
- Quality comparability (Module 3)
- Comprehensive structural analysis
- Multi-batch characterization
Comparability Protocols
Post-approval manufacturing changes require demonstration of structural comparability. We support site transfers, scale-up, and process modifications.
- Pre/post-change comparison
- Acceptance criteria development
- Trending and stability
Biologic Types We Characterize
Monoclonal Antibodies
IgG1, IgG2, IgG4 and other antibody formats. Fab/Fc domain organization, aggregation state.
Fusion Proteins
Fc-fusion proteins, receptor-Fc conjugates. Domain arrangement and linker flexibility.
Peptide Therapeutics
GLP-1 analogues, insulin variants, therapeutic peptides. Oligomerization and self-association.
Enzymes
Therapeutic enzymes, enzyme replacement therapies. Active conformation verification.
Cytokines & Growth Factors
Interferons, interleukins, growth factors. Oligomeric state and receptor binding conformation.
Antibody Fragments
Fab, scFv, nanobodies, bispecifics. Domain organization and aggregation.
Why Native Solution Analysis Matters
See the Real Structure
Analyze your biologic in its formulation buffer — the same conditions as your drug product. No crystallization, no staining, no fixing.
Detect What Others Miss
Solution scattering can detect subtle conformational differences and early aggregation that may not be visible by other methods.
Complement Other HOS Methods
Orthogonal to CD, FTIR, and HDX-MS. Provides unique information on overall molecular shape and oligomeric state.
Ensemble Average
Structural parameters averaged over billions of molecules. Statistically robust, representative of your bulk product.
Technical basis: Our analysis uses Small-Angle X-ray Scattering (SAXS) — established in structural biology and increasingly adopted for biopharmaceutical characterization. Learn more about the methodology →
How It Works
1. Consultation
Discuss your biosimilar and reference product. Define comparability parameters and acceptance criteria.
2. Sample Submission
Send biosimilar and reference samples. We handle chain-of-custody and confidential processing.
3. Analysis
Side-by-side measurement under identical conditions. Multiple concentrations if needed.
4. Comparability Report
Detailed structural comparison with statistical analysis. Regulatory-ready documentation.
Industrial Service Standards
cGMP Available
cGMP-compliant analysis available for specific sample types (not always possible — please inquire). 21 CFR Part 11 data integrity. QA-reviewed reports for regulatory submissions.
Complete Confidentiality
Your biosimilar development is protected. NDAs accepted as-is. No publication of your data.
Turnaround
Timelines discussed per project based on sample complexity and current capacity. We aim to meet your project deadlines where possible.
Expert Interpretation
Reports written for regulatory context — not academic publications. Clear conclusions on comparability.
Case Studies
IgG1 Immunoglobulin
Tertiary envelope reconstruction of monoclonal antibody. Shape determination and domain organization.
Liraglutide (GLP-1 Analogue)
Peptide therapeutic characterization. Oligomerization state and self-association analysis.
Protein Aggregation Study
Alpha-synuclein aggregation pathway. Monitoring oligomer formation and fibril development.
Request Biosimilar HOS Testing
Contact us to discuss your biosimilar comparability study. We'll help define the appropriate structural parameters for your product and regulatory pathway.
Sample requirements: Typically 50-100 µL at 1-10 mg/mL. Both biosimilar and reference product needed for comparability studies.
Confidentiality: We sign your NDA. Your development program remains confidential.