Analytical Comparability at the Center of Modern Biosimilar Development
The U.S. Food and Drug Administration (FDA) has recently updated its guidance with a set of new and revised draft Q&As on Biosimilar Development [1]. A key focus of this update is the clarification of conditions under which a non‑U.S. authorized reference product may be used in clinical studies to support a biosimilar application under section 351(k).
The FDA clarifies that clinical data generated using a non‑U.S. licensed comparator may be used to support a demonstration of biosimilarity, provided that a robust scientific justification is submitted, explaining why these data are relevant for comparison to the U.S.‑licensed reference product. Publicly available information on the relationship between the products cannot replace comparative analytical data.
The update reinforces a message that has been gaining momentum across global regulatory agencies: analytical comparability and robust bridging strategies are the cornerstone of successful biosimilar development.
This approach is closely aligned with long-standing EMA guidance, which emphasizes analytical comparability as the foundation of biosimilarity and allows the use of non-EU reference products for clinical comparability in global development programs when supported by comprehensive three-way analytical bridging [2].
In this evolving regulatory landscape, analytical data are no longer a supportive element, they are the primary evidence regulators rely on. Demonstrating that a non-local reference product is analytically comparable to the US-licensed or EU-authorized reference product is essential to ensure interpretability and regulatory value of clinical/PK data. Any observed differences must be deeply understood, scientifically contextualized and convincingly assessed for their potential clinical relevance.
From Regulatory Expectation to Analytical Excellence
At Biofidus, we view this regulatory clarity as a strategic opportunity for biosimilar developers. The alignment between FDA and EMA expectations enables more efficient global development programs, provided that analytical comparability is addressed with the required depth, rigor, and regulatory insight.
This is where an experienced analytical partner becomes critical. Designing and executing meaningful comparability studies requires more than generating data: it demands a thorough understanding of critical quality attributes (CQAs), method suitability, and the regulatory implications of observed variability. Biofidus supports clients throughout this process by translating regulatory expectations into scientifically robust analytical strategies.
Bridging That Builds Confidence
Our analytical comparability and bridging services are designed to support the totality‑of‑evidence approach regulators now prioritize. We help sponsors establish strong analytical links between biosimilars and reference products, through state‑of‑the‑art methodologies, including:
- Advanced structural and physicochemical characterization
- Comprehensive glycan and charge variant profiling
- Functional and potency assays
- Binding and affinity assessment using technologies such as surface plasmon resonance
By identifying, characterizing, and contextualizing product differences, we enable sponsors to demonstrate that these differences do not impact clinical performance or PK interpretability.
Enabling Smarter, Faster Global Development
With deep analytical expertise and a clear focus on regulatory relevance, Biofidus helps you build the evidence regulators expect: efficiently, confidently, and scientifically sound.
Let’s shape the future of biosimilars together, powered by analytics, enabled by science, and aligned with global regulatory expectations.
Interested in our biosimilar services?
https://www.biofidus.de/studies/biosimilar-studies/
References and additional resources:
- U.S. Food and Drug Administration (FDA).
New and Revised Draft Q&As on Biosimilar Development and the Biologics Price Competition and Innovation Act (Revision 4).
Draft Guidance for Industry, March 2026.
- European Medicines Agency (EMA).
Guideline on similar biological medicinal products (CHMP/437/04 Rev.1).
European Medicines Agency, adopted October 2014, effective April 2015.