Scientific and statistical considerations in evaluating the analytical similarity of ABP 501 to adalimumab.

Analytical similarity is the foundation of the totality-of-evidence-based approach for demonstrating that a proposed biosimilar is highly similar to a reference product. This review uses analytical similarity assessment of ABP 501, the first approved adalimumab biosimilar, as a case study to highlight considerations necessary to demonstrate analytical similarity. Similarity assessments start with risk-ranking the critical quality attributes based on scientific understanding of how they impact safety, efficacy, immunogenicity and/or pharmacokinetics/pharmacodynamics. Testing strategy and evaluation approaches are designed with the understanding of the analytical methods and their capabilities. Statistical considerations are used to establish objective assessment criteria. The result is a scientifically justified, objective analytical similarity assessment that demonstrates that a proposed biosimilar is structurally and functionally similar to a reference product.