Comparability and Biosimilarity Analytical Similarity Study Inspection

Inspection template for reviewing analytical and biological assay plans, statistical methods, and documentation used to demonstrate comparability or biosimilarity against a reference product.

Study Scope and Reference Product

• Study objective clearly states comparability or biosimilarity intent
  The protocol or report explicitly states whether the study is intended to support comparability, biosimilarity, or both.
• Reference product is clearly identified and justified
  The reference product, lot selection rationale, and source are documented and traceable.
• Product and process comparability boundaries are defined
  The scope includes the specific product attributes, process changes, or development stages being compared.
• Acceptance criteria are defined for the study conclusion
  Predefined decision criteria exist for determining whether similarity or comparability is demonstrated.
• Study rationale aligns with ICH Q5E principles
  The approach reflects a risk-based comparability assessment and does not rely on unsupported assumptions.

Analytical and Biological Assay Panel

• Assay panel covers critical quality attributes
  The analytical package includes assays for identity, purity, potency, glycosylation or other relevant structural attributes, as applicable.
• Biological activity assay is qualified and relevant
  A biological assay relevant to mechanism of action or functional activity is included and appropriately qualified.
• Assays are fit for purpose and method status is documented
  Each assay has a documented status such as qualified, validated, or exploratory, with rationale for its use in the similarity assessment.
• Assay sensitivity and specificity are addressed
  The study documents whether the methods can detect meaningful differences between test and reference product.
• Replicate strategy and sample panel are defined
  The number of lots, replicates, and sample selection strategy are specified for both test and reference materials.
• Assay reference documents are linked
  SOPs, method summaries, or validation reports supporting the assay panel are available and linked.

Statistical Design and Data Analysis

• Statistical analysis plan is documented before data review
  The analysis plan is defined in advance and includes the methods used to compare test and reference results.
• Similarity metrics and equivalence approach are defined
  The study specifies the statistical framework used, such as equivalence testing, confidence intervals, or multivariate similarity methods.
• Acceptance margins are scientifically justified
  Similarity margins or equivalence bounds are justified based on prior knowledge, assay variability, and product risk.
• Sample size and power assumptions are documented
  The analysis includes the rationale for lot count, replicate count, and statistical power where applicable.
• Outlier handling and missing data rules are defined
  The protocol states how outliers, missing values, and failed runs are handled in the analysis.
• Data visualization supports the similarity conclusion
  Plots, trend charts, or multivariate outputs are included to show the relationship between test and reference product results.

Documentation, Traceability, and Conclusion

• Raw data, calculations, and data lineage are traceable
  Source data, calculations, and transformations can be traced from the final report back to the original records.
• Deviations and protocol exceptions are documented
  Any deviations from the approved protocol are recorded, assessed, and dispositioned.
• Conclusion is supported by the data package
  The final conclusion is consistent with the analytical and biological data and does not overstate similarity.
• Regulatory and quality review sign-off is complete
  Appropriate CMC, quality, and regulatory stakeholders have reviewed and approved the package.
• Open issues and follow-up actions are captured
  Any deficiencies, non-conformances, or required follow-up actions are listed with owners and due dates.