Introduction Background Past Experience for In Vitro Bioequivalence Testing Analytical Similarity Assessment Scientific Factors and practical issues Aim and Scope of the Book Regulatory Approval Pathway of Biosimilar Products Introduction Regulatory requirements Analytical Studies for Functional/Structural Characterization Global harmonization Concluding remarks CMC Requirements Introduction CMC Development Manufacturing Process Validation Quality Control and Assurance Stability Analysis Concluding Remarks Assay Development and Process Validation Introduction Regulatory Requirements Analytical Method Validation Analysis of Validation Data Evaluation of Reliability, Repeatability, and Reproducibility Concluding remarks Critical Quality Attributes Introduction Identification of CQAs Classification of CQAs Concluding Remarks FDA Tiered Approach for Analytical Assessment Background Stepwise Approach Tier Equivalence Test Other tiered approaches Some Practical Considerations Concluding Remarks ¿ Sample Size Requirement Introduction Traditional Approach FDA¿s Current Thinking and Recommendation Sample Size Requirement Numerical Studies Concluding remarks Multiple References Background Method of Pairwise Comparisons Simultaneous Confidence Interval Reference Product Change Concluding remarks Extrapolation Across Indications Introduction An Example Development of Sensitivity Index Assessment of Sensitivity Index Statistical Inference of Extrapolation Concluding Remarks Case Studies - FDA Submissions FDA Abbreviated Licensure Pathway Sponsor¿s Strategy for Regulatory Submission Avastin Biosimilar Regulatory Submission Herceptin Biosimilar Regulatory Submission Concluding Remarks Practical and Challenging Issues Introduction Hypotheses versus Confidence Interval Approach Totality-of-the-evidence Inconsistencies Between Tired Approaches Individual bioequivalence Commonly Asked Questions from the Sponsors Concluding Remarks Recent Development Introduction Comparing Means versus Comparing Variances Switching Design Non-Medical Switching FDA guidance on Analytical Similarity Assessment Concluding Remarks.