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Significance of Extrapolation of Foreign Clinical Data to Asian Countries. Masahiro Takeuchi Div. of Biostatistics Kitasato University Graduate School The 2nd Kitasato-Harvard Symposium, 10/22/01. Acknowledgment. Bridging Study Working Group* Div. of Biostatistics
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Significance of Extrapolation of Foreign Clinical Data to Asian Countries Masahiro Takeuchi Div. of Biostatistics Kitasato University Graduate School The 2nd Kitasato-Harvard Symposium, 10/22/01
Acknowledgment Bridging Study Working Group* Div. of Biostatistics Kitasato University Graduate School Kazuhiro Abe, Isao Kawachi, Masahiro Takeuchi, Masako Nishikawa, Keiichiro Hirose, Yoshiharu Horie, Kazuhiro Matsui
Outline • Introduction • E5 Guideline • Application of E5 Guideline from Statistical Point of View • Future Application
Introduction • ICH - General Purpose • Unification of Necessary Documentation and its Formats for NDA Submission • ICH - Extrapolation • Avoidance of Unnecessary Clinical Trials Ethically Speaking • Globalization • Good Drugs in a Faster Time
Conditions for Extrapolation • Two factors • Intrinsic Factors • Extrinsic Factors
Review of Two Factors(APPENDIX A) • Intrinsic Factors • Genetic: race, drug metabolism, genetic diseases • Physiological and pathological conditions: Age ( children-elderly), Liver, Kidney, Cardiovascular functions, Diseases • Extrinsic Factors • Culture, Medical Practice, Regulatory practice/GCP, Methodology/Endpoints
Implication of Two Factors • Intrinsic Factors • Do we have an clearly defined comparative population to targeted/existed foreign population? • Extrinsic Factors • Can we conduct a planned clinical trial ?
Application of E5 Guideline Target Disease Population Part I Sample Intrinsic factors Yes No Part II Part III EU US US EU NR NR Extrinsic Factors Part IV Yes No Necessary Conditions Necessary Conditions
Application of E5 Guideline: Part I Target Disease Population Clinical Trial (y1, y2, … , yn) Estimation of Efficacy Sample Two Major Concerns: (i) high quality protocol Regulatory review system (ii) high quality of data GCP
Application of E5 Guideline: Part II Genetic variation Sample from EU Intrinsic Factors (yEU1, yEU2, … , yEUn1) Sample from US Sample from a Same Probability Space No (yUS1, yUS2, … , yUSn2) Sample from NR EU US NR (yNR1, yNR2, … , yNRn3)
Application of E5 Guideline: Part III Question: Are these samples (EU, US, and NR) derived from a same target disease population? Intrinsic Factors Answer: No Yes Genetic variation EU US NR Need adjustment for intrinsic factors to have a common population among three regions
Application of E5 Guideline: Part IV Extrinsic Factors Yes No Necessary conditions Necessary conditions Quality Control - Protocol Review System - GCP Conduct of suitable clinical trials subject to medical practice, clinical trial environment Study Design - placebo vs active - choice of endpoint Safety Issues - surveillance Language& culture - subsets of primary endpoint
Future Application: Past Experience Western Data Bridging Study 1 Bridging Study 2 Bridging Study 3 Region 1 Region 2 Region 3 (i) No clear scientific evidence regarding racial difference (ii) No clear statistical approach - similarity, sample size (iii) No unified regulatory authority requirements
(i) Scientific Evidence NEJM - Two drugs in heart failure May 3, 2001 - Two editorials Importance of pharmacogenomics Homogeneous target population Clear definition of efficacy Statistical approach/Sample size (ii) Statistical Evidence Shih、Lui - Consistency among trials Ware, Morris - Empirical Bayes Akahira and Takahashi, Takeuchi - Consistency by bootstrap Quality control of trials - Regulatory review system - GCP (iii) Regulatory Requirements APEC Meeting in Taiwan in May,01
Future Application Western Data Similar regions Region 1 Region 2 Region 3 Similar region: - Intrinsic factors - Extrinsic factors (medical practice, clinical trial environment,etc) - GCP
Future Challenge Target Disease Pop. EU Asia US (i) one global protocol - def. of target population - def. of expected efficacy - study design Clear def. of probability space (ii) modification subject to - intrinsic factors - extrinsic factors Each sample derived from the PS (iii) quality control of trials - protocol review - GCP Quality assurance
Good Drugs in a Faster Time Correctly Targeted Disease Population Thoroughly Planned and Collected Sample High Quality Data