手法を比較

	実用的な第II相臨床試験	適応型第II相臨床試験
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	Pragmatic framework: 1967; Phase II application: 1990s–2000s	1994 (formal framework); widespread adoption 2000s–2010s
提唱者	Conceptual basis: Daniel Schwartz & Joseph Lellouch (pragmatic vs. explanatory distinction, 1967); applied to Phase II context by drug developers and trialists from the 1990s onward	Peter Bauer & Klaus Kohne (formal statistical framework, 1994); broader adaptive trial methodology developed through FDA and ICH guidance in the 2000s
種類	Interventional study design	Experimental clinical trial design
原典	Schwartz, D., & Lellouch, J. (1967). Explanatory and pragmatic attitudes in therapeutical trials. Journal of Chronic Diseases, 20(8), 637–648.	Bauer, P., & Kohne, K. (1994). Evaluation of experiments with adaptive interim analyses. Biometrics, 50(4), 1029–1041.
別名	pragmatic Phase II trial, real-world Phase II trial, Phase II pragmatic RCT, Phase IIb pragmatic trial	Adaptive Ph II trial, seamless adaptive Phase II, adaptive dose-finding trial, response-adaptive Phase II
関連	6	1
概要	A pragmatic Phase II clinical trial is an early-to-mid-stage interventional study that evaluates a new treatment's preliminary efficacy and safety under conditions that approximate real-world clinical practice rather than tightly controlled experimental settings. It sits between pure explanatory Phase II trials and large pragmatic Phase III confirmatory trials, prioritising practical feasibility and clinical relevance while still generating the signal needed to justify further development.	An adaptive Phase II clinical trial is a prospective experimental design in which pre-specified rules allow the study protocol to be modified — such as dropping arms, adjusting sample size, or narrowing the patient population — based on accumulating interim data, without inflating the Type I error rate. The design is widely used in early-phase drug development to screen candidate doses or treatments efficiently while preserving statistical validity.