手法を比較

	実用的な第II相臨床試験	フェーズII臨床試験 ― 初期有効性と用量評価
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	Pragmatic framework: 1967; Phase II application: 1990s–2000s	1960s–1970s (formalised in US federal drug regulation)
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	U.S. Food and Drug Administration / ICH E8 guidelines (institutionalised framework)
種類	Interventional study design	Interventional clinical study design
原典	Schwartz, D., & Lellouch, J. (1967). Explanatory and pragmatic attitudes in therapeutical trials. Journal of Chronic Diseases, 20(8), 637–648.	Friedman, L. M., Furberg, C. D., DeMets, D. L., Reboussin, D. M., & Granger, C. B. (2015). Fundamentals of Clinical Trials (5th ed.). Springer. ISBN: 978-3319185392
別名	pragmatic Phase II trial, real-world Phase II trial, Phase II pragmatic RCT, Phase IIb pragmatic trial	Phase 2 trial, Phase II study, early efficacy trial, proof-of-concept trial
関連	6	6
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.	A Phase II clinical trial is the second stage in the drug or intervention development pipeline, conducted after Phase I safety testing. Its primary goal is to assess whether the intervention shows preliminary efficacy signals in a relevant patient population at the dose established in Phase I, while continuing to characterise the safety and tolerability profile. Phase II trials are generally smaller than Phase III confirmatory trials and serve as critical go/no-go decision points before large-scale investment.