手法を比較

	適応型第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	1994 (formal framework); widespread adoption 2000s–2010s	1960s–1970s (formalised in US federal drug regulation)
提唱者	Peter Bauer & Klaus Kohne (formal statistical framework, 1994); broader adaptive trial methodology developed through FDA and ICH guidance in the 2000s	U.S. Food and Drug Administration / ICH E8 guidelines (institutionalised framework)
種類	Experimental clinical trial design	Interventional clinical study design
原典	Bauer, P., & Kohne, K. (1994). Evaluation of experiments with adaptive interim analyses. Biometrics, 50(4), 1029–1041.	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	Adaptive Ph II trial, seamless adaptive Phase II, adaptive dose-finding trial, response-adaptive Phase II	Phase 2 trial, Phase II study, early efficacy trial, proof-of-concept trial
関連	1	6
概要	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.	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.