手法を比較

	フェーズII臨床試験 ― 初期有効性と用量評価	ランダム化比較試験 (RCT)
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	1960s–1970s (formalised in US federal drug regulation)	1948 (first rigorously conducted RCT — MRC streptomycin trial)
提唱者	U.S. Food and Drug Administration / ICH E8 guidelines (institutionalised framework)	Austin Bradford Hill; MRC Streptomycin Trial team
種類	Interventional clinical study design	Interventional experimental study
原典	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	Friedman, L. M., Furberg, C. D., DeMets, D. L., Reboussin, D. M., & Granger, C. B. (2015). Fundamentals of Clinical Trials (5th ed.). Springer. ISBN: 978-3319185385
別名	Phase 2 trial, Phase II study, early efficacy trial, proof-of-concept trial	RCT, randomized controlled trial, randomised controlled trial, clinical randomized trial
関連	6	6
概要	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.	A randomized clinical trial (RCT) is an experimental study design in which participants are randomly assigned to an intervention group or a control group, then followed prospectively to compare outcomes. Random allocation is the defining feature: it distributes known and unknown confounders across groups by chance, making the RCT the strongest individual study design for establishing causal efficacy of a treatment or intervention under controlled conditions.