手法を比較

	フェーズII臨床試験 ― 初期有効性と用量評価	第I相臨床試験
分野	疫学	疫学
系統	Process / pipeline	Process / pipeline
提唱年	1960s–1970s (formalised in US federal drug regulation)	1960s (formal regulatory framework established ~1963–1970s)
提唱者	U.S. Food and Drug Administration / ICH E8 guidelines (institutionalised framework)	Regulatory and clinical pharmacology community; formalized in U.S. FDA IND regulations (1963) and ICH guidelines
種類	Interventional clinical study design	Interventional clinical study design
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	Storer, B. E. (1989). Design and analysis of phase I clinical trials. Biometrics, 45(3), 925–937.
別名	Phase 2 trial, Phase II study, early efficacy trial, proof-of-concept trial	Phase 1 trial, first-in-human study, FIH study, dose-escalation study
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 Phase I clinical trial is the first stage of human testing for a new drug, biologic, or intervention. Its primary objective is to evaluate safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) rather than therapeutic efficacy. Small cohorts of participants — typically healthy volunteers or patients with advanced disease — receive sequentially increasing doses to identify the maximum tolerated dose (MTD) and the dose-limiting toxicities (DLTs) that define the boundary for subsequent trials.