เปรียบเทียบวิธี

	การทดลองทางคลินิกระยะที่ II	การทดลองทางคลินิกระยะที่ 3
สาขาวิชา	ระบาดวิทยา	ระบาดวิทยา
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1960s–1970s (formalised in US federal drug regulation)	1962 (Kefauver-Harris Amendment formalised phased drug development)
ผู้ริเริ่ม	U.S. Food and Drug Administration / ICH E8 guidelines (institutionalised framework)	FDA regulatory framework / ICH guidelines
ประเภท	Interventional clinical study design	Confirmatory randomised controlled trial
แหล่งต้นตำรับ	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
ชื่อเรียกอื่น	Phase 2 trial, Phase II study, early efficacy trial, proof-of-concept trial	Phase 3 trial, confirmatory trial, pivotal trial, Phase III RCT
ที่เกี่ยวข้อง	6	6
สรุป	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 III clinical trial is a large-scale, confirmatory randomised controlled trial designed to establish the efficacy and safety of an intervention in the target patient population before regulatory submission. It builds on the signal identified in Phase II, tests the intervention at its proposed dose under controlled conditions, and provides the primary evidence base for marketing authorisation or guideline adoption.