definiens: means a clinical study of a drug candidate in hum an patients with the primary objective of characterizing its activity in a specific diseas e state as well as generating more detailed safety, tolerability, and pharmacokinetics information as d escribed in 21 C.F.R. § 312.21(b ), or a comparable clinical study p rescribed by the relevant Regulatory Authority in a country other than the United States including a human clinical trial that is also desig ned to satisfy the requirements of 21 C.F.R. § 312.2 1(a ) or corresponding foreign regulations and is subsequ ently opt imized or expanded to satisfy the requirements of 21 C.F.R. § 312.21(b ) ( or correspond ing foreign regulations ) or otherwise to enable a Phase 3 Clinical Study ( e.g., a phase 1/2 trial ) . T he relevant drug candidate may be administered to patients as a single agent or in combination with o ther investigational or marketed agents