Discovery (2-10 years) Preclinical (lab& animal) testing Phase 1(20-30 hea thy volunteers check for safety, dosage Phase ll(100-300 patient volunteers check for efficacy, side effects) Phase Ill(1000-1500 patient volunteers check long-run drug use FDA review approval Postmarketing testing 10121416 Ye Biotech drug discovery process微生物与生化药学教研室 Biotech drug discovery process