Drug development is a lengthy, expensive, and complex process, and clinical development is the longest and the most expensive stage of drug development. To obtain market authorization of a new drug, applicants must prove the effectiveness and the safety of a drug through clinical trials. Korea has the same requirements for new drug approval as in developed countries and bridging data are required for approval of a new drug that was developed in another country. Clinical evaluation in humans consists of 3 phases, from phase 1 to phase 3, and the failure rates remain high while the clinical trial cost increases rapidly. Not only pharmaceutical sponsors but also patients and physicians want new, innovative medicines faster, simultaneously with improved productivity of drug development. With strong competition and market forces, the pressure to accelerate drug development and to predict the efficacy and safety profile of a drug candidate at an earlier stage is increasing. To improve the productivity of new drug development, modern principles of pharmaceutical sciences, clinical pharmacology, and information technology are being researched and employed by both health authorities and sponsors. Many global pharmaceutical companies are also pursuing geographical expansion strategies to enroll subjects faster among more diverse ethnic groups. To deliver innovative medicines to patients in a faster and more cost-effective ways, close and continuous collaboration among sponsors, academia, and health authorities is essential.