Objective To investigate the regulations and implementation effect for high-risk drugs of the FDA and MHRA on the basis of natalizumab, and to provide references for the risk regulation of the innovative drugs and high-risk drugs of China. Methods We searched MEDLINE, EMBASE.com, the official website of Food and Drug Administration (FDA) and the Medicines and Healthcare Products Regulatory Agency (MHRA) for the marketing/withdrawal and risk regulation information of natalizumab as well as the relevant information of drug marketing/withdrawal and approval track. Results (1) Natalizumab was initially approved by the FDA through accelerated approval in November, 2004 with the phase three clinical trial still being conducted. But in February 2005, it was withdrawn after 3 patients developed PML. FDA resumed its marketing under a specially restricted distribution program called the Touch Prescribing Program in March, 2006. (2) Natalizumab was marketed in the European Union in April 2006. No cases of PML have been reported in the UK for this drug. (3) To speed the development of drugs that treat serious diseases, the FDA developed 3 distinct and successful approaches to make such drugs available as rapidly as possible: Priority Review, Accelerated Approval, and Fast Track. The proportion of new molecular entity and new biologic approved by fast tract were 45% and 74%, respectively between 2002 and 2009. (4) Drug regulation of MHRA contained: Yellow Card Scheme, Black Triangle products, Download Drug Analysis Prints (DAPs), and Defective Medicines Report Centre (DMRC). Self-reporting and monitoring system were fairly perfect, thus they can fulfill the close monitoring for high-risk drugs under the existing conditions and then realize the risk-minimization. Conclusion (1) The risk-minimization program of FDA for high-risk drugs is effective, and plays a role in the policy support for the researching and marketing of irreplaceable innovative drugs. (2) The risk regulation for high-risk drugs of MHRA is integrated into drug regulation program and enforces hierarchical management, and acquires risk-minimization effect. (3) We should learn from the policy and operational experience for the international new molecular entity and new biologic on the re-evaluation for innovative drugs and high-risk drugs. Combined with drug specific characteristics, evaluation indicators and criteria are developed base on evidence, risk management system and mechanism for innovative drugs are established and improved, and policy and administration security for the safety application of innovative drugs and high-risk drugs are provided.