The review of drugs and medical devices is an integral part of regulatory science. The Pharmaceuticals and Medical Devices Agency (PMDA) evaluates the efficacy, safety, and quality of drugs and medical devices after applications are submitted for regulatory approval. The products are approved when their benefits exceed their risks, i.e., an application is approved if the efficacy of the product in patients was demonstrated and the safety of the product is acceptable in view of its observed benefits. However, drugs and medical devices for which efficacy was not clearly demonstrated in clinical trials makes the decision to approve a difficult process. Under those circumstances, the approval process is based on the totality of information, such as the reason why clinical trials did not succeed and medical needs in Japan. The Wingspan stent system, which was approved for the treatment of intracranial arterial stenosis, is an example of a product with a use different from that intended by the US Food and Drug Administration and PMDA.