Scientific and Regulatory Reasons for Delay and Denial of FDA Approval of Initial Applications for New Drugs, 2000-2012

Abstract

The road from medical product discovery to marketing is typically long and costly. The interval between initial clinical testing and product approval has been estimated to average 8 years¹ and only 1 in 6 drugs entering clinical trials ultimately obtains US Food and Drug Administration (FDA) approval.² Quiz Ref ID To obtain marketing approval for new drugs, developers must provide substantial evidence of safety and efficacy for the proposed indication.³ In a number of failed applications, deficiencies are successfully addressed in resubmissions resulting in delayed approval, whereas others are never approved for marketing. Nonapproval of drugs is critical to prevent the marketing of ineffective or harmful products. However, many drugs are not approved not because they are unsafe or ineffective, but because the information is unsatisfactory to make that determination. Delays and failures that occur late in development affect the availability of innovative new drugs and increase the costs of drug development.⁴ To avoid preventable late-stage deficiencies in drug development and their negative consequences, it is important to understand the nature of these deficiencies.