The December Effect in FDA Drug Approvals: Assessing the Submissions Echo Hypothesis

Abstract

It has been documented that the Food and Drug Administration's new drug approvals occur disproportionately in the month of December. We hypothesize that the observed excess December approvals reflects an excess of December New Drug Application (NDA) and Biologics License Application (BLA) submissions. Furthermore, we expect this pattern to have become more pronounced following the passage of the Prescription Drug User Fee Act (PDUFA) in 1992, which set explicit 6- and 12-month review targets. We call this the “December submissions echo” hypothesis. Contrary to our hypothesis, we find the excess December approval phenomenon to be even more pronounced before PDUFA than following it. Although the monthly pattern for NDA/BLA approvals varied minimally upon enactment of PDUFA, the proportion of NDA/BLA December submissions increased considerably in the post-PDUFA period and has continued to increase recently. As expected, PDUFA review time targets of 6 and 12 months lead to spikes in approvals around these time periods. Although the December excess approval phenomenon has been mitigated recently in response to 10-month-review targets in PDUFA II, the excess December submission phenomenon has persisted since 2001. We consider implications for FDA workloads, first-cycle approvals, industry submission strategies, and user fee policies.