Background/Aims: The U.S. Food and Drug Administration (FDA) outlines clinical studies as postmarketing requirements and commitments to be fulfilled following FDA approval of new drugs and biologics ("therapeutics"). As regulators have increasingly emphasized lifecycle evaluation of approved therapeutics, postmarketing studies are intended to advance our understanding of therapeutic safety and efficacy, yet little is known about how often clinical studies are outlined or the indications they investigate. To assess FDA's use of postmarket clinical studies to generate evidence of therapeutic safety and efficacy, we characterized FDA postmarketing requirements and commitments for new therapeutics approved from 2009-2018.
Methods: We conducted a cross-sectional study of all novel therapeutics, including small molecule drugs and biologics, receiving original FDA approval from 2009-2018, using approval letters accessed through the Drug@FDA database. Outcomes included the number and characteristics of FDA postmarketing requirements and commitments for new therapeutics at original approval, including types of studies outlined, indications to be investigated, and clinical evidence to be generated.
Results: From 2009-2018, FDA approved 343 new therapeutics with 1978 postmarketing requirements and commitments. Overall, 750 (37.9%) postmarketing requirements and commitments outlined clinical studies. For 71 of 343 (20.7%) therapeutics, no postmarketing requirements nor commitments for clinical studies were outlined, while at least 1 was outlined for 272 (79.3%; median = 2 (IQR, 1-4)). Among these 272 therapeutics, the number of postmarketing requirements and commitments for clinical studies per therapeutic did not significantly change from 2009 (median 2 (IQR, 1-4)) to 2018 (median 2 (IQR, 1-3); P = .54). Among the 750 postmarketing requirements and commitments for clinical studies, 448 (59.7%) outlined new prospective cohort studies, registries, or clinical trials, while the remainder outlined retrospective studies, secondary analyses, or completion of ongoing studies. Although 455 (60.7%) clinical studies investigated only original approved therapeutic indications, 123 (16.4%) enrolled from an expansion of the approved disease population and 61 (8.1%) investigated diseases unrelated to approved indications.
Conclusions: Most therapeutics are approved by FDA with at least 1 postmarketing requirement or commitment for a clinical study, which outline investigations of safety or efficacy for both approved and unapproved indications. However, the median number of 2 clinical studies outlined has remained relatively constant over the last decade, despite increasing emphasis on lifecycle evaluation of approved therapeutics.
Characteristics of Clinical Studies Used for US Food and Drug Administration Approval of High-Risk Medical Device Supplements