FDA Breakthrough Therapy Designation: Evaluating the Quality of the Evidence behind the Drug Approvals.

The United States Food and Drug Administration (FDA) has created approval pathways and designations to accelerate access to medications indicated for serious or life-threatening conditions with limited treatment options. Implemented in 2012, the most recent of these is the breakthrough therapy designation (BTD). The purpose of this article was to review the evidence surrounding approval of medications with nononcology indications approved with the BTD designation from 2012 to 2016. Fifteen medications were identified for eight conditions, ranging from conditions that are relatively common, such as chronic hepatitis C infection, to those that are extremely rare, such as lysosomal acid lipase deficiency. The quality of evidence behind these approvals was highly heterogeneous. Much remains unknown about the safety and efficacy of many agents approved through the BTD. Health care professionals should be aware of these limitations to better educate patients and other providers appropriately.