Since 2012, the FDA can designate a drug as a "breakthrough therapy" if preliminary clinical evidence - such as an improvement in a pharmacodynamic biomarker - suggests an advantage over existing options. The term is routinely used in press releases and prescribing resources. Although the term breakthrough leads consumers to overly optimistic beliefs about drug effectiveness, it is not known how physicians understand this term, or more generally, what FDA approval means.

In a study appearing in the April 12 issue of JAMA, Aaron S. Kesselheim, M.D., J.D., M.P.H., of Brigham and Women's Hospital, Boston, and colleagues surveyed internists and specialists to examine their knowledge about Food and Drug Administration (FDA) approval standards and perceptions of the "breakthrough therapy" designation.

Of 1,148 physicians contacted, 692 physicians (60 percent) responded. Participants were asked 3 questions about FDA approval and 5 about breakthrough therapies. Respondents showed limited knowledge of FDA approval: 73 percent incorrectly believed FDA approval meant comparable effectiveness to other approved drugs; 70 percent incorrectly believed approval required both a statistically significant and clinically important effect. Among the 3 breakthrough knowledge questions, 52 percent incorrectly believed that strong evidence (randomized trials) is needed to earn the breakthrough designation.

"The misconceptions identified may lead physicians to overprescribe newly approved drugs - particularly breakthrough therapies - and inadequately communicate how well these drugs work to the patients who will use them," the authors write.

Kesselheim AS, Woloshin S, Eddings W, Franklin JM, Ross KM, Schwartz LM. Physicians’ Knowledge About FDA Approval Standards and Perceptions of the “Breakthrough Therapy” Designation. JAMA. 2016;315(14):1516-1518. doi:10.1001/jama.2015.16984.