Questions about the US Food and Drug Administration (FDA)’s Accelerated Approval pathway are revealed today (August 15) in a study published in the Journal of the American Medical Association (JAMA).
Researchers from the London School of Economics and Political Science (LSE) and Brigham and Women’s Hospital/Harvard Medical School studied the clinical trials used by the FDA to authorise and confirm drugs via the Accelerated Approval between 2009 and 2013. They found that at least three years after being fast-tracked to market – and in some cases seven years and counting – half of the drugs had still not had the required post-approval studies completed. In most cases, the reasons behind these delays were not publicly available.
The Accelerated Approval pathway allows the FDA to expedite the approval of drugs treating serious illnesses or addressing unmet medical need on the basis of so-called surrogate measures – laboratory measurement, radiographic images, physical signs or other measures – that may not be strongly tied to actual patient clinical benefit. Once approved, these drugs must then undergo further clinical studies to determine whether the suggested benefits translate into real-life clinical improvements. If these studies fail to demonstrate clinical benefit, the FDA may withdraw the drug from market.
The researchers found that of the 50 per cent of drugs approved over these five years that had successfully completed the required studies, most did confirm the pre-approval trial findings. However, post-approval studies often also evaluated surrogate measures rather than clinical outcomes.
Huseyin Naci, Assistant Professor in LSE’s Department of Health Policy, and lead author of the study, said: “It is remarkable that the clinical studies of drugs conducted before and after Accelerated Approval have similar design deficits, including reliance on surrogate measures rather than evaluating what patients and their doctors care most about: extended survival and symptom relief.”
The researchers call for reconsideration of the required characteristics of confirmatory clinical trials for drugs approved via the Accelerated Approval pathway. In addition, says Naci, “Further clarity is needed on the FDA’s actions when there are delays in completing required clinical studies or when completed clinical studies fail to demonstrate benefit.”
Characteristics of Pre-Approval and Post-Approval Studies for Drugs Granted Accelerated Approval by the US Food and Drug Administration is by Huseyin Naci and Katelyn R. Smalley from LSE’s Department of Health Policy, and Aaron S. Kesselheim from Harvard Medical School.