FDA post-approval studies lag, leaving safety of drugs and devices uncertain

Federal data reveal that a large share of FDA-required post-market studies for drugs, biologics and medical devices are falling behind schedule, with nearly 600 studies listed as delayed. The safety study for Amgen's rare-autoimmune drug Tavneos, approved in 2021, has enrolled only 21 of the planned 300 participants, even as the agency has recorded dozens of possible liver-injury cases. Similar postponements affect devices such as the CustomFlex Artificial Iris and treatments like Paxlovid for pregnant women.

Researchers and clinicians say the shortfall creates uncertainty about long-term benefits and harms, while patients continue to use costly products. Recent policy moves to speed approvals by reducing pre-approval trial requirements could further shift the burden onto these under-performed post-approval studies. The FDA and manufacturers cite legitimate reasons for delays, but critics argue the system often rewards companies without delivering needed safety data.