A KFF Health News analysis of FDA records highlights how postmarket study requirements are often delayed or underenrolled, leaving safety questions unresolved long after approvals. The reporting centers on the delayed enrollment of a required 300-patient safety study for Tavneos after the FDA approved the drug with a proviso based on limited safety data. As of the posting described, only 21 of 300 patients had been enrolled, while the FDA has identified dozens of liver-injury cases that are possibly or probably linked to the drug. The analysis frames Tavneos as an example of broader “toothless” follow-through for post-approval commitments, with delays sometimes spanning a decade. The article adds that delayed postmarket evidence can create a fog for patients and clinicians, even when regulators seek to balance earlier access with long-term risk characterization. It also quotes UCSF cardiologist Sanket Dhruva on how postmarket requirements can fail to resolve real-world safety concerns quickly enough.