Justices press evidence on mifepristone safety, REMS changes and the Comstock question

The argument shifted from standing to technical and factual questions about safety data, post‑market surveillance and the regulatory framework FDA used to modify mifepristone’s REMS. Government counsel stressed that FDA’s determination — reached after examining multiple studies and real‑world pandemic data — fell within the zone of reasonableness under the Administrative Procedure Act. Counsel for the manufacturer likewise urged deference, warning that courts are ill‑suited to second‑guess complex clinical and statistical analyses.

Challengers’ critique: Respondents and their counsel urged the court that FDA relied on imperfect data for 2016 and 2021 decisions, failed to consider cumulative effects of removing safeguards, and that certain studies showed increases in emergency‑room visits or surgical interventions when in‑person dispensing requirements were relaxed. They also argued that the 2016 change reduced prescriber reporting requirements that had previously provided more systematic adverse‑event information.

Comstock Act and statutory limits: Justices asked whether the Comstock Act (a federal statute criminalizing certain mailings in historical contexts) should have been considered. Government and company counsel said FDA’s REMS authority is limited to safety and efficacy concerns under the FDCA and that the agency had an internal memorandum addressing Comstock issues; respondents argued the statute’s scope is relevant but that the question was not necessarily squarely presented in this case.

Data and reporting: Company counsel explained that manufacturers remain obligated to report adverse events and pointed out that many REMS no longer require the elevated prescriber reporting that existed earlier. The transcript records counsel warning that lower courts relied on studies later retracted or outside the administrative record, underscoring why agency records matter for judicial review.

Court testing and takeaways: Justices repeatedly returned to the question of what counts as a serious adverse event versus nonfatal consequences (gestational dating errors, bleeding, need for D&C), whether ultrasounds were ever mandatory, and how much weight to give pandemic-era comparisons. The court also examined whether FDA’s conclusion that increased ER visits did not equate to increased serious adverse events was a reasoned explanation.

Status: Fact‑intensive merits questions were thoroughly explored in argument; the justices’ questioning focused on evidence, causation, and the appropriate standard of review.