The FDA delayed its decision on Agios Pharmaceuticals’ supplemental New Drug Application for mitapivat in sickle cell disease, extending the Prescription Drug User Fee Act (PDUFA) target by three months to February 1, 2027. Agios said the delay followed an FDA request for additional information to assess whether a Risk Evaluation and Mitigation Strategy (REMS) would be required. Agios submitted updated safety data through October 9 from the ongoing open-label extension periods of the Phase II/III RISE UP trial (NCT05031780). The update was tied to investor concerns around the possibility of REMS requirements in SCD and the agency’s approach to risk management in this population. In a separate reported dataset cited by Agios, hemoglobin response rates were higher in the mitapivat group than placebo in the published data. Even with continued lack of hepatocellular injury signals consistent with other mitapivat settings, the FDA timeline change contributed to a sharp market reaction from investors.