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. Agios said the agency moved the target action date from November 1, 2026, to February 1, 2027 after requesting additional information to assess whether a Risk Evaluation and Mitigation Strategy (REMS) would be needed. Agios attributed the extension to what the FDA described as a major amendment and submitted updated safety data in response, covering approximately nine months of information from ongoing open-label extension periods of the Phase II/III RISE UP trial (NCT05031780). The company pointed to published findings in The Lancet (Oct. 24), reporting hemoglobin response in 41% of 138 patients in the mitapivat group versus 3% of 69 on placebo, while reporting no hepatocellular injury cases with SCD patients treated at patterns and severity similar to prior adult thalassemia experience. Market reaction was negative, with Agios shares reportedly down nearly 18% after the delay. Analysts characterized the timing as potentially signaling increased FDA caution around risk management requirements in SCD specifically.