The FDA delayed its decision on Agios Pharmaceuticals’ supplemental New Drug Application for mitapivat in sickle cell disease, extending the PDUFA target from November 1, 2026 to February 1, 2027. Agios said the delay was tied to what the FDA described as a major amendment, including additional information on whether a Risk Evaluation and Mitigation Strategy (REMS) would be needed. Agios submitted updated safety data in response to the regulator’s request, including new evidence drawn from ongoing open-label extension periods of the Phase II/III RISE UP trial. The company emphasized the risk-benefit profile remained unchanged, including continued absence of hepatocellular injury cases among relevant patient subsets. The decision triggered an immediate selloff in Agios shares, with analysts citing investor concern that the FDA’s stance could be becoming more cautious in this population.