The FDA delayed its decision on Agios Pharmaceuticals’ supplemental New Drug Application (sNDA) for mitapivat in sickle cell disease, extending the PDUFA target date by three months to February 1, 2027. Agios said the extension followed what the agency described as a major amendment requiring additional information to assess whether a Risk Evaluation and Mitigation Strategy (REMS) would be needed in the SCD population. Agios responded in late October with roughly nine months of updated safety data, submitted through October 9, drawn from ongoing open-label extension periods of the Phase II/III RISE UP trial (NCT05031780). The company pointed to recent published results in The Lancet describing hemoglobin response rates. Analysts cited market sensitivity to the possibility of a REMS, framing the FDA request as a sign of heightened caution. The stock reaction reflected that uncertainty, with Agios shares falling nearly 18% after the news. While investors focused on safety gating items, the delay also extends the timeline for potential expanded access to an oral pyruvate kinase activator intended to deliver disease-modifying effects.