Fulcrum Therapeutics Inc. announced positive initial results from the 20 mg dose cohort of the Phase 1b PIONEER trial evaluating pociredir in patients with sickle cell disease. The interim analysis showed a dose-response relationship, with a mean absolute increase in fetal hemoglobin (HbF) of 9.9% at Week 6 in the 20 mg cohort, compared to 5.6% in the 12 mg cohort. At Week 6, 58% of patients in the 20 mg cohort achieved absolute HbF levels of 20% or higher. Among patients who reached the Week 12 visit, the 20 mg cohort demonstrated a greater than 3.75-fold mean induction of HbF. Pociredir was generally well-tolerated with no treatment-related serious adverse events reported. These results were presented at the 67th American Society of Hematology Annual Meeting, and Fulcrum Therapeutics will host an investor event on December 7, 2025, to further discuss the data.