Fulcrum Therapeutics Announced Saturday, Initial Results From 20 mg Dose Cohort Of The Phase 1b PIONEER Trial Of Pociredir In Sickle Cell Disease; Clear Dose-response Observed, With Robust, Clinically Meaningful Fetal Hemoglobin Induction At Week 6 Timepoint

Fulcrum Therapeutics, Inc. Nasdaq: FULC), a clinical-stage biopharmaceutical company focused on developing small molecules to improve the lives of patients with genetically defined rare diseases, today reported positive initial results from the ongoing 20 mg dose cohort of the Phase 1b PIONEER trial of pociredir in sickle cell disease (SCD).

Clear dose-response observed, with a robust and clinically meaningful fetal hemoglobin (HbF) induction at the Week 6 timepoint (n=12): mean absolute HbF in the 20 mg cohort increased by 9.9% at Week 6 (vs. 5.6% at Week 6 in the 12 mg cohort); 7 of 12 patients in the 20 mg cohort (58%) achieved absolute HbF levels ≥20% ―

― >3.75-fold mean induction of HbF at Week 12 in the 20 mg cohort among patients who reached the Week 12 visit as of November 11, 2025 data cutoff (n=6), compared to a 2.4-fold induction at Week 12 in the 12 mg cohort ―

― Consistent early evidence of pan-cellular HbF induction, improvements in markers of hemolysis and anemia, and encouraging trends in vaso-occlusive crisis (VOC) reduction ―

― Pociredir continued to be generally well-tolerated, with no treatment-related serious adverse events (SAEs) ―