Trends of OD for SCD granted by the FDA and the EMA in the period 2000-2001. The top panel reports some of the milestones that paved the way for the drug development of SCD in the past 2 decades, also showing the main achievements gained in terms of ODs granted by the FDA and the EMA that already have impacted clinical practice and the potential game-changers in development (eg, gene therapies). Below are the main pathopsychological chapters of the disease addressed over time. HbF, fetal hemoglobin; HU, hydroxyurea; HU-FCT, hydroxyurea-film–coated tablets; RBC, red blood cell.