Casgeva, from Vertex Pharmaceuticals in collaboration with CRISPR Therapeutics, is the first approved therapy using CRISPR technology for the treatment of sickle cell disease in patients over 12 years of age with recurrent vaso-occlusive crises[1][2][5][9]. The therapy modifies the patient's stem cells in the laboratory using CRISPR/Cas9 in the region of the BCL11A gene, thus restoring the formation of fetal hemoglobin and alleviating the symptoms of the disease[1][3][4][5]. In clinical trials, healthy hemoglobin production was restored in most patients without significant safety issues[1][4]. Specifically, Casgevy completely cured 28 of 29 patients with sickle cell disease and all 42 patients with beta-thalassemia[4]. The procedure involves taking stem cells from the bone marrow, modifying them, chemotherapy to remove the old cells, and then infusing the modified cells, which takes several months[1][7][8]. Vertex is running out of time to launch Casgeva as a transformative treatment as it hits an unexpected roadblock[original content].