ICD-10 Specific code D57.1: Sickle-cell anaemia without crisis

Exagamglogene autotemcel is a cell therapy consisting of autologous CD34+ HSPCs ex vivo edited by CRISPR/Cas9-technology. The highly specific guide RNA enables CRISPR/Cas9 to make a precise DNA double-strand break at the critical transcription factor binding site (GATA1) in the erythroid specific enhancer region of the BCL11A gene. As a result of the editing, GATA1 binding is irreversibly disrupted and BCL11A expression reduced. Reduced BCL11A expression results in an increase in γ-globin expression and foetal haemoglobin (HbF) protein production in erythroid cells, addressing the absent globin in transfusion-dependent β-thalassemia (TDT) and the aberrant globin in sickle cell disease (SCD), which are the underlying causes of disease.

Thiotepa is a polyfunctional cytotoxic agent related chemically and pharmacologically to the nitrogen mustard. The radiomimetic action of thiotepa is believed to occur through the release of ethylene imine radicals that, as in the case of irradiation therapy, disrupt the bonds of DNA, e.g. by alkylation of guanine at the N-7, breaking the linkage between the purine base and the sugar and liberating alkylated guanine.

Voxelotor is a haemoglobin S (HbS) polymerisation inhibitor that binds to HbS with a 1:1 stoichiometry and exhibits preferential partitioning to red blood cells (RBCs). By increasing the affinity of Hb for oxygen, voxelotor demonstrates dose-dependent inhibition of HbS polymerisation. Voxelotor inhibits RBC sickling and improves RBC deformability.