<i>Ex vivo</i> correction of severe coagulation Factor VII deficiency in patient-derived 3D liver organoids

Coagulation factor (F) VII deficiency is the most frequent among the rare, inherited bleeding disorders and is predominantly caused by missense mutations in the F7 gene. The disease phenotype ranges from asymptomatic cases to extremely severe hemorrhagic forms, requiring prophylactic injections with plasma-derived or recombinant FVII concentrates. In response, we have developed an autologous cell-based approach that corrects the disease-causing mutation in patient- derived induced pluripotent stem cells (iPSC) and generates therapeutic, three-dimensional hepatic organoids (HO). We report the CRISPR-mediated correction of homozygous c.718G>C (p.G240R), a missense mutation associated with a severe, life-threatening bleeding phenotype. The HO contain all liver cell types and exhibit key liver functions, including coagulation factor production. After correction, our data indicate that the patient-derived HO secrete consistent amounts of functional FVII protein, resulting in improved thrombin generation times. These results represent a significant milestone toward the establishment of an autologous cell-based therapy for patients with FVII- and other coagulation factor deficiencies.