Toward gene therapy for congenital thrombotic thrombocytopenic purpura

Congenital thrombotic thrombocytopenic purpura (cTTP) is caused by a severe defi-ciency in the plasma metalloprotease ADAMTS-13. The current management of cTTP is dependent on the prophylactic administration of ADAMTS-13 via plasma infusion. This is a demanding therapy for patients because transfusions are lifelong and time-consuming and allergic reactions frequently occur. Although current management of cTTP controls acute episodes, it does not provide a long-lasting cure for this disease. The endogenous expression of ADAMTS-13 after gene transfer would provide a curative therapy and ongoing research explores various preclinical gene therapeutic approaches for cTTP. This review focuses on the current state of the literature regarding preclinical gene therapy studies for cTTP and on the challenges of developing a gene therapy medicinal product for cTTP.