Real-world Application of the Oral Factor B Inhibitor Iptacopan in Chinese Patients with Paroxysmal Nocturnal Hemoglobinuria: A Four-case Series Data

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, and potentially life-threatening clonal hematopoietic stem cell disorder. PNH predominantly affects individuals aged 30–40 years with a global incidence of 1–1.5/1,000,000. The pathogenesis of PNH involves acquired mutations in the PIG-A gene, resulting in the impaired synthesis of glycosylphosphatidylinositol-anchored proteins in hematopoietic stem cells. This impairment leads to complement system activation, which attacks PNH clone cells and induces intravascular hemolysis. The main clinical manifestations of PNH primarily include hemoglobinuria, anemia, thrombosis, and renal impairment. Before the availability of complement inhibitors, the median survival of patients with PNH was 10–15 years. While the introduction of C5 complement inhibitors has greatly improved survival, some patients remain transfusion-dependent, and only a minority achieve normalized hemoglobin levels. China has a relatively large population of patients with PNH. However, because of national conditions and health insurance policies, many patients cannot afford sufficient and complete courses of Iptacopan treatment. We report four Chinese patients of PNH with different clinical features who were treated with Iptacopan. We also review the literature to discuss treatment regimens and efficacy, providing real-world treatment options for patients with PNH in developing countries.