Burden of illness in Japanese patients with paroxysmal nocturnal hemoglobinuria receiving C5 inhibitors

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, life-threatening blood disorder characterized by hemolysis and resulting in anemia and fatigue. Current therapies for PNH in Japan rely on complement inhibitors targeting the C5 component of the complement. However, the disease burden of Japanese patients with PNH treated with C5 inhibitors (C5i) remains unclear. To investigate this topic, we conducted a cross-sectional survey study that included 59 Japanese patients with PNH treated with C5i. Although many participants received C5i for 1 year or longer, the mean hemoglobin (Hb) level was 10.2 g/dL. Fatigue and shortness of breath were the most common symptoms at the time of diagnosis and survey. In addition, patients with Hb levels ≥ 10.5 g/dL also reported fatigue, depression and reduced quality of life, albeit to a lesser extent. These results suggest that a substantial burden of illness remains in patients with C5i-treated PNH, likely resulting in low quality of life and effects of symptoms on daily life. This study contributes to understanding the unmet needs of the current therapies for PNH, highlighting the need for novel therapeutics.