C5 and paroxysmal nocturnal hemoglobinuria: In a recent report of 509 patients with PNH receiving C5 inhibitors (eculizumab and/or ravulizumab) from May 2002 to July 2022 in the United Kingdom, 23 patients had a thrombotic event, consistent with a thrombosis rate of 0.73 events per 100 patient-years eculizumab and ravulizumab are safe and effective therapies that reduce mortality and morbidity in PNH [157].