C5 and paroxysmal nocturnal hemoglobinuria: Despite the increased risk of meningococcal infection associated with the use of C5 inhibitors, no cases were reported in the 52-week findings from the pivotal phase 3 clinical trials of either eculizumab or ravulizumab in patients with PNH.28,57,58 However, there was one fatal case of meningococcal sepsis 2.2 years after a patient received their first dose of ravulizumab.88