Tanaka K, Adams B, Aris AM, et al. - In the present study, the researchers sought to test the effectiveness of ravulizumab through 50 weeks of follow-up and safety through all available follow-up in pediatric patients with atypical hemolytic uremic syndrome (aHUS), with stable thrombotic microangiopathy parameters following a switch from eculizumab to ravulizumab treatment. Ten participants took a loading dose of ravulizumab on Day 1, followed by maintenance doses initially given on Day 15, and then, every 4–8 weeks thereafter, depending on body weight. All participants finished the initial evaluation period of 26 weeks and entered the extension period. During the entire study, no patients needed dialysis. During the study, no meningococcal infections were reported, no deaths occurred, and no patients dropped out. Overall, when administered every 4–8 weeks, ravulizumab treatment in pediatric patients with aHUS who had previously obtained eculizumab resulted in stable kidney and hematologic parameters, with no unexpected safety concerns.