Jоhnny Bаnsteаd, 27 yeаrs оld, has nоticed that his urine was cola-colored in the morning for the past 5 days, and today he experienced a sudden onset of severe abdominal pain. Physical exam, blood tests, and urine analysis show that Johnny is anemic as the result of intravascular hemolysis. A Coombs test is negative, ruling out autoimmune hemolytic anemia. Flow cytometric analysis of peripheral blood cells for CD235a (glycophorin A, present on erythroid precursors and mature red blood cells) together with CD55 (decay-accelerating factor) and CD59 (protectin) reveals the absence of CD55 and CD59 on 54% of his red blood cells. Molecular analysis confirms a defective PIGA gene, which encodes the protein phosphatidylinositol glycan class A, which is involved in producing glycophosphatidylinositol anchors for many different cell-surface proteins, including CD55 and CD59. John is diagnosed with paroxysmal nocturnal hemoglobinuria. A long-term treatment regimen including the administration of intravenous eculizumab, an anti-C5 humanized monoclonal antibody, is recommended. Which of the following provides the rationale for selecting eculizumab for the long-term management of John’s condition?