As part of the Single Technology Appraisal (STA) process, the UK National Institute for Health and Care Excellence (NICE) invited Apellis Pharmaceuticals/Sobi to submit evidence for the clinical and cost effectiveness of pegcetacoplan versus eculizumab and pegcetacoplan versus ravulizumab for treating paroxysmal nocturnal haemoglobinuria (PNH) in adults whose anaemia is uncontrolled after treatment with a C5 inhibitor. The gene discussed is C5; the disease is anemia (phenotype).