Objective: This study aimed to analyze pharmacokinetic and clinical parameters (bleeding rates and joint health) before and after switching from standard half-life (SHL) factor VIII (FVIII) to extended half-life (EHL) PEGylated turoctocog alfa pegol in patients with severe/moderate hemophilia A (HA) on prophylaxis, one year prior to and following the switch in a real-world setting. This evidence concerns the gene F8 and hemophilia A.