Study of Surgical Practices in Hemophilia A Patients Treated With Efanesoctocog Alfa (Altuvoct®) (CHALE II)

Hemophilia A is an inherited bleeding disorder caused by the absence or deficiency of coagulation factor VIII. The perioperative management of individuals with hemophilia A involves replacement therapies, typically through bolus or continuous infusions of Factor VIII, to ensure effective hemostatic control during surgery.

Efanesoctocog alfa represents a significant advance in treatment. It is a highly engineered, VWF-independent, recombinant FVIII fusion molecule with an ultra-long half-life of 47 hours in adults and 40 hours in children. Efanesoctocog alfa is approved in the U.S. and Germany for adults and children with hemophilia A for multiple purposes: routine prophylaxis to reduce bleeding episodes, on-demand treatment of bleeding episodes, and perioperative management. Despite its approval, the precise optimal use of efanesoctocog alfa in the surgical setting remains underexplored. Further research is essential to define its specific benefits in surgery, thereby enhancing its clinical utility and informing treatment protocols.

The objective of this cohort study is to collect clinical data on the surgical management of patients with hemophilia A treated with Altuvoct® in a real-world setting. Data collected will include surgical context (outpatient or inpatient), number of FVIII infusions during the perioperative period, length of hospital stay, postoperative date of return to usual prophylaxis, and factor VIII use. The results will be compared with those obtained using efmoroctocog (Elocta) in the ongoing CHALE study in France.

The multicenter design is critical due to the rarity of hemophilia A, the diversity of surgical procedures, and the need to enroll a sufficient number of patients. The management of patients with hemophilia A during and after surgery is inherently multidisciplinary and requires careful coordination and adherence to numerous requirements. Given the variability in practice among centers, this study aims to support secondary harmonization of protocols and minimize intercenter variability. Such efforts are in line with the missions assigned to the National Reference Center for Hemophilia in France, coordinated by Pr Dargaud, and emphasize the importance of optimizing and standardizing care practices.

A similar study is currently underway in France with efmoroctocog alfa (Elocta), which has already included over 155 procedures under real-world conditions. Using a similar case report form (CRF) for the present study will enable a direct comparison of surgical outcomes between extended half-life and ultra-extended half-life FVIII treatments, providing deeper insight into their respective roles in perioperative care. Additionally, this approach will highlight the added value of efanesoctocog alfa compared to existing therapies.

Another key advantage of this research is the opportunity to compare outcomes in patients receiving combined therapy with efanesoctocog alfa and emicizumab. Since the ongoing CHALE study has already included patients treated with both efmoroctocog and emicizumab, this comparison will further enhance our understanding of combination treatment strategies.