Real-world evidence supports the use of recombinant porcine factor VIII (rpFVIII; susoctocog alfa) for managing bleeding episodes in adult patients with acquired hemophilia A, reinforcing findings from earlier Phase 2/3 trials. The post-authorization safety study (PASS) data, gathered across multiple sites in Europe, showed no new safety concerns, specifically highlighting the absence of hypersensitivity or thromboembolic events typically associated with bypassing agents.
Efficacy and Safety Profile
The study, led by Wolfgang Miesbach, MD, PhD, from the University Hospital Frankfurt, monitored 50 patients over 180 days, assessing the safety and effectiveness of rpFVIII in routine clinical settings. The primary endpoint focused on adverse events (AEs), serious adverse events (SAEs), and AEs of special interest (AESIs), including immunogenicity and thromboembolic events. Secondary endpoints included hemostatic effectiveness and utilization patterns of rpFVIII.
Of the 50 patients enrolled, 31 completed the study, with a median follow-up of 178 days and a median first dose of 54.0 U/kg. A total of 148 AEs were reported in 41 patients, including 46 SAEs. Five SAEs were considered potentially related to rpFVIII, including one case of lack of efficacy and four AESIs related to FVIII inhibition. Notably, most AEs were moderate, and no hypersensitivity reactions or thromboembolic events were reported.
Clinical Outcomes and Treatment Strategies
More than half of the patients received rpFVIII as a first-line treatment for initial bleeding events. Among the 50 initial events, 37 (74.0%) resolved after the rpFVIII treatment course, with a median resolution time of 8.0 days. The data indicated that initiating rpFVIII treatment sooner after the onset of bleeding could improve resolution rates.
"A higher proportion of patients receiving first-line rpFVIII achieved resolution of their initial BE than those receiving second-line therapy, suggesting that first-line rpFVIII is potentially better than second-line therapy for resolving initial bleeding events," the researchers noted in their publication.
Acquired Hemophilia A Context
Acquired hemophilia A is a rare autoimmune disorder characterized by the development of inhibitory autoantibodies against endogenous FVIII. Current treatment strategies focus on controlling bleeding and eradicating these inhibitory antibodies. While bypassing agents (BPAs) are often used, they carry a risk of thromboembolic events, particularly in patients with comorbidities. rpFVIII is approved for bleeding events in adults with acquired hemophilia A in several regions, offering an alternative first-line therapy depending on inhibitor titer, cost, and availability.
