Additional Relevant Details US FDA approved Bayer's Kovaltry antihemophilic factor VIII (recombinant) for the treatment of hemophilia A in children and adults. Kovaltry is an unmodified, full-length recombinant factor VIII product. The approval is based on results from the LEOPOLD clinical trials, which demonstrated that Kovaltry controls bleeds, and reduces frequency of bleeding episodes with routine prophylaxis in children and adults with hemophilia A when used two or three times per week.