Current and emerging biologics for the treatment of hemophilia.

INTRODUCTION: The development of new biologic agents able to restore thrombin generation has become the focus of innovation in hemophilia management. There is growing interest in the proposal of novel, non-replacement therapy with alternative mechanisms of action and route of administration, hoping to solve still unmet needs in treatment of hemophilic patients with or without inhibitors. AREAS COVERED: The review describes the new molecules, in particular the bi-specific antibody mimicking the coagulation function of FVIII and/or those which work by inhibiting the natural anticoagulants, their mechanism of action and the results of ongoing clinical trials. EXPERT OPINION: Exciting results in enhancing the protection against bleeding and improving quality of life are emerging from clinical trials. However, these molecules with their mechanisms of action also open new problems. Treatment of bleeding and management of surgery in subjects with a rebalanced hemostasis may be difficult, especially for the lack of laboratory tests perfectly reflecting the in vivo coagulation status. A careful surveillance is required to evaluate the risk of thrombotic complication in patients with rebalanced hemostasis, in addition to understand whether these new products offer the same protection on joints as regular prophylaxis with the missing clotting factors.