Advances in the treatment of inherited coagulation disorders

Inherited coagulation disorders constitute a broad spectrum of coagulation factor deficiencies that include X-linked factor (F)VIII or FIX deficiency that causes haemophilia, and autosomal recessive disorders producing heterogeneous deficiencies in fibrinogen (FI), prothrombin (FII), FV, FVII, FX, FXI, FXIII and combined FV+FVIII. Significant advances in treatments for patients with congenital haemophilia A (FVIII deficiency) and B (FIX deficiency) over the last two decades have resulted from improvements in the production, availability and patient access to factor replacement products. Translation of advances in biotechnology, namely recombinant protein technology, targeted protein modifications to improve function and potentially reduce immunogenicity, and advanced formulations to optimize bioavailability and sustain activity offer promisingly new treatments for haemophilia as well as recessively inherited bleeding disorders in patients who otherwise have few therapeutic options. Though a theoretical risk remains for blood-borne viral infections with pooled plasma-derived products, this concern has diminished with breakthroughs in purification and viral inactivation methods. Development of inhibitory antibodies is still the most daunting problem for patients with inherited bleeding disorders, complicating treatment approaches to control and prevent bleeding, and posing risks for allergic and anaphylactic reactions in susceptible patients. The objectives of this review are to (i) highlight emerging advances in hemostatic therapies that are bioengineered to improve pharmacokinetic properties and bioavailability, sustain functional activity, and possibly eliminate immunogenicity of recombinant factor proteins; and (ii) present an overview of key clinical trials of novel factor products currently in the development pipeline.