Current Therapies in Hemophilia: From Plasma-Derived Factor Modalities to CRISPR/Cas Alternatives

Since the middle of the last century, there have been amazing therapeutic advances for hemophilia such as the development of plasma-derived products and bioengineered recombinant factors VIII and IX (for hemophilia A and B, respectively) with improved stability, higher activity, and extended half-life. The recent use of a monoclonal antibody that mimics factor VIII activity (which is an efficient treatment for all hemophilia A phenotypes with or without inhibitors) has shown the great possibilities of non-factor therapies for improving the quality of life of hemophilia A patients, with a safer application and long-lasting effects. Gene therapy offers the promise of a "true cure" for hemophilia based on the permanent effect that a gene edition may render. Clinical trials developed in the last decade based on adenoviral vectors show modest but consistent results; now, CRISPR/Cas technology (which is considered the most efficient tool for gene edition) is being developed on different hemophilia models. Once the off-target risks are solved and an efficient switch on/off for Cas activity is developed, this strategy might become the most feasible option for gene therapy in hemophilia and other monogenic diseases.