When innovation goes fast. The case of hemophilia

In this Pharmacological Perspective, we discuss the fast innovation currently occurring in the field of hemophilia. On the background of standard therapy, which includes plasma-derived and recombinant products, a first wave of innovation was represented by the development of the non-factor, non-gene therapies, notably emicizumab, a bispecific monoclonal antibody that can bind activated factor IX and factor X, coupling the factors in a manner that reproduces the physiological activation of factor X. Emicizumab, which we define as a 'molecular prosthesis', appears to be able to overcome the important drawbacks of standard therapy, including immunogenicity and an unfavorable dosing schedule. While emicizumab has only recently arrived on the scene of clinical practice, the second wave of innovation is on the horizon that involves gene therapy and the prospect of curing hemophilia with a single 'magic bullet'.