Factor VIII: the protein, cloning its gene, synthetic factor and now - 35 years later - gene therapy; what happened in between?

The foundation of haemophilia A therapy in the last 35 years has been critically dependent on isolation of the Factor VIII (FVIII) protein and discovery of the cDNA sequence of the FVIII gene, published in 1984. Identification of the FVIII sequence resulted in a new era of recombinant concentrates and led to significant improvements in safety, set against the tragedy of widespread HIV and hepatitis infections in haemophilia patients from contaminated plasma-based products. We chronicle the scientific methods and race leading up to the publication of the FVIII DNA sequence and the legacy that follows through to revolutionary gene therapy treatment in clinical trials today.

Recent advances in developing specific therapies for haemophilia.

Haemophilia therapy has undergone very rapid evolution in the last 10 years. The major limitation of current replacement therapy is the short half-life of factors VIII and IX. These half-lives have been extended by the addition of various moieties, allowing less frequent infusion regimens. Entirely novel approaches have also entered the clinic, including a bispecific antibody that mimics factor VIII and strategies that rebalance the haemostatic mechanism by reducing antithrombin through inhibition of synthesis. These two treatments are available by subcutaneous injection at infrequent intervals and both can be used in patients with neutralising antibodies (inhibitors). Finally, a cure may be on the horizon with preliminary evidence of success for gene therapy in haemophilia B and A.