Gene therapy is a novel approach that is being developed for the treatment of hemophilia.¹ 

Gene therapy involves the introduction, removal or change of the genetic material, specifically DNA or RNA, in the cells of a patient to treat a specific disease.³

A gene therapy currently being investigated for the treatment of hemophilia, called gene transfer, involves the addition of a functional copy of a gene into the target cells to produce a functional protein.^3-5
 

Gene therapy for hemophilia is currently still in development and under investigation, and is neither available nor proved safe or effective.¹

Unlike factor replacement therapies that aim to replace the missing or defective factor proteins, non-replacement therapies mimic the procoagulant activity of the clotting factors or enhance coagulation by inhibiting physiological anticoagulants.²
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Some examples of non-replacement therapies include²:

• Subcutaneous bispecific monoclonal antibodies (IgG4) that mimic activated FVIIIa by bridging FIXa and the FX zymogen to enhance FX activation
• Antibodies that bind to and inhibit the activity of TFPI. The TFPI brakes the initiation phase of coagulation by inactivating FXa and the FVIIa-TF complex. Because the binding of FXa enables subsequent inhibition of the FVIIa-TF complex, the TFPI operates in a negative feedback loop that regulates the generation of FXa. Blocking TFPI activity extends the initiation phase of the coagulation, which generates more FXa. Anti-TFPI products are currently still in development and under investigation, and are neither available nor proved safe or effective.
• A subcutaneous double-stranded small interfering RNA that targets antithrombin to improve sufficient thrombin generation and promote hemostasis. Antithrombin small interfering RNA products are currently still in development and under investigation, and are neither available nor proved safe or effective.