Factor Replacement Therapy

There are two types of Factor replacement therapy – those made from human plasma, or those made artificially using DNA (recombinant) technology. Factor VIII and IX concentrates can come from either source. Both sources provide factor proteins that are nearly identical to the proteins missing in people with hemophilia.

Factor replacement therapy involves injecting clotting factor concentrates, Factor VIII (for hemophilia A) or Factor IX (for hemophilia B), directly into the vein of a person with hemophilia. The clotting Factors start to act right away to help form blood clots and stop bleeds.

Factor replacement therapy can also be used to help prevent prolonged bleeds (also called prophylaxis treatment), before an activity or more regularly. However, since the body constantly replenishes its blood supply, factor replacement therapy only temporarily replaces these missing proteins – long enough to form clots at a damaged blood vessel.

They are rare, but side effects such as allergic reactions, thrombosis and hemolysis (the breakdown of red blood cells) may occur.  There is also a risk of viral transmission.  Inhibitors can also develop when a patient is on factor replacement therapy, inhibitors are antibodies that can disrupt the function of a clotting factor.