inhibiting fibrinolysis factors which enzymatically cleave the fibrin matrix, leading to the ultimate formation of clots. rFXIII is synthetically bio-engineered through a yeast expression system and administered intravenously. In clinical trials, the drug was administered once every four weeks or administered on-demand in order to treat bleeding episodes. The introduction of rFXIII as a treatment for factor XIII deficiency eliminates the risk of pathogenic infection present in plasma-based treatments. rFXIII treatment would also not be dependent on blood donations, consequently increasing availability and product quality. One of the biggest fears in developing rFXIII was that the body would mount an immune-response to the protein; however, several safety and pharmacokinetics studies have reported no immunogenic response to rFXIII or associated yeast products. See also Factor XIII References External links Coagulopathies Haemophilia