Quality Attributes of Plasma Derived Human Fibrinogen (Fibrogen-I®)

BACKGROUND Fibrinogen is an important component of hemostasis and clot formation. Replacement therapy with a human Fibrinogen concentrate is the preferred therapeutic option for patients with congenital or acquired Fibrinogen insufficiency. To make the Fibrinogen available for treatment of such patients, Fibrogen-I®, a lyophilized product purified from pooled human plasma was developed and extensively characterized. The product quality attributes were assessed by different biochemical, functional and structural analytical methods. MATERIAL AND METHODS Functional activity of Fibrinogen in the Fibrogen-I® was demonstrated by determination of its clottable protein activity. Purity profiling of Fibrogen-I® was evaluated by SE-HPLC method. Activation and fibrinolysis markers like D-dimer, plasminogen was determined by automated coagulometer and fibrinopeptide A activity by ELISA. Far UV CD analysis was also performed by CD Spectrometer. RESULTS The product exhibited high purity 89.7% by SE-HPLC. Activation and Fibrinolysis marker proteins in the drug product were negligible. The high purity and integrity of Fibrogen-I® is underlined by the ratio of Fibrinogen activity by Clauss/clottable protein with mean calculated value of 0.9 which is in close proximity with theoretical value 1 indicating fully native Fibrinogen. The results of far-UV CD spectroscopy revealed that Fibrogen-I® exists mostly as a β-sheet secondary structure, which is in accordance with the three-dimensional structure of human Fibrinogen. Downscaling experiments for the two dedicated orthogonal pathogen inactivation steps, ie solvent detergent treatment and dry heat treatment, exhibited pathogen safety. DISCUSSION Fibrogen-I® exhibited specific functional activity, desirable quality attributes, pathogen safety and the ability to be made available to patients requiring fast and effective Fibrinogen replacement.