Heat treated New Zealand factor IX concentrate: comparison with Prothrombinex in patients with haemophilia B.

Factor IX concentrates, prepared by standard chromatographic techniques, are used primarily to treat patients with congenital factor IX deficiency. A local factor IX containing concentrate has now been prepared and heat treated. Following heat treatment, and reconstitution, the potency is 280 units per vial. The preparation, HNZFIX, has been compared with the currently available factor IX concentrate Prothrombinex. Following administration into patients with haemophilia B, ex vivo factor IX recovery and half life response have been compared for the two products. The mean recovery values were identical with an average 17 units per litre rise in factor IX activity obtained for each unit of factor IX concentrate administered per kg of body weight. For both products recovery measured as the K ratio was approximately 75% (0.75). The plasma half life responses were 17 and 22.2 h for the HNZFIX and PTX respectively. No unexpected side effects occurred with the HNXFIX which met all the British Pharmacopeia requirements for a therapeutic concentrate.