A Pharmacokinetic Study of the Plasma-Derived Factor IX AlphaNine® and Its Comparison with the Recombinant Factor IX BeneFIX®, in Previously Treated Patients with Severe Hereditary Hemophilia B.

Abstract

Objectives The objective of the present study was two fold: first, to determine the pharmacokinetic (PK) profile of the plasma-derived FIX concentrate AlphaNine® in patients with congenital severe haemophilia B (FIX:C 2%). To do this, two PK studies were carried out one six months after the first. The second objective was a comparison of the Alphanine® PK profile with the recombinant Factor IX, BeneFIX®. Patients and methods The first study was a prospective, five-center, open-label, comparative, PK study carried out in 25 severe hemophilia B patients who received 2 single doses of 65–75 IU/kg of AlphaNine® within 6 months (t=0 and t=6). The following parameters were assessed: in vivo recovery, half-life, AUC, mean residence time and clearance. As an extension of the study, a single dose of 65–75 IU/kg of BeneFIX® was administered in 9 out of 25 patients, after a wash-out period of 7–15 days. Results Table 1 summarizes the results obtained when comparing AlphaNine® within a period of time of 6 months (PK1 vs PK2) in 25 patients. Table 2 shows the results obtained when comparing the in vivo recovery of AlphaNine ® vs BeneFIX ® in the 9 patients studied. Conclusions These results confirm that AlphaNine® PK has similar profile as other plasma derived FIX products presently available to treat Hemophilia B patients. In addition, our results show that the recombinant FIX studied, BeneFIX® has a reduced in vivo recovery when is compared to AlphaNine®. Table 1 Parameter AlphaNine® (PK1) t=0 m AlphaNine® (PK2) t=6 m Results are expressed as Mean (SD) In vivo recovery (IU/dl:IU/kg) 1.0 (0.2) 1.2 (0.4) Half-life (h) 34.5 (6.2) 33.7 (5.4) Clearance (ml/min) 0.07 (0.01) 0.07 (0.01) AUC0-inf (IUxh/dl) 1602 (312) 1644 (360) MRT0-inf (h) 35.8 (5.4) 34.6 (5.2) Table 2 Parameter AlphaNine® (PK2) BeneFIX® Results are expressed as Mean (SD); * p<0.05 for the comparison of the in vivo recovery for the BeneFIX® group with the AlphaNine® PK2 In vivo recovery (IU/dl:IU/kg) 1.3 (0.5) 0.8 (0.2)*