PB0174 - Half-life of factor VIII in an adult and pediatric population: Study at 03 centers in western Algeria

Background: On-demand treatment and even standard prophylactic regimens have their limitations. The approach of personalizing prophylaxis by studying the half-life of hemophilia A patients was born following the discrepancy observed between patients without spontaneous bleeding despite FVIII levels below 1%.

Aims: The objective of our study is to determine the pharmacokinetic profile of our hemophiliac population in western Algeria and to evaluate the individual variability of our patient’s estimated using PK modeling and Bayesian analysis.

Methods: 39 patients with hemophilia A were followed at the Univeristy hospital of Oran, Pediatric establishment and Establishment of Tiaret. The Bayesian approach made it possible to calculate the difference between an individual and a population to predict an individual half-life. The most likely PK values for each patient were estimated from a limited number of FVIII levels using MyPKFiT, a web application that allows users to simulate dosing regimens using pharmacokinetic profiles (PK) individualized. The MyPKFiT application can be used with only 02 samples: the first between 03 and 04 hours (+/- 30 minutes) after the injection and, the second between 24 and 32 hours (+/- 1 hour) after the injection.

Results: The average age and weight of our population were respectively 13.56 ± 9.84 years with extremes between 1 and 42 years and 39.68 ± 23.49 Kg (9-96 Kg). Half-life 9.46±2.7 hours (3.2-14 hours), clearance (0.05 ± 0.027 dl/h/kg -61.53%), time greater than 1% (57.23 ± 17.09 hours -21.79%).Patient age and weight were positively correlated with factor VIII half-life (p=0.004, R=0.7), (p=0.019, R=0 ,7) respectively

Conclusion(s): The development of pharmacokinetics in the adjustment of individual prophylactic regimens for hemophilia A would most likely have a very significant medical and socio-economic impact in the management of the disease, particularly in developing countries. PK parameters are of great importance in the preventive treatment and management of hemophiliacs