Trenonacog alfa safety, efficacy, and pharmacokinetics in previously treated pediatric hemophilia B.

BACKGROUND

Trenonacog alfa is a recombinant factor IX approved for adolescents and adults with hemophilia B.

OBJECTIVES

The aim of this study was to assess the pharmacokinetics (PK), efficacy as prophylaxis, control of bleeding episodes, and safety of trenonacog alfa in previously treated participants aged <12 years with severe or moderately severe hemophilia B and no current or history of inhibitors.

METHODS

The study had 3 phases: (1) PK evaluation after a single infusion of 75 ± 5 IU/kg, (2) treatment phase in which participants received trenonacog alfa prophylaxis 35 to 75 IU/kg for 50 exposure days, and (3) a continuation phase in which prophylaxis could be administered for ≥50 additional exposure days.

RESULTS

The PK of trenonacog alfa was comparable between adolescents and adults except for higher clearance, shorter mean residence time and elimination half-life, and lower incremental recovery. Prophylaxis resulted in a median annualized bleeding rate of 0.86 (mean = 2.34) for the combined treatment and continuation phases; 33.3% of participants had zero bleeds; and 83.7% of bleeds treated resolved with 1 or 2 infusions. One adverse event was possibly related to trenonacog alfa, a nonserious hypersensitivity reaction leading to early study termination. The efficacy and safety of trenonacog alfa for prophylaxis and bleeding treatment in previously treated pediatric participants were consistent with those reported for adults and adolescents. There appeared to be no clinically important differences between the results for participants aged <6 years and those aged 6 to <12 years.

CONCLUSION

Trenonacog alfa is a suitable option for the management of pediatric persons with hemophilia B.