Summary
The safety and efficacy of sucrose-formulated recombinant factor VIII (rFVIII-FS;
Kogenate® FS) under usual clinical practice were evaluated for 12 months in an observational,
postmarketing surveillance study conducted at 214 treatment centres throughout Japan.
The study included 631 patients with haemophilia A, 80% of whom had severe or moderately-severe
disease (≤2% FVIII:C).Most patients (n=477;75.6%) had >100 prior exposure days (EDs),
but the study also included 62 (9.8%) patients with <20 EDs who were at high risk
for inhibitor development. A total of 71,240 infusions were administered during the
observation (mean, 113 ± 108 per patient). Physicians rated efficacy and tolerability
of rFVIII-FS as “very good” or “good” in >99% of patients. FVIII inhibitors were observed
in seven patients (5 de novo; 1 persistent/fluctuating; 1 recurrent).The overall de novo inhibitor incidence was 0.8% (5/631; or 5/599 among the subgroup of patients with
negative baseline titre and no known inhibitor history).De novo cases represented 3.2% (2/62) of patients with <20 EDs at enrollment (2/57 in the
no inhibitor subgroup) and 0.2 % (1/477) of patients pretreated with >100 EDs (1/452
in the no inhibitor subgroup) at enrollment. The results of this large observational
study demonstrate that rFVIII-FS is both safe and efficacious as used in the usual
clinical setting for the treatment of Japanese patients with mild to severe haemophiliaA.
This study supports the efficacy of rFVIII-FS with an incidence of inhibitor formation
no greater than in a comparable European study or previous phase III clinical studies.
Keywords
Haemophilia A - Kogenate - recombinant factorVIII - inhibitors
