PRO-PACT: retrospective observational study on the prophylactic use of recombinant factor VIIa in hemophilia patients with inhibitors.

INTRODUCTION: Hemophilia patients with inhibitors have frequent bleeding episodes and often develop hemophilic arthropathy which is in contradistinction to non-inhibitor patients for whom prophylaxis prevents joint disease. Recently, two prospective trials have demonstrated that secondary prophylaxis with bypassing agents in inhibitor patients offers benefit by reducing bleeding episodes. This report describes the clinical experience of secondary prophylaxis in a large population of inhibitor patients. PATIENTS/
METHODS: This retrospective, observational study was performed by abstracting data from medical records of patients in whom secondary prophylaxis with rFVIIa was prescribed. Data were collected by professional medical record abstractors and included patient demographics, dosing regimens, bleeding events, and healthcare resource utilization. Data analysis was descriptive and included sensitivity analyses.
RESULTS: Data from 86 patients from 14 countries were collected. The primary outcome measure (% reduction in bleeding) was 46% (95% CI, -54.0 to -38.2) in patients with at least one bleeding episodes prior to starting prophylaxis and 52% (95% CI, -60.7 to -43.3) in patients with at least one bleeding episode per month prior to starting prophylaxis. A variety of subanalyses were performed, including among age and bleed location; the results for pediatric patients, adults, target and non-target joint bleeds categorizations were similar to the overall primary outcome.
CONCLUSIONS: The results in this large observational study are similar to those from the previously reported prospective study of prophylaxis with rFVIIa in inhibitor positive patients, although this study represents a more typical inhibitor population who utilized prophylaxis in the clinical setting. As such, prophylaxis should be considered a potentially effective therapy in hemophilia patients with inhibitors.