Prophylactic and therapeutic recombinant factor VIIa administration to patients with Glanzmann's thrombasthenia: Results of an international survey

Background: Antibodies to glycoprotein (GP) IIb-IIIa and/or HLA may render platelet transfusions ineffective to stop bleeding or to cover surgery in patients with Glanzmann's thrombasthenia (GT). Anecdotal reports suggest recombinant factor (rF)VIIa might be a therapeutic alternative in these situations. Objectives: An international survey was conducted to evaluate further the efficacy and safety of rFVIIa in GT patients. Patients: We analyzed the use of rFVIIa during 34 surgical/invasive procedures and 108 bleeding episodes in 59 GT patients including 29 with current or previous antiplatelet antibodies, and 23 with a history of refractoriness to platelet transfusion. Results: rFVIIa was effective in 29 of the 31 evaluable procedures, and in 77 of the 103 evaluable bleeding episodes of which eight had a recurrence. A significantly higher success rate was observed in severe bleeding episodes when an arbitrarily defined 'optimal regimen' derived from the Canadian pilot study results (≥ 80 μg kg^-1 rFVIIa/injection, dosing interval ≤2.5 h, three or more doses before failure declaration) was used compared with other regimens (77%; 24/31 vs. 48%, 19/40; χ², P = 0.010). Patients given maintenance doses had significantly fewer recurrences within 48 h of bleed cessation compared with those not given any (Fisher's exact test, P = 0.022). One thromboembolic event and one blood clot in the ureter occurring in surgical patients following prolonged continuous infusion of high-dose rFVIIa and antifibrinolytic drug use have been previously reported. Conclusion: rFVIIa seems a potential alternative to platelet transfusion in GT patients, particularly in those with antiplatelet antibodies and/or platelet refractoriness.