What is the rate of thrombosis in Glanzmann patients who are treated with rFVIIa?¶
Answer: Data are very limited, but rFVIIa appears to be safe, with a thrombosis rate lower than that reported when it is used for major bleeding.
This report summarizes data from the Glanzmann's Thrombasthenia Registry (GTR), published literature, and the Novo Nordisk safety database:
Overall efficacy rates were 79 and 88%, respectively, in patients treated for bleeding episodes or for the prevention of bleeding during surgery; effectiveness was generally similar across refractoriness/antibody status categories. Median dose per infusion of rFVIIa was close to that recommended for patients with GT (90 µg/kg).
- Thrombosis in Glanzmann: 1 of 133 patients in the GTR (a deep vein thrombosis, in a patient who also received platelets and other hemostatic treatment). The postmarketing safety database recorded 5 cases with thromboembolic events, 2 in patients aged ≥65 — spontaneous reports, so no rate can be calculated.
- Comparison — off-label use for life-threatening bleeding: in a pooled analysis of 35 placebo-controlled trials (Levi et al., NEJM 2010), arterial thromboembolic events occurred in 5.5% with rFVIIa vs 3.2% with placebo, rising to 9.0% vs 3.8% in those aged ≥65; venous events were similar (5.3% vs 5.7%).
Source: The Use of Recombinant Activated Factor VII in Patients with Glanzmann's Thrombasthenia