1.
Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia
Simpson E, Lin Y, Stanworth S, Birchall J, Doree C, Hyde C
Cochrane Database of Systematic Reviews. 2012;((3):):CD005011.
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Abstract
Background: Recombinant factor VIIa (rFVIIa) is licensed for use in patients with haemophilia and inhibitory allo-antibodies and for prophylaxis and treatment of patients with congenital factor VII deficiency. It is also used for off-license indications to prevent bleeding in operations where blood loss is likely to be high, and/or to stop bleeding that is proving difficult to control by other means. This is the third version of the 2007 Cochrane review on the use of recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia, and has been updated to incorporate recent trial data. Objectives: To assess the effectiveness of rFVIIa when used therapeutically to control active bleeding or prophylactically to prevent (excessive) bleeding in patients without haemophilia. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and other medical databases up to 23 March 2011. Selection criteria: Randomised controlled trials (RCTs) comparing rFVIIa with placebo, or one dose of rFVIIa with another, in any patient population (except haemophilia). Outcomes weremortality, blood loss or control of bleeding, red cell transfusion requirements, number of patients transfused and thromboembolic adverse events. Data collection and analysis: Two authors independently assessed potentially relevant studies for inclusion, extracted data and examined risk of bias. We considered prophylactic and therapeutic rFVIIa studies separately. Main results: Twenty-nine RCTs were included: 28 were placebo-controlled, double-blind RCTs and one compared different doses of rFVIIa. In the ’Risk of bias’ assessment, most studies were found to have some threats to validity although therapeutic RCTs were found to be less prone to bias than prophylactic RCTs. Sixteen trials involving 1361 participants examined the prophylactic use of rFVIIa; 729 received rFVIIa. There was no evidence of mortality benefit (risk ratio (RR) 1.04; 95% confidence interval (CI) 0.55 to 1.97). There was decreased blood loss (mean difference (MD) -297 mL; 95% CI -416 to -178) and decreased red cell transfusion requirements (MD -261 mL; 95% CI -367 to -154) with rFVIIa treatment; however, these values were likely overestimated due to the inability to incorporate data from trials (four RCTs in the outcome of blood loss and three RCTs in the outcome of transfusion requirements) showing no difference of rFVIIa treatment compared to placebo. There was a trend in favour of rFVIIa in the number of participants transfused (RR 0.85; 95% CI 0.72 to 1.01). However, there was a trend against rFVIIa with respect to thromboembolic adverse events (RR 1.35; 95% CI 0.82 to 2.25). Thirteen trials involving 2929 participants examined the therapeutic use of rFVIIa; 1878 received rFVIIa. There were no outcomes where any observed advantage or disadvantage of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality (RR 0.91; 95% CI 0.78 to 1.06). However, there was a trend against rFVIIa for increased thromboembolic adverse events (RR 1.14; 95% CI 0.89 to 1.47). When all trials were pooled together to examine the risk of thromboembolic events, a significant increase in total arterial events was observed (RR 1.45; 95% CI 1.02 to 2.05). Authors’ conclusions: The effectiveness of rFVIIa as amore general haemostatic drug, either prophylactically or therapeutically, remains unproven. The results indicate increased risk of arterial events in patients receiving rFVIIa. The use of rFVIIa outside its current licensed indications should be restricted to clinical trials.
PICO Summary
Population
Patients without haemophilia, at risk of blood loss due to surgery, or who had received treatment to manage bleeding (29 randomised controlled trials, n= 4,290).
Intervention
Recombinant factor VIIa (rFVIIa).
Comparison
Placebo. Different dose schedules of rFVIIa.
Outcome
Sixteen trials involving 1,361 participants examined the prophylactic use of rFVIIa; 729 received rFVIIa. There was no evidence of mortality benefit (risk ratio (RR) 1.04; 95% confidence interval (CI) 0.55 to 1.97). There was decreased blood loss (mean difference (MD) -297 mL; 95% CI -416 to -178) and decreased red cell transfusion requirements (MD -261 mL; 95% CI -367 to -154) with rFVIIa treatment. There was a trend in favour of rFVIIa in the number of participants transfused (RR 0.85; 95% CI 0.72 to 1.01). However, there was a trend against rFVIIa with respect to thromboembolic adverse events (RR 1.35; 95% CI 0.82 to 2.25). Thirteen trials involving 2,929 participants examined the therapeutic use of rFVIIa; 1,878 received rFVIIa. There were no outcomes where any observed advantage or disadvantage of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality (RR 0.91; 95% CI 0.78 to 1.06). However, there was a trend against rFVIIa for increased thromboembolic adverse events (RR 1.14; 95% CI 0.89 to 1.47). When all trials were pooled together to examine the risk of thromboembolic events, a significant increase in total arterial events was observed (RR 1.45; 95% CI 1.02 to 2.05).
2.
Use of recombinant factor VIIa for the prevention and treatment of bleeding in patients without hemophilia: a systematic review and meta-analysis
Lin Y, Stanworth S, Birchall J, Doree C, Hyde C
CMAJ: Canadian Medical Association Journal. 2011;183((1):):E9-19.
Abstract
BACKGROUND The benefits and risks of off-label use of recombinant factor VIIa in patients without hemophilia are contested. We performed a systematic review to assess the effectiveness and safety of such use. METHODS We searched electronic databases including MEDLINE, EMBASE and CENTRAL for randomized controlled trials comparing recombinant factor VIIa with placebo in any patient population except those with hemophilia up to January 2010. Eligible articles were assessed for inclusion, data were extracted, and study quality was evaluated. Outcomes included mortality, blood loss, requirements for red blood cell transfusion, number of patients transfused and thromboembolic events. RESULTS We identified 26 trials: 14 on off-label prophylactic use of recombinant factor VIIa (n = 1137) and 12 on off-label therapeutic use (n = 2538). In the studies on prophylactic use, we found no significant difference in mortality or thromboembolic events between the treatment and placebo groups. We found modest benefits favouring recombinant factor VIIa in blood loss (weighted mean difference -276 mL, 95% confidence interval [CI] -411 to -141 mL), red blood cell transfusion (weighted mean difference -281 mL, 95% CI -433 to -129 mL) and number of patients transfused (relative risk 0.71, 95% CI 0.50 to 0.99). In the therapeutic trials, we found a nonsignificant decrease in mortality and a nonsignificant increase in thromboembolic events but no difference in control of bleeding or red blood cell transfusion. INTERPRETATION Clinically significant benefits of recombinant factor VIIa as a general hemostatic agent in patients without hemophilia remain unproven. Given its potential risks, such use cannot be recommended, and in most cases, it should be restricted to clinical trials.