Retrospective Comparison of Andexanet Alfa and 4-Factor Prothrombin Complex for Reversal of Factor Xa-Inhibitor Related Bleeding

The aim of this retrospective study was to compare andexanet alfa and 4-factor prothrombin complex (4F-PCC) for reversal of factor Xa (FXa)-inhibitor bleeding. Patients that received andexanet alfa for reversal were included. An equivalent number of patients administered 4F-PCC for FXa-inhibitor bleeding were randomly selected as historical controls. The primary outcome was effective hemostasis achievement within 12 h, defined using ANNEXA-4 criteria. Thromboembolic events and mortality within 30 days were also evaluated. A total of 32 patients were included. Baseline characteristics were not statistically different between andexanet alfa (n = 16) and 4F-PCC (n = 16). Intracranial bleeding was the primary reversal indication in 43.8% versus 62.5% of patients, respectively. Effective hemostasis was reached in 75.0% of andexanet alfa patients compared to 62.5% of 4F-PCC patients (P = .70). Thromboembolic events occurred in 4 (25.0%) patients and 3 (18.8%) patients, respectively (P = .99). Mortality incidence was 12.5% and 31.3%, respectively (P = .39). Andexanet alfa and 4F-PCC attained hemostasis in a majority of patients. A high, but a similar rate of thromboembolic events was seen with both treatments. Prospective studies are needed to elucidate comparative risks and benefits of the 2 agents.

Coagulation Factor Xa (Recombinant), Inactivated-Zhzo (Andexanet Alfa) Hemostatic Outcomes and Thrombotic Event Incidence at an Academic Medical Center

Andexanet alfa is approved for the reversal of factor Xa inhibitors in patients with major bleeding events. We aimed to review the incidence of effective hemostasis with andexanet alfa in a real-world environment. This retrospective cohort included patients hospitalized for a major bleed that resulted in andexanet alfa administration. The primary outcome was effective hemostasis at 12 hours after andexanet alfa treatment. Thromboembolic events and mortality within 30 days were also assessed. Over a 14-month period, 13 patients received andexanet alfa with a mean age of 69 ± 10 years, 54% male, 69% exposed to apixaban (31% rivaroxaban), and had intracranial (46%) and nonintracranial (54%) bleeding sites. Effective hemostasis was observed in 10 (77%) patients. Four (31%) patients experienced 5 thromboembolic events with a median time to event of 6.5 days (range: 0.5-29). Four thrombotic events occurred during the period in which anticoagulation (prophylaxis or therapeutic) was not restarted. Mortality rate was 15%. Andexanet alfa was effective in obtaining hemostasis in a majority of patients. However, the incidence of thromboembolic events was high and may be attributed to a delay in restarting anticoagulation.

A Systematic and Evidence-Based Review of Published and Pending Reports of Andexanet Alfa

Andexanet alfa is the newly approved factor Xa inhibitor reversal agent for the treatment of life-threatening or uncontrolled bleeding from apixaban or rivaroxaban. This decoy protein directly binds factor Xa inhibitors reversing their action. A systematic and evidence-based evaluation of the available clinical trials is lacking in the literature. This research will provide a systematic and evidence-based evaluation of published clinical trials for andexanet alfa. It will also present an evaluation of active research. Reports of research were identified through multiple databases using search terms andexanet alfa, andexanet, or PRT064445. The level of evidence and strength of recommendation were accomplished using the Strength of Recommendation Taxonomy. There are 2 published articles presenting 3 clinical trials. Two trials had a low level of evidence and the third trial, a preliminary report of results, showed a moderate level of evidence. The review of active research found 3 unique studies and a preliminary results study. The level of evidence is low for 2 of these studies, moderate for a third, and potentially high for the fourth. The strength of recommendation for all 6 studies is a C. Four of the studies present disease-oriented evidence resulting in a low level of evidence. Another study is unblinded and uncontrolled but presents patient-oriented evidence resulting in a moderate level of evidence. Only one study could score high because the outcome is patient-oriented evidence, and it could achieve follow-up of 80%. There is a need for well-controlled and blinded evaluation to improve the recommendation strength.