scholarly journals Hemostatic Efficacy and Anti-FXa (Factor Xa) Reversal With Andexanet Alfa in Intracranial Hemorrhage

Stroke ◽  
2021 ◽  
Author(s):  
Andrew M. Demchuk ◽  
Patrick Yue ◽  
Elena Zotova ◽  
Juliet Nakamya ◽  
Lizhen Xu ◽  
...  

Background and Purpose: Andexanet alfa is a recombinant modified human FXa (factor Xa) developed to reverse FXa inhibition from anticoagulants. Hemostatic efficacy and reversal of anti-FXa activity with andexanet were assessed in patients from the ANNEXA-4 study (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of FXa Inhibitors) with intracranial hemorrhage (ICrH). Methods: ANNEXA-4 was a single-arm study evaluating andexanet in patients presenting with major bleeding ≤18 hours after taking an FXa inhibitor. Patients received a bolus plus 2-hour infusion of andexanet. Brain imaging in patients with ICrH was performed at baseline and at 1 and 12 hours postandexanet infusion. Coprimary efficacy outcomes were change in anti-FXa activity and hemostatic efficacy at 12 hours (excellent/good efficacy defined as ≤35% increase in hemorrhage volume/thickness). Safety outcomes included occurrence of thrombotic events and death at 30 days. Results: A total of 227 patients with ICrH were included in the safety population (51.5% male; mean age 79.3 years) and 171 in the efficacy population (99 spontaneous and 72 traumatic bleeds). In efficacy evaluable patients, excellent/good hemostasis 12 hours postandexanet occurred in 77 out of 98 (78.6%) and in 58 out of 70 (82.9%) patients with spontaneous and traumatic bleeding, respectively. In the subanalysis by FXa inhibitor treatment group in the efficacy population, median of percent change in anti-FXa from baseline to nadir showed a decrease of 93.8% for apixaban-treated patients (n=99) and by 92.6% for rivaroxaban-treated patients (n=59). Within 30 days, death occurred in 34 out of 227 (15.0%) patients and thrombotic events occurred in 21 out of 227 (9.3%) patients (safety population). Conclusions: Andexanet reduced anti-FXa activity in FXa inhibitor-treated patients with ICrH, with a high rate of hemostatic efficacy. Andexanet may substantially benefit patients with ICrH, the most serious complication of anticoagulation. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02329327.

Circulation ◽  
2020 ◽  
Vol 141 (21) ◽  
pp. 1681-1689 ◽  
Author(s):  
Nicholas G. Panos ◽  
Aaron M. Cook ◽  
Sayona John ◽  
G. Morgan Jones ◽  
Hallie Kelly ◽  
...  

Background: Since the approval of the oral factor Xa inhibitors, there have been concerns regarding the ability to neutralize their anticoagulant effects after intracranial hemorrhage (ICH). Multiple guidelines suggest using prothrombin complex concentrates (PCCs) in these patients on the basis of research that includes a limited number of patients with ICH. Given this, we aimed to evaluate the safety and efficacy of PCCs for factor Xa inhibitor–related ICH in a large, multicenter cohort of patients. Methods: This was a multicenter, retrospective, observational cohort study of patients with apixaban- or rivaroxaban-related ICH who received PCCs between January 1, 2015, and March 1, 2019. The study had 2 primary analysis groups: safety and hemostatic efficacy. The safety analysis evaluated all patients meeting inclusion criteria for the occurrence of a thrombotic event, which were censored at hospital discharge or 30 days after PCC administration. Patients with intracerebral, subarachnoid, or subdural hemorrhages who had at least 1 follow-up image within 24 hours of PCC administration were assessed for hemostatic efficacy. The primary efficacy outcome was the percentage of patients with excellent or good hemostasis on the basis of the modified Sarode criteria. Secondary outcomes included an evaluation of in-hospital mortality, length of stay, infusion-related reactions, and thrombotic event occurrence during multiple predefined periods. Results: A total of 663 patients were included and assessed for safety outcomes. Of these, 433 patients met criteria for hemostatic efficacy evaluation. We observed excellent or good hemostasis in 354 patients (81.8% [95% CI, 77.9–85.2]). Twenty-five (3.8%) patients had a total of 26 thrombotic events, of which 22 occurred in the first 14 days after PCC administration. One patient had documentation of an infusion-related reaction. For the full cohort of patients, in-hospital mortality was 19.0%, and the median intensive care unit and hospital lengths of stay were 2.0 and 6.0 days, respectively. Conclusions: Administration of PCCs after apixaban- and rivaroxaban-related ICH provided a high rate of excellent or good hemostasis (81.8%) coupled with a 3.8% thrombosis rate. Randomized, controlled trials evaluating the clinical efficacy of PCCs in patients with factor Xa inhibitor–related ICH are needed.


2019 ◽  
Vol 25 ◽  
pp. 107602961986349 ◽  
Author(s):  
Fakiha Siddiqui ◽  
Alfonso Tafur ◽  
Lorenzo Storino Ramacciotti ◽  
Walter Jeske ◽  
Debra Hoppensteadt ◽  
...  

Recombinant coagulation factor Xa (FXa), inactivated Zh-zo, also known as andexanet alfa (AA), is a modified version of human FXa that has been developed to neutralize FXa inhibitors. We studied the reversal effect of AA for these inhibitors in various anticoagulant and thrombin generation (TG) assays. Individual aliquots of normal human plasma containing 1 µg/mL of apixaban, betrixaban, edoxaban, and rivaroxaban, were supplemented with saline or AA at a concentration of 100 µg/mL. Clotting profiles include prothrombinase-induced clotting time, activated partial thromboplastin time, and prothrombin time. Factor Xa activity was measured using an amidolytic method. Thrombin generation was measured using a calibrated automated thrombogram. Differential neutralization of all 4 anticoagulants was noted in the activated clotting time and other clotting tests. The FXa activity reversal profile varied with an observed decrease in apixaban (22%), betrixaban (56%), edoxaban (28%), and rivaroxaban (49%). Andexanet alfa also led to an increased TG in comparison to saline. The peak thrombin was higher (40%), area under the curve (AUC) increased (15%), whereas the lag time (LT) decreased (17%). Andexanet alfa added at 100 µg/mL to various FXa supplemented systems resulted in reversal of the inhibitory effects, restoring the TG profile; AUC, LT, and peak thrombin levels were comparable to those of unsupplemented samples. Andexanet alfa is capable of reversing anti-Xa activity of different oral FXa inhibitors but overshoots thrombogenesis in both the saline and FXa inhibitor supplemented systems. The degree of neutralization of Xa inhibitor is specific to each agent.


2021 ◽  
Vol 27 ◽  
pp. 107602962110390
Author(s):  
Victoria M. Stevens ◽  
Toby C. Trujillo ◽  
Tyree H. Kiser ◽  
Robert MacLaren ◽  
Paul M. Reynolds ◽  
...  

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.


Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Alexander P Benz ◽  
Lizhen Xu ◽  
John W Eikelboom ◽  
Saskia Middeldorp ◽  
Truman J Milling ◽  
...  

Introduction: We previously reported results of a prospective cohort study evaluating andexanet alfa (andexanet) for anticoagulation reversal in patients with acute bleeding on a factor Xa inhibitor. Study enrollment continued to accumulate additional data on patients on edoxaban, which are presented here. Methods: Patients with acute major bleeding within 18 hours of edoxaban intake were prospectively enrolled. Patients received a 400 or 800 mg bolus and a 480 or 960 mg 2-hour follow-on infusion of andexanet, depending on edoxaban dosage and time of last dose. The co-primary efficacy outcomes were change in anti-factor Xa activity and the rate of excellent or good hemostasis, 12 hours after andexanet treatment, as determined by an independent adjudication committee. Efficacy was analyzed in patients with confirmed major bleeding and baseline anti-factor Xa activity ≥75 ng/mL. Safety was analyzed in all patients. Results: A total of 36 patients (mean age 82 years, 61.1% male and 91.7% with atrial fibrillation) with acute major bleeding on edoxaban received andexanet. The primary site of bleeding was intracranial in 29 (80.6%) patients. In the efficacy population (n=20), median anti-factor Xa activity decreased from 160.5 (interquartile range [IQR] 106.2-222.2) ng/mL at baseline to 50.9 (IQR 19.9-119.4) ng/mL at the end of bolus (median decrease 69.2%, 95% confidence interval [CI] 25.5-80.2%). Excellent or good hemostasis at 12 hours was achieved in 75.0% (95% CI 50.9-91.3%) of patients overall and in 81.3% (95% CI 54.4-96.0%) of those with intracranial hemorrhage (ICH). Within 30 days, a total of 4 (11.1%) patients experienced at least one thrombotic event and 4 (11.1%) others died. Conclusions: In patients with acute bleeding on edoxaban, andexanet significantly decreased anti-factor Xa activity. Excellent or good hemostasis at 12 hours was observed in 75.0% of patients overall and 81.3% of those with ICH. Thrombotic events occurred at a rate expected in such patients.


Author(s):  
Joseph Friedli

<p>A critical appraisal and clinical application of Connolly SJ, Milling TJ, Eikelboom JW, et al. Andexanet alfa for acute major bleeding associated with factor Xa inhibitors. <em>N Engl J Med</em>. 2016;375(12):1131-1141. doi: <a href="https://doi.org/10.1056/NEJMoa1607887">10.1056/NEJMoa1607887</a>.</p>


2020 ◽  
Vol 49 (1) ◽  
pp. 301-301
Author(s):  
Gregory Semon ◽  
Angela Straughn ◽  
Claire Hardman ◽  
Barbara Steel ◽  
Akpofure Ekeh

2019 ◽  
Vol 10 ◽  
pp. 204209861988813 ◽  
Author(s):  
Elise Carpenter ◽  
Divita Singh ◽  
Eric Dietrich ◽  
John Gums

Background: Review of clinical data on andexanet alfa for the reversal of factor Xa (FXa) inhibitor associated anticoagulation. Data sources: In the present review, we identified articles via PubMed using the combined keywords andexanet alfa, apixaban, enoxaparin, edoxaban, and rivaroxaban. Additional online searches via PubMed, Google Scholar, and Lexicomp were conducted for both prescribing and cost information. Portola Pharmaceuticals was contacted for information used for United States Food and Drug Administration approval of andexanet alfa. Study selection and data extraction: English-language clinical trials and reviews published between January 2008 and April 2019 were included for review. Bibliographies of selected articles were reviewed manually for relevant publications, focusing on reversal strategies for apixaban, enoxaparin, edoxaban, or rivaroxaban associated anticoagulation using andexanet alfa. Review articles were excluded. Data synthesis: The safety and tolerability of andexanet alfa were evaluated in one phase I, two phase II, and one phase III clinical trials. The use of andexanet alfa for reversing FXa inhibitor-associated anticoagulation were evaluated in the phase III ANNEXA-4 study. Conclusions: Studies evaluating laboratory parameters for coagulation show that andexanet alfa rapidly neutralizes the anticoagulant effects of apixaban, enoxaparin, edoxaban, and rivaroxaban. Clinical studies show that andexanet alfa improves markers related to coagulation, and reverses major bleeding in healthy volunteers and patients with life-threatening bleeding. Interruption of anticoagulation may result in thromboembolic and ischemic events. The use of andexanet alfa requires close monitoring for signs and symptoms of thromboembolic events, ischemic events, and cardiac arrest. Furthermore, anticoagulation should be resumed following the administration of andexanet alfa as soon as medically appropriate.


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