What is the evidence for using Andexxa (andexanet alfa) vs. Kcentra (4-factor prothrombin complex concentrate [4F-PCC]) for DOAC reversal?

Comment by InpharmD Researcher

According to a 2019 Anticoagulation Forum, Kcentra® (4-factor prothrombin complex concentrate [4F-PCC]) is suitable for factor Xa inhibitor-associated major bleeding if Andexxa® (andexanet alfa) is unavailable. While available literature indicating andexanet alfa is associated with significantly higher rates of hemostasis compared to 4F-PCC, a 2020 cost comparative study showed 4F-PCC is significantly less expensive and is associated with lower rates of thrombosis versus andexanet alfa. A 2021 meta-analysis limited by lack of a control in all identified studies indicated the products have similar efficacy but andexanet alfa-treated patients may have a higher rate of thromboembolic events.

Background

A 2016 guidance statement from the Neurocritical Care Society and the Society of Critical Care Medicine suggest activated charcoal 50 g to intubated intracranial hemorrhage patients presenting within 2 hours of ingestion of an oral factor Xa inhibitor. If the intracranial hemorrhage occurred within 3-4 half-lives of ingestion, then Kcentra® (4-factor prothrombin complex concentrate [4F-PCC]) 50 units/kg or activated PCC (aPCC) 50 units/kg is recommended. However, since Andexxa® (andexanet alfa) was not approved at time of the statement's publication, it was not mentioned in this guideline. [1]

A 2019 guidance document from the Anticoagulation Forum suggests treatment with andexanet alfa in patients with rivaroxaban-associated or apixaban-associated major bleeding in whom a reversal agent is warranted. If andexanet alfa is not available, treatment with 4F-PCC 2,000 units is suggested. Similarly, Praxbind (idarucizumab) 5 g IV is recommended for dabigatran-associated major bleeding and aPCC 50 units/kg IV is suggested if idarucizumab is unavailable. In patients with edoxaban-associated or betrixaban-associated major bleeding in whom a reversal agent is warranted, off-label treatment with either high dose andexanet alfa (800 mg bolus given at 30 mg/min followed by a continuous infusion of 8 mg/min for up to 120 min) or 4F-PCC 2,000 units is suggested. These recommendations come from clinical trials involving andexanet alfa and prospective, cohort studies involving 4F-PCC for reversal of factor Xa-associated major bleeding. While some authors recommend weight‐based dosing of 4F-PCC (50 units/kg) for factor Xa inhibitor reversal, the Anticoagulation Forum prefers a fixed dose of 2000 units because it has been studied in patients with factor Xa inhibitor‐associated bleeding. Additional advantages of fixed dosing include greater simplicity for the ordering provider and pharmacy and reduced cost. [2]

A 2019 meta-analysis, including 10 studies with 340 patients, evaluated the safety and efficacy of 4F-PCC as an alternative for managing major bleeding caused by direct factor Xa (fXa) inhibitor. No comparative studies were found, so the studies selected included only patients who received 4F-PCCs for direct fXa inhibitor-related bleeding. Two studies used the International Society on Thrombosis and Haemostasis (ISTH) to define the effectiveness of major bleeding management, while the other eight did not. In these two studies, 69% (95% CI 0.61 to 0.76) of patients were successfully managed with 4F-PCCs. In the studies that did not use ISTH criteria, 77% (95% confidence interval [CI] 0.63 to 0.92; i^2 85%) of patients were managed. Out of the nine studies that reported mortality, 16% (95% CI 0.07 to 0.26) of patients died during the follow-up period. The authors highlight the limitation of not having a comparator group, but nevertheless suggest 4F-PCC may be a reasonable option for reversal of fXa inhibitor-related bleeding. [3]

A 2021 meta-analysis compared hemostatic effectiveness and thromboembolic event rates between andexanet (n= 396) and PCC (n= 1,428). A pooled proportion of Annexa-4 criteria patients demonstrated a hemostatic effectiveness of 0.82 (95% CI, 0.78‐0.87) in andexanet studies and 0.85 (95% CI, 0.80‐0.90) in PCC. Thromboembolic events were 0.11 (95% CI, 0.04‐0.18) in andexanet studies and 0.03 (95% CI, 0.02‐0.04) in PCC. The authors concluded the products have similar efficacy but andexanet-treated patients may have a comparatively higher rate of thromboembolic events. The study was limited by lack of a control in all identified studies which limits pooled comparison. [4]

A 2020 cost comparative study predicted the cost of andexanet alfa would exceed the national average hospital reimbursement/patient in nearly 75% of patients by over USD $7,500 per hospitalization. The authors concluded 4F-PCC was significantly less expensive, had lower rates of thrombosis, but also lower rates of hemostasis compared to published data for andexanet alfa. [5]

References:

[1] Frontera JA, Lewin JJ, Rabinstein AA, et al. Guideline for Reversal of Antithrombotics in Intracranial Hemorrhage: Executive Summary. A Statement for Healthcare Professionals From the Neurocritical Care Society and the Society of Critical Care Medicine. Crit Care Med. 2016;44(12):2251-2257.
[2] Cuker A, Burnett A, Triller D, et al. Reversal of Direct Oral Anticoagulants: Guidance from the Anticoagulation Forum. Am J Hematol. 2019;94(6):679-709.
[3] Piran S, Khatib R, Schulman S, et al. Management of direct factor Xa inhibitor-related major bleeding with prothrombin complex concentrate: a meta-analysis. Blood Adv. 2019;3(2):158–167.
[4] Jaspers T, Shudofsky K, Huisman MV, Meijer K, Khorsand N. A meta-analysis of andexanet alfa and prothrombin complex concentrate in the treatment of factor Xa inhibitor-related major bleeding. Res Pract Thromb Haemost. 2021;5(4):e12518. Published 2021 May 24. doi:10.1002/rth2.12518
[5] Frontera JA, Bhatt P, Lalchan R, et al. Cost comparison of andexanet versus prothrombin complex concentrates for direct factor Xa inhibitor reversal after hemorrhage. J Thromb Thrombolysis. 2020;49(1):121-131. doi:10.1007/s11239-019-01973-z

Literature Review

A search of the published medical literature revealed 8 studies investigating the researchable question:

What is the evidence for using Andexxa (andexanet alfa) vs. Kcentra (4-factor prothrombin complex concentrate [4F-PCC]) for DOAC reversal?

Level of evidence

C - Multiple studies with limitations or conflicting results  Read more→



Please see Tables 1-8 for your response.


 

Real-world management of oral factor Xa inhibitor-related bleeds with reversal or replacement agents including andexanet alfa and four-factor prothrombin complex concentrate: a multicenter study

Design

Retrospective, multi-center study

N= 1,075

Objective

To describe the real-world utilization and outcomes associated with managing oral factor Xa inhibitor (FXai)-related major bleeds

Study Groups

Andexanet alfa (n= 342)

4F-PCC (n= 733)

Inclusion Criteria

Hospitalized adult patients for FXai-related bleeding, indicative of bleeding due to extrinsic factors at the time of inpatient admission or during the hospital stay

Exclusion Criteria

N/A

Methods

Patient data from electronic health records from 45 U.S. hospitals were collected for analysis. The study included different agents used to reverse FXai. For the purpose of the table, only the results from andexanet alfa and 4F-PCC were included.

Duration

Data collection period: January 2016 to September 2019

Outcome Measures

In-hospital mortality due to all bleed types and stratified by gastrointestinal bleed, intracranial hemorrhage, critical compartment, trauma, and other bleeds; median length of stay in the hospital and intensive care unit (ICU)

Baseline Characteristics

 

Andexanet alfa (n= 342)

4F-PCC (n= 733)

Age, years

69.1 70.1

Female

154 (45%) 364 (50%)

FXa inhibitor

Apixaban

Edoxaban

Rivaroxaban

Other

 

47%

3%

50%

0

 

51%

8%

41%

0

Bleed type

Gastrointestinal

Intracranial hemorrhage

Critical compartment

Traumatic

Other

 

40%

20%

3%

31%

6%

 

41%

23%

29%

4%

3%

Results

Endpoint

Andexanet alfa (n= 342)

4F-PCC (n= 733)

In-hospital mortality due to all bleed types

GI bleed

Intracranial hemorrhage

Critical compartment

Trauma

Other bleeds

 

12 (4%)

2/137 (1%)

6/67 (9%)

0/11

4/105 (4%)

0/22

 

74 (10%)

12/303 (4%)

43/170 (25%)

1/26 (4%)

16/214 (7%)

2/20 (10%)

Median length of stay, days

5 5

ICU length of stay, days

2 3

Adverse Events

Not disclosed

Study Author Conclusions

In-hospital mortality differed by bleed type and agents administered. Andexanet alfa was associated with the lowest rate of in-hospital mortality across all bleed types.

InpharmD Researcher Critique

The baseline characteristics were sparse and did not capture the previous medical/prescription history nor longitudinal outcomes of the patients after discharge. There could be confounders that influenced the results. Andexanet alpha was approved in May 2018 which limited the data collection period compared to 4F-PCC.



References:

Coleman CI, Dobesh PP, Danese S, Ulloa J, Lovelace B. Real-world management of oral factor Xa inhibitor-related bleeds with reversal or replacement agents including andexanet alfa and four-factor prothrombin complex concentrate: a multicenter study. Future Cardiol. 2021;17(1):127-135. doi:10.2217/fca-2020-0073

 

Andexanet alfa and four‐factor prothrombin complex concentrate for reversal of apixaban and rivaroxaban in patients diagnosed with intracranial hemorrhage

Design

Retrospective, single-center, case series

N= 56

Objective

To evaluate clinical outcomes of four‐factor prothrombin complex concentrate (4F-PCC) and andexanet alfa for the reversal of intracranial hemorrhage (ICH) associated with oral factor Xa inhibitors

Study Groups

Andexanet alfa (n= 21)

4F-PCC (n= 35)

Inclusion Criteria

Age ≥ 18 years; diagnosed with ICH; anticoagulated with apixaban or rivaroxaban prior to presentation; received either andexanet alfa or 4F-PCC 

Exclusion Criteria

Received either andexanet alfa or 4F-PCC for non-ICH indication; reversal of anticoagulants other than apixaban or rivaroxaban; received both andexanet alfa and 4F-PCC; or received alternative dosing of 4F-PCC

Methods

Eligible patients received either andexanet alfa or 4F-PCC in either the Emergency Department or Neuroscience Intensive Care Unit (ICU). Based on provider consensus (when the factor Xa inhibitor drug, dose, and/or timing of the last dose is unknown), if rivaroxaban level returns as > 0.15 ug/mL or an apixaban level > 200 ng/mL, then an additional low dose bolus is ordered, and infusion rate is increased to match the high-dose regimen of andexanet alfa.

Duration

Andexanet alfa: July 1, 2018 to September 1, 2019

4F-PCC: July 1, 2013 to September 1, 2019

Outcome Measures

Hematoma expansion, 30-day all-cause mortality, time from presentation to the administration of reversal agent, ICU length of stay, hospital length of stay, and 30-day readmission rate

Baseline Characteristics

 

Andexanet alfa (n= 21)

4F-PCC (n= 35)

Age, years

73.29 ± 11.97 74.51 ± 13.37

Male

15 (71.4%) 14 (40.0%)

White

17 (80.9%) 28 (80.0%)

DOAC

Apixaban

Rivaroxaban

 

14 (66.7%)

7 (33.3%)

 

20 (57.1%)

15 (42.9%)

Timing of last DOAC dose

< 8 h

≥ 8 h to < 18 h

≥ 18 h

 

4 (19.0%)

6 (28.6%)

6 (28.6%)

 

1 (2.9%)

6 (17.1%)

1 (2.9%)

Apixaban dosing

2.5 mg BID

5 mg BID

10 mg BID

 

4 (19.0%)

10 (47.6%)

 

8 (22.9%)

11 (31.4%)

1 (2.9%)

Rivaroxaban dosing

15 mg once daily

15 mg BID

20 mg once daily

 

1 (4.8%)

6 (28.6%)

 

2 (5.7%)

1 (2.9%)

11 (31.4%)

Admission laboratory results (interquartile range [IQR])

Apixaban assay level, ng/mL

Rivaroxaban assay level, μg/mL

Prothrombin time, seconds

INR

Activated partial thromboplastin time, seconds

Platelets (×109/L)

 

104 (88.5 to 149.5)

0.16 (0.10 to 0.24)

14.4 (13.0 to 15.7)

1.2 (1.1 to 1.3)

30.2 (27.5 to 34.2)

213 (151 to 272)

 

 43 (41.5 to 44.5)

0.21 (0.16 to 0.26)

14.3 (13.4 to 17.0)

1.2 (1.2 to 1.5)

29.2 (26.6 to 32.0)

226 (200 to 268)

Hemorrhage location

Intracerebral

Subdural

Subarachnoid

Multicompartmental

 

17 (81.0%)

2 (9.5%)

2 (9.5%)

 

18 (51.4%)

1 (2.9%)

6 (17.1%)

10 (28.6%)

Dosing

Andexanet alfa

400 mg IV bolus + 480 mg infusion

800 mg IV bolus + 960 mg infusion

4F-PCC

Units

Units/kg

 

 

20 (95.2%)

1 (4.8%)

 

-

-

 

 

-

-

 

3,920.34 ± 940.48

48.25 ± 4.41

 

Results

Endpoint

Andexanet alfa (n= 21)

4F-PCC (n= 35)

Hematoma expansion

Yes

No

 

6 (35.3%)

11 (64.7%)

 

14 (45.2%)

17 (54.8%)

30-day all-cause mortality

6 (30.0%)  14 (45.2%)

Time from presentation to the administration of reversal agent, hours (IQR)

2.67 (1.75 to 4.13)

1.73 (1.21 to 3.55)

Length of stay, days (IQR)

ICU 

Hospital

 

3.78 (2.54 to 6.69)

7.75 (4.64 to 15.87)

 

2.29 (1.37 to 5.83)

5.02 (2.72 to 8.56)

30-day readmission

 2/18 (11.1%) 2/22 (9.1%)
 

Adverse Events

Refer to the results section

Study Author Conclusions

In this cohort, patients with ICH anticoagulated with apixaban or rivaroxaban, hemostatic efficacy rates differed between andexanet alfa and 4F-PCC. Additionally, 4F-PCC was found to have a higher rate of thrombotic events and mortality compared to andexanet alfa in this cohort of patients.

InpharmD Researcher Critique

This study is subject to limitations inherent to retrospective analysis, single-center, observational nature and historical bias. Additionally, patients receiving 4F-PCC were noted to have a lower GCS on admission and a high ICH score, thus limiting the ability to perform a direct comparison of the two reversal agents.



References:

Vestal ML, Hodulik K, Mando-Vandrick J, et al. Andexanet alfa and four-factor prothrombin complex concentrate for reversal of apixaban and rivaroxaban in patients diagnosed with intracranial hemorrhage [published online ahead of print, 2021 Jun 8]. J Thromb Thrombolysis. 2021;10.1007/s11239-021-02495-3. doi:10.1007/s11239-021-02495-3

 

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

Design

Retrospective cohort study

N= 32

Objective

To compare hemostatic efficacy and safety outcomes between andexanet alfa and 4F-PCC for reversal of FXa-inhibitor-related bleeding

Study Groups

Andexanet alfa (n= 16)

4F-PCC (n= 16)

Inclusion Criteria

Age > 18 years, received andexanet alfa for apixaban or rivaroxaban reverse for major bleeding events

Exclusion Criteria

Patients presenting after June 28, 2018

Methods

This study collected patients who received andexanet alfa for the reversal of factor-Xa inhibitors and compared it with records of patients who have received 4F-PCC in the past (for a separate purpose). The patients selected from the 4F-PCC records were random until an equivalent number of andexanet alfa patients was achieved.

The cut-off point of June 28, 2018, was to limit selection bias during a period where both products are available. Hemostasis was defined based on the ANNEXA-4 study definitions, classifying as excellent, good, or poor.

Duration

Data collection period: June 2018 to August 2020

Outcome Measures

Primary: difference in the achievement of excellent or good hemostasis within 12 hours of andexanet alfa administration versus 4F-PCC

Baseline Characteristics

 

Andexanet alfa (n= 16)

4F-PCC (n= 16)

 

Age, years

69.1 ± 9.4 69.0 ± 17.2  

Male

8 (50.0%)

11 (68.8%)

 

Primary indication for anticoagulation

Myocardial infarction

Stroke

Deep vein thrombosis

Heart failure

Diabetes

 

3 (18.8%)

0

5 (31.3%)

4 (25.0%)

3 (18.8%)

 

1 (6.3%)

3 (18.8%)

1 (6.3%)

6 (37.5%)

5 (31.3%)

 

DOAC received

Apixaban

Rivaroxaban

 

11 (68.8%)

5 (31.3%)

 

7 (43.8%)

9 (56.3%)

 

Site of bleeding

Intracranial

Nonintracranial

 

7 (43.8%)

9 (56.3%)

 

10 (62.5%)

6 (37.5%)

 

Results

Endpoint

Andexanet alfa (n= 16)

4F-PCC (n= 16)

p-value

Effective hemostasis overall

Excellent

Good

Poor

12 (75.0%)

10 (62.5%)

2 (12.5%)

4 (25.0%)

10 (62.5%)

10 (62.5%)

0

6 (37.5%)

0.70

-

-

-

Effective hemostasis for ICH

Excellent

Good

Poor

4/7 (57.1%)

3/7 (42.9%)

1/7 (14.3%)

3/7 (42.9%)

7/10 (70.0%)

7/10 (70.0%)

0

3/10 (30.0%)

0.64

-

-

-

Effective hemostasis for non-ICH

Excellent

Good

Poor

8/9 (88.9%)

6/9 (66.7%)

2/9 (22.2%)

1/9 (11.1%)

3/6 (50.0%)

3/6 (50.0%)

0

3/6 (50.0%)

0.24

-

-

-

Five patients were lost to follow-up due to thromboembolic complications or death (one in the andexanet alfa group and four in the 4F-PCC group). Their last observation was carried forward.

Adverse Events

Thrombotic events were not statistically different between andexanet alfa (25%) and 4F-PCC (18.8%).

Study Author Conclusions

Andexanet alfa and 4F-PCC both achieved effective hemostasis in a majority of the patients. However, both groups also had a high incidence of thromboembolic events. A small sample size, co-administration of other procoagulants, and delay in restarting anticoagulation may have contributed to thromboembolic risk.

InpharmD Researcher Critique

Patients in the 4F-PCC group were randomly chosen from a previous set of data. For a retrospective study, the results would have been strengthened by matching patients with certain baseline stats.



References:

Stevens VM, Trujillo TC, Kiser TH, MacLaren R, Reynolds PM, Mueller SW. Retrospective Comparison of Andexanet Alfa and 4-Factor Prothrombin Complex for Reversal of Factor Xa-Inhibitor Related Bleeding. Clin Appl Thromb Hemost. 2021;27:10760296211039020. doi:10.1177/10760296211039020

 

Andexanet Alfa Versus 4-Factor Prothrombin Complex Concentrate for Reversal of Factor Xa Inhibitors in Intracranial Hemorrhage

Design

Retrospective review

N= 44

Objective

To describe theexperience with andexanet alfa (AA) or four-factor prothrombin complex concentrate (4F-PCC) in patients with oral reverse factor Xa inhibitors (FXi)-related traumatic and spontaneous intracranial hemorrhage (ICH)

Study Groups

Andexanet alfa (n= 28)

4F-PCC (n= 16)

Inclusion Criteria

Patients with life-threatening traumatic or spontaneous intraparenchymal, subarachnoid, subdural hemorrhages, and other intracranial bleeds after receiving apixaban or rivaroxaban; treated with at least one dose of AA or 4F-PCC

Exclusion Criteria

Received both AA and 4F-PCC

Methods

Patients that required reversal of FXi received either AA dosed according to the product labeling for life-threatening bleeding associated with factor Xa inhibitors or 4F-PCC dosed with 25 units/kg up to 2,500 units per dose.

Duration

Data collection period: July 2018 to April 2019

Outcome Measures

Primary: ICH stability based on head computer tomography scans (CT) were defined as similar amount of blood from the initial scan at the onset of ICH to subsequent scans at 6 and 24 hours of treatment

Baseline Characteristics

 

Andexanet alfa (n= 28)

4F-PCC (n= 16)

p-value

Age, years

78 80 0.88

Female

11 (39%) 5 (31%) 0.84

White

24 (86%) 13 (81%) 0.84

Past medical history

Atrial fibrillation

Myocardial infarction

Stroke

 

20 (71%)

8 (29%)

8 (29%)

 

10 (62%)

1 (6%)

1 (6%)

 

0.74

0.12

0.12

Anticoagulant received

Apixaban

Rivaroxaban

 

19 (68%)

9 (32%)

 

12 (75%)

4 (25%)

 

0.74

0.74

Hemorrhage type

Spontaneous intracranial hemorrhage

Traumatic intracranial hemorrhage

 

20 (71%)

8 (29%)

 

8 (50%)

8 (50%)

0.20

Results

Endpoint

Andexanet alfa (n= 28)

4F-PCC (n= 16)

p-value

ICH stability based on CT scan

6 hours

24 hours

 

78%

88%

 

71%

60%

 

0.71

0.15

Incidence of thromboembolic events

7% 0 0.53

Study Author Conclusions

In this limited sample of patients, no difference was found in neuroimaging stability, functional outcome, and thrombotic events when comparing AA and 4F-PCC in patients with FXi-related ICH. Since the analysis is likely underpowered, a multi-center collaborative network devoted to this question is warranted.

InpharmD Researcher Critique

As mentioned, the small sample size likely leads to an underpowered result which remains speculatory at best. The p-value may be reporting false negatives despite the potential for andexanet alfa to be more beneficial to 4F-PCC as seen in the results.



References:

Ammar AA, Ammar MA, Owusu KA, et al. Andexanet Alfa Versus 4-Factor Prothrombin Complex Concentrate for Reversal of Factor Xa Inhibitors in Intracranial Hemorrhage. Neurocrit Care. 2021;35(1):255-261. doi:10.1007/s12028-020-01161-5

 

Evaluation of andexanet alfa and four-factor prothrombin complex concentrate (4F-PCC) for reversal of rivaroxaban- and apixaban-associated intracranial hemorrhages

Design

Retrospective, single-center case series

N= 29

Objective

To evaluate the clinical and hemostatic outcomes of patients with oral FXa inhibitor-associated intracranial hemorrhage (ICH) treated with andexanet alfa or 4F-PCC and describe the operational procedures associated with each therapeutic agent

Study Groups

Andexanet alfa (n= 18)

4F-PCC (n= 11)

Inclusion Criteria

Age ≥ 18 years; on rivaroxaban or apixaban therapy at baseline; received andexanet alfa (Andexxa) or 4F-PCC (Kcentra) for reversal of ICH

Exclusion Criteria

Received andexanet alfa or 4F-PCC antithrombotic reversal for any reason other than reversal for ICH

Methods

Consecutive patients, using a medication dispense report, who received andexanet alfa or 4F-PCC for rivaroxaban- and apixaban-associated traumatic or spontaneous ICH admitted to a Level 1 trauma center. Andexanet alfa was administered to patients meeting eligibility criteria for ANNEXA-4 clinical trial enrollment or to patients presenting with an acute ICH with last known administration of apixaban or rivaroxaban within 18 hours.

4F-PCC was dosed 25 to 50 units/kg, dosed per treating clinician discretion, with a maximum dose of 5000 units. The low-dose andexanet alfa regimen was 400 mg intravenous bolus administered over 15 minutes followed by 480 mg infused over 2 hours while the high-dose andexanet alfa regimen was 800 mg intravenous bolus over 30 minutes followed by 960 mg infused over two hours. Re-treatment with andexanet alfa was not recommended.

Duration

April 1, 2016 to April 30, 2019

Outcome Measures

Primary: percentage of patients with good or excellent hemostasis on repeat imaging within 24 hours of antithrombotic

Secondary: incidence of good functional outcome at hospital discharge (defined as a Glasgow Outcome Score [GOS]> 3); the incidence of thromboembolic events within 30 days

Baseline Characteristics

 

4F-PCC (n= 11)

Andexanet alfa (n= 18)

Age (range), years

71.0 (68.6 to 73.2) 83.4 (70.3 to 88.8)

Female

2 (18.2%) 8 (44.4%)

Creatine clearance (range), ml/min

56.7 (37.8 to 72.3) 52.8 (30.7 to 77.5)

Liver disease

1 (9.1%) 2 (11.1%)

Apixaban use at baseline

Dose (range), mg/day

Time since last dose, hours

< 8 

8-18 

> 18 

3 (27.3%)

10 (5 to 10)

 

1 (33.3%)

1 (33.3%)

1 (33.3%)

15 (83.3%)

5 (5 to 10)

 

5 (33.3%)

4 (26.7%)

Rivaroxaban use at baseline

Dose (range), mg/day

Time since last dose, hours

< 8 

8-18 

> 18 

8 (72.7%)

20 (20 to 20)

 

1 (12.5%)

0

3 (37.5%)

3 (16.7%)

15 (10 to 20)

 

1 (33.3%)

0

0

Concurrent antiplatelet therapy

Aspirin

P2Y12 inhibitor

Dual antiplatelet therapy

 

4 (36.4%)

0

0

 

3 (16.7%)

2 (11.1%)

0

Coagulation parameters on presentation

PT, seconds

PTT, seconds

INR

Platelets, K/μL

 

16.5 (15 to 18.8)

30.3 (26.5 to 32.3)

1.4 (1.2 to 1.6)

197 (180 to 262)

 

14.8 (14 to 16.3)

33.2 (27.3 to 38.9)

1.2 (1.1 to 1.3)

175 (127 to 222) 

Prothrombin complex concentrate

Dose, units/kg

Dose, units

11 (100%)

26.9 (21.8 to 43.7)

2,500 (2,364 to 3,231)

1 (5.6%)

9.4

500

Andexaanet alfa

High dose regimen

Low dose regimen

 

-

-

 

0

18 (100%)

 

Results

Endpoint

4F-PCC (n= 11)

Andexanet alfa (n= 18)

Hemostatic effectiveness

Excellent

Good

Poor

 

6 (60.0%)

0

4 (40.0%)

 

14 (77.8%)

2 (11.1%)

2 (11.1%)

Discharge functional status

Glasgow Outcome Score (range)

 

1 (1 to 3)

 

4 (3 to 4)

Incidence of new thrombosis

1 (9.1%)

3 (16.7%)

 

Adverse Events

N/A

Study Author Conclusions

Higher rates of occurrence of good or excellent hemostasis and GOS > 3 were observed on hospital discharge and increased incidence of thrombosis in patients who received andexanet alfa compared to 4F-PCC for oral factor Xa inhibitor reversal. However, patients receiving 4F-PCC had lower pre-reversal Glasgow Coma Scale (GCS) scores and larger pre-reversal ICH volume.

InpharmD Researcher Critique

Since this study was limited based on the retrospective nature, single-center design and a small heterogenous patient population of both traumatic and spontaneous hemorrhage, a direct comparison of treatments was not possible. Additionally, patients who received 4F-PCC at an outside hospital and then transferred to the institution were not taken into consideration. 



References:

Barra ME, Das AS, Hayes BD, et al. Evaluation of andexanet alfa and four-factor prothrombin complex concentrate (4F-PCC) for reversal of rivaroxaban- and apixaban-associated intracranial hemorrhages. J Thromb Haemost. 2020;18(7):1637-1647. doi:10.1111/jth.14838

 

Safety, efficacy, and cost of four-factor prothrombin complex concentrate (4F-PCC) in patients with factor Xa inhibitor-related bleeding: a retrospective study

Design

Retrospective, cohort study

N= 31

Objective

To assess the safety and efficacy of 4F-PCC for the management of major bleeding related to oral factor Xa (fXa) inhibitors

Study Groups

4F-PCC (n= 31)

Methods

Inclusion criteria: >18 years, received 4F-PCC (Kcentra) for fXa inhibitor-related major bleeding

Exclusion criteria: pregnancy, incarceration, perioperative reversal unrelated to bleeding

Patients received 4F-PCC (Kcentra) 25-50 units/kg of actual body weight (max dose 5,000 units) per an institutional protocol from a hospital in South Carolina. Additional doses to achieve hemostasis were given at the provider's discretion.

Duration

July 2014 to May 2018

Outcome Measures

Effectiveness of 4F-PCC for the management of fXa inhibitor-related major bleeding, incidence of thromboembolism, length of stay, mortality, cost analysis comparing 4F-PCC to andexanet alfa for reversal of oral fXa inhibitors

Baseline Characteristics  

4F-PCC (n= 31)

Age, years

74

Men

23 (74.2%) 

Race

White

African American

 

28 (90.3%)

3 (9.7%)

Leading indication for reversal

Intracranial hemorrhage

Pericardial

 

18 (58%)

5 (16.1%)

Factor Xa inhibitors involved

Apixaban 

Rivaroxaban

 

17 (54.8%)

14 (45.2%)

Results

 

4F-PCC (n=31)

Dose of 4F-PCC, units

Needed repeat doses

3,070 ± 1,225

2 (6.5%)

Hemostatic effectiveness

25 (80.6%)

Thrombotic events

0

Length of ICU stay, days

2.6

In-hospital mortality

5 (16.1%)

Based on this population and the average wholesale price (AWP) of Kcentra being $1.62 per unit, the mean cost for reversal would be $4,973. If an additional 500 units were required for hemostasis, leading to an additional cost of $810, this would result in a total cost of $5,783.

Based on the current AWP of $3,300 per 100 mg, andexanet alfa costs $29,040 for the low dose regimen and $58,080 for the high dose regimen. This presents a cost difference of about $53,107 between the therapies.

Adverse Events

Serious adverse events: pericardial tamponade (9.7%), intracranial bleeding (6.5%), intrathoracic bleeding (3.2%)

Study Author Conclusions

Administration of 4F-PCC was effective for most patients requiring emergent reversal of anticoagulation with apixaban or rivaroxaban and was associated with a low risk of thromboembolic events.

Considerable cost differences limit the use of andexanet alfa and may warrant further study of 4F-PCC for fXa inhibitor reversal.

InpharmD Researcher Critique

Some of the limitations are based on Caucasian and African American patients, small sample size, and lack of comparator arms of a retrospective study. Only half of the patients received the recommended 50 units/kg dose of 4F-PCC. Lastly, the definition of major bleeding was derived from an institutional protocol for anticoagulation reversal and used any blood product administration.



References:

Smith MN, Deloney L, Carter C, Weant KA, Eriksson EA. Safety, efficacy, and cost of four-factor prothrombin complex concentrate (4F-PCC) in patients with factor Xa inhibitor-related bleeding: a retrospective study. J Thromb Thrombolysis. 2019;48(2):250-255.

 

Reversal of dabigatran-associated major bleeding with activated prothrombin concentrate: A prospective cohort study

Design

Prospective, multicenter, observational, cohort study

N= 14

Objective

To evaluate the safety and effectiveness of aPCC at a dose of 50 units/kg for reversal of major bleeding on dabigatran

Study Groups

aPCC (n= 14)

Supportive care (n= 28)

Methods

Inclusion criteria: acute and active major bleeding due to dabigatran administration, treated with aPCC

Exclusion criteria: Do Not Resuscitate (DNR) orders given based on the severity of the bleeding, drop in hemoglobin without evidence of source of bleeding, ACS or ischemic stroke within 30 days

Participants were given aPCC (FEIBA®) 50 units/kg per hospital protocol at health systems in Canada. A second dose of the same amount of aPCC could be given after 1 h in case of lack of improvement. 

This prospective group was compared to a historical cohort who received supportive care at a ratio of 1:2.

Duration

Follow-up: 30 ± 2 days

Outcome Measures

Effectiveness, transfusions, length of stay

Baseline Characteristics

 

aPCC (n= 14)

Supportive care (n= 28)

 

Age, years

79 ± 8.1 79 ± 8.1  
Male 11 (79%) 18 (64%)  
Weight, kg 82 83  
Time since last dabigatran dose, hours 15.5 N/A  

Bleeding type

Intracranial

Gastrointestinal

 

5 (36%)

3 (21%)

 

10 (36%)

10 (36%)

 

Trauma-related bleeding

6 (43%)

5 (18%)

 

Results

 

aPCC (n=14)

Supportive care (n=28) P-value

Primary effectiveness*

Good

Moderate

Poor

 

9 (63%)

5 (36%)

0

 

16 (57%)

4 (14%)

8 (29%)

0.037

 

 

 

Transfusions, median units (range)

Red blood cells

Fresh frozen plasma

 

0.5 (0-4)

0 (0)

 

2.0 (0-7)

0 (0-6)

0.58

 

 

Length of stay, days (range)

6 (1-11)

5.5 (0-27)

0.76

*A standardized Assessment Guide was used for this study by remote, independent adjudicators using standardized case narratives and general instructions for assessment for the historic matched cases.

Adverse Events

Thromboembolism occurred in one patient (4%) of the supportive care group.

Study Author Conclusions

Although supportive care is sufficient to manage many patients with dabigatran-associated bleeding, aPCC might provide an additional benefit to control life-threatening bleeding in selected cases and does not appear to cause an excess of thromboembolic events.

InpharmD Researcher Critique

A limitation of this study is the small sample size of only 14 patients within 2.5 years. The study was also cut short due to the approval and availability of Praxbind, which is another reason the sample size is smaller than anticipated.

During the study, a protocol required approval for aPCC infusion required by the physician on call for Thrombosis or Transfusion, so cases that could be safely managed with supportive therapies did not receive aPCC.



References:

Schulman S, Ritchie B, Nahirniak S, et al. Reversal of dabigatran-associated major bleeding with activated prothrombin concentrate: A prospective cohort study. Thromb Res. 2017;152:44-48.

 

Full study report of Andexanet Alfa for Bleeding Associated with Factor Xa inhibitors

Design

Multicenter, prospective, open-label, single-group cohort study

N= 352

Objective

To assess the efficacy and safety of andexanet alfa in patients with acute major bleeding occurring while taking a factor Xa inhibitor

Study Groups

Andexanet alfa safety cohort (N= 352)

Efficacy cohort (n= 254)

Methods

Inclusion criteria: at least 18 years of age; presented with acute major bleeding; received apixaban, rivaroxaban, edoxaban, or enoxaparin within 18 hours

Exclusion criteria: planned surgery within 12 hours after andexanet treatment; intracranial hemorrhage in a patient with a score of less than 7 on the Glasgow Coma Scale or an estimated hematoma volume of more than 60 mL; expected survival of less than 1 month; the occurrence of a thrombotic event within 2 weeks before enrollment; use of any of the following agents within the previous 7 days: vitamin K antagonist, dabigatran, prothrombin complex concentrate, recombinant factor VIIa, whole blood, or plasma

Patients received a bolus of andexanet over 15-30 minutes, followed by a 2-hour infusion.

Safety analyses included all the patients who had received andexanet. The efficacy analysis population included only patients who retrospectively met both of two criteria: baseline anti-factor Xa activity of at least 75 ng/mL (or ≥0.25 IU/mL for patients receiving enoxaparin) and confirmed major bleeding at presentation.

Duration

Follow-up: at least 30 days after andexanet treatment or until death

Outcome Measures

Percent change in anti-factor Xa activity after andexanet treatment, the percentage of patients with excellent or good hemostatic efficacy at 12 hours after the end of the infusion.

Safety outcomes: death, thrombotic events

Baseline Characteristics

 

Andexanet alfa safety cohort (N= 352)

Efficacy cohort (n= 254)

Age, years

77.4 ± 10.8 77 ± 11.1

Male 

187 (53%) 129 (51%)

White

307 (87%) 222 (87%)

Baseline medical history

Myocardial infarction

Stroke

Deep vein thrombosis

 

48 (14%)

69 (20%)

67 (19%)

 

36 (14%)

57 (22%)

53 (21%) 

Primary indication for anticoagulation

Atrial fibrillation

 

280 (80%)

 

201 (79%)

Factor Xa inhibitors

Rivaroxaban (median daily dose 20mg)

Apixaban (median daily dose 10mg)

Edoxaban (daily dose 30 mg and 60 mg) 

Enoxaparin 

 

128 (36%)

194 (55%)

10 (3%)

20 (6%)

 

100 (39%) 

134 (53%)

4 (2%)

16 (6%)

Primary site of bleeding

Intracranial 

Gastrointestinal

 

227 (64%)

90 (26%)

 

171 (67%)

62 (24%)

Results

  Andexanet alfa safety cohort (N= 352)

Efficacy cohort (n= 254)

Antifactor-Xa activity reduction (%)

Rivaroxaban 

Apixaban

Enoxaparin

 

N/A

N/A

N/A

 

92%

92% 

75% 

Hemostatic efficacy

Eligible for hemostatic efficacy

Exellent hemastatic efficacy at 12 hours

Good hemastatic efficacy at 12 hours

 

N/A

N/A

N/A

 

249 (98%)

171 (69%)

33 (16%)

Adverse Events

Thrombotic event within 30 days: 34 (10%)

Death within 30 days: 49 (14%)

Study Author Conclusions

In patients with acute major bleeding associated with the use of a factor Xa inhibitor, treatment with andexanet markedly reduced anti-factor Xa activity, and 82% of patients had excellent or good hemostatic efficacy at 12 hours, as adjudicated in patients with intracranial hemorrhage.

InpharmD Researcher Critique

A decrease in anti-factor Xa activity and hemostatic efficacy in the patients with intracranial hemorrhage was observed in the study; however, this relationship is not robust as the measurement of a change in anti-factor Xa activity is not likely to be useful for the prediction of clinical response in clinical practice.

Also, the most important limitation of this trial is that it did not include a randomized comparison with a control group and used an open-label design.



References:

Connolly SJ, Crowther M, Eikelboom JW, et al. Full Study Report of Andexanet Alfa for Bleeding Associated with Factor Xa Inhibitors. N Engl J Med. 2019;380(14):1326-1335.