CClinicalTrials.gg
TerminatedNCT04593784Updated Apr 20, 2026Results posted

Study of Ciraparantag for Reversal of Anticoagulation Induced by Edoxaban, Apixaban or Rivaroxaban in Healthy Adults

A Phase 2 interventional study of Ciraparantag and Placebo in Healthy, sponsored by AMAG Pharmaceuticals, Inc.. Terminated at 3 sites in United States. Open to participants aged 18 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-20.

Sponsored by AMAG Pharmaceuticals, Inc. · Phase 2, Interventional, and Treatment

Why this study was terminated
Sponsor decision unrelated to safety
Phase
Phase 2
Study type
Interventional
Enrollment
41
Allocation
Randomized
Ages
18 Years to 75 Years
Sex
All
01

Study summary

A randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of ciraparantag for reversal of anticoagulation induced by different anticoagulant drugs in generally healthy adults as measured primarily by an automated coagulometer device.

Read the detailed description

This is a randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of ciraparantag for reversal of anticoagulation induced by different anticoagulant drugs (edoxaban, apixaban or rivaroxaban) in generally healthy adults. Throughout the study, coagulation status will be determined by whole blood clotting time (WBCT), which will be measured primarily by the Perosphere Technologies' PoC Coagulometer and at selected timepoints using a manual testing method.

The study will be conducted in three separate cohorts; each cohort will evaluate the reversal of a different anticoagulant drug. Within each cohort, an initial group of subjects (Group 1) will be enrolled for evaluation of a target dose of ciraparantag. Depending on the efficacy and safety results from Group 1, a second group (Group 2) may be enrolled to evaluate a different dose of ciraparantag for that cohort.

02

Conditions studied

  • Healthy

Keywords

  • ciraparantag
  • PER977
  • Apixaban
  • Rivaroxaban
  • Whole Blood Clotting Time (WBCT)
  • Coagulometer
  • AMAG 977
  • Edoxaban
03

In context

Lead sponsor

AMAG Pharmaceuticals, Inc. is the lead sponsor of 24 studies on the registry; 2 are open to participants now.

Of its 6 completed or terminated interventional studies of FDA-regulated products, 5 (83%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  1. Provide written informed consent.
  2. 18 to 75 years of age.
  3. Be in generally good health
  4. BMI 18 to 32 kg/m2, inclusive, at Screening.
  5. If female, be surgically sterile or post-menopausal or if of child-bearing potential, using an acceptable method of contraception (other than a combination estrogen/progestin hormonal contraceptive) for at least 1 month prior to Day 1.
  6. If male, be surgically sterile, or agree to use appropriate contraception.
  7. Have suitable venous access for multiple venipunctures.

Exclusion criteria

Exclusion Criteria:

  1. Have any of the following findings at Screening:

    1. Hemoglobin or hematocrit value outside the normal range
    2. Platelet count outside the normal range
    3. PT or aPTT outside the normal range
    4. Plasma fibrinogen outside the normal range
    5. Serum triglycerides or total cholesterol outside the normal range
    6. Serum creatinine >1.5 mg/dL (133 μmol/L) or known renal disease
    7. Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >2 x the upper limit of normal, or known liver disease
    8. Total bilirubin outside the normal range
    9. Positive viral screen for hepatitis B virus, hepatitis C virus (HCV), or human immunodeficiency virus (HIV)
    10. Positive pregnancy test (females)
    11. Positive drug, tobacco or alcohol screen
    12. Any clinically significant findings on 12-lead ECG or urinalysis
  2. Have a personal or family history of clotting disorder or hematologic abnormality.
  3. Have a history of unexplained syncope.
  4. Have a history within 6 months prior to Screening of major bleeding, trauma, surgical procedure of any type, or vaginal delivery
  5. Have a history within 6 months prior to Screening of peptic ulcer or gastrointestinal bleeding.
  6. Have received any blood product or anticoagulant within 3 months prior to Screening.
  7. Have donated blood or blood products within 3 months prior to Screening
  8. Have a history of minor bleeding episodes within 1 month prior to Screening, or a long-standing history of such bleeding.
  9. If female, have a history of excessive or dysfunctional uterine bleeding (unless the subject had a subsequent hysterectomy).
  10. Have used any tobacco or nicotine-containing products within 3 months prior to Screening.
  11. Have used any systemic prescription or non-prescription drugs within 14 days prior to Day 1 (except for permitted contraceptives).
  12. If female, be pregnant, breastfeeding, or planning to become pregnant during the study.
  13. Have received ciraparantag in any prior clinical study.
  14. Have received another investigational drug within 5 half-lives or 30 days, whichever is longer, prior to Day 1.
  15. Known allergy to edoxaban, apixaban or rivaroxaban.
  16. Have any other condition that, in the opinion of the Investigator, would interfere with a subject's ability to adhere to the protocol, interfere with assessment of the investigational product, or compromise the safety of the subject or the quality of the data.
05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Sequential assignment
Masking
Triple (Participant, Care provider, Investigator)
Enrollment
41 participants (actual)

Study arms

  • Experimental
    Cohort 1

    Subjects receive 60 mg edoxaban orally once daily in the morning on Days 1 to 4. On Day 4, approximately 3 hours after administering edoxaban, study drug (ciraparantag or placebo) will be intravenously administered.

    Drug: Ciraparantag · Drug: Placebo · Device: Point-of-Care Coagulometer (investigational device)

  • Experimental
    Cohort 2

    Subjects receive 10 mg apixaban orally every 12 hours on Days 1 to 3, with a final dose in the morning on Day 4. On Day 4, approximately 4 hours after administering apixaban, study drug (ciraparantag or placebo) will be intravenously administered.

    Drug: Ciraparantag · Drug: Placebo · Device: Point-of-Care Coagulometer (investigational device)

  • Experimental
    Cohort 3

    Subjects receive 20 mg rivaroxaban orally once daily in the morning on Days 1 to 4. On Day 4, approximately 4 hours after administering rivaroxaban, study drug (ciraparantag or placebo) will be intravenously administered.

    Drug: Ciraparantag · Drug: Placebo · Device: Point-of-Care Coagulometer (investigational device)

Interventions

  • DrugCiraparantag

    Ciraparantag: 180 mg, intravenous

    Also known as: PER977, AMAG 977

  • DrugPlacebo

    Placebo: 0.9% sodium chloride, intravenous

    Also known as: PBO

  • DevicePoint-of-Care Coagulometer (investigational device)

    Perosphere Technologies' Point of Care (POC) Coagulometer Device will be used to measure whole blood clotting time.

    Also known as: Coagulometer

06

What researchers measure

Primary outcomes

  1. Subjects Achieving WBCT ≤120% of Baseline

    The primary efficacy endpoint is achieving a WBCT (measured by PoC coagulometer) ≤ 120% of baseline within 1 hour after administration of ciraparantag/PBO, which is subsequently sustained after 1 hour through at least 6 hours after ciraparantag/PBO dosing (Responder).

    Time frame: Within 1 hour and sustained through 6 hours

07

Results

Posted Apr 20, 2026

Participant flow

Screening occurred between Oct 2021 and Aug 2023 at 3 phase 1 clinics. Subjects were enrolled into the cohorts listed below (i.e., no participants were enrolled in Cohort 2, Apixaban 10mg).

Participant flow — Overall Study
MilestoneCohort 1 (Edox) PBOCohort 1 (Edox) Cira 180 mgCohort 3 (Riva) Cira 180 mgCohort 3 (Riva) PBO
Started612136
Completed612126
Not completed0010
Withdrew: Randomized, not dosed w ciraparantag, due to not meeting threshold for sufficient anticoagulation0010

Outcome measures

PrimarySubjects Achieving WBCT ≤120% of Baseline

The primary efficacy endpoint is achieving a WBCT (measured by PoC coagulometer) ≤ 120% of baseline within 1 hour after administration of ciraparantag/PBO, which is subsequently sustained after 1 hour through at least 6 hours after ciraparantag/PBO dosing (Responder).

Time frame:
Within 1 hour and sustained through 6 hours
Reported as:
Count of participants · Participants
Subjects Achieving WBCT ≤120% of Baseline
ParticipantsCohort 1 (Edox) Cira 180 mgCohort 1 (Edox) PBOCohort 3 (Riva) Cira 180 mgCohort 3 (Riva) PBO
Subjects Achieving WBCT ≤120% of Baseline0100
Statistical analysis
  • Cohort 1 (Edox) Cira 180 mg vs Cohort 1 (Edox) PBO · Baschloo Test · p = 0.248 · Risk difference (rd): -16.7Risk (Responder) Difference (ciraparantag - placebo) represents the difference in response percentage between treatments. Responders were subjects with non-missing WBCT \<=120% of BL at all time points; all other subjects were deemed a Non-responder.
  • Cohort 3 (Riva) Cira 180 mg vs Cohort 3 (Riva) PBO · Baschloo Test · Risk difference (rd): 0.0Risk (Responder) Difference (ciraparantag - placebo) represents the difference in response percentage between treatments. Responders were subjects with non-missing WBCT \<=120% of BL at all time points; all other subjects were deemed a Non-responder.

Adverse events

Collected over Adverse events were monitored from the time the informed consent was signed through the last study visit / study completion which occurred five days after IP-dosing. Serious Adverse Events were reported through 30 days after the last dose of ciraparantag/placebo.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Cohort 1 (Edox) PBO0/6 (0%)0/6 (0%)0/6 (0%)
Cohort 3 (Riva) PBO0/6 (0%)0/6 (0%)0/6 (0%)
Cohort 1 (Edox) Cira 180 mg0/12 (0%)0/12 (0%)7/12 (58.3%)
Cohort 3 (Riva) Cira 180 mg0/12 (0%)0/12 (0%)3/12 (25%)
Enrolled Not Treated0/4 (0%)0/4 (0%)0/4 (0%)
Most frequent other events
Most frequent other events
EventCohort 1 (Edox) PBOCohort 3 (Riva) PBOCohort 1 (Edox) Cira 180 mgCohort 3 (Riva) Cira 180 mgEnrolled Not Treated
Feeling HotGeneral disorders0/60/62/123/120/4
Infusion site erythemaGeneral disorders0/60/61/120/120/4
ConstipationGastrointestinal disorders0/60/61/120/120/4
Arthropod biteInjury, poisoning and procedural complications0/60/61/120/120/4
Back painMusculoskeletal and connective tissue disorders0/60/61/120/120/4
Musculoskeletal painMusculoskeletal and connective tissue disorders0/60/61/120/120/4
Pain in extremityMusculoskeletal and connective tissue disorders0/60/61/120/120/4
PhlebitisVascular disorders0/60/61/120/120/4
Paraesthesia oralGastrointestinal disorders0/60/60/121/120/4
Abdominal tendernessGastrointestinal disorders0/60/61/120/120/4

Baseline characteristics

Demographic analysis population utilized the Efficacy Population, consisting of 36 subjects randomized and dosed with ciraparantag or placebo.

Age, Continuous
Age, Continuous(Years)Cohort 1 (Edox) PBOCohort 1 (Edox) Cira 180 mgCohort 3 (Riva) PBOCohort 3 (Riva) Cira 180 mgTotal
Mean44.7 ± 15.3845.3 ± 14.4643.5 ± 15.647.0 ± 14.7645.4 ± 14.30
Sex: Female, Male
Sex: Female, Male(Participants)Cohort 1 (Edox) PBOCohort 1 (Edox) Cira 180 mgCohort 3 (Riva) PBOCohort 3 (Riva) Cira 180 mgTotal
Female171413
Male555823
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Cohort 1 (Edox) PBOCohort 1 (Edox) Cira 180 mgCohort 3 (Riva) PBOCohort 3 (Riva) Cira 180 mgTotal
Hispanic or Latino371617
Not Hispanic or Latino355619
Unknown or Not Reported00000
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Cohort 1 (Edox) PBOCohort 1 (Edox) Cira 180 mgCohort 3 (Riva) PBOCohort 3 (Riva) Cira 180 mgTotal
American Indian or Alaska Native00000
Asian01001
Native Hawaiian or Other Pacific Islander00000
Black or African American12418
White5921127
More than one race00000
Unknown or Not Reported00000
Baseline Whole Blood Clotting Time (WBCT) as measured by PoC Coagulometer
Baseline Whole Blood Clotting Time (WBCT) as measured by PoC Coagulometer(seconds)Cohort 1 (Edox) PBOCohort 1 (Edox) Cira 180 mgCohort 3 (Riva) PBOCohort 3 (Riva) Cira 180 mgTotal
Mean235.2 ± 37.69239.0 ± 35.76213.7 ± 30.85235.4 ± 28.52232.9 ± 32.80
08

Study locations

3 sites
  • Qps-Mra, Llc.
    South Miami, Florida 33143, United States
  • Frontage Clinical Services
    Secaucus, New Jersey 07094, United States
  • ICON Early Phase Services, LLC
    San Antonio, Texas 78209, United States
09

References and documents

Study documents

  • Study protocol · Oct 14, 2022
  • Statistical analysis plan · Jul 31, 2024

Documents are hosted by the registry — open the source record to download them.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 20, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT04593784
Lead sponsor
AMAG Pharmaceuticals, Inc.
Collaborators
Ciraparantag Holdings GmbH
Responsible party
Sponsor
First posted
Oct 20, 2020
Start date
Oct 13, 2021
Primary completion
Aug 26, 2023
Completion
Aug 26, 2023
Results posted
Apr 20, 2026
Last update
Apr 20, 2026

Study contacts

Advisor
study director · Apollo Investment Management

Oversight

FDA-regulated drug
Yes
FDA-regulated device
Yes
View the source record on ClinicalTrials.gov ↗

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This study is terminated, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.

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