Phase 2 Study of Rivaroxaban Reversal by Ciraparantag as Measured by WBCT

Phase 2 Placebo-Controlled, Single-Site, Single-Blind Study of Rivaroxaban Reversal by Ciraparantag as Measured by WBCT

This study is a randomized, single-blind, placebo-controlled study to assess the efficacy and safety of ciraparantag administered to healthy volunteers anticoagulated with rivaroxaban measuring clotting times using Whole Blood Clotting Time (WBCT).

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Drug: Ciraparantag; Drug: Placebo; Drug: Rivaroxaban

Detailed Description

This is a randomized, single-blind, placebo-controlled assessment of the efficacy and safety of ciraparantag administered to healthy volunteers measuring clotting times using WBCT as determined by the manual testing method. All subjects will undergo screening up to 36 days prior to enrollment.

All enrolled subjects are to receive a single dose of 20 mg rivaroxaban in the morning on Days 1-3. On Day 3 (3.75 hours post rivaroxaban), subjects who have a minimum increase in clotting time of 25% (as measured by WBCT) are randomized and will receive a single IV dose 4 hours after the rivaroxaban dose, followed by serial testing of manual WBCT.

Subjects are enrolled sequentially in up to 4 ciraparantag dose cohorts. There will be a safety review after completion of treatment in one cohort and prior to initiation of treatment in the subsequent cohort.

• Study Type: Interventional
• Enrollment (Actual): 69
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • New Jersey
    • Secaucus, New Jersey, United States, 07094
      • Frontage Clinical Services Inc.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

General Inclusion Criteria:

1. Adults age 50 to 75 years
2. Laboratory tests (chemistry, hematology and coagulation assessments) and urinalysis performed during screening up to 36 days prior to administration of study treatment deemed not clinically significant by the principal investigator.
3. No clinically significant findings on 12-lead electrocardiogram (ECG) performed during screening
4. Body mass index (BMI) 18 to ≤ 32 kg/m2, inclusive
5. Male subjects agree to use appropriate contraception in addition to their partner using an acceptable form of contraception, when engaging in sexual activity during the course of the study. Moreover, male subjects should not donate sperm or attempt to impregnate a partner during the course of the study and for a period of 12 weeks following discharge from the study.
6. Female subjects must have a negative urine pregnancy test at screening AND: be surgically sterile OR postmenopausal for the last three months, OR in a monogamous relation with a male partner who has undergone a documented vasectomy a minimum of 6 months prior to study commencement. All females must agree to continue to use their method of birth control for the duration of the study and for a minimum of one complete menstrual cycle or 28 days following discharge from the study
7. Subjects who have participated in a prior study of ciraparantag must have been discharged from the study a minimum of 1 month prior to the planned treatment.
8. Subjects must understand and agree to comply with the requirements of the study and they must be willing to sign the informed consent form indicating voluntary consent to participate in the study prior to initiation of screening or study-related activities

General Exclusion Criteria:

1. History of major bleeding or clotting disorder
2. Females with a history of dysfunctional uterine bleeding
3. Smokers or use of tobacco and/or nicotine containing products within 3 months prior to dosing as determined by the subject's verbal history
4. Pregnant or breast-feeding
5. Males with a history of hormone therapy within 3 months prior to screening
6. Taking any type of chronic medication (including vitamin, nutritional and herbal supplements) for more than 14 consecutive days within the 4 weeks prior to study entry (use of hormonal contraceptives is acceptable)
7. Positive serologic test for human immunodeficiency virus (HIV), Hepatitis C virus antibody (HCV-Ab), or Hepatitis B surface antigen (HBsAg)
8. Donation of blood or blood products within 56 days prior to screening
9. Participation in any study with an investigational compound or device within 30 days prior to signing informed consent
10. Active drug or alcohol dependence within the prior 12 months or any condition that, in the opinion of the Investigator, would interfere with adherence to study protocol

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Single

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cohort 1; ciraparantag (60 mg)	Drug: Ciraparantag; Ciraparantag (administered over 10 minutes); Other Names: PER977; AMAG 977; Drug: Rivaroxaban; Rivaroxaban 20 mg given once per day (QD) in the morning
Experimental: Cohort 2; ciraparantag (120 mg)	Drug: Ciraparantag; Ciraparantag (administered over 10 minutes); Other Names: PER977; AMAG 977; Drug: Rivaroxaban; Rivaroxaban 20 mg given once per day (QD) in the morning
Placebo Comparator: Placebo; placebo (saline for injection)	Drug: Placebo; Saline for injection; Other Names: PBO; Drug: Rivaroxaban; Rivaroxaban 20 mg given once per day (QD) in the morning
Experimental: Cohort 3; ciraparantag (180 mg)	Drug: Ciraparantag; Ciraparantag (administered over 10 minutes); Other Names: PER977; AMAG 977; Drug: Rivaroxaban; Rivaroxaban 20 mg given once per day (QD) in the morning
Experimental: Cohort 4; ciraparantag (30 mg)	Drug: Ciraparantag; Ciraparantag (administered over 10 minutes); Other Names: PER977; AMAG 977; Drug: Rivaroxaban; Rivaroxaban 20 mg given once per day (QD) in the morning

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjects Achieving Complete Reversal of Anticoagulation (WBCT is ≤ 110% of Baseline)	Complete reversal is achieved if WBCT (manual method) is ≤ 110% of baseline at any post-baseline time point up to and including 1 hour following ciraparantag/placebo administration)	Within 1 Hour
Subjects Achieving Complete and Sustained Reversal of Anticoagulation (WBCT is ≤115%of Baseline)	Complete and sustained reversal of anticoagulation is achieved for a subject if WBCT (manual method) is ≤ 115% of baseline at all time points between 1 and 8 hours (inclusive) following ciraparantag/placebo administration.	Between 1 and 8 Hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pharmacokinetic parameters of rivaroxaban, ciraparantag and its major metabolite.	Pharmacokinetic parameters (including maximum concentration values and area under the curve) will be summarized for each treatment group.	10 days

Collaborators and Investigators

• Sponsor: Perosphere Pharmaceuticals Inc, a wholly owned subsidiary of AMAG Pharmaceuticals, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): May 8, 2017
• Primary Completion (Actual): November 12, 2019
• Study Completion (Actual): November 12, 2019

Study Registration Dates

• First Submitted: May 19, 2017
• First Submitted That Met QC Criteria: May 30, 2017
• First Posted (Actual): June 1, 2017

Study Record Updates

• Last Update Posted (Estimated): September 2, 2025
• Last Update Submitted That Met QC Criteria: August 13, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Rivaroxaban; PER977; Ciraparantag; Whole Blood Clotting Time (WBCT)
• Additional Relevant MeSH Terms: Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Substandard Drugs; Pharmaceutical Preparations; Morpholines; Oxazines; Thiophenes; Rivaroxaban; Counterfeit Drugs; PER977
• Other Study ID Numbers: PER977-02-012

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No