Study of Ciraparantag Administered to Volunteers Anticoagulated With Rivaroxaban, Measure Clotting Times Using WBCT

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