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Phase 2 Healthy Volunteer Study to Evaluate the Ability of PRT064445 to Reverse the Effects of Several Blood Thinner Drugs on Laboratory Tests (Module 2 of 4)

Phase 2
Completed
Conditions
Healthy Volunteers
Interventions
Combination Product: PRT064445/Rivaroxaban
Drug: Placebo
Combination Product: Placebo/Rivaroxaban
Registration Number
NCT03578146
Lead Sponsor
Portola Pharmaceuticals
Brief Summary

The purpose of this study is to evaluate the ability of PRT064445 to reverse the effects of several blood thinner drugs on laboratory tests. The study also is evaluating the blood levels of PRT064445 given at different doses.

Detailed Description

A randomized, double-blind, vehicle-controlled study to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of intravenously administered PRT064445 after dosing to steady state with one of four direct/indirect factor Xa (fXa) inhibitors in healthy volunteers.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
48
Inclusion Criteria
  • Healthy men or women between the ages of 18 and 45 years old
Exclusion Criteria
  • History (including family history) or symptoms of, or risk factors for bleeding
  • History (including family history) of or risk factors for a hypercoagulable or thrombotic condition
  • Absolute/relative contraindication to anticoagulation or treatment with specific anticoagulants
  • History of major surgery, severe trauma or bone fracture within 3 months prior to dosing; or planned surgery within 1 month after dosing.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Module 2 (720 mg bolus + 240 mg infusion)PRT064445/Rivaroxaban720 mg IV bolus administered over 24 minutes \[\~30 mg/min\] followed by 240 mg continuous IV infusion \[4 mg/min over 60 min)
Module 2 (800 mg bolus + 960 mg infusion)Placebo/Rivaroxaban800 mg IV bolus administered over 26.7 minutes \[\~30 mg/min\] followed by 960 mg continuous IV infusion \[8 mg/min over 120 min\]
Module 2 (420 mg)Placebo/Rivaroxaban420 mg andexanet IV bolus administered over 14 minutes (\~30 mg/min)
Module 2 (600 mg)Placebo/Rivaroxaban600 mg andexanet IV bolus administered over 20 minutes (\~30 mg/min)
Module 2 (720 mg bolus + 240 mg infusion)Placebo/Rivaroxaban720 mg IV bolus administered over 24 minutes \[\~30 mg/min\] followed by 240 mg continuous IV infusion \[4 mg/min over 60 min)
Module 2 PlaceboPlaceboPlacebo administered intravenously (IV) as a bolus or a bolus followed by continuous fusion.
Module 2 (210 mg)Placebo/Rivaroxaban210 mg andexanet IV bolus administered over 7 minutes (\~30 mg/min)
Module 2 (420 mg)PRT064445/Rivaroxaban420 mg andexanet IV bolus administered over 14 minutes (\~30 mg/min)
Module 2 (800 mg bolus + 960 mg infusion)PRT064445/Rivaroxaban800 mg IV bolus administered over 26.7 minutes \[\~30 mg/min\] followed by 960 mg continuous IV infusion \[8 mg/min over 120 min\]
Module 2 (210 mg)PRT064445/Rivaroxaban210 mg andexanet IV bolus administered over 7 minutes (\~30 mg/min)
Module 2 (600 mg)PRT064445/Rivaroxaban600 mg andexanet IV bolus administered over 20 minutes (\~30 mg/min)
Primary Outcome Measures
NameTimeMethod
Efficacy: Percent Change From Baseline in Anti-fXa Activity at 2 Mins Following Andexanet/Placebo AdministrationBaseline to 2 minutes following the end of andexanet/placebo administration

Anti-fXa activity was measured immediately prior to (Baseline) and at 2 mins following andexanet/placebo administration. Anti-fXa activity was measured using a commercial kit (Coamatic Heparin-82 33 9363, DiaPharma)

Secondary Outcome Measures
NameTimeMethod
Efficacy: Percent Change From Baseline in Thrombin Generation at 2 Mins Following Andexanet/Placebo AdministrationBaseline to 2 minutes following the end of andexanet/placebo administration

Thrombin generation was measured immediately prior to (Baseline) and at 2 mins following andexanet/placebo administration. Thrombin generation was measured using a TF-initiated thrombin generation assay.

Efficacy: Percent Change From Baseline in Unbound Rivaroaxaban Plasma Concentration at 2 Mins Following Andexanet/Placebo AdministrationBaseline to 2 minutes following the end of andexanet/placebo administration

Unbound rivaroxaban concentrations was measured immediately prior to (Baseline) and at 2 mins following andexanet/placebo administration. Unbound plasma concentrations for rivaroxaban were determined by a rapid equilibrium dialysis method followed by Liquid Chromatography-Mass Spectometry assay.

Andexanet Maximum Observed Plasma Concentration (Cmax)Blood was collected at predose, 0.033, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5 and 14.5 hours postdose.

Plasma concentrations of andexanet was determined using a validated method that involved analysis of citrated human plasma by an electrochemiluminescent assay.

Andexanet Area Under the Drug Concentration-time Curve From Time 0 Extrapolated to Infinity (AUC0-inf )Blood was collected at predose, 0.033, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5 and 14.5 hours postdose.

Plasma concentrations of andexanet was determined using a validated method that involved analysis of citrated human plasma by an electrochemiluminescent assay. AUC0-inf was calculated using a non-compartmental approach

Andexanet Time of Maximum Observed Plasma Concentration (Tmax)Blood was collected at predose, 0.033, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5 and 14.5 hours postdose.

Plasma concentrations of andexanet was determined using a validated method that involved analysis of citrated human plasma by an electrochemiluminescent assay. Tmax was taken directly from the raw data.

Andexanet Apparent Terminal Elimination Half-life (t1/2)Blood was collected at predose, 0.033, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5 and 14.5 hours postdose.

Plasma concentrations of andexanet was determined using a validated method that involved analysis of citrated human plasma by an electrochemiluminescent assay. t1/2 was determined by linear regression of the log concentration on the terminal portion of the plasma concentration-time curve.

Andexanet Total Systemic Clearance (CL)Blood was collected at predose, 0.033, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5 and 14.5 hours postdose.

Plasma concentrations of andexanet was determined using a validated method that involved analysis of citrated human plasma by an electrochemiluminescent assay. CL was calculated using a non-compartmental approach, calculated as Dose/AUC0-inf

Andexanet Total Volume of Distribution (Vss)Blood was collected at predose, 0.033, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5 and 14.5 hours postdose.

Plasma concentrations of andexanet was determined using a validated method that involved analysis of citrated human plasma by an electrochemiluminescent assay. Vss was calculated using a non-compartmental approach.

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