Vorapaxar as an Add-On Antiplatelet Therapy in Patients With and Without Diabetes Mellitus

Phase 4

Completed

Conditions: Diabetes Mellitus
Myocardial Infarction
Peripheral Arterial Disease

Interventions: Drug: Vorapaxar
Drug: Clopidogrel
Drug: Aspirin

Registration Number: NCT02548650

Lead Sponsor: University of Florida

Brief Summary: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor, more frequently clopidogrel, represents the standard of care for the long-term secondary prevention of atherothrombotic events in patients with myocardial infarction (MI) or peripheral arterial disease (PAD). However, rates of ischemic recurrences remain high. Vorapaxar is a protease-activated receptor (PAR)-1 inhibitor, which exerts potent inhibition of thrombin-mediated platelet aggregation. Patients with diabetes mellitus (DM) are known to be at increased risk of recurrent atherothrombotic events, which translates into worse outcomes, despite the use of standard of care therapy. This is in part due to the hyperreactive platelet phenotype, which characterizes DM patients, and to inadequate response to oral antiplatelet agents, including clopidogrel. Therefore, vorapaxar is an attractive treatment option for DM patients with a prior MI. The pharmacodynamic (PD) effects of vorapaxar in DM patients and how these may differentiate from non-DM patients has not been explored. Further, the role of vorapaxar as part of a dual antithrombotic treatment regimen combined with clopidogrel (and stopping aspirin) represents another important area of clinical interest. The proposed prospective, parallel-design study conducted in patients post-MI or with PAD with and without DM will aim the assess the pharmacodynamic effects of vorapaxar in addition to standard DAPT with aspirin and clopidogrel as well as in combination with clopidogrel only following aspirin withdrawal.

Detailed Description: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor, more frequently clopidogrel, represents the standard of care for the long-term secondary prevention of atherothrombotic events in patients with myocardial infarction (MI) or peripheral arterial disease (PAD). However, rates of ischemic recurrences remain high, in part due to the fact that other platelet signaling pathways, such as thrombin-induced platelet aggregation, continue to be activated. Vorapaxar is a novel, orally active, competitive and slowly reversible protease-activated receptor (PAR)-1 inhibitor, which exerts potent inhibition of thrombin-mediated platelet aggregation. It is approved for clinical use by the Food and Drug Administration for the reduction of thrombotic cardiovascular events in patients with a history of MI or with peripheral arterial disease. Patients with DM are known to be at increased risk of recurrent atherothrombotic events, which translates into worse outcomes, despite the use of standard of care therapy. This is in part due to the hyperreactive platelet phenotype, which characterizes DM patients, and to inadequate response to oral antiplatelet agents, including clopidogrel. Importantly, in DM patients with prior MI included in the TRA 2P trial, vorapaxar reduced the primary composite end point at 3 years by 27% and led to a greater absolute risk reduction compared with those without DM. Therefore, vorapaxar is an attractive treatment option for DM patients with a prior MI. However, to date the PD effects of vorapaxar in DM patients and how these may differentiate from non-DM patients has not been explored. Further, current trends in clinical practice are seeing many patients discontinue aspirin and maintain clopidogrel. Hence, the role of vorapaxar as part of a dual antithrombotic treatment regimen combined with clopidogrel (and stopping aspirin) represents another important area of clinical interest, in order to maximize ischemic protection while reducing the risk of bleeding. The proposed prospective, parallel-design study conducted in patients post-MI or with PAD with and without DM will aim the assess the pharmacodynamic effects of vorapaxar in addition to standard DAPT with aspirin and clopidogrel as well as in combination with clopidogrel only following aspirin withdrawal. Pharmacodynamic assessments will be performed at multiple time point, with different assays exploring multiple pathways of platelet aggregation.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 66

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Patients with diabetes	Clopidogrel	Triple therapy (vorapaxar 2.5mg od plus clopidogrel 75 mg od and aspirin 81 mg od) will be administered for 30 days; then patients will stop aspirin and will take dual treatment (vorapaxar 2.5mg od plus clopidogrel 75 mg od ) for other 30 days.
Patients with diabetes	Aspirin	Triple therapy (vorapaxar 2.5mg od plus clopidogrel 75 mg od and aspirin 81 mg od) will be administered for 30 days; then patients will stop aspirin and will take dual treatment (vorapaxar 2.5mg od plus clopidogrel 75 mg od ) for other 30 days.
Patients without diabetes	Clopidogrel	Triple therapy (vorapaxar 2.5mg od plus clopidogrel 75 mg od and aspirin 81 mg od) will be administered for 30 days; then patients will stop aspirin and will take dual treatment (vorapaxar 2.5mg od plus clopidogrel 75 mg od ) for other 30 days.
Patients without diabetes	Aspirin	Triple therapy (vorapaxar 2.5mg od plus clopidogrel 75 mg od and aspirin 81 mg od) will be administered for 30 days; then patients will stop aspirin and will take dual treatment (vorapaxar 2.5mg od plus clopidogrel 75 mg od ) for other 30 days.
Patients with diabetes	Vorapaxar	Triple therapy (vorapaxar 2.5mg od plus clopidogrel 75 mg od and aspirin 81 mg od) will be administered for 30 days; then patients will stop aspirin and will take dual treatment (vorapaxar 2.5mg od plus clopidogrel 75 mg od ) for other 30 days.
Patients without diabetes	Vorapaxar	Triple therapy (vorapaxar 2.5mg od plus clopidogrel 75 mg od and aspirin 81 mg od) will be administered for 30 days; then patients will stop aspirin and will take dual treatment (vorapaxar 2.5mg od plus clopidogrel 75 mg od ) for other 30 days.

Primary Outcome Measures

Name	Time	Method
Maximal Platelet Aggregation in DM	30 days	Comparison of maximal platelet aggregation (%) measured by light transmittance aggregometry between between triple (vorapaxar plus DAPT) and dual (vorapaxar plus clopidogrel) therapy in diabetic patients

Secondary Outcome Measures

Name	Time	Method
Maximal Platelet Aggregation in Non-DM	30 days	Comparison of maximal platelet aggregation (%) measured by light transmittance aggregometry between between triple (vorapaxar plus DAPT) and dual (vorapaxar plus clopidogrel) therapy in non-diabetic patients