A Randomized, Pharmacodynamic Comparison of Low Dose Ticagrelor to Clopidogrel in Patients With Prior Myocardial Infarction
Status:
Completed
Trial end date:
2017-06-01
Target enrollment:
Participant gender:
Summary
Taken together the results from CHARISMA and PEGASUS-TIMI54, it appears that physicians may
consider extending beyond 1 year or reinitiating treatment with clopidogrel 75 mg od or
ticagrelor 60mg bid in patients with a prior MI and features of high ischemic and low
bleeding risk. Comparative clinical or pharmacodynamic studies, however, between clopidogrel
75 mg od and ticagrelor 60 mg bid in the chronic phase of stable post MI patients have not
been performed.
In a platelet substudy of PEGASUS-TIMI 54, 180 patients who had received >4 weeks of study
medication had platelet reactivity assessment. Ticagrelor 60mg bid achieved high levels of
peak and trough platelet inhibition in nearly all patients, with similar consistency of
effect compared to 90mg bid. Platelet reactivity (PRU) was significantly reduced with
ticagrelor 60mg bid compared to placebo.
In light of this, we believe that a dedicated pharmacodynamic study of ticagrelor 60 bid mg
vs clopidogrel 75 mg od in a PEGASUS-like population would be informative for the practicing
clinician, thus setting the rationale for conducting this specifically designed
investigation.
This is a prospective, randomized, single blind, single center, crossover study. Eligible
patients undergoing P2Y12 receptor antagonist therapy before screening will undergo a 14-day
minimum washout period before randomization. Following screening/washout period (visit 1),
patients will be randomized (visit 2, time 0) in 1:1 fashion to either clopidogrel 75 mg od
or ticagrelor 60 mg bid. Following 14±2 days (visit 3) patients will receive alternate
treatment for additional 14 days (visit 4). Platelet reactivity assessment will be performed
with the VerifyNow P2Y12 reaction assay at time 0, prior to first study drug dose. At visit 3
platelet function will be assessed at 2-4 hours post dose and prior to crossover. At visit 4
also platelet function will be assessed at 2-4 hours post study drug post dose. All patients
will receive concomitant aspirin (100 mg/d) and standard secondary prevention medication.
The primary endpoint is the platelet reactivity measured in P2Y12 reaction units (PRU) at the
end of the 2 study periods (pre-crossover and post-crossover).