Roche Commences TROPICAL-ACS Study on Multiplate-Guided Antiplatelet Therapy in ACS Patients

September 4, 2013—Roche Group (Basel, Switzerland) announced the start of the TROPICAL-ACS (Testing Responsiveness To Platelet Inhibition On Chronic Antiplatelet Treatment For Acute Coronary Syndromes) trial, an investigator-initiated multicenter study designed to evaluate the benefit of personalized antiplatelet therapy in patients who have acute coronary syndrome (ACS) treated with percutaneous coronary intervention.

The TROPICAL-ACS trial's primary purpose is to evaluate whether a treatment approach guided by platelet function testing with Roche's Multiplate analyzer is noninferior to a 12-month standard therapy with prasugrel. The study will involve 2,600 patients from 15 investigational centers in Europe.

The Multiplate applied platelet aggregometer is available worldwide outside of the United States, where it is available for research use only. The analyzer device, which was first introduced in 2005, uses simple whole blood analysis and intuitive software. The Multiplate system allows for analysis of platelet function, which helps clinicians to determine what antiplatelet therapy a patient will best respond to after a heart attack or stent placement.

According to Roche, TROPICAL-ACS is a prospective, randomized, parallel-group, open-label, noninferiority trial and will be the first large evaluation conducted to assess the benefits of tailored antiplatelet treatment in ACS patients with combined ischemic and bleeding events. Enrollment of patients is expected to be completed in mid-2015 with a subsequent 12-month period to conclude the entire follow-up.

Dirk Sibbing, MD, Principal Investigator of TROPICAL-ACS, commented in the company's press release, “The innovative design of the TROPICAL-ACS trial focuses on a high-risk ACS patient cohort, provides potent drug intervention for clopidogrel low responders, and uses a biomarker that is able to accurately identify patients at increased thrombotic risk. Most of the benefit for potent platelet inhibition with prasugrel over conventional clopidogrel treatment in ACS patients was seen in the early and acute phase of treatment; however, in the long term, high levels of platelet inhibition may even be harmful due to the increased bleeding risk. In the past, we have seen some negative results with the GRAVITAS and ARCTIC clinical trials, but we also have promising experiences from studies with Multiplate in clinical routine. These favor an individualized treatment approach.”

The company noted that a tailored antiplatelet approach may trigger significant cost savings while maintaining the clinical benefit for patients without exposing them to a potentially elevated risk of bleeding.

The TROPICAL-ACS trial is designed to randomize the 2,600 patients under investigation into two groups. While one group will continue receiving standard treatment with prasugrel over the course of 12 months, a second group will receive short-term prasugrel in the first week after percutaneous coronary intervention, followed by a treatment with clopidogrel in the second week. Individuals with an adequate response will continue on clopidogrel therapy for another 11.5 months, whereas patients with high on-clopidogrel platelet reactivity will switch to an 11.5-month course of treatment with prasugrel.

According to Roche, results of previous studies provide evidence that Multiplate aids in predicting thrombotic and bleeding risk in patients undergoing coronary stenting. A consensus document by the Working Group on High Platelet Reactivity published in September 2010 in the Journal of the American College of Cardiology acknowledged the high predictive value of Multiplate (2010;56:919-933). Additionally, three recently published registry studies with more than 2,000 total patients, including the ISAR-HPR registry published by Katharina Mayer, MD, et al with Dr. Sibbing, which was presented in a poster (P4872) at the European Society of Cardiology Congress 2013 and published in the meeting's supplement in the European Heart Journal, confirm Multiplate's utility for routine guidance of antiplatelet treatment in patients undergoing coronary stenting.