The Dual Antiplatelet Therapy Study (DAPT) was a landmark clinical trial which we designed and managed, with the objective of determining the appropriate duration of dual antiplatelet therapy following placement of a drug-eluting coronary stent. Prior to this study, The American College of Cardiology and American Heart Association recommended 12 months of dual antiplatelet therapy (the combination of aspirin and a second anti-clotting medication to reduce the risk of blood clots) after placement of a drug-eluting stent, and the European Society of Cardiology recommended 6-12 months of dual antiplatelet therapy for the same indication. Given a lack of data within the international scientific community, considerable uncertainty and variation in clinical practice existed.
The DAPT Study was an international initiative that came in response to a U.S. Food and Drug Administration (FDA) request following the recommendation of a December 2006 Advisory Panel for post-market studies of DES that would yield sufficient data to answer these important public health questions. As a result, a unique public-private collaboration to design and conduct the DAPT Study formed amongst the U.S. FDA, stent and thienopyridine manufacturers and our organization.
This independent, large-scale study in size and scope was intended to determine the appropriate duration for dual antiplatelet therapy to protect patients from stent thrombosis and major adverse cardiovascular and cerebrovascular events (MACCE) following the implantation of drug-eluting coronary stents.
Following a competitive proposal process, we were selected to lead and implement the study, with complete responsibility for design, operationalization, and strategic leadership, as well as the role of regulatory sponsor.
The study was a prospective, randomized, double-blind trial conducted at 452 centers in 11 countries. A total of 25,682 subjects were enrolled into the DAPT Study. This included four participating stent manufacturer-sponsored studies that we coordinated to follow the DAPT Study protocol. At an operational level, we developed and implemented a global strategy, overseeing the four manufacturer-sponsored studies and two international CROs, while directly managing 176 sites in the US. We also held responsibility for managing the data and adjudicating all relevant clinical events. In order to successfully manage this complex study, we designed and led an effective engagement plan for all stakeholders throughout the life of the trial, including FDA and the Manufacturers, maintaining effective communication through an integrated set of governance committees, which created a platform for identifying and negotiating strategic solutions.
In order to meet the critical FDA timelines as well as manage to key budgetary considerations, we provided our considerable experience, augmented by insight from internal and external experts on the implementation of clinical trial innovations. There are many operational highlights of this study that enabled us to complete our responsibilities. This included core strategies that were identified and developed during the design phase with the study stakeholders, leading to innovation and best practices to:
The final results of the DAPT Study were announced on November 16, 2014 at the American Heart Association Scientific Sessions. Results showed that patients who were treated with dual antiplatelet therapy for 30 months after getting a stent placed were 3.5 times less likely to develop a blood clot than patients who were treated for 12 months. Patients who received longer-term treatment also had about half the risk of heart attack. Moderate to severe bleeding was more common in patients who had 30 months of treatment, but serious and fatal bleeding was rare in both groups of patients.
Primary and key secondary results were presented at a special session during the American Heart Association Scientific Sessions in November 2014 and were followed by a panel discussion which included both FDA’s CDRH and CDER.
To see more on main findings, published in New England Journal of Medicine, and additional study publications, presentations and materials, go to: www.daptstudy.org
FDA Commissioner, at the time of presentation of the primary results, Margaret A. Hamburg, M.D. stated: “This study is the first postmarket investigation in which the FDA brought together industry competitors who put aside competition and achieved an unprecedented level of cooperation with regulators and academia to answer a major public health question.” Bram Zuckerman, MD, Director, Division of Cardiovascular Devices, US FDA Center for Device and Radiologic Health, summed up DAPT as: “This is a real step forward in how clinical trials in medical devices can be done.”