Positive Data for Boston Scientific’s Drug Coated Balloon Presented at TCT Could Support FDA Approval for In-Stent Restenosis
Boston Scientific Corporation has released positive 12-month results from the pivotal AGENT IDE clinical trial, presenting findings at the Transcatheter Cardiovascular Therapeutics (TCT) annual scientific symposium. The trial marked the first clinical assessment in the U.S. of the AGENT™ Drug-Coated Balloon (DCB), aiming to determine its safety and effectiveness in treating coronary in-stent restenosis (ISR).
Coronary in-stent restenosis (ISR) is a condition in which the stented section of an artery becomes obstructed or narrowed by plaque or scar tissue. While coronary stenting is a commonly used approach to restore blood flow in patients with coronary artery disease, ISR still occurs in some cases and is addressed in around 10% of percutaneous coronary interventions in the United States.
The AGENT DCB is a paclitaxel-coated balloon catheter designed to reopen these blocked vessels and subsequently transfer a therapeutic drug to the vessel wall. This process helps prevent the recurrence of ISR. While the AGENT DCB was approved in Japan in 2023 and received CE Mark in 2014 for the treatment of patients with ISR and previously untreated small vessel coronary disease, the successful outcomes of the AGENT IDE trial will support its potential FDA approval.
The AGENT IDE trial involved the participation of the first 480 out of 600 patients enrolled across 40 U.S. sites. Within this patient population, 44% had multiple stent layers in the target lesion, and 51% were diabetic. The AGENT IDE clinical trial successfully met its primary endpoint of target lesion failure (TLF) at 12 months, with the AGENT DCB demonstrating statistical superiority to uncoated balloon angioplasty (17.9% vs. 28.7%; P=0.006). The differences observed were mainly due to significantly reduced rates of myocardial infarction related to the target vessel (TV-MI or heart attack) and the need for a target lesion revascularization (TLR or a repeated percutaneous coronary intervention). The data showed an approximate 38% relative risk reduction in TLF. Additionally, there were no definite/probable cases of clotting within the stent (stent thrombosis) with AGENT DCB (0.0% vs. 3.9% for the control group, P=0.001). There was a 51% risk reduction in TLR (12.4% vs. 24.0%, P=0.002) and a 49% risk reduction in TV-MI (6.4% vs. 12.3%, P=0.03).
Dr. Robert W. Yeh, the principal investigator of the trial, emphasized the positive outcomes in a complex trial population. He highlighted the marked reduction in target lesion failure, the significant decrease in heart attack cases, and the complete absence of stent thromboses. These results indicate the AGENT DCB as a promising alternative treatment option for coronary in-stent restenosis. Dr. Yeh is the section chief of interventional cardiology at the Beth Israel Deaconess Medical Center and the Katz-Silver Family Professor of Medicine at Harvard Medical School.