BackgroundDrug-coated balloon (DCB) technology was developed as an alternative treatment for obstructive coronary artery disease (CAD) and in-stent restenosis (ISR). Management of coronary ISR is clinically challenging and frequently encountered in practice. The Agent DCB uses an inactive excipient to effectively deliver a targeted, therapeutic dose of paclitaxel to the vessel wall. Study DesignAGENT IDE is a prospective, multicenter, randomized controlled trial to evaluate superiority of the Agent DCB to balloon angioplasty in treating patients with ISR. A total of 480 patients with ISR of a previously treated lesion length <26 mm and reference vessel diameter >2.0 mm to ≤4.0 mm will be initially randomized. Subjects presenting with recent myocardial infarction (MI), complex lesions, or thrombus in the target vessel will be excluded. An adaptive group sequential design with one formal interim analysis for sample size re-estimation will be conducted, and the sample size may be increased to a maximum of 600 subjects. The primary endpoint is the rate of 12-month target lesion failure (TLF; composite of any ischemia-driven revascularization of the target lesion (TLR), target vessel related MI, or cardiac death) and will be tested for superiority in the test arm against the control. Functional status and general health-related quality of life will be measured by changes in the EQ-5D scores. Subjects will be followed for 5 years following the index procedure. ConclusionThis study will prospectively evaluate the safety and efficacy of Agent DCB in patients treated for coronary ISR.