Trial design and rationale of TY-51924 as a novel Na+/H+ exchanger inhibitor in patients with ST-elevation acute myocardial infarction undergoing percutaneous coronary intervention

BackgroundReperfusion therapy limits infarct size and improves survival in patients with ST-elevation myocardial infarction (STEMI). However, reperfusion itself may, in some cases, deteriorate myocardial damage, causing the so-called ischemia-reperfusion injury. Activation of the Na+/H+ exchanger (NHE) at the time of reperfusion plays an important role in ischemia-reperfusion injury. We designed a Phase IIa proof of concept clinical trial to evaluate the potential of TY-51924, an NHE inhibitor, as adjunctive therapy to primary percutaneous coronary intervention (pPCI) for patients with STEMI.MethodsThis is a multicenter, randomized, double-blind, placebo-controlled clinical trial designed to evaluate the efficacy and the safety of TY-51924 in patients with first anterior STEMI who are undergoing pPCI. Immediately before pPCI, a bolus intravenous injection followed by infusion of TY-51924 (up to 30 mg/kg) or placebo was administered. Primary endpoints were myocardial salvage index (MSI) determined by 201Tl/123I-beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP) dual-isotope single photon emission computed tomography (SPECT) performed 3-5 days after pPCI, and safety up to 7 days. Secondary endpoints were the degree of myocardial injury based on cardiac enzyme release and QRS score by electrocardiogram (ECG), cardiac functions determined by SPECT or magnetic resonance imaging (MRI), and safety up to 3 months following pPCI. Furthermore, MRI studies were also performed where possible 3-7 days and 3 months after pPCI.DiscussionThe appropriateness of assessing safety and efficacy of TY-51924 as adjunctive therapy to pPCI for patients with STEMI will be discussed in this study plan.