Assessment of the Safety and Efficacy of the Novel Tetrapeptide ITF-1697 on Infarct Size after Primary PTCA in Acute Myocardial Infarction

Objective and design: ITF-1697 is a chemically modified LYS-Pro tetrapeptide that corresponds to sequence 113–116 of C-reactive protein. Previous studies have demonstrated significant anti-ischaemic and antithrombotic activity of this tetrapeptide. The aim of this prospective, randomised, double-blind study in patients with acute myocardial infarction undergoing coronary revascularisation was to investigate the safety and efficacy of prolonged intravenous (IV) infusion of ITF-1697 at different doses on reduction of infarct size, as assessed by radionuclide imaging. Patients and methods: Injection of technetium-99m (Tc99m) was followed by injection of ITF-1697 or placebo bolus and 24-hour infusion in patients with acute myocardial infarction. Percutaneous transluminal coronary angioplasty (PTCA) was performed and succeeded by radionuclide imaging. A second Tc99m injection and radionuclide imaging was performed 7 days after the PTCA or at hospital discharge. The primary efficacy variable was set as the ratio between the myocardial salvage (size of the initial perfusion defect minus the final size of the infarct) and the initial area at risk (myocardial salvage index). Twenty-three patients were included in the study protocol, of whom nine were randomised to the ITF-1967 dose 1 group (loading dose 55 μg/kg IV, infusion 0.5 μg/kg/min for 24 hours), a further nine to the ITF-1697 dose 2 group (loading dose 110 μg/kg IV, infusion 1.0 μg/kg/min for 24 hours), and the remaining five to the placebo group. Results: The defined safety variables (adverse events, laboratory parameters, vital signs and clinical outcome) exhibited no relationship to the application of ITF-1697. Comparison of myocardial salvage index revealed no statistical difference within the three groups (p = 0.65). Hypothesis testing on the myocardial salvage as well as the empirical and bias-correct confidence intervals (CIs) revealed significant differences between the ITF-1697 dose 2 group and the placebo group (95% CI 2.75, 18.07). Conclusion: The application of the tetrapeptide ITF-1697 during acute myocardial infarction to reduce infarct size was found to be feasible and safe in this pilot trial.