Background: Zalunfiban is a glycoprotein IIb/IIIa (integrin αIIbβ3) inhibitor designed for subcutaneous administration on first medical contact with patients with suspected ST-segment elevation myocardial infarction (STEMI).
Methods: An international, double-blind, placebo-controlled trial randomly assigned patients with STEMI in a 1:1:1 ratio to receive a single subcutaneous injection of zalunfiban (0.11 mg/kg or 0.13 mg/kg) or placebo. The primary efficacy end point was a hierarchical proportional odds model ranking seven end points from worst to best: all-cause death, stroke, recurrent myocardial infarction, acute stent thrombosis, new-onset or rehospitalization for heart failure, larger infarct size, or no end point through 30 days. The primary safety end point was the occurrence of severe or life-threatening bleeding as per the global use of strategies to open occluded coronary arteries (GUSTO) criteria.
Results: The trial randomly assigned 2467 patients (853 to zalunfiban 0.11 mg/kg, 818 to zalunfiban 0.13 mg/kg, and 796 to placebo). The primary efficacy end point was significantly improved by zalunfiban (adjusted odds ratio 0.79; 95% confidence interval, 0.65 to 0.98; P=0.028). GUSTO severe bleeding was similar between those who received zalunfiban versus placebo (1.2% vs. 0.8%; P=0.40), but GUSTO mild to moderate bleeding was increased (6.4% vs. 2.5%; P<0.001). Angiography showed faster coronary blood flow with zalunfiban versus placebo (corrected frame count of the infarct-related artery 109 [interquartile range 35 to 176] vs. 176 [interquartile range 40 to 176]; P=0.012).
Conclusions: In patients with STEMI, zalunfiban administered at first medical contact significantly improved preintervention infarct-related patency and reduced the likelihood of a worse 30-day multicomponent hierarchical clinical end point. Zalunfiban was not associated with increased severe or life-threatening bleeding but was associated with increased mild to moderate bleeding. (Funded by CeleCor Therapeutics; CELEBRATE ClinicalTrials.gov number, NCT04825743.).