The US Food and Drug Administration (FDA) has accepted CeleCor Therapeutics' New Drug Application (NDA) for zalunfiban, an investigational subcutaneous glycoprotein (GP) IIb/IIIa inhibitor for patients with ST-segment elevation myocardial infarction (STEMI).1
The agency assigned a Prescription Drug User Fee Act (PDUFA) target action date of June 18, 2027. CeleCor announced the acceptance on September 30, 2026. The NDA is supported by positive endpoint data from the phase 3 CeleBrate trial. CeleCor completed its NDA submission on June 24, 2026.1,2
“If zalunfiban is approved by the FDA, we’ll be able to provide rapid, effective treatment for STEMI heart attacks at the first point of medical contact,” C. Michael Gibson, MD, professor of medicine at Harvard Medical School, said in a statement. “[The CeleBrate] data show that we can make heart attack care more effective by opening arteries and significantly reducing the risk of severe, irreversible heart damage for those who experience these dangerous events.”3
Unlike intravenous GP IIb/IIIa inhibitors, zalunfiban is a small molecule developed as a single subcutaneous injection for use in the prehospital setting at first medical contact. The approach aims to begin platelet inhibition before patients reach the catheterization laboratory. Earlier work with abciximab in the ADMIRAL trial linked upstream GP IIb/IIIa inhibition with improved patency before percutaneous coronary intervention (PCI) and better clinical outcomes.1
Zalunfiban Efficacy in the Phase 3 CeleBrate Trial
CeleBrate was a multinational, double-blind, placebo-controlled trial conducted at 45 sites in the United States, Canada, Mexico, and Europe. Investigators enrolled 2467 patients with presumed STEMI presenting within 4 hours of symptom onset.2,3
Patients were randomly assigned in a 1:1:1 ratio to a single subcutaneous injection of zalunfiban 0.11 mg/kg (n = 853), zalunfiban 0.13 mg/kg (n = 818), or placebo (n = 796). The primary endpoint was a 30-day hierarchical composite ranking death, stroke, recurrent MI, acute stent thrombosis, new or worsening heart failure, larger infarct size, or none of these events. Pooled zalunfiban improved the composite compared with placebo (adjusted odds ratio, 0.79; 95% CI, 0.65 to 0.98; P = .028).1,2
Acute stent thrombosis occurred in 0.2% of zalunfiban-treated patients vs 1.0% of placebo-treated patients, and new or recurrent heart failure occurred in 6.5% vs 8.1%. The proportion of patients free of any major adverse clinical event was 13.3% vs 9.8%. Death (2.3% vs 2.2%) and stroke (0.7% vs 0.8%) rates were similar, while recurrent MI was numerically higher with zalunfiban (1.9% vs 1.2%).2
Benefits were observed on top of contemporary background therapy, including aspirin, heparin, and P2Y12 inhibitors, predominantly ticagrelor.2
Zalunfiban Angiographic Outcomes and Bleeding Risk in STEMI
Zalunfiban improved infarct-related artery flow before PCI. Median corrected TIMI frame count was 109 frames with zalunfiban vs 176 frames with placebo (difference, −66; 95% CI, −93 to −39). TIMI grade 2 or 3 flow at index angiography occurred in 52.0% vs 45.1% of patients (difference, 6.8; 95% CI, 2.5 to 11.2).2
ST-segment resolution 1 hour after PCI did not differ significantly between groups (52.1% vs 50.7%; P = .42).² Bailout use of intravenous GP IIb/IIIa or P2Y12 inhibitors was also similar (8.6% vs 9.5%).2
GUSTO severe or life-threatening bleeding, the primary safety endpoint, occurred in 1.2% of zalunfiban recipients vs 0.8% of placebo recipients (P = .40). Mild to moderate bleeding was more frequent with zalunfiban, according to the investigators.2
“We look forward to working with the FDA as we seek approval for zalunfiban,” Rob Hillman, president and chief executive officer of CeleCor, said in a statement.1
References
Van't Hof AWJ, Gibson CM, Rikken SAOF, et al. Zalunfiban at first medical contact for ST-elevation myocardial infarction. NEJM Evid. Published online November 10, 2025. doi:10.1056/EVIDoa2500268
CeleCor Therapeutics. CeleBrate results presented at AHA Scientific Sessions, published in NEJM Evidence. Accessed October 2, 2026. https://www.celecor.com/celebrate-results/
