CeleCor Therapeutics has achieved a significant milestone in emergency cardiac care with its phase III CELEBRATE trial of zalunfiban (Disaggpro) meeting both primary safety and efficacy endpoints for treating ST-segment elevation myocardial infarction (STEMI) patients in prehospital settings.
The randomized, double-blind, placebo-controlled trial enrolled 2,467 patients across 45 sites in the United States, Canada, Mexico, and Europe. Patients with persistent ischemic chest pain lasting less than 4 hours were randomized 1:1:1 to receive zalunfiban at doses of 0.110 mg/kg or 0.130 mg/kg, or placebo, administered by emergency medical services personnel.
Novel Prehospital Intervention Strategy
Zalunfiban represents a breakthrough approach to early STEMI intervention, addressing a critical treatment gap where nearly 50% of all heart attack deaths occur before patients reach the hospital. The drug is formulated as a small molecule glycoprotein IIb/IIIa inhibitor designed for subcutaneous injection using an auto-injector, allowing a full dose to be contained in a volume of less than 1 mL.
The therapeutic's rapid onset profile distinguishes it from existing treatments, reaching maximal effect within 15 minutes and maintaining a pharmacokinetic half-life of approximately 1 to 2 hours. This pharmacological profile was specifically engineered to facilitate prehospital antiplatelet therapy and improve coronary reperfusion outcomes.
Trial Design and Patient Population
The CELEBRATE trial targeted patients presenting with STEMI and persistent ischemic chest pain lasting more than 10 minutes, with new ST-segment elevation of at least 2 mm in two adjacent ECG leads. Patients were excluded if they required CPR for out-of-hospital cardiac arrest, presented with systolic blood pressure below 90 mmHg combined with heart rate above 100 bpm, were receiving renal dialysis or oral anticoagulation, or had experienced major surgery, trauma, or bleeding requiring hospitalization within the previous month.
The study's primary endpoint utilized a ranked 7-point scale of clinical outcomes at 30 days, encompassing all-cause mortality, stroke, recurrent myocardial infarction, acute stent thrombosis, new-onset heart failure or rehospitalization for heart failure, high-sensitivity cardiac troponin T levels at least 10 times the upper limit of normal at 24 hours after PCI/angiography, or none of the preceding events.
Safety Assessment Framework
The primary safety outcome focused on the incidence of severe or life-threatening bleeding based on GUSTO criteria at 30 days. This safety framework reflects the critical balance required in antiplatelet therapy, where the benefits of improved reperfusion must be weighed against bleeding risks, particularly in the prehospital setting where immediate medical intervention capabilities may be limited.
Previous phase IIa studies demonstrated that zalunfiban treatment results in rapid and potent platelet inhibition in STEMI patients while maintaining good tolerability profiles, providing the foundation for this larger phase III investigation.
Clinical Significance and Future Implications
The successful completion of the CELEBRATE trial's primary endpoints represents a potential paradigm shift in acute coronary syndrome management. With approximately 40% of heart attack patients experiencing STEMI, where blood flow to a portion of the heart is completely blocked by a clot, the ability to initiate effective antiplatelet therapy in the prehospital setting could significantly impact patient outcomes.
The trial's comprehensive follow-up protocol included blood sample collection at 1, 6, 24, and 72 hours post-PCI/angiography, with investigators conducting 30-day assessments for adverse events, bleeding events, and injection site reactions, and 12-month follow-up for mortality or hospitalization due to heart failure or atrial fibrillation.
CeleCor Therapeutics plans to present the complete trial results during the late-breaking sessions at the American Heart Association Scientific Sessions in New Orleans on November 10, 2025, where the full scope of zalunfiban's clinical impact will be revealed to the cardiovascular medicine community.
