Parsippany, NJ - The Medicines Company has halted patient enrollment in a phase 3 safety trial of its perioperative antihypertensive agent clevidipine (Clevelox™), after patients randomized to the drug showed more frequent atrial fibrillation (AF) following surgery compared with patients randomized to comparative treatments. Clevidipine is being investigated as a blood pressure-lowering drug in people undergoing cardiac surgery.

A press release issued by the company notes that AF after surgery is not uncommon and that the incidence of AF in the clevidipine group was "well within the ranges reported in the cardiac surgery literature." Still, a planned interim analysis of the trial data—including approximately half the study population—indicated that AF was higher in the on-drug group than in the patients treated with nitroglycerin, sodium nitroprusside, or nicardipine, "a difference we cannot ignore," Clive Meanwell, chair and CEO of The Medicines Company commented.

Meanwell also acknowledged that further clinical studies "are needed to sort out the meaning of the interim findings" from the ECLIPSE data and that these studies would delay the company's new drug application beyond 2005.

An earlier small-scale trial testing clevidipine's efficacy—ESCAPE II—was promising, indicating that clevidipine can reduce systolic blood pressure by >15% in the postoperative setting, as reported by heartwire. The primary objective of ECLIPSE is to establish the safety of clevidipine in the treatment of perioperative high blood pressure, examining the incidences of death, stroke, myocardial infarction, and renal dysfunction between the clevidipine and comparative-treatment groups.