Safety and tolerability of high-dose ulinastatin after 2-hour intravenous infusion in adult healthy Chinese volunteers: A randomized, double-blind, placebo-controlled, ascending-dose study

Ulinastatin, is a broad-spectrum protease inhibitor purified from human urine, inhibits endogenous proteases such as trypsin, α-chymotrypsin, hyaluronidase, and plasmin. It is widely being used at increasingly higher doses for the treatment of acute or chronic pancreatitis, severe infection, and acute organ failure. We aimed to evaluate the safety and tolerability of high-dose ulinastatin in healthy volunteers in our single center, randomized, double-blind, placebo-controlled, single-dose escalation study. Fifty-one healthy Chinese subjects were enrolled in 9 dose cohorts (3×105 U, 6×105 U, 12×105 U, 20×105 U, 30×105 U, 45×105 U, 60×105 U, 70×105 U, or 80×105 U of ulinastatin) and randomized to UTI or matching placebo (n = 1). Each dose cohort was composed of 3-7 subjects. All subjects were required to have 2 h of intravenous infusion. Safety and tolerability were assessed throughout the study via monitoring of vital signs, physical examinations, clinical laboratory tests, 12-lead electrocardiograms, and interviews with the subjects about adverse events. Fifty-one subjects (35 men and 16 women) completed the study. A total of 13 AEs were reported by 10 subjects: 11 adverse events in the ulinastatin groups and 2 adverse events in the placebo group. Twelve of the adverse events were possibly related to the study drug. The most common drug-related adverse events included dizziness, pain at injection site, and a decrease in white blood cell count. All adverse events were of mild severity; none were serious. In conclusion, 2 hours of intravenous infusion of ulinastatin (3×105 to 80×105 U) was well tolerated by healthy Chinese subjects.