Bactericidal/permeability-increasing protein (rBPI21) in patients with hemorrhage due to trauma: results of a multicenter phase II clinical trial. rBPI21 Acute Hemorrhagic Trauma Study Group.

BACKGROUND

Infection and organ failure are the most common causes of death or serious complication in trauma patients surviving initial resuscitation and operation. Of the many possible causes of these complications, bacterial translocation and release of harmful cytokines and oxygen free radicals may play an important role in the pathogenesis of the complications associated with traumatic hemorrhage. Recombinant human bactericidal/permeability-increasing protein (rBPI21) has antibacterial and antiendotoxin properties, reduces cytokine levels, and increases survival in animal models of hemorrhagic shock. The primary objective of this study was to evaluate the safety and efficacy of prophylactic rBPI21 infusion in patients with hemorrhage due to trauma.

METHODS

This was a phase II, multicenter, randomized, double-blind, placebo-controlled trial. Patients who required at least 2 U of blood were randomized to receive rBPI21 (4 mg x kg(-1) x d(-1) for 2 consecutive days) or an equivalent volume of placebo by continuous infusion within 12 hours of injury. The primary efficacy end point was mortality or serious complication occurring during the first 15 days of the study. Safety was monitored clinically and by laboratory panels during the study period.

RESULTS

A total of 401 patients were treated (202 in the rBPI21 group and 199 in the placebo group). The composite end point rate of mortality or serious complication through day 15 was 46% in the placebo group and 39% in the rBPI21 group (hazard ratio = 0.79; p = 0.13). Secondary analysis, which adjusted for age, mechanism of injury, Injury Severity Score (1990 version), and units of blood received before study drug infusion showed similar results (hazard ratio = 0.79; p = 0.14). The proportion of patients who developed at least one serious organ dysfunction was 22% in the placebo group and 16% in the rBPI21 group (hazard ratio = 0.71; p = 0.14). The proportion of patients who developed either pneumonia or acute respiratory distress syndrome was 32% in the placebo group and 22% in the rBPI21 group (hazard ratio = 0.66; post hocp = 0.03). The beneficial trends of rBPI21 were observed in both blunt and penetrating trauma and were generally observed across different age groups, Injury Severity Scores, and units of blood transfused. No treatment difference was observed in mortality or resource utilization in this phase II study.

CONCLUSION

rBPI21 was well-tolerated and demonstrated a favorable trend in reducing the composite primary end point of mortality or serious complication through day 15, especially respiratory complications, in patients with hemorrhage due to trauma. A phase III study is currently in progress.