Reevaluation of the efficacy and safety of the neutrophil elastase inhibitor, Sivelestat, for the treatment of acute lung injury associated with systemic inflammatory response syndrome; a phase IV study

Sivelestat, a neutrophil elastase inhibitor, has been approved in Japan for the treatment of patients with acute lung injury (ALI) associated with systemic inflammatory response syndrome (SIRS). The Pharmaceuticals and Medical Devices Agency (PMDA) has ordered to conduct a postmarket clinical study in order to reevaluate the efficacy and safety of Sivelestat in actual clinical settings in Japan. According to the PMDA’s order, we evaluated the efficacy and safety of Sivelestat in Japanese patients with ALI associated with SIRS using ventilator-free days (VFD) as the primary endpoint. The surrogate endpoints are ventilator-weaning rate, ICU discharge rate, and 180-day survival rate. Study design was an open-label, non-randomized, multi-center clinical trial. Sivelestat was intravenously administered at 0.2 mg/kg/h continuously for a maximum of 14 days. Sivelestat group and control group were compared by adjusting the outcome values using an inverse probability of treatment weighted method based on the propensity scores. Four hundred and four Sivelestat group patients and 177 control group patients were enrolled. The adjusted mean number of VFD was 15.7 and 12.1 in the Sivelestat group and control group, respectively (P = 0.0022). Both the adjusted ventilator-weaning rate and ICU discharge rate were significantly higher in the Sivelestat group than in the control group (P = 0.0028 and P = 0.019, respectively). The adjusted 180-day survival rate was significantly higher in the Sivelestat group than in the control group (71.8 percent vs. 56.3 percent). Sivelestat contributed to early weaning from the mechanical ventilation, while showing no negative effect on the long-term outcomes of ALI associated with SIRS. The results of this study suggest the clinical usefulness of Sivelestat in this patient population.