Efficacy and Safety of Recombinant Human Soluble Thrombomodulin (ART-123) in Disseminated Intravascular Coagulation (DIC): Results of Phase III Randomized, Double-Blind, Clinical Trial.

Background: Thrombomodulin is a thrombin receptor on the endothelial cell surface that plays an important role in the regulation of intravascular coagulation. Recombinant human soluble thrombomodulin (ART-123) is composed of the active, extracellular domain of thrombomodulin. ART-123 has been shown to have a wider safety margin than other anticoagulants and to have a favorable antithrombotic profile with less bleeding in animal and in vitro experiments. ART-123 is a promising therapeutic natural anticoagulant that is comparable to antithrombin, tissue factor pathway inhibitor and activated protein C.

Objective: We conducted a multicenter, double-blind, randomized parallel-group trial to compare the efficacy and safety of ART-123 to those of heparin for the treatment of disseminated intravascular coagulation (DIC) associated with infection or hematologic malignancy.

Methods: DIC was diagnosed according to the diagnostic criteria established by the Japanese Ministry of Health and Welfare. DIC patients were assigned to receive ART-123 (0.06 mg/kg for 30 min, once a day) or heparin sodium (8 units/kg/h for 24 h) for six days using a double dummy method. The primary efficacy endpoint was DIC resolution rate (rate of recovery from DIC). The secondary endpoints included clinical course of bleeding symptoms, and mortality at 28 days.

Results: 234 DIC patients were randomized (117 in each arm). DIC resolution rate was 66.1% for the ART-123 group and 49.9% for the heparin group (difference 16.2%; 95% CI 3.3–29.1), thus demonstrating that ART-123 is significantly superior to heparin for the improvement of DIC. Patients in the ART-123 group also showed more marked improvement in clinical course of bleeding symptoms (p=0.0271) and the disappearance rate of bleeding symptoms in the ART-123 group was higher than that in the heparin group (35.2% vs 20.9%; difference 14.3%). The incidence of bleeding-related adverse events up to 7 days after the start of administration was lower in the ART-123 group than in the heparin group (43.1% vs 56.5%; difference; −13.4%; p=0.0487). The mortality rate at 28 days in the ART-123 group was 22.0% vs 25.5% in the heparin group (difference −3.4%; p=0.5396). Although no significant differences were seen, 28-day mortality for the ART-123 group was slightly lower. The mortality rate of patients with DIC secondary to infection in the ART-123 and heparin groups was 28.0% (14/50) and 34.6% (18/52), respectively, indicating a 6.6% lower mortality in the ART-123 group.

Conclusion: When compared with low-dose heparin, ART-123 more significantly improves DIC and alleviates bleeding symptoms in DIC patients. The incidence of bleeding-related adverse events is significantly lower with ART-123 than with heparin. Because of its safety and efficacy, ART-123 appears to be a first-line agent in the management of DIC.