Coagulant Effect and Tolerability of Yeast-Produced Recombinant Batroxobin in Healthy Adult Subjects

Abstract

Background and Objective Batroxobin, a snake venom thrombin-like enzyme, converts fibrinogen into fibrin by cleaving fibrinopeptide A. It is used for hemostasis; however, the supply of native batroxobin is limited. Therefore, we developed a recombinant batroxobin (r-batroxobin) from Pichia pastoris and evaluated its pharmacodynamics and safety in humans. Methods A randomized, double-blind, placebo-controlled, single ascending-dose study was performed. Eight healthy subjects were enrolled in each r-batroxobin dose group (2.5, 5.0, or 10.0 BU/2.0mL administered intravenously), and randomized to receive r-batroxobin (n=6) or matching placebo (n=2). Safety was evaluated during the study, and pharmacodynamics was assessed using prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen level. Results All subjects in each cohort completed the study. No significant changes in PT or aPTT occurred after intravenous r-batroxobin administration. Compared with the placebo group, the fibrinogen level in all r-batroxobin dose groups decreased significantly to 8.68-33.57% from the baseline within 12h (p <= 0.05). The TT in the 5.0 and 10.0 BU/2.0mL groups significantly increased to 7.53-18.48% from baseline within 12h compared with that of the placebo group (p <= 0.05), whereas that of the 2.5 BU/2.0mL group exhibited non-significant changes compared with the placebo group. No serious adverse events occurred. Conclusions A single intravenous injection of r-batroxobin within a dose range of 2.5-10.0 BU/2.0mL was well tolerated and resulted in a significant decrease in fibrinogen and prolongation of TT.