batroxobin (Tobishi Pharmaceutical)

Batroxobin (DF-521) is a thrombin-like serine protease enzyme originally isolated from the venom of the pit viper *Bothrops atrox moojeni*. It functions as a defibrinogenating agent by selectively cleaving the Aα-chain of fibrinogen, leading to the formation of fibrin I monomers that are subsequently cleared from the circulation by the reticuloendothelial system or degraded by plasmin. This process results in a controlled reduction of plasma fibrinogen levels, which reduces blood viscosity and may improve microvascular perfusion. Developed by Tobishi Pharmaceutical, batroxobin is marketed under the brand name Defibrase in Japan for indications such as sudden sensorineural hearing loss and peripheral circulatory disorders. The company also explored DF-521 for the treatment of amyotrophic lateral sclerosis (ALS), based on the hypothesis that reducing fibrinogen-mediated neuroinflammation and vascular dysfunction could slow disease progression. However, an exploratory clinical study in Japan for ALS was terminated early due to high patient withdrawal rates and safety concerns, including an unexpected decrease in respiratory function.

Brand names

Defibrase

Other names

batroxobin