AstraZeneca is developing the oral Direct Thrombin Inhibitor – DTI to be known as Exanta. As the first fixed dosage, oral anti-coagulant to be approved ever since the introduction of warfarin over 50 years back, it was seen as the significant new treatment for the prevention and treatment for Venous Thrombo Embolism – VTE and possibly for the prevention of stroke in patients having arterial fibrillation. 

Exanta functions by reducing the action of thrombin in the coagulation cascade. Thrombin transforms the soluble protein fibrinogen to soluble fibrin in the final stage of blood coagulation. By reducing the action of thrombin, the wonder drug Exanta prevents blood clot formations. AstraZeneca had filed the application for the drug approval in Europe and the US during the year 2003 and later attained the approval in France for the Venous Thrombo Embolism – VTE prevention in those patients who were undergoing orthopedic surgeries.

However, the application was rejected by the United States Food and Drug Administration for Exanta for the recommendation of its cardiovascular and renal drug’s advisory committee. During March of 2006, AstraZeneca decided to withdraw Exanta from the market due to the reasons of safety and terminate further development of that drug. The efficacy and safety of Exanta for the prevention of VTE in the patients undergoing most important orthopedic surgeries has been investigated during the series of large scale phase 3 trials.

The stroke prevention is the most vital clinical need that remains unmet. The possibilities of using Exanta in the stroke prevention in patients having arterial fibrillation are under investigation in a series of clinical trials that include SPORTIF III and SPORTIF V – Stroke Prevention Oral Thrombin Inhibitor in Arterial Fibrillation. Though the eligible patients would no longer have access to Exanta due to its recent withdrawal for safety reasons, AstraZeneca however, remain committed to develop the oral anti-coagulants. The development work on the related compound is already on.