The US Food and Drug Administration has granted orphan designation to a new drug designed to treat patients suffering from hereditary antithrombin deficiency (HD).

ATryn, developed by GTC Biotherapeutics, is a form of an anti-coagulant, anti-inflammatory protein that patients who do not suffer from the condition have in their blood naturally.

Patients with HD either have too little antithrombin or what they have does not perform its anti-clotting function efficiently, which can lead to the formation of clots that can interfere with blood flow and cause serious damage to vital organs.

Geoffrey Cox, the chairman and chief executive officer of GTC, added that the firm was currently awaiting the end of its phase III study of the drug's usefulness when used to treat people with the condition who "are at risk for developing deep vein thrombosis or thromboembolism while undergoing surgery or childbirth".

In a separate trial LEO Pharma is examining ATryn as a treatment for those with disseminated intravascular coagulation, another rare condition.

Masters can help health providers obtain orphan drugs for patients who have rare medical conditions through its named patient supply programme, which can deliver medicines to locations across the world.