In August, Alnylam Pharmaceuticals, Inc., announced that the US Food and Drug Administration (FDA) had granted Orphan Drug Designation to ALN-AT3 for the treatment of hemophilia A. The company, based in Cambridge, Massachusetts, is developing ALN-AT3, a subcutaneously administered (injection just under the skin) RNAi therapy that targets antithrombin (AT) as a way to treat hemophilia A or B, hemophilia A or B with inhibitors, and other rare bleeding disorders. AT is a small plasma protein molecule that inactivates factor Xa and thrombin, which are needed for blood clotting.
ALN-AT3 incorporates Alnylam’s proprietary gene-silencing technology called RNAi, or RNA interference. Discovered by scientists in the late 1990s, RNAi is a natural process in which cells turn off, or silence, the activity of specific genes. ALN-AT3 silences certain genes associated with AT generation, “switching off” the protein’s production.
At the XXIV Congress of the International Society on Thrombosis and Haemostasis, June 29-July 4, in Amsterdam, Alnylam shared preclinical data from animal trials. The studies revealed that ALN-AT3 improved thrombin generation in mice and nonhuman primates.
Alnylam plans to file an investigational new drug application for ALN-AT3 in late 2013. It will initiate a Phase I clinical trial in humans in early 2014.
“We are very pleased that the FDA has granted Orphan Drug Designation for ALN-AT3 now for both the treatment of hemophilia A and hemophilia B. As a subcutaneously delivered RNAi therapeutic, we believe it represents an innovative approach for the management of hemophilia and has great potential to make a meaningful impact in the treatment of this often debilitating bleeding disorder,” said Saraswathy (Sara) Nochur, PhD, Senior Vice President, Regulatory Affairs and Quality Assurance at Alnylam. “ALN-AT3 is a key program in our ‘Alnylam 5x15’ product development and commercialization strategy, and we look forward to advancing this promising RNAi therapeutic into the clinic in the months to come.”
Sources: The Wall Street Journal, August 14, 2013, and Alnylam news release dated August 20, 2013