The results were published by Dr Beverly Davidson of the University of Iowa, an academic collaborator of Sirna, Targeted Genetics’ partner for the development of novel therapies for the treatment of Huntington’s disease (HD), and appeared in the online early edition of Proceedings of the National Academy of Sciences (PNAS).
With RNA interference therapy, researchers for the first time have been able to attack the fundamental cause of HD and reduce the protein expression from the disease gene. The study is the first to show that a therapy designed to inhibit the expression of this protein has a beneficial effect on the disease symptoms.
The study used RNA interference (RNAi) to treat a mouse model of HD. Adeno-associated viral (AAV) vectors were used to express the siRNAs (short interfering RNAs) and were directly injected into the brain of mice with HD. Results of the study demonstrated nearly normal movement in the mice and significant improvements in characteristic neurological damage compared to untreated mice.
“Many of the current approaches aimed at treating HD are indirect and target the symptoms of the disease. RNAi gives us the first opportunity to attack the fundamental problem and reduce protein expression from the disease gene,” Davidson commented. “Our results showed that with a partial reduction, disease progression can be delayed, and possibly prevented if given prior to onset.”
In January 2005, Targeted Genetics formed a collaboration to combine its AAV delivery platform with Sirna’s RNAi expertise. The two companies will co-develop an AAV vector-based treatment for HD, sharing development costs and revenues.