Subsidiary Companies: Leonardo Biosystems

Leonardo Biosystems is a drug delivery company built around technology developed by Dr. Mauro Ferrari, one of the world's best-known nano-cancer scientists.  Leonardo has a multi-stage delivery platform that has been shown in animal models to be highly effective in targeting delivery of siRNA and small molecule drugs.  The company expects to enter into commercial development partnerships in 2010.  Leonardo was co-founded by Dr. Chris Anzalone, Arrowhead Research's CEO, prior to his employment by Arrowhead. Dr. Anzalone serves as the CEO of Leonardo. 

Arrowhead Research (Nasdaq: ARWR) holds minority interest in Leonardo Biosystems.