The latest foray in the oft-thorny RNAi patent landscape sees Arrowhead Research Corp. nabbing the entire RNAi portfolio of Novartis AG, picking up rights to a host of intellectual property (IP) and assets, including an existing license agreement with RNAi powerhouse Alnylam Pharmaceuticals Inc., a pipeline of three preclinical candidates and a patent estate the Pasadena, Calif.-based biotech said falls safely outside the scope of competitors' IP.