Alnylam Pharmaceuticals said this week that the US Patent and Trademark Office has issued a notice of allowance for a company patent application covering "certain chemically modified siRNAs of any length directed to any target, including siRNAs with sterol conjugates, for in vivo delivery."
The patent application, No. 20050107325, is entitled "Modified iRNA Agents," and specifically claims RNAi agents that "preferably include a monomer in which the ribose moiety has been replaced by a moiety other than ribose," its abstract states. "The inclusion of such a monomer can allow for modulation of a property of the … agent into which it is incorporated," for example by using the non-ribose moiety as a point to which a ligand or other entity, such as cholesterol, is directly or indirectly tethered.