Alnylam’s McSwiggen patent upheld in European opposition proceedings

The McSwiggen patent estate broadly describes chemical modifications of RNAi therapeutics that the company believes are critical for achieving ‘drug-like’ properties in siRNA, the molecules that mediate RNAi.

The patent is owned by Alnylam, and was recently obtained through the company’s acquisition of Sirna Therapeutics from Merck. The McSwiggen patent family comprises a core component of Alnylam’s overall intellectual property (IP) estate for the advancement of RNAi therapeutics as a new class of medicines.

Alnylam senior vice president and chief business officer Dr Laurence Reid noted the company is pleased with the European Patent Office’s decision to uphold the ‘406 patent from our McSwiggen patent family, a key component of the IP estate we recently obtained through our acquisition of Sirna Therapeutics from Merck.

"This patent has broad and significant claims describing chemical modifications of RNAi therapeutics, which we believe are critical for the development and commercialization of all RNAi therapeutics.

"Our IP estate remains a cornerstone in our efforts to advance RNAi therapeutics to patients in need," Dr Reid added.

The McSwiggen patent family includes 21 granted or issued patents around the world, including patents in the U.S. (7,923,547; 7,956,176; 7,989,612; 8,202,979; 8,232,383; 8,236,944; 8,242,257; 8,268,986; 8,273,866) and the EU (1423406; 1458741; 1627061; 2278004; 2287306), and generally describes the chemical modification of siRNA.

The claims for the McSwiggen ‘406 patent cover compositions for siRNA, including, in general terms, a chemically modified double-stranded RNA that down regulates expression of a target gene by RNAi, wherein:

– each strand is independently 18 to 24 nucleotides in length and each duplex comprises 17 to 23 base pairs; and

– 10 or more pyrimidine nucleotides of the sense and/or antisense strand are chemically modified with 2′-deoxy, 2′-OMe, or 2’F with one or more phosphorothioate and/or a terminal cap at the 5′, 3′ or both, present in the same or different strand.

Granted claims of the ‘406 patent as well as other granted Alnylam owned or licensed patents are provided on the company’s website, and in aggregate broadly cover siRNA and their use in a wide range of lengths from 15 to 49 nucleotides, and chemical modifications with naturally or non-naturally occurring nucleotides, including, for example acyclic nucleotides such as those termed ‘unlocked nucleobase analogs’.

In addition, Alnylam’s owned or licensed patents broadly cover delivery of RNAi therapeutics, including those that employ GalNAc-siRNA conjugate technology. Finally, Alnylam’s IP estate also includes patents that broadly cover siRNA toward a wide range of disease targets.