Leading RNA interference (RNAi) therapeutics company, Silence Therapeutics plc, has received the US Patent and Trademark Office (USPTO) Notice of Allowance indicating that it will grant patents based on two applications: 12/986,389 and 13/230,084. These cover respectively interfering RNA molecules and lipid complexes used in drug delivery.

The claims allowed on interfering RNA molecules cover any double-stranded ribonucleic acid molecule where O-alkyl modified nucleotides are alternating with unmodified or differently modified nucleotides on both strands having a length of 17 to fewer than 30 ribonucleotides. This kind of modified double-stranded ribonucleic acid molecules form a key component of Silence's RNAi therapeutics. The patent will extend Silence's intellectual property related to double-stranded ribonucleic acid molecules to include molecules of 17 to fewer than 30 base pairs in length for use in methods for the treatment of disease. Importantly, the patent will protect any such double-stranded ribonucleic acid molecule across all therapy areas and cover double-stranded ribonucleic acid molecules irrespective of the specific nucleotide sequence used.

The claims allowed on lipid complexes, the proprietary lipid which is a key element of Silence's drug delivery technology Atufect, cover any composition irrespective of the class of compound to be delivered and irrespective of the disease to be treated.  The patent will both extend and widen Silence's intellectual property IP related to the field of drug delivery.

Commenting on the announcement Dr Klaus Giese, chief scientific officer of Silence, said: "These notifications from the USPTO further strengthens Silence's IP position in the arena of RNAi therapeutics and builds upon the already strong proprietary technology Silence offers its partners. The broad range of RNAi therapeutics in terms of their possible length of base pairs again distinguishes Silence from competitors which provide coverage for only very few lengths, if any.

"We welcome the decision of the USPTO on drug delivery as an appreciation of Silence's contribution. Drug delivery is key for the therapeutic use of functional nucleic acid molecules such as siRNA and miRNA. With this patent, Silence is becoming an even more attractive partner for companies interested in the delivery of a variety of classes of compounds with siRNA and miRNA being only two of them."