RNA drugs work only if they reach the right tissue, and muscle is notoriously hard to deliver to. US11525137B2 - "Compositions and methods of treating Facioscapulohumeral muscular dystrophy," issued December 13, 2022 to Avidity Biosciences, Inc. - claims a delivery answer: bolt the silencing RNA onto a muscle-targeting antibody.
The load-bearing limitation is the conjugate architecture. The claim recites an antibody-oligonucleotide conjugate (Avidity's AOC platform) in which a monoclonal antibody that homes to muscle is chemically linked to an oligonucleotide that silences the disease-driving gene. Neither the antibody nor the oligonucleotide alone is the invention - the coupling is.
The CPC profile captures the hybrid nature precisely: C12N 15/113 (antisense/RNAi oligonucleotides), A61K 47/6849 and A61K 47/6807 (antibody-conjugate chemistry), C07K 16/2881 (the targeting antibody), with A61P 21/00 / A61P 21/06 (muscular-disorder treatment) for the indication. This cross-class signature is the fingerprint of a conjugate platform - antibody chemistry plus oligonucleotide chemistry in one claim.
Why does the coupling decide scope? Because the prior art holds plenty of silencing oligonucleotides and plenty of antibodies. The claimed novelty is the specific conjugate that delivers the RNA to muscle for FSHD. A competitor administering a naked oligonucleotide, or a different conjugate, may fall outside a claim drawn to this antibody-oligonucleotide construct for this indication.
For the landscape, antibody-oligonucleotide conjugates represent a convergence neighborhood - the place where the antibody estate (C07K) and the RNAi estate (C12N 15/113) overlap. A freedom-to-operate read for any tissue-targeted RNA therapy has to cover both heritages, because the conjugate claims sit squarely on the seam between them.