An antibody-drug conjugate has three parts - antibody, linker, payload - but only one of them is usually where the patent fight lives. The 2025 ADC facet confirms it: the contested IP is the conjugation and linker chemistry, not the antibodies.
Aggregate the 2025 ADC grants by owner and the field is full of conjugation specialists. GeneQuantum Healthcare (US12318457B2, glycan-remodeled conjugation), Multitude Therapeutics (US12496354B2, a CD142 ADC), and R.P. Scherer's dual-cleavage linker (US12187810B2) anchor the linker layer; the broader facet adds Sutro Biopharma, Regeneron, Immunome, and Memorial Sloan Kettering.
The CPC clustering is conjugation chemistry throughout: A61K 47/6849 (antibody-cytotoxic conjugates), A61K 47/68031 / 47/6803 (payload-conjugate classes), A61K 47/6889 (linker classes), A61P 35/00 (antineoplastic). The antibody-target tags (C07K 16/xx) appear, but the distinguishing, recurring tags are the conjugation classes - the signature of a linker-and-attachment battleground.
Why does the chemistry dominate over the antibody? Because the therapeutic window of an ADC - the gap between efficacy and toxicity - is set largely by how stably the linker holds the payload in circulation and how cleanly it releases it at the target. Site-specific conjugation, cleavage control, and payload design are the variables, and each advance is separately claimable. The antibody is often a known binder; the chemistry is the edge.
For freedom-to-operate, the consequence is that an ADC program's biggest exposure is its conjugation and linker technology. Clearing the antibody target is necessary but rarely sufficient; the program must also navigate the dense, multi-owner linker-and-conjugation estate that the 2025 facet maps. The conjugation specialists - Sutro, GeneQuantum, and others - hold the leverage points that any ADC ultimately has to license or design around.