The ranking covers 100 companies, with the single leading assignee holding 3,186 records against a fifth-place figure of 579 and a tenth-place figure of 385. That gradual drop-off means the field is led by a handful of large biotech and pharma portfolios but is not dominated by any one of them — the top 10 combined account for 37.3% of all 26,460 records in scope. Anyone doing freedom-to-operate work should treat the ranked leaders as the first screen, then check the long tail of smaller filers for narrower blocking claims.

Annual filings peaked at 1,369 in 2020 and had eased to 1,150 by 2024, a -6% change over that three-year span rather than continued growth. Figures for 2025 and 2026 look lower still, but that reflects publication lag of roughly 18 months rather than an actual collapse in filing. The safest reading is that the field has plateaued after its 2020 peak, not that it is shrinking.

Both terms sit inside the same search scope used to build this landscape, and records frequently claim mechanism-of-action or resistance-mechanism language that applies across payload families rather than to one chemistry alone. The technology composition data shows heavy overlap between C07K peptide claims (28.6% of records) and C07D heterocyclic compound claims (17.9%), which is consistent with both payload classes being claimed alongside shared formulation and delivery language under A61K. Distinguishing the two chemistries precisely requires reading claim language directly rather than relying on IPC classification alone, since neither payload family maps to a single subclass.