One assignee leads clearly with 1,574 records, well ahead of the next four combined, which together with the leader make up 23.2% of all 12,252 records in scope. Filing counts drop steeply after the leader and then flatten into a long tail across the full 100-company ranking. This pattern suggests the format’s foundational claim space was staked out early by one specialist, while the rest of the field files more narrowly around specific targets or constructs.

Filings rose from 610 in 2017 to a peak of 1,001 in 2021, then declined to 627 by 2024, a 37% drop across that complete-year span. Figures for 2025 and 2026 are still incomplete because publication typically lags filing by around 18 months, so they should not yet be read as a continuation of that decline. The honest read is a post-peak cooling through 2024, with the most recent trajectory still unresolved.

The search underlying this dataset pairs the core single domain antibody or variable heavy domain format with a specific engineering problem: thermal refolding, tissue penetration, epitope accessibility, multivalent construct design, expression yield, or framework humanization. Classification data shows most records sit in C07K (peptides & proteins, 80.1% of records) and A61K (medicinal preparations, 62.2%), meaning the bulk of filings combine a molecule claim with a therapeutic-use claim. Production and analytical classes such as C12P and C12Q are far less represented, at under 5% each.