Fc Engineering Patents: Leaders, Trends & White Space 2026
- 29.1% concentration. The five leading assignees hold 19,775 of the 67,903 records in scope — a genuinely top-heavy field for a therapeutic antibody sub-domain.
- Filings cooled from a 2021 peak. Volume ran from 1,636 records in 2021 to 985 in 2024, a 40% pullback over that span, though 2025-26 figures are still filling in as publications lag filing.
- Two of the five most-cited documents are pre-2000 filings. US6737056B1 and US5648260A still anchor effector-function claim language two decades on, a sign of how much foundational IP underlies current designs.
Filing growth compares 2021 (1,636 records) with 2024 (985) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 67,903 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Fc engineering spans the amino-acid, glycan and receptor-binding modifications that tune how an antibody’s constant region interacts with Fc receptors and complement. This landscape pulls records that combine core concepts — Fc engineering, effector function, neonatal Fc receptor — with the specific mechanisms used to deliver them: afucosylation, complement activation, half-life extension, silenced Fc variants, glycan profiling and receptor binding assays. The scope therefore captures both the biology (what the modification does to ADCC, ADCP or CDC) and the engineering route (how the modification is made and measured).
67,903 published records sit in scope, spanning filings from 2015 through the 2026-07-31 cut-off. Because publication trails filing by roughly 18 months, the most recent one to two years understate real filing activity and should be read as provisional.
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Filing trend and technology composition
Two views of the same 67,903-record corpus: how filing volume has moved year over year, and which IPC subclasses carry the claim density.
Filing trend: a 2021 peak, then a pullback
Annual filings rose to a peak of 1,636 records in 2021, then eased to 985 by 2024 — a 40% decline over that three-year window. 2017 opened the tracked window at 1,124 records; years from 2025 onward are still incomplete because of publication lag and should not be read as a continued fall.
Where the claims sit: peptide chemistry and formulation dominate
C07K (peptides and proteins) covers 25.6% of the 67,903 records, ahead of A61K (medicinal preparations) at 19.4% and A61P (therapeutic activity) at 12.8%. Downstream production and analysis classes — C12N, G01N, C12P — sit in the single digits, suggesting the field's claim pressure is concentrated on the molecule itself rather than on manufacture or assay method, which is where openings tend to sit.
Shares are the percentage of the 67,903 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Fc Engineering and Effector Function with Eureka
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Try EurekaThe documents anchoring this field
US7790858B2 — Polypeptide variants with altered effector function
The present invention concerns polypeptides comprising a variant Fc region. More particularly, the present invention concerns Fc region-containing polypeptides that have altered effector function as a consequence of one or more amino acid modifications in the Fc region thereof.Filed by Genentech, granted 2010-09-07 — part of a family that includes several of the field's most-cited prior documents.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US6737056B1 | Polypeptide variants with altered effector function | 7,652 |
| 2 | US5648260A | DNA encoding antibodies with altered effector functions | 7,516 |
| 3 | US6194551B1 | Polypeptide variants | 6,894 |
| 4 | WO2000042072A2 | Polypeptide variants with altered effector function | 4,987 |
| 5 | WO1999051642A1 | Antibody variants and fragments thereof | 4,771 |
| 6 | US20030157108A1 | Glycoprotein compositions | 4,087 |
| 7 | US6982321B2 | Altered antibodies | 3,434 |
| 8 | US7332581B2 | Polypeptide variants with altered effector function | 3,101 |
| 9 | WO2010077634A1 | Anti-PD-l1 antibodies and their use to enhance t-cell function | 2,970 |
| 10 | US20050123546A1 | Antigen binding molecules with increased Fc receptor binding affinity and effector function | 2,849 |
Citation counts reflect an older, foundational skew: pre-2010 filings accumulate citations simply by being available longer, so treat this as a map of influence, not of current claim strength.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three read-throughs from the concentration, trend and citation data above.
A top-heavy field, but not a closed one
The five leading assignees hold 29.1% of the 67,903 records in scope, and the top ten extend that to 35.5%. That leaves the majority of filings spread across a long tail of single- and few-filing entrants, so freedom-to-operate work still needs to check well past the household names.
Volume has eased from its 2021 high, not collapsed
Filings ran from 1,636 records at the 2021 peak to 985 in 2024. Several of the most active assignees also show sharp year-on-year drops in the latest tracked year, but that year is still filling in under publication lag, so read the direction rather than the exact percentage.
Molecule-level claims crowd out process claims
C07K and A61K together touch close to half of all records once overlap is accounted for, while assay and production classes (G01N, C12P, C12Q) sit under 4% each. That imbalance is where less-contested claim territory tends to sit — in how a variant is made or measured rather than in the variant itself.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to fc engineering and effector function, with the prior art for and against each one.
Who is filing, and where the activity is slowing
The ranked leaders span both large-molecule originators and specialist antibody-engineering houses. Recent-year momentum figures should be read with the same publication-lag caveat as the overall trend: a steep year-on-year drop in the latest tracked year is partly an artefact of records not yet published.
A single assignee well ahead of the field
The leading assignee holds 11,107 records, well clear of fifth place at 993 and tenth place at 825 — a gap that says more about filing volume over a decade than about any single blocking patent.
A tight band from fifth to tenth
The drop from fifth place (993 records) to tenth (825) is far shallower than the drop from first to fifth, indicating a genuine mid-tier of comparably active filers rather than a sharp cliff after the leader.
Co-filing concentrates around a handful of pairs
Ten co-assignee pairs recur across the corpus, with the strongest pairing appearing 389 times and the next two above 200 — evidence of durable, structured research partnerships rather than one-off joint filings.
| Assignee | Recent year | YoY |
|---|---|---|
| Genentech, Inc. | 7 | -89% |
| F. Hoffmann-La Roche Ltd | 7 | -50% |
| Alexion Pharmaceuticals, Inc. | 5 | -62% |
| F. Hoffmann-La Roche AG | 4 | -90% |
| Omeros Corporation | 2 | -50% |
| Chugai Pharmaceutical Co., Ltd. | 2 | -78% |
| Genmab A/S | 2 | -83% |
| Xencor, Inc. | 1 | -93% |
Where to take this from here
The landscape points to specific next checks rather than a single conclusion.
Check freedom-to-operate against the long tail
With 70.9% of records held outside the top five assignees, a clearance search needs to extend well past the obvious originators into the long tail of few-filing entrants.
Run a freedom-to-operate check in Eureka →Map the under-claimed process classes
Assay, production and measurement classes carry far less claim density than the molecule classes. That gap is worth mapping in detail before committing to a filing strategy.
Explore white space in Eureka →Track momentum, not just totals
Recent-year drops across several leading assignees may reflect publication lag as much as a real slowdown. Re-checking this trend in a future data cut will separate the two.
Set up a monitoring search in Eureka →Common questions on Fc engineering patents
One assignee leads clearly with 11,107 records, well ahead of the field. Filing density then narrows into a tighter mid-tier between fifth place (993 records) and tenth place (825 records), rather than falling off a cliff after the leader. Together the five leading assignees account for 29.1% of the 67,903 records in scope, so the field is concentrated but far from closed to new entrants.
Filing volume peaked in 2021 at 1,636 records and eased to 985 by 2024, a 40% decline over that span. Data for 2025 and 2026 shows much lower counts, but that reflects publication lag of roughly 18 months rather than a real drop, since filings made in the last year or two are still working through to publication. The honest read is a cooling from a 2021 high, not a collapse.
US7790858B2, assigned to Genentech, claims polypeptides comprising a variant Fc region that carries altered effector function as a result of one or more amino acid modifications to the Fc region. It sits within a family that includes some of the field's most-cited prior filings, including US6737056B1 and US6194551B1. Anyone modifying an Fc region's amino acid sequence to change ADCC, ADCP or CDC activity should review this family's claim scope before finalising a construct.
The technology composition data shows claim density concentrated in molecule-level classes: C07K (peptides and proteins) at 25.6% of records and A61K (medicinal preparations) at 19.4%. Classes tied to production, assay and measurement — G01N, C12P, C12Q — each sit under 4% of records. That gap suggests less-contested ground in how variants are manufactured, assayed or profiled for glycan content, rather than in the variant composition itself.
Recent-year momentum data shows several of the historically active assignees filing in single digits in the latest tracked year, with year-on-year drops as steep as 90% for some. This should be read cautiously: the most recent year or two of any patent trend is understated because publication lags filing by about 18 months, so current activity is likely higher than the raw counts show. A monitoring search refreshed against a later data cut is the only reliable way to confirm whether this is a genuine slowdown.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.