United States Patent 10,088,479: What the Claims Really Cover and Where the Landscape Can Be Cleared

United States Patent 10,088,479 (US10088479) claims antibody- or MS-based detection of citrullinated tenascin-C (TNC) “fibrinogen-like globe (FBG) domain” and specific citrullinated fragments, and the use of those measurements to diagnose rheumatoid arthritis (RA), monitor progression, and monitor treatment efficacy. The claims also cover detection of autoantibodies that bind citrullinated tenascin-C (citr-TNC), including embodiments using immobilized analytes/antibodies and immunoassay formats, and a diagnosis-and-treat method that maps positive binding results to RA treatment categories including standard-of-care drug classes.

From a portfolio and freedom-to-operate (FTO) lens, the patent’s enforceable hooks are (1) the specific antigen definition (citrullinated TNC FBG domain or citrullinated fragments) and (2) the specific capture/detection architecture (antibody binds citrullinated arginine residues in the FBG domain, plus optional quantification relative to reference values; or MS detection). The landscape risk concentrates around any prior art that discloses citrullinated TNC immunoreactivity (especially in RA), similar immobilized binding assays, and any mass-spectrometry profiling of citrullinated TNC epitopes.

What the Independent Claim(s) Actually Claim (and What They Don’t)

1? Is the core invention detection of citrullinated TNC for RA association?

Yes. Claim 1 is a method of detecting “a citrullinated fibrinogen-like globe (FBG) domain of tenascin-C or a citrullinated fragment of the FBG domain of tenascin-C associated with the presence of rheumatoid arthritis,” via either:

(i) Immunodetection: contacting a biological sample with an antibody that specifically binds citrullinated arginine residues in the TNC FBG domain (or citrullinated fragments of that domain) and detecting antibody binding; or
(ii) Mass spectrometry: detecting the citrullinated TNC FBG domain (or fragments) directly by MS.

Claim 1 is broad on modality (antibody vs MS) but constrained on target (citrullinated TNC FBG domain or its citrullinated fragments) and epitope class (citrullinated arginine residues in the FBG domain are explicitly required for the antibody embodiment).

4? Is monitoring progression and treatment efficacy part of the same inventive concept?

Yes. Claim 4 uses claim 1’s target in a longitudinal design:

First time point: measure (i) citrullinated TNC FBG domain/fragments relative to normal/reference values and/or (ii) autoantibodies binding to citrullinated TNC FBG domain/fragments relative to normal/reference values; then
Second (and optionally subsequent) time point: detect changes in the same analytes relative to reference values, with directions tied to RA progression versus effective/in-effective treatment.

This is not “just diagnosis.” It is a paired time-point monitoring protocol tying assay signals to clinical decisions.

10, 15, 19? Do the claims also cover autoantibodies and full diagnosis-treatment workflows?

Yes, in separate claim families:

Claim 10: detect autoantibodies against citrullinated TNC FBG domain or citrullinated fragments using a support-bound citrullinated antigen.
Claims 15 and 19: broaden to specific citrullinated residues or fragments mapped to particular SEQ ID NO: 70 residue selections (citr50, cit51, cit55, cit72, cit120, cit169, cit173, cit209, cit214, cit219m, cit220, cit222). These map citrullination sites/peptide definitions to antibodies or antigens immobilized on a support, and then to diagnosis (claim 19).
Claim 19: explicitly adds diagnosing RA when specific binding is detected relative to control/reference and then treating RA in the diagnosed subject.

Claim-by-Claim Critical Scope (Where Enforcement Is Likely and Where It Is Narrow)

Claim 1 (detection)

Enforcement leverage

Strongest constraints:
- the antigen is citrullinated TNC FBG domain or a citrullinated fragment of that FBG domain
- antibody must bind citrullinated arginine residues in that region (for the antibody arm)
The MS arm requires detection of the same antigen/fragments by MS.

What claim 1 does not clearly cover

Non-AB detection methods other than MS: the claim’s alternative is “detecting … using mass spectrometry.” It lists antibody-based detection and MS; it does not expressly claim other orthogonal platforms like LC-MS/MS with defined sample prep, or signal amplification formats beyond generic “detect binding.”

Claims 2, 5 (relative quantification and reference logic)

Claim 2 requires measuring levels of citrullinated TNC FBG domain/fragments relative to normal/reference values.
Claim 5 clarifies reference values can be initial levels (within-subject longitudinal comparator), previously tested levels (within-subject), or both.

Practical implication

A design-around could attempt to avoid “relative to normal and/or reference values” by using absolute cutoffs or fixed thresholds not framed as “reference values.” But the claim wording is broad enough that “reference values” can include baselines; the safe route is unclear.

Claims 3, 8 (immobilized antibody and/or antigen on support)

Claim 3: immobilized antibody.
Claim 8: immobilized antibody and/or immobilized citrullinated TNC/fragment on a support.

Portfolio impact

Many RA antibody assays use immobilized capture anyway (ELISA/sandwich formats), so these limitations often do not meaningfully narrow real-world infringement risk.

Claims 4, 7, 9 (longitudinal monitoring + “directionality” to progression/effectiveness)

Claim 7 explicitly ties:
- decreased citr-TNC levels and/or decreased autoantibodies to reduced progression/effective treatment, or
- increased citr-TNC levels and/or increased autoantibodies to progression/ineffective treatment.

This matters because it can anchor the patent to clinical interpretation rather than “mere measurement,” which can affect enforcement posture (medical device/diagnostic claims often live or die on the exact clinical decision logic).

Claims 6, 9, 12, 16, 22 (sample types)

Covered samples include blood/serum/plasma/synovial fluid/joint tissue (and in claim 22 adds CSF, urine, saliva, stool). This breadth reduces the chance of avoiding the patent by switching matrices.

Claims 10 to 14 and 17 to 18 (autoantibody detection + assay detection methods)

Claim 11 lists multiple detection readouts: immunoassay, ELISA, sandwich ELISA, immunoprecipitation, immunoblotting (Western), slot/dot blot, isoelectric focusing, SDS-PAGE, antibody microarrays, immunohistological staining, RIA, fluoroimmunoassay, avidin-biotin/streptavidin-biotin immunoassay.
Claim 13 lists similar modalities for claim 1 (antibody binding detection).

Critical point The claim language is permissive. If your RA diagnostic uses immobilized citrullinated TNC antigens and reads out binding with standard immunoassay formats, it maps well to these claim families.

Claims 15, 24-27 (specific citrullination residue/peptide definitions)

These claims pivot from “citrullinated TNC FBG domain/fragments” to explicitly defined citrullinated residues within SEQ ID NO: 70:

Residues: cit50, cit51, cit55, cit72, cit120, cit169, cit173, cit209, cit214, cit219m, cit220, cit222.
Peptides: SEQ ID NO: 55, 57, 59, 61, 63, 64.
Claims 24-27 tie the antigen definitions to RA diagnosis and autoantibody detection.

Critical scope consequence

These claims are narrower than claim 1 in target specificity, but they increase certainty about what “the invention” is biologically and what epitopes are anchored for enforcement.

Claims 19 to 21 (diagnose and treat + specific therapy classes)

Claim 19: diagnose RA based on specific binding to immobilized citrullinated TNC (including defined citrullinated residues/peptides) and/or specific binding of autoantibodies to those antigens, then treat.
Claim 20 lists therapy categories including:
- anti-TNF, anti-IL17, T-cell co-stimulation modulator (abatacept), IL-6 inhibitor, anti-CD20, BAFF, JAK inhibitor, Syk inhibitor
- anti-TNC antibody and antibody to citrullinated domains of citrullinated TNC
- agent modulating biological activity of citrullinated/non-citrullinated TNC
Claim 21 provides specific examples including tocilizumab, rituximab, abatacept, and named small molecules for JAK and Syk.

Enforcement reality If a commercial diagnostic directly drives a therapeutic decision, claim 19’s combination approach becomes relevant. If a provider uses the diagnostic for triage but treatment is decided independently, practical infringement analysis becomes fact-specific. Still, the claim as written ties diagnosis and treatment in the method.

Technical and Legal “Claim Hooks” That Matter for FTO

Hook A: “citrullinated TNC FBG domain” is the antigen boundary

The claims repeatedly anchor to TNC FBG domain and fragments. Any prior art or competitor assay that uses citrullinated TNC but not the FBG domain, or targets different TNC domains, may fall outside the narrow scope.

Hook B: “citrullinated arginine residues” in that domain for antibody binding

For antibody-based detection (claim 1 i), the antibody must specifically bind citrullinated arginine residues in the TNC FBG domain (or fragment). A diagnostic using antibodies that bind non-citrullinated TNC, or citrullinated epitopes outside this domain, does not neatly map.

Hook C: Immobilized format is repeatedly claimed

The support-bound architecture is standard in immunoassays and is explicitly claimed in multiple places (claims 3, 8, 10, 15, 19).

Hook D: Reference/baseline logic is claimed

The longitudinal monitoring claims expect comparisons to reference or baseline values. Competitors that use purely prognostic scoring without reference change logic could attempt to avoid claim 4/7, but the boundary is not clean given the breadth of “reference values” in claim 5.

Patent Landscape: What to Search and How the Claims Shape the Search Strategy

This landscape analysis focuses on identifying patent classes that would most likely collide with the independent claim themes: citrullinated tenascin-C antigen/epitope detection; RA diagnostics; immobilized citrullinated antigen arrays; longitudinal RA monitoring using citrullinated biomarkers; and MS-based profiling of citrullinated proteins.

1? Patents covering “citrullinated proteins as RA biomarkers”

Collision likelihood: medium to high.

Claim 1 is not limited to tenascin-C generally; it is limited to citrullinated TNC FBG domain/fragments. Broad RA citrullinated protein diagnostics are less directly anticipating claim 1, but they can still supply obviousness combinations.
The most relevant prior art is citrullinated biomarker panels for RA and anti-citrullinated protein antibody (ACPA)-like detection platforms that might adapt citr-TNC.

2? Patents covering tenascin-C or TNC antibodies in RA

Collision likelihood: medium.

Any TNC-targeting in RA can create obviousness pressure, but claim 1 requires citrullination and the FBG domain/fragments. So the key is whether earlier documents use citrullinated TNC epitopes or citrullination-specific antibodies.

3? Patents covering citrullinated tenascin-C specifically

Collision likelihood: high.

The residue/peptide mapping in claims 15/24-27 is a major sign that the inventors characterized specific citrullinated epitopes. If prior art already discloses citrullinated TNC epitopes (especially in RA) and antibody/autoantibody detection, it can directly narrow freedom to operate.

4? Patents covering immobilized antigen autoantibody detection formats

Collision likelihood: high (format-level).

The claims list common immunoassay modalities, microarrays, and immunoblotting. Many diagnostic patents can anticipate or render obvious the “support-bound antigen to capture autoantibodies” structure even if they use different antigens. The risk is higher if the antigen is citr-TNC FBG domain/fragments.

5? Patents covering MS detection of citrullinated protein domains

Collision likelihood: medium.

Claim 1 includes MS detection of citrullinated TNC FBG domain/fragments. If prior art uses LC-MS/MS to profile citrullination of extracellular matrix proteins in RA, obviousness risk rises. Anticipation requires the same antigen definition.

Practical Infringement Scenarios Based on the Claim Set

Scenario	Mapped claim language	Likely risk level
ELISA where wells are coated with citrullinated TNC FBG domain or fragments; patient serum is added; signal is measured	Claim 10 + claim 11; Claim 15/19 antigen immobilized on support	High
Diagnostic kit uses immobilized citrullinated peptide(s) corresponding to SEQ ID NO: 55/57/59/61/63/64 with citrullinated residues from SEQ ID NO: 70; detects RA via binding to immobilized antigen and/or autoantibodies	Claim 15 + 19 (diagnose) + 24-27	High
Assay measures citrullinated TNC FBG domain directly in patient plasma using MS (LC-MS/MS)	Claim 1 (MS arm)	Medium to High
Longitudinal monitoring: baseline then follow-up, reporting change in citr-TNC FBG signal vs reference/baseline; clinician uses directionality for treatment effectiveness/progression	Claim 4 + 7 + reference logic in claim 5	Medium to High
TNC-agnostic RA citrullinated biomarker panel (e.g., citrullinated vimentin) not using citr-TNC FBG domain/fragments	Not directly mapped to claim antigen definition	Low for direct anticipation; medium for obviousness in combinations

Key Patent-Strategy Implications

A: The strongest threat is not the assay format; it is the antigen definition

Even if competitors use different ELISA/sandwich formats, claim 1’s antigen definition and claim 10/15/19’s immobilized citrullinated antigen definitions are the primary infringement axis. Unless the competitor changes target chemistry (domain/fragments) or avoids citrullination epitopes in the defined FBG region, format changes alone do not provide a reliable design-around.

B: The SEQ ID residue/peptide mapping increases the “known identity” of the epitopes

Claims 24-27 and 25/27 provide explicit citrullinated residues and specific peptide sequences. That makes it easier to argue that a specific competitor antigen includes (or excludes) the same epitope set.

C: The diagnostic decision logic can matter for method claims

Claim 19 ties diagnostic detection to RA diagnosis and then treatment. If a commercial workflow packages both the test and a protocol for diagnosing RA in a way that drives treatment, the claim set becomes more operational. If the test is used as an informational biomarker without the claimed diagnostic step, infringement exposure depends on how the method is practiced.

Key Takeaways

US10088479 centers on citrullinated tenascin-C FBG domain (or citrullinated fragments) detection in RA using (i) citrullination-specific antibodies or (ii) mass spectrometry (Claim 1).
The patent extends detection into longitudinal RA monitoring and treatment efficacy/progression interpretation via baseline and follow-up comparisons (Claims 4, 5, 7).
It also covers autoantibody detection by capturing autoantibodies with immobilized citrullinated TNC antigens/peptides (Claims 10, 11, 15, 19).
The residue/peptide mapping to citrullinated residues from SEQ ID NO: 70 and specific peptides (SEQ ID NO: 55, 57, 59, 61, 63, 64) narrows biological identity and supports targeted enforcement (Claims 15, 24-27).
The landscape collision is most likely around patents that already disclose citrullinated TNC immunoreactivity or citrullinated TNC autoantibody diagnostics, plus the standard immobilized autoantibody assay format.

FAQs

1) What is the patent’s main diagnostic readout?

It is detection of citrullinated TNC FBG domain/fragments either by citrullination-specific antibody binding or by mass spectrometry (Claim 1), and optionally detection of autoantibodies that bind those citrullinated antigens (Claims 4, 10, 15, 19).

2) Does the patent require immobilization of the antibody or antigen?

Not for all independent pathways. Claim 1 includes a non-immobilized antibody possibility in the abstract sense, but multiple dependent claims require immobilized antibody and/or immobilized antigen on a support, and autoantibody detection claims use immobilized citrullinated antigen on a support (Claims 3, 8, 10, 15, 19).

3) Is mass spectrometry only an alternative, or does it define a separate protected scope?

Mass spectrometry defines an alternative detection arm in Claim 1: detecting the citrullinated TNC FBG domain/fragments “using mass spectrometry.”

4) Are the claims tied to specific citrullination sites?

Yes in the narrower claim set: Claims 15 and 19 and their dependencies define citrullinated amino acid residues selected from cit50, cit51, cit55, cit72, cit120, cit169, cit173, cit209, cit214, cit219m, cit220, or cit222 of SEQ ID NO: 70, and/or peptides specified by SEQ ID NO: 55, 57, 59, 61, 63, 64 (Claims 15, 19, 24-27).

5) Does the patent cover diagnosing and then treating RA?

Yes. Claim 19 explicitly requires diagnosing RA based on detected binding and then treating RA in the diagnosed subject, with treatment categories listed in Claims 20-21.

References

[1] US Patent 10,088,479 (United States Patent Application Publication/Issued Patent record).

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Genentech, Inc.	RITUXAN	rituximab	Injection	103705	November 26, 1997	10,088,479	2035-01-13
Bristol-myers Squibb Company	ORENCIA	abatacept	For Injection	125118	December 23, 2005	10,088,479	2035-01-13
Bristol-myers Squibb Company	ORENCIA	abatacept	Injection	125118	July 29, 2011	10,088,479	2035-01-13
Bristol-myers Squibb Company	ORENCIA	abatacept	Injection	125118	June 07, 2016	10,088,479	2035-01-13
Bristol-myers Squibb Company	ORENCIA	abatacept	Injection	125118	March 30, 2017	10,088,479	2035-01-13
Genentech, Inc.	ACTEMRA	tocilizumab	Injection	125276	January 08, 2010	10,088,479	2035-01-13
>Applicant	>Tradename	>Biologic Ingredient	>Dosage Form	>BLA	>Approval Date	>Patent No.	>Expiredate

Summary for Patent: 10,088,479