US Patent 10,040,859 landscape analysis: IL-33R antibody methods for treating hemophagocytic lymphohistiocytosis (HLH)
Bottom line: U.S. Patent 10,040,859 claims a method of inhibiting/treating cytokine-related diseases using an IL-33 pathway inhibitor that is specifically an IL-33 receptor (IL-33R)–specific antibody or fragment. The claims are written broadly to cover HLH in multiple subtypes (familial/primary, secondary, malignancy-associated) and also cover combination therapy with standard HLH agents (including IL-1 blockade via rilonacept, canakinumab, gevokizumab). From a competitive and litigation perspective, the key issue is whether competitors’ IL-33 axis drugs either bind IL-33 itself or bind IL-33R, and whether they practice the claimed “IL-33R antibody or fragment” method steps in HLH (including FHL/SHLH forms).
What is US Patent 10,040,859 and what do its claims cover?
Patent: U.S. Patent 10,040,859
Claim set (as provided): 1 to 9.
Core inventive concept: treating hemophagocytic lymphohistiocytosis (HLH) by administering an IL-33 pathway inhibitor that is an antibody or fragment immunologically specific for IL-33R.
Claim-by-claim claim scope (practical infringement mapping)
Claim 1 (independent):
- Method: “inhibiting or treating a cytokine-related disease or disorder”
- Disease target: HLH
- Inhibitor: IL-33 pathway inhibitor
- Limitation: antibody or fragment immunologically specific for IL-33 receptor (IL-33R)
- Implied clinical act: administering the antibody/fragment to a subject diagnosed with HLH (any causative category unless further limited by dependent claims).
Claim 2 (dependent): adds combination therapy with therapies selected from:
- immunosuppressant
- glucocorticoid
- cyclosporine A
- etoposide
- methotrexate
- IL-1 blocking agent
- rilonacept
- canakinumab
- gevokizumab
This is a formulation-agnostic and regimen-agnostic “further comprises” structure. Any adjudicator will look for actual administration/combination in the claimed context.
Claims 3 to 6:
- Claim 3 adds bone marrow transplant in the method.
- Claim 4 limits HLH to familial (primary) HLH (FHL).
- Claim 5 limits to secondary HLH (SHLH).
- Claim 6 limits to malignancy-associated HLH.
Claims 7 to 9 (antigen specificity refinement):
- Claim 7 narrows the antibody target to the extracellular domain of IL-33R.
- Claim 8 is an administration of an IL-33R-specific antibody.
- Claim 9 is the extracellular domain–specific version.
Practical reading: The independent claim already requires IL-33R-specific antibodies. Claims 7 and 9 add an additional binding epitope constraint (extracellular domain), which matters for “design-around” (binding IL-33R but to a non-extracellular epitope, if feasible) and for claim construction.
What is the relevant IL-33/IL-33R biology and how does it affect claim interpretation?
IL-33 axis in hyperinflammation: HLH is driven by cytokine dysregulation and macrophage activation. The IL-33/IL-33R pathway contributes to inflammatory signaling via IL-33R-expressing immune cells.
How this maps to patent language:
- The claim does not require a particular downstream pathway marker or a dosing schedule.
- It requires an IL-33 pathway inhibitor that is an IL-33R-binding antibody/fragment.
- That ties infringement to biological target engagement: the accused antibody/fragment must be immunologically specific for IL-33R (and in dependent claims 7/9 for the extracellular domain).
Key litigation-relevant term: “immunologically specific for IL-33 receptor (IL-33R)”
- In practice, this typically means binding specificity and functional immunoreactivity. It can be proven by binding assays, cross-reactivity data, epitope mapping, or characterization in the accused product literature.
What patents protect IL-33R antibody methods for HLH in the US?
Critical limitation: With only the claim text and no application metadata (publication number, priority date, assignee, specification identifiers) it is not possible to produce a complete, accurate cross-reference of the complete US patent family and all relevant continuations. Under the operating constraint, only an analysis that can be grounded in identifiable, citable patent records can be produced. With no patent number family data beyond 10,040,859 and no additional bibliographic identifiers, the landscape can only be analyzed at the claim-architecture level.
What can be stated from the claim structure alone:
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US 10,040,859 is an HLH-use patent tied to IL-33R antibodies. The landscape therefore likely includes:
- earlier IL-33R antagonist patents (composition/antibody),
- additional method-of-use continuations covering HLH subtypes and/or combination regimens,
- potentially adjacent IL-33 ligand–neutralizing patents, and
- IL-1 axis combination patents, including rilonacept and canakinumab/gevokizumab use in hyperinflammatory disorders (though those may not be HLH-specific).
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Enforcement leverage: This is a method patent. Competitors can reduce risk by:
- using IL-33 (ligand)–neutralizing antibodies rather than IL-33R–binding antibodies, or
- not practicing the HLH-specific method steps (hard in clinical settings if the indication is used off-label or the label includes it), or
- using alternatives that do not meet the “IL-33R antibody/fragment” requirement (or do not bind the extracellular domain if dependent claims 7/9 are asserted).
How strong is the patent estate for the IL-33R HLH use case?
Claim strength drivers:
- Specific biological target: IL-33R. This narrows the universe of possible infringers to antibodies/agents that bind IL-33R (not merely blocking IL-33 signaling indirectly).
- Specific disease: HLH. That narrows further to clinical use in HLH and its categories.
- Combination coverage (Claim 2): covers broad standard-of-care add-ons; this can reduce “switching” designs where competitors add steroids/immunosuppressants anyway.
Potential weakness drivers (legal and technical):
- “Method of treating HLH” breadth: If IL-33R inhibition is known in HLH, obviousness and motivation arguments can arise, but the assessment depends on the specification and cited prior art in the prosecution record.
- Antibody scope breadth: “antibody or fragment immunologically specific for IL-33R” can be attacked as functionally defined if the claim is supported by limited exemplars and the specification does not provide adequate enablement for the full genus of IL-33R-binding antibodies.
- Epitope refinement (Claim 7/9): if an accused antibody binds IL-33R but not its extracellular domain, dependent claims may be avoided, though the independent claim still targets IL-33R generally.
Enforcement pattern to expect: This type of method claim typically gets asserted against:
- product developers seeking HLH indications for their IL-33R antibody,
- clinical investigators if combination regimens are prescribed in ways that match Claim 2,
- hospitals/contract research only indirectly (most often enforcement is directed at the manufacturer/prescriber via induced infringement theories, depending on case facts).
When does US 10,040,859 lose exclusivity?
Can’t be calculated from provided inputs. Patent exclusivity end dates depend on:
- issue date (known: patent number indicates issuance, but exact issuance date is not supplied),
- application filing date and priority chain,
- term adjustments (PTA),
- patent term for US patents (20 years from earliest non-provisional filing, plus PTA, subject to terminal disclaimers).
Under the constraint, no definitive expiration date is produced without the earliest filing/priority and PTA/terminal disclaimer data.
What is the likely “design-around” space versus IL-33R antibody claims?
Most relevant design alternatives:
-
Use IL-33 neutralization rather than IL-33R binding
- If the accused biologic binds IL-33 ligand and not IL-33R, it may fall outside “immunologically specific for IL-33 receptor (IL-33R).”
- Claim 1 is explicitly IL-33R-binding, so ligand-neutralizing antibodies create an infringement defense.
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Use non-antibody IL-33R inhibitors
- The claim requires “antibody or fragment.” Small molecules, receptor decoys that are not antibody fragments, or other modalities may not meet the literal claim.
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Avoid the extracellular domain epitope (dependent claims)
- If an antibody binds IL-33R in a way that excludes the extracellular domain, Claims 7/9 might be avoidable. Independent Claim 1 could still be asserted, since it only requires IL-33R specificity broadly.
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Avoid HLH as the treated disease
- If a drug is not used for HLH and the label/indication is different, method-of-treatment infringement becomes much harder, depending on whether induced infringement theories are pursued. Clinician off-label use remains a risk vector, but enforceability depends on jurisdiction-specific standards and evidence.
What generic entry risks exist for this patent?
High-level: No “generic” biologic substitute exists for an antibody with a narrow target. The real competitive threat is:
- biosimilar versions of the same IL-33R antibody (if the antibody is off-patent and biosimilar pathway applies), or
- a different IL-33 pathway inhibitor that does not infringe (ligand antibodies, receptor decoys not meeting “antibody or fragment,” or different antigen epitopes with different binding specificity).
Key point for risk modeling: Because US 10,040,859 is a method-of-use patent, even a biosimilar manufacturer may still be blocked from marketing the same HLH indication until method patents expire or are licensed/invalidated.
How does US 10,040,859 compare with adjacent IL-33/IL-1 cytokine patents?
Claim-anchored comparisons (based on claim text):
- The patent ties IL-33R inhibition to HLH treatment and allows combination with IL-1 blockers including rilonacept, canakinumab, gevokizumab.
- This placement suggests the broader patent architecture in the IL-1 space may already exist for hyperinflammatory disorders, but Claim 2 does not require the IL-1 agent to be the sole IL-1 blocker; it is listed as part of a permitted combination set.
Business impact: Even if IL-1 blocker patents expire or license status is favorable, IL-33R HLH method claims can preserve exclusivity for combination regimens.
What patent litigation events would most likely affect HLH IL-33R programs?
Most likely litigation triggers:
- A company files an HLH clinical trial (or seeks a label for HLH) with an IL-33R antibody and then faces a license demand.
- Settlement around a co-development or supply agreement that conditions HLH indication marketing on royalty or carve-outs.
- An inter partes review (IPR) targeting claim validity if the IL-33R approach is considered obvious or not adequately enabled.
What would matter in the record:
- prosecution history for claim construction (e.g., whether IL-33R extracellular domain language was added to distinguish prior art),
- prior art antibody disclosures targeting IL-33R for other diseases,
- whether HLH-specific treatment using IL-33R blockade was known.
No case file details were provided, so litigation status cannot be stated.
What is the Orange Book status of IL-33R HLH therapies under this patent?
Not determinable from provided inputs. Orange Book listings apply to FDA-approved small molecules and certain biologics when they have NDA-type approvals. IL-33R antibodies are typically approved via biologics licensing pathways (and listing details require exact product names/holders).
Key takeaways
- US 10,040,859 claims an HLH method that hinges on administering an IL-33R-specific antibody or fragment as the IL-33 pathway inhibitor.
- Dependent claims expand coverage to HLH subtypes (FHL, SHLH, malignancy-associated) and to typical HLH regimens, including IL-1 blockers (rilonacept, canakinumab, gevokizumab) and bone marrow transplant.
- Design-around is most feasible via modality and target selection: ligand-neutralizing IL-33 antibodies or non-antibody modalities reduce direct fit to “IL-33R antibody or fragment” language; epitope-level differences may matter for the extracellular-domain dependent claims.
- Method patent enforcement means market entry risk is less about “generic manufacturing” and more about indication-specific practice and whether a competitor’s IL-33R-binding biologic is used for HLH.
FAQs
1) Does US 10,040,859 cover IL-33 ligand antibodies or only IL-33R antibodies?
The claim language requires an antibody/fragment immunologically specific for IL-33 receptor (IL-33R), not IL-33 ligand.
2) If a therapy blocks IL-33 signaling downstream, does it infringe?
Only if it is an IL-33 pathway inhibitor that is an IL-33R-specific antibody or fragment under the claim language; downstream-only inhibitors without IL-33R antibody specificity likely do not meet the literal target limitation.
3) Are FHL, SHLH, and malignancy-associated HLH all covered?
Yes. They are expressly covered in dependent claims 4 to 6.
4) Does the patent require bone marrow transplant?
No. Bone marrow transplant is in dependent claim 3. It is optional unless that dependent claim is asserted.
5) What combination therapies are explicitly included?
Claim 2 includes standard immunosuppressants and glucocorticoids plus cyclosporine A, etoposide, methotrexate, and IL-1 blocking agents including rilonacept, canakinumab, and gevokizumab.
References (APA)
No sources were cited because no bibliographic or evidentiary records (e.g., publication data, assignee, priority dates, prosecution history, litigation dockets, FDA product labels) were provided in the input.
