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Patent landscape, scope, and claims: |
Patent 8,999,932 Landscape Analysis: Scope, Claim Boundaries, and U.S. Enforcement Risk for Disulfide-Linked SEQ ID NO:2 Conjugates for SHPT
United States Patent 8,999,932 claims a peptide–conjugating group conjugate in which the peptide contains SEQ ID NO:2 and is linked to the conjugating group via a disulfide bond. The core scope is set by: (i) the sequence identity to SEQ ID NO:2, (ii) the disulfide linkage, (iii) the allowable N- and/or C-terminal chemical modifications (including N-terminal acetylation and C-terminal amidation), and (iv) the allowable conjugating group stereochemistry (notably L-Cys and D-Cys, and in one method claim O-Cys). The dependent claim structure expands coverage to pharmaceutical compositions, treatment methods for secondary hyperparathyroidism (SHPT), and PTH lowering, with additional coverage for administration routes (intravenous, transdermal) and combination therapy with vitamin D / analogs / cinacalcet.
Critical enforcement hinge: any accused product or method must match both the SEQ ID NO:2 identity and the linking modality (disulfide bond) to a specified cysteine-type conjugating group. If a competitor uses an alternative linkage chemistry (e.g., thioether, amide, maleimide-thiol adduct not retained as disulfide, non-cysteine carriers, or different conjugation topologies) the claim set tightens sharply.
What is the scope of US Patent 8,999,932 claims for disulfide-linked peptide–cysteine conjugates (SEQ ID NO:2)?
Claim 1 is the independent claim defining the technology core. It requires:
- A conjugate
- Comprising a peptide and a conjugating group
- Peptide comprises amino acid sequence carrrar (SEQ ID NO:2)
- Peptide is linked to the conjugating group by a disulfide bond
What claim 1 covers (practical boundary)
Claim 1 captures a conjugate where the conjugating moiety is attached to the peptide in a way that creates or maintains a disulfide linkage between peptide and conjugating group. With dependent claims, the conjugating group is narrowed to cysteine stereoisomers and in one method dependent claim expanded to O-Cys.
What claim 1 does NOT cover
From the claim set provided, claim 1 does not explicitly cover:
- Non-disulfide linkers
- Conjugating groups other than those later specified in dependent claims (though claim 1 text broadly says “conjugating group,” the dependent claims show the intended focus on cysteine forms; without the full spec, the allowed universe under claim 1 cannot be conclusively bounded beyond the language in the claim itself)
- Peptides that do not include SEQ ID NO:2
How do dependent claims narrow or broaden peptide terminal modifications in US 8,999,932?
Dependent claims 2–3 and 16–17 and 23–24 build terminal chemistry scope.
Claim 2
- N-terminus and/or C-terminus chemical modification is allowed.
Claim 3 (specific terminal modifications)
- N-terminal acetylation
- C-terminal amidation
These terminal modifications matter for both infringement and design-around:
- A competitor that uses unmodified termini may fall outside claims that require acetylation/amidation, but still potentially within claim 1 (which only requires SEQ ID NO:2 + disulfide linkage).
- A competitor that uses acetylation/amidation but changes linkage chemistry would likely avoid claim coverage.
Interpreting impact on enforcement
Because claim 2 is broad (“chemically modified at the N-terminus, the C-terminus, or both”), products with any approved N/C-terminal modifications may still be captured under claim 1 plus claim 2, unless modifications change peptide identity such that SEQ ID NO:2 no longer matches as claimed.
Which conjugating groups and disulfide linkage forms are claimed in US 8,999,932 (L-Cys, D-Cys, O-Cys)?
Claims 4 and 5 (conjugating group stereochemistry)
- Claim 4: conjugating group is L-Cys
- Claim 5: conjugating group is D-Cys
Method claim with O-Cys
- Claim 22: in the PTH-lowering method, conjugating group can be O-Cys
Enforcement implications
- If a product uses L-cysteine or D-cysteine as the conjugating handle and maintains a disulfide linkage, claim 4 or claim 5 pathways are directly implicated.
- If a product uses a different carrier (non-cysteine, or cysteine but linked via a different bond type), the claim chart breaks at the linkage element or the conjugating group element.
- O-Cys being present in method claim 22 suggests a broader definition than L/D cysteine in the method context; any accused product using O-Cys should be assessed against that specific claim set, not just composition or SHPT method claims.
What pharmaceutical compositions are protected by US 8,999,932 (including excipients and formulation scope)?
Independent composition coverage does not exist beyond claim 6, which depends on claim 1.
Claim 6
- Pharmaceutical composition
- Contains the conjugate of claim 1
- Plus a pharmaceutically acceptable excipient
Claims 7–10
- Mirror claims 4–3 in the composition context:
- 7–8: conjugating group L-Cys or D-Cys
- 9: peptide terminal chemical modification (N/C)
- 10: N-terminal acetylation and C-terminal amidation
Practical reading
- Claim 6 captures formulation infringement risk even if the active is already known, so long as the active conjugate matches claim 1 (SEQ ID NO:2 + disulfide-linked conjugate).
- “Pharmaceutically acceptable excipient” is standard and typically hard to design around. The meaningful design-around remains the conjugate structure.
What treatment methods does US 8,999,932 claim for secondary hyperparathyroidism and PTH lowering?
SHPT treatment method
- Claim 11 (independent method):
- Treat secondary hyperparathyroidism (SHPT)
- Administer a conjugate with:
- peptide including SEQ ID NO:2
- disulfide bond to the conjugating group
Route-dependent dependent claims
- Claim 12: intravenously
- Claim 13: transdermally
Conjugating group-dependent dependent claims
- Claim 14: L-Cys
- Claim 15: D-Cys
Terminal modification-dependent dependent claims
- Claim 16: N/C terminal chemical modifications
- Claim 17: N-terminal acetylation + C-terminal amidation
PTH lowering method
- Claim 18 (independent method):
- Decrease parathyroid hormone levels
- Administer the same core conjugate requirements as claim 11
Route-dependent dependent claims
- Claim 19: intravenous
- Claim 20: transdermal
Conjugating group-dependent dependent claims
- Claim 21: L-Cys
- Claim 22: O-Cys
Terminal modification-dependent dependent claims
- Claim 23: N/C chemical modifications
- Claim 24: N-terminal acetylation + C-terminal amidation
How method claims increase infringement surface
Method claims often increase exposure when:
- A competitor’s generic/biologic label mirrors indication and route.
- A competitor argues “product-only” noninfringement, but practice of a covered method occurs through clinicians using the drug.
What combination therapy scope exists in US 8,999,932 (second therapeutic agent including vitamin D or cinacalcet)?
Claim 25
- “A method for treating a subject” comprising administering:
- the conjugate meeting the claim 1 structural requirements, and
- a second therapeutic agent
Claim 26 (examples)
- Second therapeutic agent is:
- vitamin D
- vitamin D analog
- cinacalcet hydrochloride
Dependent claim structure
- Claims 27–30 replicate conjugating group and terminal modification variants:
- conjugating group L-Cys or D-Cys
- N/C terminal chemical modifications
- N-terminal acetylation + C-terminal amidation
Infringement pattern to monitor
Combination method claims are a risk in:
- Labeling or co-administration protocols for SHPT in CKD-MBD.
- Fixed-dose combinations if they exist or are clinically adopted under the label.
How strong is the patent estate’s coverage based on the claim set text provided (what elements control validity and infringement)?
Infringement elements likely to dominate:
- Identity to SEQ ID NO:2: “peptide comprises the amino acid sequence carrrar (SEQ ID NO:2).” If SEQ ID NO:2 is essential and narrowly defined in the specification, claim scope is sequence-locked.
- Disulfide bond linkage: This is the structural control point; many design-arounds use different chemistry to avoid disulfide.
- Conjugating group identity: Dependent claims specifically cover L-Cys, D-Cys, and in one method context O-Cys.
- Route of administration: Intravenous and transdermal appear in dependent claims. Route matters if only those routes are practiced or if a label includes them.
Claim scope granularity:
- Claim 1 is relatively broad structurally, but depends on two hard constraints: SEQ ID NO:2 and disulfide linkage.
- Dependent claims then add practical narrowing to specific terminals and cysteine stereochemistry.
- Combination therapy creates broader “real-world” infringement opportunities even if the conjugate is used off-cycle with standard-of-care.
What patent landscape issues typically arise around a disulfide-linked peptide conjugate claim like 8,999,932?
Likely adjacent patent categories (based on claim architecture)
The claim set itself suggests common neighboring IP families:
- Peptide sequence / composition of matter families around SEQ ID NO:2 and terminal modifications.
- Conjugation chemistry families (disulfide linking methodology, cysteine conjugation handles).
- Formulation patents (excipients and dosage forms) built off the conjugate.
- Method-of-use patents for SHPT and PTH lowering.
- Combination regimen patents with vitamin D analogs and cinacalcet.
Freedom-to-operate fault lines
For FTO in the U.S., infringement risk depends less on excipients or routes and more on whether the active conjugate:
- Uses SEQ ID NO:2
- Maintains a disulfide bond between peptide and conjugating group
- Uses a conjugating group matching L/D/O-Cys under the relevant dependent claims
What generic entry risks exist under US 8,999,932 (and how do you evaluate design-arounds)?
Because claim 1 is a conjugate of a specific peptide sequence linked by a disulfide bond, the main generic entry risk is tied to whether a follow-on can be made that:
- Avoids the disulfide linkage, or
- Uses a non-matching peptide sequence (not “SEQ ID NO:2”), or
- Uses a conjugating group outside the claimed cysteine variants and dependent claim scope.
Design-around evaluation checklist (claim-mapping logic):
- Linkage chemistry: disulfide vs non-disulfide.
- Peptide: exact sequence inclusion vs different terminal processing that breaks SEQ ID NO:2 identity.
- Conjugating group: L-/D-/O-Cys vs other handles.
- Indication and route: if infringement is litigated under method claims, label and administration route matter.
What litigation, Orange Book status, and FDA exclusivity affect enforcement of US 8,999,932?
None of the above can be deterministically analyzed from the information provided: the supplied text is limited to claim language and does not include the drug name, assignee, application number, FDA product code, Orange Book listing, or expiration/term details. Without those identifiers, any attempt to map 8,999,932 to a specific marketed product, listed patent, or exclusivity mechanism would be speculative.
Key Takeaways
- US 8,999,932 centers on a SEQ ID NO:2 peptide conjugate connected through a disulfide bond to a cysteine-type conjugating group.
- The strongest infringement hook is claim 1: SEQ ID NO:2 + disulfide linkage.
- Dependent claims expand coverage to:
- N-terminal acetylation and C-terminal amidation (claims 3, 10, 17, 24, 30)
- L-Cys and D-Cys conjugating groups (claims 4, 5, 7–8, 14–15, 21, 27–28)
- O-Cys in the PTH-lowering method (claim 22)
- Formulations with pharmaceutically acceptable excipients (claim 6)
- SHPT treatment and PTH lowering by intravenous or transdermal administration (claims 12–13, 19–20)
- Combination therapy with vitamin D/analogs/cinacalcet (claims 25–26)
- Design-around strategies, if available, must target the hard elements: disulfide linkage and SEQ ID NO:2 identity.
FAQs
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What claim element is the primary design-around target for US 8,999,932?
The disulfide bond linkage between the SEQ ID NO:2 peptide and the conjugating group.
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Does US 8,999,932 cover unmodified peptide termini?
The independent claim requires SEQ ID NO:2 + disulfide linkage; terminal modifications are required only in the dependent claims that specifically recite acetylation and amidation.
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Do L-Cys and D-Cys conjugates both fall within the patent?
Yes. Separate dependent claims cover L-Cys and D-Cys conjugating groups.
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Are intravenous and transdermal administration included?
Yes, both appear in dependent method claims for SHPT treatment and PTH lowering.
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Does the patent claim combination use with cinacalcet?
Yes. The combination method claim lists cinacalcet hydrochloride among the permissible second therapeutic agents.
References
No sources were provided or cited in the prompt.
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