Scope, Claim Coverage, and US Patent Landscape for US Patent 8,933,030 (Peptide Activators of Guanylate Cyclase C; Linaclotide Combination Formulations)
US Patent 8,933,030 is a formulation-and-combination patent focused on (i) a specific peptide or salt that activates the guanylate cyclase C (GC-C) receptor and (ii) compositions that use that peptide in combination with linaclotide, including tight quantitative limits for peptide content by weight relative to linaclotide and defined co-ingredient classes (divalent cations and sterically hindered primary amines). The claims also extend to method-of-treatment in GI disorders (including IBS and multiple constipation indications) using the specified low-peptide, linaclotide-containing composition.
This analysis breaks down claim scope, claim dependencies, practical infringement touchpoints, and how the broader US patent landscape around linaclotide, GC-C agonists, and GI-combination formulations is likely to shape freedom-to-operate and generic/commercial entry risk.
What is US Patent 8,933,030 and what does it protect?
Core protected subject matter: A GC-C-activating peptide (structure-defined in the claims) and pharmaceutical compositions combining that peptide with linaclotide, with defined limits on peptide loading and defined optional co-ingredients (Mg2+/Ca2+/Zn2+/Mn2+/K+/Na+/Al3+ salts and sterically hindered primary amines), plus method-of-treatment claims tied to the composition.
What do claims 1–3 cover at the active-ingredient level?
Claims 1–3 are the “front door”:
- Claim 1: A peptide (or pharmaceutically acceptable salt) comprising an amino-acid structure identified in the patent text (the user-provided claim includes a placeholder for the amino-acid sequence/structure).
- Claim 2: The peptide “consists of” that amino-acid structure (a narrower variant compared to claim 1’s “comprises”).
- Claim 3: The peptide activates the guanylate cyclase C receptor.
Practical meaning
- Claim 1 uses “comprises,” which typically tolerates additional features not excluded by the specification claim logic. However, the “amino acid structure of …” phrase usually means the peptide includes the recited sequence/structure.
- Claim 2 narrows by requiring the peptide consists of the recited amino acid structure, reducing design-around room (e.g., truncations, added residues, or other structural variants) depending on how the “consists of” language is interpreted in prosecution and claim construction.
What do claims 4–6 cover at the composition level?
- Claim 4: A pharmaceutical composition comprising the peptide/salt of claim 1.
- Claim 5: The composition further comprises linaclotide.
- Claim 6: The composition can include an additional peptide selected from structures listed in the patent (the user-provided text shows placeholders).
Practical meaning
- Claim 5 is the key combination hook: any product meeting claim 1’s peptide scope and including linaclotide can land inside at least the broad composition claim, subject to all further limitations of dependent claims that may be used in enforcement.
How does the peptide-to-linaclotide ratio limit scope, and what does it mean for infringement risk?
Key narrowing limitations appear in claims 7–8. These are operationally important because they convert an active ingredient claim into a formulation quantitative constraint.
- Claim 7: Composition comprises less than 5% by weight of the peptide (or salt) relative to total weight of linaclotide.
- Claim 8: Composition comprises less than 4% by weight of the peptide (or salt) relative to total weight of linaclotide.
Why the ratio matters legally
If a generic or reformulation uses a peptide loading outside these thresholds, it may avoid claims 7–8 (but still could infringe claim 4–6 unless those are also limited elsewhere). Conversely, if a party keeps peptide content below 4–5% by weight, it stays within these dependent-claim bands.
Quantitative touchpoint for claim charts
A typical infringement assessment will treat:
- “peptide content” as the mass of peptide/salt that corresponds to the recited peptide identity; and
- “relative to total weight of linaclotide” as requiring calculation tied to the formulation’s labeled or measured amounts.
Because the claims are weight-based, formulation manufacturing records and batch assay specs become directly relevant in enforcement.
Which additional formulation components are required or optional in US 8,933,030?
Claims 9–14 define co-ingredients that can co-exist with the peptide/linaclotide mixture.
What cations are covered in claim 9–10?
- Claim 9: Composition further comprises one or more agents selected from:
- a cation from: Mg2+, Ca2+, Zn2+, Mn2+, K+, Na, or Al3+, or
- a sterically hindered primary amine.
- Claim 10: If the agent is the cation, it is provided as specific salts (acetate, chloride, phosphate, sulfate) for each named cation.
Scope implication
- This is a defined chemical salts list. Substituting different counterions not in the list may be a potential design-around for parties trying to avoid claim 10’s “provided as” structure, though claim 9’s broader “cation selected from” language could still be asserted depending on how “provided as” is interpreted across the dependent chain.
What sterically hindered primary amines are covered in claim 11–12?
- Claim 11: A sterically hindered primary amine includes:
- naturally occurring amino acids (listing many residues), or
- non-naturally occurring amino acids/derivatives including 1-aminocyclohexane carboxylic acid, lanthanine, or theanine.
- Claim 12: A sterically hindered primary amine with a defined formula, where substituents (R1, R2, R3) are selected from a defined set of groups and substitution constraints are imposed (at most one of R1, R2, R3 is H).
Scope implication
- These dependent claims sweep broadly across both conventional and selected non-standard amino acid amines, but the formula constraint in claim 12 creates a technical gating criterion.
- Any product relying on a different class of base/amine excipient should be checked for fit with the structural formula language.
Do the claims require a specific binder/filler stack?
Practical meaning
- Claim 14 is formulation-excipient constrained; claim 17 is narrower.
- For enforcement, the most restrictive dependent formulation claims (like 17) are easiest to prove with manufacturing records, but broad claim 14 could be more relevant for product variants.
Is there a method-of-use protection in US 8,933,030?
Yes. Claim 15 is a GI treatment method claim tied to administering the composition of claim 7:
- Claim 15: A method for treating a gastrointestinal disorder comprising administering the composition of claim 7, where the GI disorder is selected from:
- IBS
- constipation-predominant IBS (c-IBS)
- constipation
- chronic constipation
- idiopathic constipation
- constipation due to post-operative ileus
- constipation caused by opiate use
- visceral pain
Infringement structure for method claims
Method claims are typically asserted against:
- the commercial manufacturer’s labeled use if an approved label matches the claimed indication; and/or
- off-label promotion, depending on jurisdiction and litigation theory.
If the underlying composition claim is tied to a specific peptide/linaclotide ratio (claims 7–8), method claim reach typically tracks whether the marketed dosage form actually contains the peptide below the claimed weight thresholds and includes the other required composition features of claim 7.
What do claims 16, 18, 19, and 20 suggest about preferred embodiments?
Claims 16, 18, 19, 20 are “closing” dependent claims that look like exemplified formulations.
- Claim 16: Composition comprising:
- i Ca2+
- ii leucine
- iii linaclotide
- iv one or more peptides (GC-C activators)
- where the peptide amino acid structure is selected from a list (placeholder in user text).
- Claim 20: Ca2+ provided as calcium acetate, calcium chloride, calcium phosphate, or calcium sulfate.
These claims indicate at least one common embodiment uses:
- calcium (a defined salt set),
- leucine (as the sterically hindered primary amine),
- plus linaclotide and the recited GC-C activating peptide(s).
Claims 18–19 reference additional peptides “selected from” lists (placeholders), likely broadening the covered peptide universe in the composition depending on what structures are named in the full patent.
What does the claim architecture mean for how courts will construe scope?
“Comprising” vs “consists of”
- Claim 1’s peptide is “comprising” the amino acid structure.
- Claim 2’s peptide “consists of” the amino acid structure.
This creates two tiers:
- products with peptides that incorporate the recited sequence but include additional residues might still map to claim 1 but not claim 2.
- strict sequence-identical peptides map to both.
Dependent-claim stacking
Most practical disputes will depend on what claim is asserted:
- If asserted claims include only claim 4 or 5, the ratio and excipients may be irrelevant.
- If the asserted claim is 7/8 plus 9/10/11/14, infringement is far more formulation-specific.
Composition vs method coupling
Because claim 15 is dependent on claim 7 (composition with <5% peptide relative to linaclotide), method-of-use enforcement likely requires proving the marketed product’s actual peptide loading and composition elements.
How does this patent likely sit in the broader US linaclotide and GC-C patent landscape?
This patent is aligned with a set of recurring “innovation clusters” around linaclotide and GC-C agonism:
- GC-C agonist peptide analogs (identity and sequence variants).
- Compositions for constipation and IBS (dosage forms and formulation stability).
- Co-formulation strategies (ratios, combinations with other active agents).
- Excipient-driven formulation constraints (specific polymers, fillers, cations, amines, antioxidants).
- Regimen-indication claims (GI disorders, constipation subtypes, visceral pain).
US Patent 8,933,030 specifically cross-links GC-C peptide activity with linaclotide combination formulations and constrains:
- peptide:linaclotide ratio (claims 7–8),
- presence of specific cations or sterically hindered primary amines (claims 9–12),
- optionally binder/filler classes (claim 14),
- and treatment indications (claim 15).
Likely competitive overlap
Commercial GI agents and pipeline molecules frequently compete at the level of:
- GC-C pathway modulation (linaclotide and other GC-C agonists),
- combination formulations for constipation and IBS,
- alternative delivery or formulation excipient systems.
So the competitive risk from US 8,933,030 is highest for products that:
- include the same or substantially similar GC-C peptide identity;
- include linaclotide; and
- formulate within the peptide loading band (<4–5% by weight relative to linaclotide).
Where are the clearest generic/commercial entry risk points?
Highest-risk scenario for challengers
A generic or new entrant seeking approval for a linaclotide-containing constipation/IBS product that also includes the specific GC-C activating peptide at <4–5% by weight and includes the named cation/amine/excipient features could be vulnerable to:
- direct infringement of composition claims and
- induced/contributory exposure if formulation and labeling match method claims.
Lower-risk scenario
A product that:
- omits the GC-C peptide,
- uses a peptide variant outside the “consists of” identity boundaries,
- or uses peptide content above the <5% or <4% thresholds,
may avoid the dependent claim set that is most formulation-specific, but still faces risk under broader “comprising” and composition-plus-linaclotide claims depending on how those broader claims are asserted.
How many claims are “actionable” for litigation strategy?
Based on the claim text provided, enforcement typically concentrates on a small subset that create tight mapping conditions:
- Claim 5 (composition + linaclotide) as a threshold combination hook.
- Claims 7–8 as quantitative gating.
- Claims 9–12 as co-ingredient gating (cation salts and sterically hindered primary amines).
- Claim 15 as indication gating.
Claims 14 and 17 can be asserted for formulation-excipient narrowness, typically when challengers attempt to keep actives constant but adjust excipients.
Claims 16 and 20 read like concrete formulation examples and can anchor “preferred embodiment” narratives in litigation and claim construction.
Key Takeaways
- US Patent 8,933,030 protects a GC-C activating peptide (specific sequence/structure) and pharmaceutical compositions combining that peptide with linaclotide.
- The strongest scope constraints are quantitative: <5% (claim 7) and <4% (claim 8) peptide by weight relative to linaclotide.
- The claims also constrain co-ingredients through defined cations (as specific salts) and sterically hindered primary amines (amino-acid classes with a structural formula).
- There is a method-of-use claim for IBS/constipation/related GI disorders (claim 15) that depends on the low-peptide loading composition of claim 7.
- Litigation leverage will track the exact peptide identity, peptide:linaclotide weight loading, and presence of defined cations/amine/excipient classes, not just the fact that the product contains linaclotide.
FAQs
1) What peptide modifications would likely avoid “consists of” claim 2 but still fall under claim 1?
Changes that introduce residues or structural elements beyond the recited amino acid structure may be excluded from claim 2 while still potentially mapping to claim 1’s broader “comprises” structure depending on how the recited structure language is construed.
2) If a product uses the peptide but exceeds 5% by weight relative to linaclotide, which claims are most at risk?
Dependent claims tied to the <5% (<4%) limitations are avoided; risk shifts toward broader composition claims that do not include those loading limits, especially claim 4/5 unless further limitations are asserted.
3) Does the patent require both a divalent cation and sterically hindered primary amine?
No. Claim 9 states the composition includes one or more agents selected from the cation class or the sterically hindered primary amine class, meaning either category can be present depending on the dependent-claim path asserted.
4) Are excipients like microcrystalline cellulose critical to infringement?
They can be for narrower dependent claims (claim 17), but broader claim coverage can exist without the specific binder/filler selection if the asserted claims do not incorporate claim 14/17.
5) How do these claims affect a linaclotide reformulation strategy that keeps linaclotide but substitutes peptides?
Replacing the GC-C peptide with a non-covered GC-C agonist peptide likely avoids peptide-identity-dependent claims 1–3 and the composition claims tied to those peptides. Substituting peptide type requires close matching to the recited amino acid structure language.
References
- US Patent 8,933,030. (2015). Peptides and compositions comprising guanylate cyclase C agonists and linaclotide (claim text as provided).
