Executive summary
US Patent 11,918,628 covers a specific parathyroid hormone (PTH) conjugate defined by (i) a PTH moiety whose amino-acid sequence is SEQ ID NO:51, (ii) attachment via an amide bond to the PTH N-terminal nitrogen, and (iii) attachment to a second “moiety” in which m and p are each independently integers from 150 to 1000 (with dependent coverage for ~15–80 kDa conjugate size and pharmaceutical compositions and liquid formulations, including aqueous solvent and pH 4–6). The claim set, as provided, is not limited to a single administration route or specific clinical indication, but it is narrowed by the exact PTH sequence identity and by the polymeric/size parameter range (m and p 150–1000), which is typically the key differentiator in this conjugation space.
Scope and claim coverage centers on:
- the molecule (conjugate structure defined by SEQ ID NO:51 and m/p integers),
- salt/form variants,
- pharmaceutical compositions and liquid formulations (with excipients, pH 4–6, and water solvent), and
- size-based dependent limits (~15–80 kDa) and symmetry (m=p).
Patent-landscape conclusion (from the claims text provided): US 11,918,628 is a composition-of-matter plus formulation add-on patent with a structure-defined core. Its effective moat against generics/biosimilar-like entrants will depend on whether competitors can (a) use a different PTH sequence (not SEQ ID NO:51), (b) use different attachment chemistry (not N-terminal amide), or (c) use a different conjugate architecture where m and/or p fall outside 150–1000, or the conjugate size is outside ~15–80 kDa for dependent coverage. Litigation and licensing exposure will track those “entry points,” not general PTH-conjugate prior art.
What is US Patent 11,918,628 and what PTH conjugate does it claim?
Short answer (claim-defined invention):
US 11,918,628 claims a PTH conjugate where:
- the PTH portion is a sequence-identical moiety with amino-acid sequence SEQ ID NO:51,
- the conjugation attaches to the N-terminal nitrogen of the PTH via an amide bond, and
- the conjugate is linked to a second moiety parameterized by m and p (each independently 150 to 1000).
Core claim map: Claim 1 defines the structural boundary
Claim 1 states the conjugate is of “formula” (structural diagram omitted in the prompt) with:
- Attachment to N-terminal nitrogen of PTH through an amide bond.
- PTH sequence is SEQ ID NO:51 (this is the principal identity constraint).
- Second moiety attachment parameter: m and p independently an integer from 150 to 1000.
What does “m and p from 150 to 1000” typically gate in enforcement?
Practically, this kind of range controls polymer length / repeat-unit count or molecular-architecture dimensions that drive:
- conjugate mass distribution,
- functional spacing,
- solubility and clearance,
- and whether the accused conjugate reads on claim parameters.
If an accused product uses conjugate specifications that place repeat counts outside 150–1000 or shifts the architecture so m/p are not as defined, infringement risk drops unless doctrine-of-equivalents arguments are available.
Dependent claim scope: what extra limits are added
- Claim 2: moiety has molecular weight ~15–80 kDa.
- Claim 3: m = p.
- Claims 4–5: pharmaceutical composition with excipients; pH 4–6.
- Claims 6–9: liquid pharmaceutical composition with solvent (including water), and repeats the conjugate structural requirements; dependent molecular weight and m=p limitations apply to the liquid form.
How broad are US 11,918,628 claims: molecule, salts, and parameter ranges?
Short answer: Broad for “PTH conjugate defined by sequence + N-terminal amide + m/p range,” narrow for any variant that changes SEQ ID NO:51 or steps outside m/p and ~15–80 kDa in the dependent claims.
Molecule coverage breadth
Claim 1 is a classic structure-parameter claim: it covers
- any pharmaceutically acceptable salt, and
- any conjugate that uses the SEQ ID NO:51 PTH sequence and the defined attachment rule plus the m/p range.
That breadth can be meaningful because salts and many formulation-related changes may not avoid claim 1 if the same conjugate is used.
Key narrowing levers competitors can use
For infringement avoidance, design-around typically targets at least one of:
- PTH identity: replacing the SEQ ID NO:51 sequence with a different PTH sequence variant.
- Conjugation site/chemistry: avoiding N-terminal nitrogen amide attachment.
- Conjugation architecture parameterization: using a different repeat-unit scheme so that m and/or p do not map to 150–1000.
- Size outside dependent bounds: for claims 2 and 7, shifting conjugate size outside ~15–80 kDa.
- Symmetry constraint: avoiding m = p for dependent claims 3 and 8.
What is the claim coverage for pharmaceutical compositions and liquid formulations?
Short answer: Claims 4–5 and 6–9 add protection for formulated drug products containing the claimed conjugate, including a pH 4–6 formulation window and water solvent liquid embodiments.
Composition claim set
- Claim 4: “pharmaceutical composition comprising” the claim 1 conjugate and at least one excipient.
- Claim 5: pH 4–6.
These are formulation constraints that could matter if competitors adopt significantly different pH regimes and do not rely on the same composition claim.
Liquid formulation claim set
- Claim 6: liquid pharmaceutical composition comprising the claim 1 conjugate and a solvent; attachment rules and SEQ ID NO:51 remain required; m/p range remains required.
- Claim 7: moiety molecular weight ~15–80 kDa (dependent).
- Claim 8: m=p (dependent).
- Claim 9: solvent is water (dependent).
Practical enforcement implication
The molecule claim (claim 1) can be infringed even by a competitor whose product is not marketed as a liquid composition, assuming the sold active conjugate matches claim 1. The composition and liquid claims mainly increase leverage for product-level settlements, especially when the accused product is a liquid and falls within pH 4–6.
When does US 11,918,628 lose exclusivity and what determines the end of patent term?
No complete, accurate exclusivity timeline can be produced from the claims text provided alone.
A correct answer requires patent bibliographic data (filing date, priority date, grant date, and any PTA or terminal disclaimers) and regulatory exclusivity data if tying to FDA reference products. The prompt includes no such facts, and exclusivity must be computed from those exact dates.
What patents likely overlap or compete with US 11,918,628 for PTH conjugates?
No complete and accurate US patent landscape map can be generated from the claims text provided alone.
A defensible “scope-and-claims” landscape requires at minimum: (i) the assignee/inventor, (ii) the full title/abstract, (iii) claim dependency structure beyond what is pasted, and (iv) search results across the USPTO and EPO family members. Without those, any list of overlapping patents would be speculative.
How strong is the patent estate for structure-defined PTH conjugate claims like this?
Short answer: Strength is high on enforceable structure parameters that are hard to circumvent without changing the therapeutic molecule. Strength is moderated by the need to prove that an accused product’s conjugate truly matches SEQ ID NO:51 and the m/p integer range.
What makes this claim style strong
- Sequence identity is a hard boundary: SEQ ID NO:51 acts like a molecular “fingerprint.”
- Conjugation definition includes site and chemistry: N-terminal amide linkage narrows candidate designs.
- m/p range is quantitative: easier to argue non-infringement if conjugate specifications are outside range.
- Formulation claims extend leverage: composition and liquid embodiments can support broader product settlements.
Where enforceability can compress in practice
- If competitors use conjugates that are close but not identical on sequence or attachment site, they can attempt non-infringement.
- For m/p-based parameter ranges, disputes often hinge on whether the accused material’s average or distribution maps to the claimed integer parameters.
- Dependent limits (molecular weight ~15–80 kDa; m=p; pH 4–6) create multiple possible escape routes if a product is tuned outside those windows.
What generic entry risks exist for products that might use similar PTH conjugates?
Short answer: Entry risks are highest if a generic/competitor uses the same SEQ ID NO:51 PTH moiety and the same N-terminal amide-conjugation with m/p in 150–1000, because then claim 1 is directly implicated regardless of formulation. Risk drops if entry uses different sequence identity or conjugation architecture that fails m/p parameter mapping.
Most likely “near-miss” design-arounds
- switching to a different PTH sequence (avoid SEQ ID NO:51),
- changing conjugation from N-terminal nitrogen amide to a different linkage chemistry or site,
- using conjugates whose repeat-unit parameters do not fall in 150–1000, or whose effective molecular weight is outside ~15–80 kDa for dependent claim coverage.
How does this patent compare with typical PTH conjugate IP patterns (PEGylation and carrier conjugates)?
Short answer: This patent follows the common pattern of (i) sequence-defined peptide conjugates plus (ii) parameterized carrier/molecular-size ranges plus (iii) formulation windows. Its distinctiveness is the combination of SEQ ID NO:51 and m/p integer range tied to the conjugation structure.
Where this differs from broader “class” patents
Class-level patents (not identifiable from the prompt) often claim “PTH conjugates” generically, leaving room for multiple peptide sequences and carrier variations. A sequence-specific claim reduces that breathing room.
Where this might still be competed around
Even a sequence-specific claim can be bypassed if the competitor selects a different SEQ ID and linkage definition while maintaining a similar pharmacological profile.
Key takeaways
- US 11,918,628 is a structure-defined PTH conjugate patent with enforceability anchored on SEQ ID NO:51, N-terminal nitrogen amide linkage, and m/p integers 150–1000 (claim 1).
- Dependent claims narrow to ~15–80 kDa moiety size and m=p, and extend to pharmaceutical compositions (including pH 4–6) and liquid/water formulations.
- The main generic/competitor risk hinges on whether the accused conjugate is the same at the sequence and attachment-site level and falls within the m/p and size windows.
- A complete landscape for overlapping patents, litigation, Orange Book status, and exclusivity end dates cannot be computed from the claim text alone.
FAQs
- Can a salt form avoid infringement of a PTH conjugate claim covering “pharmaceutically acceptable salts”?
- If an accused product uses the same SEQ ID NO:51 but a different conjugation site, would that avoid claim 1?
- How do “m and p are integers from 150 to 1000” claims typically get proven or attacked in infringement?
- If an accused product is a liquid but formulated outside pH 4–6, is it still at risk under composition claims?
- What is the practical difference between attacking claim 1 (molecule) versus claims 5 or 9 (formulation windows)?
References (APA)
- United States Patent 11,918,628, claims provided in prompt (claim 1–9 text).
