United States Patent 11,389,510: Scope, Claim Strength, and US Landscape
What does US 11,389,510 claim?
US Drug Patent 11,389,510 is directed to controlled-release CNP (C-type natriuretic peptide) agonists that deliver a CNP-derived “D-H” moiety through a polymer conjugate with a linker cleavable in aqueous buffer (pH 7.4, 37°C, no enzymes). The patent is written to separate the pharmacology of the prodrug-like conjugate from the released active CNP fragment, using EC50 gap requirements and release-half-life requirements.
Independent claim 1 (core scope)
Claim 1 defines a controlled-release CNP agonist with all of the following elements:
(A) Active pharmacophore architecture
- A CNP moiety comprising:
- A ring moiety (−D)
- The ring moiety has the amino acid sequence of SEQ ID NO:96
- The ring moiety is between two cysteine residues forming a disulfide bridge
- The ring moiety is conjugated to a polymer via a linker
(B) Linker cleavage conditions
- Linker is cleavable in aqueous buffer at:
- pH 7.4
- 37°C
- in the absence of enzymes
- Release kinetics are constrained by:
- Half-life of release half-life up to six months (interpreted as conjugate stability / release profile bounded by months)
(C) Polymer constraints
Claim 1 is drafted with two alternate polymer modes:
- Water-soluble polymer conjugated via the linker to an amino group side chain of a lysine of SEQ ID NO:96, or
- Water-insoluble polymer (still conjugated through the linker)
(D) “D-H” release and release kinetics
- D-H is released from the controlled-release CNP agonist by cleavage of the linker
- Release half-life requirement:
- at least 6 hours in aqueous buffer at pH 7.4, 37°C, in the absence of enzymes
(E) Functional potency separation requirement
- The controlled-release conjugate has an EC50 at least 20-fold higher than the EC50 of D-H
- This establishes a designed reduction in immediate potency and emphasizes a prodrug-like control mechanism.
Dependent claim set (claim differentiation)
- Claim 2: EC50 of conjugate is at least 50-fold higher than D-H
- Claim 3: EC50 of conjugate is at least 100-fold higher than D-H
- Claim 4: release half-life ≥ 24 hours
- Claim 5: release half-life ≥ 168 hours (7 days)
- Claim 6: pharmaceutical composition including the conjugate plus excipients
Net effect: claim 1 is the broadest set of requirements; claims 2-5 tighten the pharmacology gap and release rate. Claim 6 adds formulation.
How broad is the claim in practice?
The breadth comes from how much is left open versus fixed by explicit structure and sequence requirements.
What is fixed
- SEQ ID NO:96 sequence for the “ring moiety (−D)”
- Two cysteines forming a disulfide bridge in that ring moiety
- A controlled-release construct where:
- The active “D-H” is released by a linker cleavage under defined in vitro release conditions (pH 7.4, 37°C, no enzymes)
- The EC50 separation (prodrug-like potency gap) is met
What is open (interpretation space)
- The patent does not fix a specific polymer identity in the claim text you provided:
- It allows water-soluble polymer (linked to lysine amino side chain) or water-insoluble polymer.
- The claim does not enumerate linker chemistry beyond functional behavior:
- It only constrains cleavability under specified aqueous conditions and no enzymes.
The practical “gatekeeping” parameters
Infringement analysis will usually turn on whether an accused product satisfies the functional gates:
- Release half-life (≥6 hours) and potentially ≥24 hours or ≥168 hours (if dependent claims are asserted)
- No-enzyme cleavage in aqueous buffer at pH 7.4 / 37°C
- EC50 ratio thresholds:
- ≥20-fold (claim 1)
- ≥50-fold (claim 2)
- ≥100-fold (claim 3)
These functional constraints can narrow enforcement to products that match the in vitro prodrug behavior.
What is the claim’s legal and technical strength?
Strengths
- Functional separation is built into the claim language
- “EC50 at least 20-fold higher than D-H” is a measurable property tied to the construct.
- Release kinetics are constrained under “no enzyme” conditions
- That reduces ambiguity versus claims requiring in vivo or enzyme-mediated cleavage.
- Dependent claims lock in time thresholds
- ≥24 hours and ≥168 hours create distinct claim tiers that map to formulation and linker selection strategies.
- Composition claim
- Claim 6 provides a direct formulation hook.
Weaknesses / potential vulnerability points
- SEQUENCE and cysteine/disulfide placement are hard constraints
- Any design that changes the ring moiety sequence away from SEQ ID NO:96 or removes the disulfide bridge likely avoids literal coverage.
- Polymer identity is flexible, but conjugation mechanics must match
- For water-soluble polymer, claim language indicates conjugation via linker to a lysine amino group side chain of the specific ring moiety (SEQ ID NO:96).
- EC50 gap thresholds can be attacked
- If an accused product shows a smaller EC50 increase relative to released D-H, it may fall outside the EC50 gating.
What does this imply about the patent’s coverage of design-around options?
Potential design-around vectors
- Alter the ring moiety identity
- Changing away from SEQ ID NO:96 or disrupting the two-cysteine disulfide bridge is the clearest literal avoidance path.
- Change the linker cleavage mechanism
- If cleavage does not occur at pH 7.4 / 37°C without enzymes within the required half-life window, it may not satisfy the linker functional limitations.
- Change the functional exposure relationship
- If the conjugate has EC50 that is not ≥20-fold higher than D-H, literal infringement may fail.
- Avoid the specified conjugation position (lysine side-chain for soluble polymer)
- The claim ties the soluble polymer mode to lysine side-chain conjugation (within the context of SEQ ID NO:96). If conjugation uses a different residue or different chemoselective attachment, it may be outside literal scope.
How does the claim structure map to enforcement strategy?
If asserting claim 1
A plaintiff needs evidence that the accused product:
- Contains a CNP-derived “D-H” moiety matching SEQ ID NO:96 in the disulfide ring format
- Is polymer conjugated through an aqueously cleavable linker meeting release half-life conditions (no enzymes, pH 7.4, 37°C)
- Releases D-H with release half-life ≥6 hours
- Exhibits an EC50 ratio of ≥20x versus D-H
If asserting dependent claims
- Claim 2: push EC50 ratio to ≥50x
- Claim 3: push EC50 ratio to ≥100x
- Claim 4: show release half-life ≥24 hours
- Claim 5: show release half-life ≥168 hours
- Claim 6: show the drug is sold as a formulation with excipients, which is typically easier.
US patent landscape: what competitors typically target around CNP controlled-release
Even without the full document set for US 11,389,510 in your prompt, the landscape logic for CNP agonist controlled release in the US is consistent: companies usually build around one or more of the claim gates above.
Common ways competitors design around
- Different peptide variant
- Change sequence away from the specific ring motif used here (SEQ ID NO:96).
- Different disulfide topology
- Replace or remove disulfide formation.
- Different release mechanism
- Avoid linker cleavage that occurs “in absence of enzymes” under pH 7.4/37°C conditions.
- Different release kinetics
- Target faster or slower release than the specific windows tied to dependent claims.
- Different prodrug effect profile
- Aim for a smaller EC50 gap (or bypass the prodrug mechanism) to avoid the EC50 gating.
Where overlap is likely
- Products that intentionally create:
- a polymer-conjugated CNP prodrug
- that is stable in buffer without enzymes
- and then releases a D-H-like active fragment over hours to days
- are structurally and functionally close, especially where the ring moiety is unchanged.
Key claim terms that drive infringement and validity fights
The following terms function as the “decision points” for claim construction, test design, and non-infringement proofs.
| Claim element |
Why it matters |
Typical dispute path |
| “ring moiety has the amino acid sequence of SEQ ID NO:96” |
Literal identity requirement |
Sequence comparison to accused product released structure |
| “between two cysteine residues forming a disulfide bridge” |
Structural requirement |
Disulfide presence/topology in characterization |
| “linker cleavable in aqueous buffer at pH 7.4 and 37°C in absence of enzymes” |
Functional cleavage gate independent of biology |
In vitro cleavage assay design; enzyme contamination control |
| “release half-life at least 6 hours” |
Sets minimum release kinetics |
Half-life calculation method; sampling and analytics |
| “polymer is water-soluble and conjugated… via linker to lysine amino group side chain… or polymer is water-insoluble” |
Conjugation topology constraint |
Linker attachment site identification |
| “EC50 at least 20-fold higher than EC50 of D-H” |
Prodrug-like potency gate |
Bioassay design; comparing EC50 of conjugate vs D-H |
What is the effective scope of claim 6 (composition)?
Claim 6 is straightforward:
- A pharmaceutical composition containing:
- the controlled-release CNP agonist of claim 1
- at least one excipient
In enforcement, claim 6 usually becomes the easiest hook once claim 1 (active ingredient) is established.
Key Takeaways
- US 11,389,510 is a controlled-release CNP prodrug-type patent that requires a SEQ ID NO:96 disulfide ring CNP moiety and polymer conjugation via an aqueous-cleavable, no-enzyme linker.
- The core novelty and constraint are functional: the conjugate’s EC50 must be ≥20x (or higher in dependent claims) relative to D-H, and release half-life must be ≥6 hours (with dependent tiers at ≥24 hours and ≥168 hours).
- Enforcement will be narrow where the ring motif or cleavage mechanism differs. The claim text fixes peptide sequence/disulfide architecture and constrains cleavage behavior, leaving room mainly in polymer identity and linker chemistry so long as the functional gates are met.
- Competitors will most often design around by altering SEQ ID NO:96 content/disulfides, changing the conjugation site, or engineering linker behavior that fails the no-enzyme cleavage or EC50 ratio thresholds.
- If an accused product matches the release and EC50 gates, claim 6 adds a formulation-level infringement path.
FAQs
-
Is US 11,389,510 limited to one polymer type?
No. It covers both water-soluble polymer conjugates (with lysine side-chain conjugation in the soluble polymer mode) and water-insoluble polymer conjugates, provided the functional linker cleavage and release criteria are met.
-
Does the patent require enzyme-mediated cleavage?
No. The linker is defined as cleavable in aqueous buffer at pH 7.4 and 37°C in the absence of enzymes, and D-H release kinetics are measured under those conditions.
-
What is the minimum release profile required?
Claim 1 requires D-H release with a release half-life ≥ 6 hours in buffer at pH 7.4, 37°C without enzymes.
-
How much weaker must the conjugate be than D-H?
Claim 1 requires the controlled-release agonist’s EC50 be at least 20-fold higher than D-H. Dependent claims require ≥50-fold (claim 2) and ≥100-fold (claim 3).
-
Does the patent cover the drug product formulation?
Yes. Claim 6 covers a pharmaceutical composition containing the controlled-release agonist of claim 1 plus at least one excipient.
References
[1] United States Patent No. 11,389,510.
