United States Patent 7,767,429: Claim Scope, Validity Friction Points, and Competitive Patent Landscape
United States Patent 7,767,429 is built around a substantially purified hyaluronidase glycoprotein defined by (i) a specific amino-acid sequence window from SEQ ID NO: 1 (mostly residues 1-477 or 36-477/36-483), (ii) a high similarity ceiling of at least 95% identity to those sequence windows (allowing substitutions), (iii) a glycosylation constraint requiring at least one N-linked sugar moiety covalently attached to an asparagine residue (with a specific enumerated subset in dependent claim 4), and then (iv) broad downstream formulation and delivery wrappers (carrier, concentration ranges, excipients, device packaging, timed release, topical to intravenous routes, and kits/combination products).
From an enforcement and investment perspective, the patent’s value is primarily driven by whether its “core protein definition” survives novelty/obviousness attacks against prior hyaluronidase glycoprotein disclosures, and whether its “95% identity” framing is sufficiently tethered to the claimed polypeptide to avoid enablement/claim indefiniteness issues. The rest of the patent is mostly incremental pharma-formulation and packaging claim craft.
1) What exactly is the “core invention” in this patent?
How the independent claim 1 defines the hyaluronidase glycoprotein
Claim 1 is the only real “protein claim anchor.” It requires:
- A substantially purified hyaluronidase glycoprotein
- That it consists of one of multiple sequence variants corresponding to windows of SEQ ID NO: 1, or it contains substitutions in those windows.
- The resulting protein must have at least 95% amino-acid sequence identity with the specified windows.
- The protein must contain at least one covalently attached sugar moiety on an asparagine residue.
The sequence windows listed in claim 1 include:
- 1-477 / 36-477
- 1-478 / 36-478
- 1-479 / 36-479
- 1-480 / 36-480
- 1-481 / 36-481
- 1-482 / 36-482
- 1-483 / 36-483
All are relative to SEQ ID NO: 1.
Glycosylation constraint: “at least one sugar moiety covalently attached to an asparagine (N) residue” with no explicit glycosite requirement in claim 1 (the glycosite specifics appear in claim 4). This means claim 1 is satisfied by any N-linked site(s) within the allowed protein range, as long as at least one is occupied.
Claim 2 narrows the protein to the C-terminal window variant set
Claim 2 further limits to the 36-x families:
- 36-477, 36-478, 36-479, 36-480, 36-481, 36-482, 36-483.
It also retains the 95% identity requirement for substitution-tolerant versions.
Claim 3 narrows to an explicit “consists of” set
Claim 3 requires the exact sequences from claim 2 with no substitutions: “consists of the sequence… set forth in SEQ ID NO: 1.”
Claim 4 ties glycosylation to a named glycosite subset
Claim 4 requires the sugar moiety be attached to N residues selected from:
- 82, 166, 235, 254, 368, and 393 (as set forth in SEQ ID NO: 1).
This is a material narrowing. It turns an occupancy-agnostic “at least one N sugar” into an enumerated glycosylation-position requirement.
Claim 6 and 7 add activity and physicochemical constraints
Claim 6 requires, in addition to claim 1-like structural limits:
- neutral active
- the sugar requirement
- and one of the 1-477 to 1-483 sequence windows (plus 95% identity substitution variants).
Claim 7 requires:
- soluble
- neutral active
- sugar requirement
- and the 36-x window family (with 95% identity substitution variants).
These attributes are not merely descriptive. They can become friction points if prior art hyaluronidase glycoproteins are either:
- acidic-active rather than neutral-active,
- insoluble/aggregated under relevant conditions, or
- not produced as the same glycoprotein form.
Claims 8 and 13 create even tighter embodiments
- Claim 8: “consists of the sequence of amino acids set forth in SEQ ID NO: 4” (dependent on claim 7).
- Claim 13: adds a CHO production and secretion method, specifically introducing an expression vector with a polynucleotide sequence defined by nucleotide windows:
- nucleotides 106-1446 of SEQ ID NO: 6 (or degenerates)
- or nucleotides in SEQ ID NO: 48 (or degenerates)
- into a vector between flanking sequences, then expressing in CHO cells and recovering the secreted glycoprotein.
This is one of the few “how-it’s made” claim components, which can matter against manufacturing workarounds.
2) How broad are the downstream formulation and device claims?
The remaining claims are largely wrappers around the claimed protein.
Pharmaceutical composition breadth (claims 15-38)
Key claim elements:
-
A pharmaceutical composition with carrier (claim 15).
-
Concentration ranges:
- about 80 Units/ml (claim 16)
- 1 to 5000 Units/ml (claim 17)
- 1 to 300 Units/ml (claim 18)
- 1 to 150 Units/ml (claim 19)
-
Excipients:
- calcium or magnesium ions (claim 20)
- timed release or site-triggered release (claim 21)
- spray/foam/aerosol or liquid suspension/solution (claim 22)
- tablets/capsules (claims 23-25)
- lyophilized powder (claim 26)
- formulation routes: topical, local, enteric, parenteral, intracrystal (as written), intracutaneous, intravitreal, subcutaneous, intramuscular, intravenous (claim 27)
- optional pharmaceutically active agent across an extensive list (claim 28-31 and claim 33-34)
-
Enteric coating list (claim 25) is detailed and includes:
- cellulose acetate phthalate, polyethylene glycol, polyoxyethylene sorbitan, castor oil, ethyl cellulose pseudolatex, phenyl salicylate, n-butyl stearate, stearic acid, carnauba wax.
-
Stabilizing solution in claim 35 onward:
- NaCl with CaCl2 or MgCl2 (claim 36)
- EDTA (claim 37)
- carrier can include albumin, detergent, surfactant (claim 38)
- examples including phenol red, human serum albumin, HEPES, NaCl, and calcium or magnesium (claim 39)
Packaging and kit constraints
- Sterile vial (claim 40) with single dose (claim 41), and concentration between 1 and 5000 Units/ml (claim 42).
- Kit with packaging/instructions (claim 43).
- Sterile syringe (claims 44-48) with:
- concentration 1 to 5000 units/ml
- dissolved in 5 µl to 50 µl sterile water
- syringe volume 5 to 50 µl
- Combination with second syringe containing another pharmaceutically active agent (claims 49-52).
Critical takeaway on claim breadth
Except for the protein-definition dependent chain (claims 1-8 and 13), the remainder of the claims are extremely broad and designed to cover:
- concentration windows,
- delivery formats,
- route-of-administration permutations,
- device packaging, and
- co-administration combinations.
This claim architecture is typical of a patent intended to “surround” a therapy product with multiple entry points. The question for enforceability is whether the core protein limits are defensible, not whether the formulation wrappers are.
3) Patentability friction: where challenges are most likely
Because the claim text provided contains the full independent structural hook, the main invalidity risk areas are the usual ones for sequence-based protein claims: anticipation, obviousness, and sometimes enablement/definiteness depending on how “substantially purified,” “neutral active,” “soluble,” and the “95% identity” standard are implemented in the specification.
A. Novelty and anticipation risk against earlier hyaluronidase glycoprotein disclosures
Hyaluronidases have long been studied and commercialized in multiple forms, including glycosylated enzymes. A validity fight typically turns on whether prior art discloses:
- a hyaluronidase glycoprotein with N-linked sugar,
- having a specific sequence window matching SEQ ID NO: 1 (or at least the same truncation boundaries such as 36-x),
- and having neutral activity and solubility.
If earlier publications or patents disclose the same or near-identical sequences (including truncations and glycosylation patterns), claim 1’s “at least 95% identity” can become a liability: 95% identity over a ~400-480 aa polypeptide often reads onto many close variants.
B. Obviousness risk: “sequence windows + 95% identity” is not always enough
Even if no single document perfectly anticipates the exact sequence window and the glycosylation constraint, an obviousness case can argue:
- hyaluronidase enzymes exist across species and recombinant forms,
- signal peptide processing and truncations produce common N-terminal variants,
- the “95% identity” tolerance is large enough that it covers variants that a skilled person could reasonably obtain by routine engineering or by known ortholog swaps.
The patent’s dependent claims (notably claim 4’s specific N residues and claim 7’s soluble/neutral active constraints) provide tighter hooks, but they are narrower coverage. If prior art includes glycoprotein hyaluronidase forms with N-linked glycosylation and similar truncations, an obviousness attack can still land.
C. Claim construction risk: “consists of” and identity-based substitution
Claim 1 alternates between:
- “consists of the sequence …” and
- “contains amino acid substitutions … whereby the substituted glycoprotein consists of a sequence … at least 95% identity…”
This can generate construction disputes:
- Is the “consists of” language meant to exclude additional sequence changes outside the enumerated windows?
- Does the identity standard override the “consists of” boundary?
- What counts as “contains at least one sugar moiety” in a way that is operationally consistent across batches?
Those disputes affect infringement more than validity, but they still influence how litigation risk is evaluated.
D. Manufacturing-method claim vulnerability (claim 13)
Claim 13 relies on a defined polynucleotide region inserted into a vector and expressed in CHO cells with secretion.
Manufacturers can reduce risk by switching:
- host cell line (e.g., HEK, NS0, PER.C6, yeast systems),
- vector/polynucleotide design (even if encoding the same protein),
- or production workflow that does not use the claimed inserted sequence windows as defined.
Even if infringement on claim 13 is less likely for alternative manufacturing routes, claim 1’s protein coverage can still capture the final product regardless of the method claims, depending on interpretation.
4) How to read the landscape strategically (what matters to competitors)
If you are developing a hyaluronidase therapy: what parts of the claims constrain you
-
Protein definition
- You must avoid a final product that matches the SEQ ID NO: 1 window definitions (1-477 through 1-483, and 36-477 through 36-483) with ≥95% identity.
- You must also avoid glycoprotein formats that have N-linked glycosylation meeting claim 1 (and potentially claim 4 if asserted).
- Neutral activity and solubility can become additional filters.
-
Glycosylation site selection
- If the patent is asserted, claim 4 becomes a high-leverage narrowing target.
- A competitor may attempt to engineer glycosylation occupancy patterns away from N82, N166, N235, N254, N368, N393.
-
Formulation is not the main escape hatch
- Concentration ranges, excipients, and delivery routes appear extensively covered.
- Changing from topical to parenteral, switching buffers, or changing packaging is unlikely to provide a clean non-infringing design if the protein core matches.
-
Device and kit design is low-risk to attack
- Packaging claims are easier to design around if a protein is cleared, but they rarely solve the core infringement problem.
If you are investing or licensing: what the claim set implies
- The patent’s enforceability posture is tied to the protein’s actual sequence and glycoform.
- If your due diligence does not confirm the competitor product’s amino-acid sequence identity relative to the claimed windows and the presence/positions of glycosylation, you cannot gauge true risk.
- Conversely, if you can establish that another product is outside the ≥95% identity band or does not carry glycoforms meeting claim 1 and claim 4, the downstream wrapper claims become largely irrelevant.
Key Takeaways
- Claim 1 is the real moat. It defines a substantially purified hyaluronidase glycoprotein using SEQ ID NO: 1 truncation windows (1-477 to 1-483 or 36-477 to 36-483), a ≥95% identity tolerance, and at least one N-linked sugar.
- Claim 4 is a critical narrowing lever by enumerating glycosylation asparagine positions (82, 166, 235, 254, 368, 393).
- Claims 6-8 and 7-8 add functional/physical constraints (neutral active, soluble) and a specific SEQ ID NO: 4 embodiment that tighten the protein net.
- Claims 15-52 are broad formulation, dosing, and packaging wrappers that are unlikely to be the primary non-infringement path if the protein core matches.
- The highest validity and infringement risk is tied to protein identity and glycoform, not excipients or delivery format.
FAQs
1) What single claim most determines infringement risk?
Claim 1. It defines the protected hyaluronidase glycoprotein by sequence-window boundaries, ≥95% identity, and N-linked glycosylation presence.
2) What claim narrows glycosylation to specific sites?
Claim 4, which requires the sugar moiety be attached to an asparagine residue selected from N82, N166, N235, N254, N368, N393.
3) How do the “36-x” claims differ from the “1-x” claims?
They shift the allowed sequence boundaries to a shorter N-terminal region starting at residue 36, while still imposing ≥95% identity and N-linked glycosylation requirements.
4) Do the formulation and device claims create a separate infringement path?
They add coverage, but they generally cannot substitute for or overcome the need to practice the claimed protein core (claims 1 and dependents). If the protein is outside the claim scope, wrappers typically do not matter.
5) Can competitors reduce risk by changing host cells or expression vectors?
It can reduce risk against method claim 13, but the main sequence-based protein claims (especially claim 1) can still capture the final product if the amino-acid sequence and glycosylation meet the thresholds.
References (APA)
[1] United States Patent 7,767,429.
