Patent: 9,677,061

Summary for Patent: 9,677,061

Title:	Soluble hyaluronidase glycoprotein (sHASEGP), process for preparing the same, uses and pharmaceutical compositions comprising thereof
Abstract:	Provided are soluble neutral active Hyaluronidase Glycoproteins (sHASEGP\'s), methods of manufacture, and their use to facilitate administration of other molecules or to alleviate glycosaminoglycan associated pathologies. Minimally active polypeptide domains of the soluble, neutral active sHASEGP domains are described that include asparagine-linked sugar moieties required for a functional neutral active hyaluronidase domain. Included are modified amino-terminal leader peptides that enhance secretion of sHASEGP. Sialated and pegylated forms of the sHASEGPs also are provided. Methods of treatment by administering sHASEGPs and modified forms thereof also are provided.
Inventor(s):	Bookbinder; Louis H. (San Diego, CA), Kundu; Anirban (San Diego, CA), Frost; Gregory I. (Del Mar, CA)
Assignee:	Halozyme, Inc. (San Diego, CA)
Application Number:	12/928,890
Patent Claims:	see list of patent claims

US 9,677,061 Viral Vectors Encoding C-Terminal Truncated Soluble Neutral Hyaluronidase: Claim-Level Validity and US Patent Landscape

US Patent 9,677,061 claims viral vectors encoding a soluble, neutral-active C-terminally truncated hyaluronidase polypeptide and related constructs (adenovirus, retrovirus, vaccinia), with additional dependent claim limitations on expression cassette design (stop codon placement, cDNA), signal peptides (IgG kappa leader), and cell/cell culture embodiments (including CHO).

The landscape turns on two technical pillars that drive infringement and validity: (i) the specific truncation window and identity thresholds for the hyaluronidase polypeptide, and (ii) vector format and expression elements (viral genome type, secretion signal, and “adjacent stop codon” producing the truncation).

What exactly do the independent claim elements cover?

Claim 1 is broad on vector type, narrow on the hyaluronidase truncation and solubility/neutral activity

Independent claim 1 requires a viral vector comprising nucleotides that encode a C-terminal truncated hyaluronidase polypeptide produced by expression due to an adjacent stop codon. The truncated polypeptide must meet all of the following:

1. Soluble, neutral active hyaluronidase polypeptide

2. Not full-length of the polypeptide set forth in SEQ ID NO: 1

3. Must be selected from one of two categories:

   Category (i): contiguous fragment containment + defined termination residues

   • The polypeptide consists of a contiguous sequence of amino acids contained within SEQ ID NO:1
   • It contains residues 36-464 of SEQ ID NO:1
   • It terminates at a C-terminal residue chosen from: 477, 478, 479, 480, 481, 482, or 483 (SEQ ID NO:1)

   Category (ii): substitutions allowed but identity and termination constrain scope

   • Includes amino acid substitutions relative to Category (i)
   • Has at least 95% sequence identity with the Category (i) polypeptide
   • Terminates at a residue corresponding to any of 477-483 (SEQ ID NO:1)

4. Expression design constraint

   • A stop codon positioned so that the truncated polypeptide is produced upon expression (adjacent in the adenovirus subgroup, but the concept is in claim 1 generically)

This structure matters for both infringement and validity because claim 1 is not just “a truncated hyaluronidase,” but a truncated construct with a specific N-boundary (residue 36), a defined C-terminal termination residue set (477-483), and (optionally) a 95% identity tolerance.

Claims 2-4 layer vector-type embodiments

Claim 1 does not restrict the viral vector subtype. It adds dependent coverage for:

• Claim 2: adenovirus vector
• Claim 3: retrovirus vector
• Claim 4: vaccinia virus vector

This gives the patent multiple entry points for infringement, but it also pulls the claim closer to prior art that discloses “use of viral vectors to express secreted enzymes,” making the truncation-defined enzymatic payload the critical differentiator.

Claims 5-6 hard-code specific sequences and nucleotide windows

• Claim 5: nucleotides SEQ ID NO:48 encoding amino acids 1-482 of SEQ ID NO:1
• Claim 6: nucleotides SEQ ID NO:6 encoding amino acids 36-482 of SEQ ID NO:1

The dependent claims narrow further by tying scope to specific SEQ ID-defined constructs. For validity, these sequence-tethered claims are easier to search and compare against published sequences; for infringement, they require matching at least the SEQ ID-defined constructs (or equivalents that still fall within the literal claim language).

Claims 7-9 impose a secretion signal and define it tightly

• Claim 7: encodes a signal sequence for secretion
• Claim 8: signal is IgG kappa chain leader peptide
• Claim 9: nucleotide sequence for that leader is SEQ ID NO:43

This combination can narrow infringement to vectors that express the hyaluronidase as a secreted protein with the specific kappa leader. It also creates a likely prior art hook because Ig kappa leader is a common secretion element in mammalian expression.

Claims 10-16 cover isolated cells and cell culture embodiments

• Claim 10: isolated cell comprising vector of claim 1
• Claim 11: encoded polypeptide is secreted
• Claims 12-14: eukaryotic, mammalian, specifically CHO
• Claims 15-16: cDNA encoding nucleic acid; cell culture comprising vector

These claims broaden the patent’s reach beyond vector manufacturing into downstream biological use and production.

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How does the adenovirus subgroup (claims 17-30) narrow the same concept?

Claim 17 is the adenovirus-focused independent claim with explicit identity threshold

Claim 17 recites:

• adenovirus vector encoding a hyaluronidase polypeptide
• polypeptide has at least 98% sequence identity to amino acids 36-483 of SEQ ID NO:1
• adenovirus vector includes a sequence of nucleotides encoding a stop codon positioned adjacent so the truncation is produced upon expression

This is a tighter constraint than claim 1’s 95% identity threshold and categorical termination definition. It also adds a new anchor: 36-483 as the reference full comparison region for sequence identity.

Claims 18-20 align adenovirus dependent claims with the same truncation windows

• Claim 18: polypeptide includes contiguous residues 36-464 and terminates at 477-483
• Claim 19: SEQ ID NO:48 encoding amino acids 1-482
• Claim 20: nucleotides SEQ ID NO:6 encoding amino acids 36-482

Claims 21-23 mirror secretion signal limitations

• Claim 21: secretion signal
• Claim 22: IgG kappa leader peptide
• Claim 23: leader nucleotide sequence = SEQ ID NO:43

Claims 24-30 cover isolated cells and culture using the adenovirus version

• isolated cell of claim 17; secretion; eukaryotic, mammalian, CHO
• cell culture comprising claim 17
• claim 30: truncated hyaluronidase cDNA

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What is the critical claim construction risk: do termination residues 477-483 create ambiguity?

The claims define truncation by termination residue identity set (477-483) rather than an explicit “end at residue 464 and then remove everything after.” On paper, the selection implies the truncated polypeptide contains 36-464 and extends to one of 477-483, meaning the truncation window permits skipping a region (or includes additional residues 465-476 depending on the numbering interpretation). That is a claim-scope lever:

• If accused products match a construct that ends at residue 464 (or 465) exactly, they may fall outside literal termination sets.
• If they terminate at 477-483, they can land in-scope even if other boundaries differ.

For enforcement, the key is whether the infringing sequence ends at one of the enumerated residues and contains residues 36-464 as contiguous sequence, or at least satisfies the 95%/98% identity thresholds relative to the defined reference sequences.

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Where the patent is strong vs where it is vulnerable

Strength: the enzyme payload is the differentiator

Many viral-vector patents exist for “expressing an enzyme,” but this patent forces a very specific payload:

• soluble neutral-active hyaluronidase
• C-terminal truncation constrained to residue 477-483 termination
• strict SEQ ID-tethered versions and secretion leader limitations

Those constraints limit the pool of prior art that can anticipate.

Vulnerability: common modular pieces exist in the prior art

The following elements are likely widely disclosed across biotechnology literature:

• adenovirus/retrovirus/vaccinia expression systems
• secretion signals, including Ig kappa leader peptides
• cDNA expression cassettes
• general use of hyaluronidase to degrade hyaluronan

If prior art contains any construct that overlaps materially with the truncation boundary and termination residues plus expression in viral vectors, that becomes the core novelty challenge.

Vulnerability: identity thresholds can be attacked

Claim 1’s ≥95% identity and claim 17’s ≥98% identity can be targets for:

• lack of written description for the substitution space
• obviousness arguments that minor substitutions are routine
• anticipation by earlier sequences that fall within those identity bands

Identity-based claims often face the question of how comprehensively the patent teaches the substituted variants.

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How to map likely infringement pathways

Literal infringement entry points

A defendant would likely trip over literal scope if they use any viral vector (adenovirus, retrovirus, or vaccinia depending on claim asserted) encoding:

• a secretion-formulated soluble neutral hyaluronidase truncated to the enumerated C-terminal residues (477-483)
• stop codon placement that ensures the truncated product is produced
• optionally: IgG kappa leader (if dependent claims 7-9 or 21-23 asserted)

Downstream infringement

Independent cell and culture claims extend exposure if the accused product includes:

• an isolated cell line producing the encoded truncated enzyme secreted from the cell
• CHO as the host cell if dependent claim 14 or 28 is asserted

Practical enforcement note

The strongest enforcement posture usually couples:

• vector manufacturing evidence (sequence-level match to SEQ IDs or termination motifs)
• expression evidence (secreted soluble neutral-active hyaluronidase)
• sequence confirmation (termination residue and contiguous residue inclusion)

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US patent landscape: what will control novelty and freedom to operate

Because the prompt provides only claim text and not the patent’s specification, prosecution history, or bibliographic identifiers, an accurate, citation-backed landscape cannot be completed without risking incorrect prior-art attribution. Under the operating constraints, only analysis grounded in the provided claim set can be produced.

The landscape assessment that is still actionable from the claims alone is the following: the landscape is organized around three overlap axes that map to how earlier US filings and publications will be found.

Axis 1: hyaluronidase truncation architecture

Search for prior US disclosures that encode:

• soluble neutral-active hyaluronidase variants (not full-length)
• truncation around the same numeric residue regions (a fragment starting at or around residue 36)
• constructs terminating within 477-483 range (or containing close termination points)
• sequence identity-defined variant families (95% or 98% identity to a reference fragment)

Axis 2: viral expression vehicle and expression cassette design

Search within US prior art for:

• adenovirus vectors with a defined stop codon adjacent to the coding region
• secretion-signal-coupled viral expression cassettes
• retroviral and vaccinia vectors expressing secreted enzymes

Axis 3: secretion signal and production host

Search for combination disclosures that add:

• Ig kappa chain leader peptide in viral vectors encoding secreted payloads
• CHO cell production of secreted hyaluronidase variants

In freedom-to-operate terms, the closer prior art must match both payload truncation constraints and at least one vector and expression element (secretion signal or stop codon/adjacent termination design).

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Key Takeaways

• US 9,677,061 is built around a highly specific C-terminal truncation of soluble neutral-active hyaluronidase, constrained by contiguous residues 36-464 and termination at residues 477-483, plus identity thresholds for substitution variants (≥95% in claim 1; ≥98% in claim 17).
• The patent expands reach through dependent limitations on vector type (adenovirus/retrovirus/vaccinia), expression design (stop codon positioning, cDNA), secretion signal (IgG kappa leader with defined SEQ ID nucleotide), and host/culture embodiments (including CHO).
• The main enforcement lever is sequence-level proof: termination residue set compliance plus contiguous region inclusion and identity threshold matching. The main validity and non-infringement levers in a landscape are prior art overlap on the same truncation architecture combined with common viral delivery and secretion modules.

FAQs

1. Which claim elements most constrain the hyaluronidase payload in US 9,677,061?
   The contiguous inclusion of residues 36-464 and C-terminal termination at 477-483, with substitution variants limited by ≥95% identity (claim 1) or ≥98% identity to a 36-483 reference (claim 17).

2. Does the patent require the hyaluronidase to be secreted?
   It is required in the constructs covered by dependent claims (claims 7-9, and cell claims 11, 24-28) via a secretion signal and secretion-from-cell limitations; claim 1 itself focuses on “soluble” and neutral active properties rather than explicitly adding the Ig kappa leader requirement.

3. What viral vectors are explicitly covered?
   Claim 2-4 cover adenovirus, retrovirus, and vaccinia as dependent vector embodiments under claim 1, while claim 17-30 focus specifically on adenovirus.

4. What role do the IgG kappa leader requirements play?
   Claims 8-9 and 22-23 restrict dependent coverage to the IgG kappa chain leader peptide with a defined nucleotide sequence (SEQ ID NO:43), narrowing infringement to constructs using that secretion leader.

5. What is the most practical sequence-level test for infringement?
   Confirm the expressed product’s C-terminal termination residue is within 477-483, verify the presence of a contiguous 36-464 segment (claim 1/18 constraints), and evaluate whether any substitutions maintain the 95% (claim 1) or 98% (claim 17) identity thresholds relative to the claim’s reference sequences.

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References

[1] US Patent 9,677,061 (claim set provided in prompt).

Details for Patent 9,677,061

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Bausch & Lomb Incorporated	VITRASE	hyaluronidase	Injection	021640	May 05, 2004		2030-12-21
Bausch & Lomb Incorporated	VITRASE	hyaluronidase	Injection	021640	December 02, 2004		2030-12-21
Amphastar Pharmaceuticals, Inc.	AMPHADASE	hyaluronidase	Injection	021665	October 26, 2004		2030-12-21
Akorn, Inc.	HYDASE	hyaluronidase	Injection	021716	October 25, 2005		2030-12-21