Patent: 9,416,371

Summary for Patent: 9,416,371

Title:	T-cell vaccination with viral vectors via mechanical epidermal disruption
Abstract:	Attenuated, replication-deficient viruses such as vaccinia viruses are used to deliver an exogenous viral, bacterial, parastic or tumor antigen to an epidermal tissue such as the skin, lungs or gastrointestinal tract, which has been mechanically disrupted, in an amount effective to elicit or stimulate a cell mediated immune response. The epidermis may be mechanically disrupted prior to, at the same time, or immediately after the administration of the vaccine. The vaccine can be used to induce immunity against a pathogen, such as a virus, bacteria, or parasite, or against a cancer in a subject that has or is at risk of developing cancer.
Inventor(s):	Kupper; Thomas S. (Weston, MA), Liu; Luzheng Lisa (Vernon Hills, IL), Clark; Rachel A. (Belmont, MA)
Assignee:	TremRx, Inc. (Boston, MA)
Application Number:	14/165,126
Patent Claims:	see list of patent claims

United States Patent 9,416,371: What the Claims Actually Cover in Epithelial Tissues

US Patent 9,416,371 claims a therapeutic method and kit for inducing a T cell-mediated immune response to an exogenous T cell antigen by applying a live, modified, non-replicating poxvirus that expresses the antigen to human epithelial tissue under a specific physical delivery constraint: skin disruption that penetrates the stratum corneum but does not penetrate the entire epidermis.

The patent’s legal center of gravity is not simply “poxvirus vaccination.” It is the combination of:
1) poxvirus engineered to express an antigen (tumor, pathogen, or other exogenous antigens),
2) a local skin infection sufficient to drive inflammatory signals and antigen expression in the epithelium, and
3) a controlled ex vivo-to-in vivo delivery pathway that stops at the stratum corneum while preserving the broader epidermal barrier architecture.

That combination positions the claims against both (i) classic systemic viral vector vaccines and (ii) simple skin-surface immunogens that do not create local infected-cell antigen expression. The strongest novelty argument in claim scope is the physical penetration limitation plus non-replicating live poxvirus used to trigger antigen presentation and lymph node T cell priming.

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Claim 1: What Is Required for Infringement

Claim 1 sets the full method stack:

• Method objective: “inducing or stimulating a T cell mediated immune response” to an exogenous T cell antigen.
• Delivery site: “epithelial tissues of a human subject” specifically “epithelial skin tissue.”
• Agent: “a live, modified, non-replicating poxvirus expressing the antigen.”
• Local effect: administered “to cause a local infection” in epithelial skin tissue “in an amount sufficient” to drive:
  • infected cells expressing viral proteins,
  • infected cells expressing the exogenous T cell antigen,
  • infected cells producing inflammatory factors that stimulate a T cell response.
• Immune routing: stimulation “in the lymph nodes.”
• Key physical constraint: the live modified poxvirus is administered to epithelial skin tissue that is disrupted to penetrate the stratum corneum without penetrating the entire epidermis.

Scope implications

• The “exogenous T cell antigen” language is broad: it is not limited to tumor antigens. Claims 6-10 expand examples, but Claim 1 already covers any antigen that is “exogenous” to the subject’s immune system prior to dosing.
• The “local infection” requirement is functional, not merely presence of antigen. It requires that dosing achieves infected-cell viral protein expression and antigen expression in epithelium.
• The “non-replicating” limitation narrows vector biology. It helps distinguish from replicating orthopox strategies while preserving the “live virus” adjuvanticity through innate signaling.

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Is the Penetration Mechanism a Real Differentiator or a Vulnerable Element? (Claim 1 constraint)

The “stratum corneum without penetrating the entire epidermis” limitation is structurally clear but operationally fact-specific in practice. It creates two business-relevant outcomes:

1) Prosecution leverage: It narrows prior art that uses full-thickness epidermal penetration, needle inoculation to dermis, or tape-stripping protocols that disrupt deeper layers. 2) Enforcement leverage: It gives a defendant a pathway to non-infringement by using:

• delivery tools that go deeper than allowed, or
• delivery formats that do not rely on stratum corneum-only disruption. 3) Risk concentration: If a competitor’s platform uses a different disruption depth, the dispute shifts into histology-like technical proof of penetration depth and method equivalence.

For portfolio purposes, this is the key element to model in claim charts: the vector and antigen could be similar, but penetration depth is often the differentiator that can be tested and argued.

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Claims 2-4: How Much Vector Freedom Is Actually Allowed

Claim 2

Virus is selected from a broad orthopox-adjacent set:

• orthopox, suipox, avipox, capripox, leporipox, parapoxvirus, molluscpoxvirus, yatapoxvirus.

This is not a tight limitation. It creates broad coverage around many poxvirus genera.

Claim 3

If orthopox is used, it is “a vaccinia virus.”

Claim 4

Vaccinia can be derived from natural or artificial modification of viruses including:

• WR, Wyeth, ACAM2000, Lister, LC16m8, Elstree-BnM, Copenhagen, Tiantan.

Scope implications

• Claim 4 is both narrow (named strains) and broad (natural or artificial modification).
• Competitors using a vaccinia backbone that is not a direct modification of these listed strains could try to route around, but the “derived by natural or artificial modification” language supports doctrine-of-equivalents arguments if the backbone is still functionally and genetically derived.

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Claim 5: Timing Synchronization Between Skin Disruption and Dosing

Claim 5 adds:

• vector is delivered at the “same time as the skin is disrupted” to penetrate the stratum corneum without penetrating the entire epidermis.

This matters because many skin delivery systems apply pretreatment (chemical disruption, occlusion, or separate procedures). Claim 5 ties vector dosing to the physical opening.

From a landscape view, this increases risk for platforms that decouple disruption from dosing. If a competitor performs disruption first and waits, they can argue they do not satisfy Claim 5 (though Claim 1 may still be asserted depending on how dependent claims are litigated and how infringement theory is constructed).

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Claims 6-8: Cancer Indications Expand to a Broad Tumor Taxonomy

Claim 6: cancer risk/condition and antigen must be:

• TAA, TSA, or “tissue-specific antigen.”

Claim 7: cancer types include:

• skin,
• oral mucosa,
• esophagus,
• reproductive and urogenital mucosa.

Claim 8: claim provides an extensive list including (not exhaustive transcription rewrite logic, but representative):

• melanoma,
• squamous cell carcinoma (including skin),
• basal cell carcinoma,
• Merkel cell carcinoma,
• adenexal carcinoma,
• cutaneous T or B cell lymphoma,
• sarcomas,
• adenocarcinoma (including multiple organ contexts),
• prostate adenocarcinoma and prostatic intraepithelial neoplasia,
• squamous cell lung carcinoma,
• lung adenocarcinoma and small cell lung carcinoma,
• ovarian epithelial origin adenocarcinoma,
• colorectal adenocarcinoma,
• leiomyosarcoma,
• stomach adenocarcinoma and leiomyosarcoma,
• hepatocellular carcinoma,
• cholangiocarcinoma,
• pancreatic ductal adenocarcinomas and endocrine pancreatic tumors,
• renal cell carcinoma,
• transitional cell carcinoma of kidney and bladder,
• bladder squamous cell carcinoma.

Scope implications

• The patent is not confined to one cancer or even one tissue. It is a platform claim that tries to cover any tumor-associated antigen where the dosing is delivered to epithelial surfaces under the penetration constraint.
• The breadth can be used offensively in negotiations and licensing because it forces competitors to discuss whether their antigen, tissue, and delivery depth fit.

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Claims 9-10: Infectious Disease Antigen Breadth Is Very Large

Claim 9: if subject has or is at risk of:

• viral, bacterial, fungal, or protozoal infection then antigen must be the corresponding type.

Claim 10 enumerates a long list, including:

• viral infections: HIV, influenza, dengue, Hep A, Hep B, Hep C, HPV, Ebola, Marburg, rabies, Hanta, West Nile, “SARS-like coronaviruses,” HSV, VZV, EBV, HHV-8, alpha viruses, St. Louis encephalitis
• bacterial: M. tuberculosis, S. typhi, Bacillus anthracis, Yersinia pestis, Francisella tularensis, Legionella, Chlamydia, Rickettsia typhi, Treponema pallidum
• fungal: Coccidioides immitis, Blastomyces dermatitidis, Cryptococcus neoformans, Candida albicans, Aspergillus species
• protozoal: Plasmodium species, Leishmania species, African and American trypanosomes, cryptosporidiums, isospora species, Naegleria fowleri, Acanthamoeba species, Balamuthia mandrillaris, Toxoplasma gondii, Pneumocystis carinii.

Scope implications

This is a major strategic signal: the patent is drafted to avoid a narrow “oncology-only” story. It is structured as a generic “poxvirus antigen expression via controlled skin disruption” platform with organism-agnostic coverage.

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Claim 11-12: Optional Immune Modulators Are Layered In

Claim 11 allows adding or co-expressing:

• co-stimulatory molecule,
• growth factor,
• adjuvant and/or cytokine, administered or co-expressed:
• before, at the same time, or after the antigen,
• at the same or a distant site.

Claim 12 expands co-expressed co-stimulatory molecules selected from:

IL-1, IL-2, IL-7, IL-12, IL-15, IL-18, IL-23, IL-27, B7-2, B7-H3, CD40, CD40L, ICOS-ligand, OX-40L, 4-1BBL, GM-CSF, SCF, FGF, Flt3-ligand, CCR4.

Scope implications

This claim drafting increases infringement surface area because a competitor using the same poxvirus skin-delivery concept but adding cytokine payloads does not avoid coverage. It also weakens “we didn’t include adjuvant X” defenses because the claim includes broad adjuvant/cytokine classes and timing flexibility.

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Claim 13: Kit Claim Ties Device + Vector + Penetration Depth

Claim 13 claims a kit comprising:

• “a device for delivering poxvirus to a human subject’s epidermal tissue,”
• device penetrates the stratum corneum without penetrating the entire epidermis,
• plus:
  • “live, modified, non-replicating poxvirus expressing an antigen”
  • “in an amount sufficient” to cause local infection and T cell response in lymph nodes.

Landscape implications

Kit claims are often where enforcement becomes practical: a manufacturer can be sued even if they argue they sold the device and vector separately. Claim 13 suggests the assignee is targeting end-to-end commercialization.

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How Strong Is the Patent Versus the Likely Landscape? (Critical assessment)

Without relying on the claims alone, the legal landscape for “skin delivery of viral vectors and immune activation” typically includes at least three bodies of prior art risk:

1) Skin disruption for immunization (stratum corneum penetration technologies; microneedle-like approaches; tape-stripping/abrasion; topical delivery methods). 2) Live poxvirus or orthopox vector vaccines for inducing cellular immunity, including tumor immunotherapy and infectious disease immunogens. 3) Armed poxvirus vectors expressing antigens plus immune modulators.

US 9,416,371 attempts to defend novelty by binding these elements together with three constraints:

• live, modified, non-replicating poxvirus,
• local infection in epithelial tissue sufficient for infected-cell viral protein and antigen expression and inflammatory factor induction, and
• controlled penetration: stratum corneum only, not entire epidermis.

Where the patent is likely strong

• If the competitor’s method actually achieves “local infection” in the epithelium with viral protein expression and relies on stratum corneum-only disruption, it fits the core of Claim 1.
• The poxvirus genus and vaccinia strain lists provide broad coverage across common orthopox platforms.

Where the patent is likely vulnerable

• Any platform that delivers the vector by routes that deeper penetrate beyond entire epidermis may avoid literal penetration limitation (and force reliance on equivalence).
• Platforms that do not use a “live, non-replicating” poxvirus (for example, replication-competent constructs) could be outside the literal claim, even if immunologically similar.
• If a competitor’s approach does not produce the required local “infection” and inflammatory factor-mediated infected-cell antigen expression in the targeted epithelial layer, infringement arguments weaken.

Claim drafting effect

The dependent claims on timing (Claim 5), virus specificity (Claims 2-4), and antigen categories (Claims 6-10) create a ladder of coverage. That can help the patentee by enabling multiple infringement theories across different product programs, even when defendants attempt to narrow the dispute to one contested element.

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Practical Freedom-to-Operate (FTO) View: What to Map Against This Patent

For business decisioning, the infringement analysis should track only the claim “gates” that control scope:

Gate A: Vector identity and biology

• Is the vector a live, modified, non-replicating poxvirus?
• If vaccinia: is it derived from listed strains (WR, Wyeth, ACAM2000, Lister, LC16m8, Elstree-BnM, Copenhagen, Tiantan)?

Gate B: Antigen linkage

• Is the antigen one that falls into the claim’s allowed categories (TAA/TSA/tissue-specific for oncology) or pathogen antigens (viral/bacterial/fungal/protozoal) or other “exogenous T cell antigens” under Claim 1?

Gate C: Physical delivery depth

• Does the delivery method disrupt skin to penetrate stratum corneum but not penetrate the entire epidermis?

Gate D: Timing

• Is vector delivered at the same time as disruption (Claim 5)?

Gate E: Local infected-cell effect

• Does dosing achieve local epithelial infection resulting in infected cells expressing viral proteins, antigen, and inflammatory factors, and then stimulating T cells in lymph nodes?

Gate F: Optional payloads

• Are co-stimulatory molecules/cytokines/adjuvants included, and if so, do they matter under Claims 11-12 (they usually do not help avoid coverage because the claim is permissive)?

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Key Takeaways

• US 9,416,371 claims a platform method and kit for eliciting T cell immunity using live, modified, non-replicating poxvirus expressing an exogenous antigen, delivered to skin via stratum corneum penetration without penetrating the entire epidermis.
• The patent’s enforceability and competitive threat depend heavily on the penetration-depth element and whether the competitor achieves local infection in epithelium with infected-cell viral protein and antigen expression plus inflammatory factor production.
• The claim set is broad across vector types, oncology indications, and infectious disease antigens, and it allows immune modulator additions with wide timing flexibility.
• The most actionable FTO focus is mapping each competitor program to the claim “gates”: (1) non-replicating live poxvirus, (2) exogenous antigen expression, (3) stratum corneum-only penetration, and (4) local infected-cell inflammatory and lymph node T-cell outcomes.

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FAQs

1) What is the single most important technical limitation in Claim 1?

The method requires skin disruption that penetrates the stratum corneum without penetrating the entire epidermis, while delivering a live, modified, non-replicating poxvirus that causes local infected-cell expression of viral proteins and the antigen.

2) Does the patent restrict the antigen to tumors only?

No. Claim 1 covers an “exogenous T cell antigen.” Claims 6-8 provide oncology examples, and Claims 9-10 provide infectious disease examples.

3) Does adding cytokines or co-stimulatory molecules help a competitor avoid infringement?

It is unlikely. Claims 11-12 broaden permissible immune modulators and timing, which typically increases overlap with competitor designs rather than decreasing it.

4) Are vaccinia strains constrained?

Vaccinia is constrained in Claim 3-4 to vaccinia virus, and Claim 4 lists strains (WR, Wyeth, ACAM2000, Lister, LC16m8, Elstree-BnM, Copenhagen, Tiantan) with modifications. Still, the “derived by natural or artificial modification” language supports broad coverage.

5) What does the kit claim add beyond the method claim?

Claim 13 adds a device that delivers poxvirus with the same penetration depth constraint (stratum corneum-only), plus the live modified non-replicating poxvirus expressing an antigen in sufficient amount for local infection and lymph node T-cell response.

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References

[1] United States Patent 9,416,371. Claims provided in the prompt.

Details for Patent 9,416,371

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Emergent Biodefense Operations Lansing Llc	BIOTHRAX	anthrax vaccine adsorbed	Injection	103821	November 12, 1998	9,416,371	2034-01-27
Emergent Product Development Gaithersburg, Inc.	ACAM2000	smallpox (vaccinia) vaccine, live	For Injection	125158	August 31, 2007	9,416,371	2034-01-27