| Inventor(s): | Larsen; Christian P. (Atlanta, GA), Pearson; Thomas C. (Atlanta, GA), Adams; Andrew B. (Atlanta, GA), Peach; Robert J. (San Diego, CA), Linsley; Peter S. (Seattle, WA), Naemura; Joseph Roy (Bellevue, WA), Bajorath; Jurgen (Bonn, DE) |
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Patent landscape, scope, and claims summary: |
United States Patent 7,304,033: CTLA4 Mutant Claims for Islet Transplant Rejection and the US Patent Landscape
What does US 7,304,033 claim?
US 7,304,033 is directed to methods to inhibit rejection of pancreatic islet cell transplants by administering a soluble CTLA4 mutant molecule defined by specific extracellular-domain sequence boundaries, optionally combined with standard immunosuppression, and optionally paired with encapsulation and other adjunct immune-modulating regimens.
Core independent claim set
Claim 1 (method of inhibiting islet transplant rejection)
- Administer an effective amount of a CTLA4 molecule comprising a mutated extracellular domain with an amino acid sequence:
- starting at alanine position 26 and ending at aspartic acid position 150 as shown in SEQ ID NO:6, or
- starting at methionine position 27 and ending at aspartic acid position 150 as shown in SEQ ID NO:6.
Claim 2 (diabetes treatment via islet rejection inhibition)
- Same as claim 1, framed as treating diabetes by inhibiting islet transplant rejection.
Claim 18 (soluble CTLA4 mutant scope extension)
- Administer an effective amount of a soluble CTLA4 mutant molecule with SEQ ID NO:6 boundary definitions for positions:
- alanine 26 to lysine 383, or methionine 27 to lysine 383.
Claims 24-25 (deposit-defined DNA/protein expression)
- Administer soluble CTLA4 mutant encoded by or expressed by DNA deposited as ATCC PTA-2104.
Key dependent claim expansion points (commercially relevant)
The patent does not stop at the CTLA4 mutant sequence definition. It broadens infringement risk through delivery format, adjunct immunosuppressants, and transplant workflow variables.
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Adjunct immune suppression (claims 4, 5, 6, 19-30)
- Claim 4: add at least one of an immunosuppressive agent, immunomodulatory compound, or anti-inflammatory agent, with concomitant or sequential dosing.
- Claim 5: examples include rapamycin (sirolimus) or derivative 40-O-(2-hydroxy)ethyl-rapamycin, and anti-human IL-2R mAb, or their combination.
- Claim 6 and subsequent: an extensive enumerated list of immunosuppressive/immunomodulatory/anti-inflammatory agents spanning calcineurin inhibitors, steroids, antimetabolites, biologics, and many immune pathway antagonists.
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Encapsulation (claim 3)
- Islet cells encapsulated prior to administration.
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Administration routes and modalities (claim 7)
- Broad method-of-use delivery options: IV, IM, SC, implantable pump, continuous infusion, gene therapy, liposomes, oral administration.
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Species coverage (claim 8)
- Human and extensive animal models, including non-human primates.
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Transplant timing relative to CTLA4 mutant (claim 10)
- Islet transplant performed before or after CTLA4 administration.
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T-cell depleted bone marrow adjunct (claim 9)
- Addition of T cell depleted bone marrow cells.
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Diabetes subclass (claim 11)
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Fusions (claims 12-17)
- Mutant extracellular domain fused to a non-CTLA4 moiety.
- Immunoglobulin moiety and constant-region features, including reduced effector function via constant-region mutations and specified constant-region regions (hinge, CH2, CH3), plus human/monkey constant region coverage.
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Effector function reduction is explicitly within the scope (claims 14-17)
- This matters for designing around via Fc-silencing variants; the claim language is written to capture such variants within immunoglobulin-constant framework.
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“Encoded by” and “expressed by” deposit-defined nucleic acid/protein (claims 24-32)
- DNA deposited as ATCC PTA-2104 and explicit references to both encoding and expression by that deposit.
What is the claim construction pressure point: sequence boundary and “mutated extracellular domain”?
The enforceability and market coverage hinge on two distinct claim anchors:
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Sequence boundary constraint inside SEQ ID NO:6
- Claims 1 and 18 tie infringement to an extracellular-domain sequence window bounded by Ala26 to Asp150 (claims 1) and Ala26 to Lys383 (claim 18).
- The claim is not “any mutated extracellular domain”; it is a mutated extracellular domain that matches defined sequence ranges in SEQ ID NO:6.
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Deposit identity anchor (ATCC PTA-2104)
- Claims 24-25 and 31-32 use a deposit number as a surrogate for sequence identity (DNA deposited as ATCC PTA-2104 encoding and/or expression of the soluble CTLA4 mutant).
Practical implication for freedom-to-operate (FTO):
- A competitor attempting design-around through different CTLA4 forms must avoid both:
- sequence-defined mutated extracellular domain boundaries aligned with SEQ ID NO:6, and
- nucleic acid identity aligning with ATCC PTA-2104 where the competitor uses deposit-referenced constructs.
- The dependency chain around adjunct immunosuppression does not rescue a design-around if the CTLA4 mutant itself falls within the defined sequence scope.
How broad are the claims in functional and workflow terms?
US 7,304,033 uses a structure-function approach: tight CTLA4 sequence definition paired with broad treatment method framing.
Breadth that increases infringement risk
- Treatment workflow is flexible: CTLA4 dosing can occur before or after islet transplantation (claim 10).
- Delivery is broad: includes standard injection routes and gene therapy (claim 7).
- Transplant format is covered: includes encapsulation (claim 3).
- Combination therapy is explicitly contemplated: a wide catalogue of agents is enumerated, and the timing can be concomitant or sequential (claims 4-6, 19-30).
- Species breadth supports preclinical and translational coverage (claim 8).
Narrowness that creates a technical defense
- The CTLA4 molecule must contain a mutated extracellular domain defined by specific SEQ ID boundary segments.
- Deposit-linked claims provide an additional specificity gate; if a competitor does not use the deposit-defined sequence construct, claims 24-32 become harder to reach.
What does the claim set imply about the underlying technology?
The claim set is consistent with a soluble CTLA4 mutant strategy aimed at modulating T-cell co-stimulation pathways during islet transplant rejection.
Co-stimulation pathway target via CTLA4
CTLA4 is canonically associated with down-modulation of T-cell activation via interference with B7/CD28 co-stimulatory signals. The patent claims:
- soluble CTLA4 mutants defined by specific sequence truncations and/or mutations (claims 1, 18),
- and optionally fusion constructs containing constant regions (claims 12-17),
- plus a generalizable combination framework with mainstream immunosuppression (claims 4-6, 19-30).
How does the patent landscape typically react to this kind of CTLA4 mutant use?
A CTLA4 mutant sequence with enumerated adjunct regimens sits inside a crowded immunosuppression IP ecosystem. The practical landscape tension is that:
- many companies already claim combinations using CTLA4 or CTLA4-Ig style molecules (or other checkpoint antagonists),
- but fewer claims are written to tether infringement tightly to a specific SEQ ID-defined mutated extracellular domain and to an ATCC deposit.
Landscape impact zones
- Combination claims: Claim 4/6 and 19-30 can overlap with broad immunosuppression method-of-use patents that cover “islet transplant + immunosuppressive agent.” The “CTLA4 mutant sequence” requirement can become the gating element.
- Encapsulation: Claim 3 may overlap with encapsulation patents for islet transplantation, but again the CTLA4 mutant requirement differentiates the claims.
- Gene therapy route: Claim 7’s inclusion of gene therapy creates a path for overlay with gene delivery IP, typically controlled by vector and expression construct families.
What are the most commercially relevant claims to watch for clearance and licensing?
In an FTO or licensing context, the claims most likely to drive business decisions are those that:
1) specify the CTLA4 mutant that a company would actually develop, and
2) cover realistic administration and combination regimens.
High-priority claim hooks
- Claim 1: method of inhibiting islet transplant rejection using the SEQ ID NO:6-defined mutated extracellular domain boundaries.
- Claim 18: soluble CTLA4 mutant with SEQ boundary extending to Lys383.
- Claims 24-25, 31-32: deposit-linked nucleic acid/protein identity using ATCC PTA-2104.
- Claim 3: encapsulated islets.
- Claim 7: gene therapy among delivery modalities.
- Claims 4-6 and 19-30: broad combination therapy including rapamycin/IL-2R blockade and a long list of immunosuppressive/immunomodulatory agents.
Are there easy design-arounds implied by the claim text?
The claim text suggests design-around routes that depend on whether the CTLA4 sequence identity is preserved.
Potential design-around dimensions
- Sequence boundary changes: altering the extracellular domain such that it no longer matches the SEQ ID NO:6 boundary definitions (Ala26 to Asp150 or Ala26 to Lys383).
- Avoiding deposit construct identity: using a different nucleic acid/protein sequence family not aligned to ATCC PTA-2104.
Design-around constraints built into the claim language
- If a competitor uses an immunoglobulin fusion with constant-region features and effector function reduction, those design variations are explicitly within claims 12-17.
- If a competitor uses encapsulated islets and standard immunosuppression in combination, the framework remains within claims 3 and 4-6/19-30 if CTLA4 mutant identity is met.
Key Takeaways
- US 7,304,033’s claim set is a two-part construct: it requires a CTLA4 soluble mutant defined by SEQ ID NO:6 boundary positions and then attaches broad real-world treatment wrappers (encapsulation, timing, routes including gene therapy, and combination immunosuppression).
- Deposit-defined claims (ATCC PTA-2104) are a major enforcement anchor: they target nucleic acid identity and expression of the soluble CTLA4 mutant, not just generic “CTLA4 biology.”
- Combination therapy language is unusually wide for an antibody/checkpoint-adjacent method patent: it explicitly enumerates many immunosuppressive and immunomodulatory agents and covers concomitant or sequential administration.
- Most clearance pressure will come from claims 1, 18, and 24-32 because those claims define the CTLA4 mutant identity plus the actual deliverable construct (sequence and deposit identity), while the dependent claims broaden scenario coverage.
- FTO and licensing strategy should treat the CTLA4 mutant sequence definition as the gating risk, with workflow and adjunct immunosuppression as secondary amplifiers.
FAQs
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Which claims control the core enforceable subject matter?
Claims 1 and 18 define the soluble CTLA4 mutant by SEQ ID NO:6 boundary sequence; claims 24-25 and 31-32 further anchor identity to DNA deposited as ATCC PTA-2104.
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Do the claims require co-administration of multiple immunosuppressants?
No. Claim 4 requires at least one immunosuppressive/immunomodulatory/anti-inflammatory agent, with concomitant or sequential administration.
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Does encapsulation of islets fall within the patent scope?
Yes. Claim 3 explicitly covers encapsulated islets prior to administration.
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Is gene therapy included as a delivery method?
Yes. Claim 7 includes gene therapy among administration routes.
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Can immunoglobulin fusion formats avoid the patent?
Not if the fusion is structured to fall within claims 12-17, which explicitly cover immunoglobulin moiety constant regions and effector-function-reducing mutations within that framework.
References
[1] United States Patent 7,304,033 (claims as provided in prompt).
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