|
Patent landscape, scope, and claims summary: |
RE46323 (US Patent) CD200-CD200R blockade plus immunosuppressant combination for transplant rejection: claim-by-claim scope and US patent landscape
Executive summary
US Patent RE46323 is a reissue centered on methods that combine (i) an anti-CD200 antibody or antigen-binding fragment that blocks CD200-CD200R interaction and has reduced or eliminated effector function (no ADCC and/or no CDC in dependent claims) with (ii) a conventional immunosuppressive drug (broadly enumerated, including calcineurin inhibitors cyclosporine A and tacrolimus; mTOR inhibitor sirolimus; and a wide catalog of other immunosuppressants/antineoplastics/biologics). The independent claim set is method-of-treatment, with broad treatment populations (cell, tissue, or organ transplant; allograft; humoral vs antibody-mediated rejection; allo- or xenotransplant; acute vs chronic; multiple transplant types including hematopoietic, islet, and solid organs) and broad administration timing (before, after, or simultaneous; including during rejection episodes). The dependent claims tighten antibody effector function by specifying Fc engineering and benchmarked ADCC/CDC thresholds relative to a defined SEQ ID NO:28-derived Fc.
What patents protect CD200-CD200R blocking antibodies combined with cyclosporine A or rapamycin for transplant?
RE46323 protects combination methods where the immunological mechanism is anchored on CD200-CD200R blockade plus reduced-effector anti-CD200 binding, used with standard-of-care immunosuppressants to prevent rejection or promote graft survival.
Core claim architecture: what is being protected
- Independent method of inhibiting immune response in transplant recipients
Claim 1 requires:
- A transplant recipient (or patient who will receive a transplant)
- An anti-CD200 agent that:
- inhibits interaction between CD200 and CD200R
- is an anti-CD200 antibody (or antigen-binding fragment)
- has reduced effector function
- An immunosuppressive drug (specified broadly in dependent claims)
- Dependent claim network expands outcome and scope
- Humoral response and antibody-mediated rejection (claims 2-4, 13, 17)
- Specific drug exemplars (claims 5, 8-11)
- Administration timing and setting (claims 14-16)
- Administration route (systemic vs local) (claims 24-25)
- Transplant types (claim 18) including hematopoietic cell/bone marrow, pancreatic islet allografts, and a list of solid organs
- Outcome durability: at least 6 months, 1 year, 5 years (claims 22-23)
- Mechanistic readout: decreased production of anti-donor antibodies (claim 19)
- Secondary independent-style claim: dose reduction / “less drug required” concept
Claim 28 adds a comparative framing:
- Co-administer the anti-CD200 reduced-effector agent with the immunosuppressive drug
- Less immunosuppressive drug is required to achieve immunosuppression vs drug alone
- Rejection-episode method
Claim 30 focuses on inhibiting rejection during a rejection episode by administering only the anti-CD200 reduced-effector agent (no immunosuppressant explicitly required in that claim text, but the patent family structure indicates the broader combination thesis across the claims).
“Reduced effector function” is functionally defined in dependent claims
Dependent claims 32-40 operationalize the reduced effector function limitation:
- No ADCC and/or no CDC (claims 32 and 35 and 38)
- Fc region sources include multiple Ig classes (claims 33, 36, 39)
- Specific Fc mutation set tied to ADCC/CDC equality-or-less thresholds:
- glutamic acid substitution at amino acid 236
- glutamine substitution at amino acid 298
- alanine substitutions at positions 319, 321, 323
relative to SEQ ID NO:28 (claims 34, 37, 40)
What is “immune response” coverage
RE46323 is not limited to T-cell mediated rejection. The claim set explicitly targets:
- Humoral immune response (claims 2, 13)
- Antibody-mediated response (claim 3)
- Decrease in anti-donor antibody production (claim 19)
- Acute vs chronic humoral rejection (claim 17)
- Acute or chronic allo- or xenotransplant rejection (claims 20-21)
Comparative risk positioning created by claim scope
From a freedom-to-operate perspective, RE46323 is built so that infringement can be triggered by:
- Use of any anti-CD200 antibody/fragment that blocks CD200-CD200R with reduced effector function, even if the antibody format varies (Fab/F(ab’)2/Fv/single-chain domain antibodies; claim 7)
- Broad lists of immunosuppressants and biologics (claims 10-11)
- Broad patient types and organ types (claim 18)
- Timing and route flexibility (claims 14-16, 24-25)
What formulations and antibody Fc engineering are protected by RE46323?
The claim set is method-focused, but the anti-CD200 agent’s immunological properties are tightly constrained.
Antibody formats covered
Claim 7 enumerates typical antibody fragment formats that confer specific binding:
- Single-chain antibody, Fab, Fab’, F(ab’)2, F(ab’)3, Fd, Fv, domain antibody
- Any fragment of an anti-CD200 immunoglobulin that binds CD200
Effector-function limitations: what “reduced effector function” means
Dependent claims create clear infringement hooks:
- No ADCC and/or no CDC (claims 32, 35, 38)
- Fc constant-region engineering via benchmark comparisons to an Fc with defined substitutions (claims 34, 37, 40)
- Ig-class-derived Fc variants (claims 33, 36, 39)
Fc constant region: mutation set and functional thresholds
The Fc mutation set and benchmark logic is important for claimant vs challenger positions:
- Claims 34/37/40 specify that ADCC/CDC activity can be equal to or less than what it would be with a particular Fc constant region containing the SEQ ID NO:28-relative substitutions.
- That drafting can complicate “design-around” strategies where a developer tries to preserve some effector function.
When does anti-CD200 plus immunosuppression lose exclusivity under RE46323?
No usable exclusivity timeline can be produced from the information provided. The answer requires the patent’s priority date, reissue history, expiration adjustments, and any terminal disclaimer. Without those data, producing an exclusivity or generic launch date would be incomplete.
How strong is the patent estate for CD200 blockade in transplant rejection?
Strength indicators inside RE46323’s text
- Mechanism-driven agent limitation: CD200-CD200R interaction blockade is a specific target.
- Effector-function narrowing: “reduced effector function” coupled with dependent “no ADCC/no CDC” claims can reduce prior-art overlap with conventional Fc-competent antibodies.
- Broad clinical application: multiple transplant types, humoral/antibody-mediated rejection, allo- and xenotransplant, and broad drug lists increase coverage.
Strength constraints created by the same features
- Prior art breadth risk for the combination concept: pairing checkpoint-like blockade of an immune receptor axis with conventional immunosuppressants is a common pattern in transplant patenting. Without family-level mapping (related claims/patents in the same assignee estate) the litigation strength can’t be scored.
- Design-around room exists via CD200R axis alternatives: if competing approaches target related ligands or different epitopes that do not “inhibit interaction between CD200 and CD200R,” the literal scope narrows, but this cannot be assessed without the commercial products’ exact binding and functional assays.
Which companies are challenging RE46323 or competing with CD200-CD200R blockade in transplant?
No company challenge map can be produced from the information provided. A credible response requires litigation dockets and/or patent-family assignment-to-entity mapping, neither of which is present.
What patent litigation affects CD200 blockade plus immunosuppressant combinations?
No litigation status can be produced from the information provided.
What is the Orange Book status of RE46323 and how does it affect generic competition?
RE46323 is a method-of-treatment patent. It is not associated with an NDA/ANDA “Orange Book listing” in the way drug product patents are listed. Without the specific drug(s) to which the patent is tied through regulatory listings (and without the underlying non-reissue patent number(s) and covered products), no determinate Orange Book status can be stated.
What generic entry risks exist for methods using cyclosporine A, tacrolimus, or sirolimus plus anti-CD200 antibodies?
The practical risk
- Small-molecule generics of cyclosporine A, tacrolimus, and sirolimus generally do not raise method-of-treatment infringement risk by themselves, because RE46323 covers administering an anti-CD200 agent plus the immunosuppressive drug under specified immunological effects.
- The primary “entry risk” sits with developers using:
- an anti-CD200 antibody or antigen-binding fragment with reduced effector function
- administered in combination with any immunosuppressive drug enumerated or covered in the independent claim logic (depending on claim construction)
The strongest generic-style infringement pathway would be for biologic mAbs
- If a competitor develops an anti-CD200 antibody biosimilar or an alternative anti-CD200 biologic that fits the reduced-effector and CD200-CD200R blockade limitations, it creates a direct method infringement risk when used in the covered transplant settings.
How does RE46323 compare with other CD200-pathway transplant patents (CD200R agonists, ligand mimetics, or different Fc designs)?
A family-to-family comparison cannot be produced without identifying:
- the related US applications/patents in the same estate as RE46323
- other CD200-pathway inventions (CD200R agonism, alternative blocking approaches, different effector designs)
None of these are available in the prompt.
Which dependent claims most matter for claim construction and infringement?
Highest-leverage dependent claim clusters
- Drug identity tightening
- Calcineurin inhibitors: cyclosporine A and tacrolimus (claims 5 and 8-9)
- mTOR: rapamycin/sirolimus (claims 5 and 10)
- Humoral vs global rejection
- Humoral/antibody-mediated rejection (claims 2-3, 13, 17)
- Administration timing
- Prior, subsequent, or simultaneous (claim 15)
- During rejection episode (claim 16)
- Effector function and Fc engineering
- No ADCC/no CDC (claims 32, 35, 38)
- Ig-class Fc sourcing (claims 33, 36, 39)
- Specific Fc mutation set with ADCC/CDC threshold logic (claims 34, 37, 40)
Infringement sensitivity
- Litigation usually turns on whether the administered anti-CD200 agent:
- blocks CD200-CD200R interaction as claimed
- has “reduced effector function,” and whether it meets the “no ADCC/no CDC” dependent limitations or the FC mutation/threshold benchmarks
- is used in the claimed transplant contexts (humoral/antibody-mediated rejection and/or specified outcomes)
Key claim chart (condensed)
| Claim |
What must be administered / shown |
Scope levers (infringement/design-around) |
| 1 |
Anti-CD200 antibody/fragment blocking CD200-CD200R + immunosuppressive drug; transplant recipient |
Reduced effector function; CD200-CD200R inhibition; any enumerated or construed immunosuppressive drug |
| 2-3 |
Immune response is humoral; antibody-mediated |
Limits to humoral/antibody-mediated rejection framing |
| 4 |
Agent has no effector function |
Adds strict limitation |
| 5 |
Immunosuppressive drug is cyclosporine A or rapamycin |
Drug identity tightening |
| 6 |
Anti-CD200 antibody formats including human/humanized/chimeric/murine/de-immunized |
Broader antibody sourcing |
| 7 |
Fragment types covered |
Format flexibility |
| 8-9 |
Calcineurin inhibitor: tacrolimus or cyclosporine A |
Tight drug subset |
| 10 |
Immunosuppressive drug from wide list |
Broad list increases likelihood of “covered drug” usage |
| 11 |
Antibody immunosuppressants list (muromonab-CD3 etc.) |
Biologic immunosuppressant coverage |
| 13 |
Prevents graft rejection/promotes survival |
Outcome framing |
| 14-16 |
Timing: before; after; simultaneous; during rejection |
Timing and episode-specific activity |
| 17 |
Acute/chronic humoral rejection |
Acute vs chronic |
| 18 |
Patient/transplant types list |
Broad clinical coverage |
| 19 |
Decrease anti-donor antibodies |
Mechanistic endpoint |
| 20-21 |
Acute/chronic allo- or xenotransplant |
Expands beyond allografts |
| 22-23 |
Long-term survival at 6 months/1/1/5 years; accommodation |
Outcome durations |
| 24-25 |
Systemic vs local administration |
Route coverage |
| 28 |
“Less drug required” comparative method |
Requires comparative dosing/effect showing reduction vs drug alone |
| 29 |
Drug is cyclosporine A or rapamycin |
Specific subset of claim 28 |
| 30 |
Inhibiting rejection during rejection episode with anti-CD200 alone |
Agent-only method during episode |
| 31 |
Cell/tissue/organ transplant is allograft |
Allograft limitation |
| 32,35,38 |
No ADCC, no CDC, or both |
Effector-function requirements |
| 33,36,39 |
Variant Fc region derived from Ig classes |
Fc source coverage |
| 34,37,40 |
Fc mutation set and ADCC/CDC threshold logic vs SEQ ID NO:28 |
Specific biochemical benchmark |
Key Takeaways
- RE46323 protects transplant rejection prevention and immune response inhibition methods anchored on anti-CD200 blockade of CD200-CD200R with reduced effector function, combined with conventional immunosuppression, including cytosporine A/tacrolimus/rapamycin and broad other immunosuppressants.
- The claim set meaningfully targets humoral/antibody-mediated rejection and provides administrative flexibility (route and timing) plus outcome durability (up to 5-year survival).
- Dependent claims sharply constrain the anti-CD200 agent’s functional profile (notably ADCC/CDC absence) and, in key cases, specify Fc variant benchmark logic using a defined mutation set relative to SEQ ID NO:28.
- Exclusivity timing, Orange Book status, and company-specific litigation cannot be resolved from the prompt data because they require the patent’s bibliographic details, reissue history, and regulatory/litigation records.
FAQs
-
Does RE46323 cover anti-CD200 antibodies with partial ADCC/CDC activity?
Coverage depends on whether the agent meets “reduced effector function” as construed and the dependent “no ADCC/no CDC” or Fc benchmark thresholds in the relevant claims.
-
Can a transplant protocol infringe RE46323 if anti-CD200 is given after rejection onset?
The claim set includes methods where the agent is administered during a rejection episode and covers administration prior to, subsequent to, or simultaneous with the immunosuppressive drug.
-
Is the patent limited to allografts or also xenotransplants?
Dependent claims explicitly include allo- and xenotransplant rejection contexts.
-
Would generic cyclosporine A or tacrolimus manufacturing alone infringe RE46323?
Infringement risk arises from the covered method of administering an anti-CD200 reduced-effector agent with the immunosuppressive drug to the claimed patient population under the claimed therapeutic objectives.
-
Are Fc mutations required for every infringement theory under RE46323?
Not necessarily for Claim 1 as written (“reduced effector function”), but Fc mutation language becomes central for dependent claims that define effector-function benchmarks and mutation sets.
References (APA)
[No sources were provided in the prompt to cite.]
More… ↓
⤷ Start Trial
|
