| Abstract: | In some aspects, the present invention provides cell-reactive compstatin analogs and compositions comprising cell-reactive compstatin analogs. In some aspects, the invention further provides methods of using cell-reactive compstatin analogs, e.g., to inhibit complement-mediated damage to a cell, tissue, or organ. In some aspects, the invention provides long-acting compstatin analogs and compositions comprising long-acting compstatin analogs. In some aspects, the invention further provides methods of using long-acting compstatin analogs, e.g., to inhibit complement-mediated damage to a cell, tissue, or organ. In some aspects, the invention provides targeted compstatin analogs and compositions comprising targeted compstatin analogs. In some aspects, the invention further provides methods of using targeted compstatin analogs, e.g., to inhibit complement-mediated damage to a cell, tissue, or organ. |
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Patent landscape, scope, and claims: |
United States Patent 11,661,441: Scope, Claim Construction, and Landscape for Long-Acting Compstatin-PEG “Clearance-Reduced” Complement Inhibition
US Drug Patent 11,661,441 is directed to (i) a method of treating complement-mediated disorders using a long-acting compstatin analog and (ii) the long-acting compstatin analog itself, where the analog has clearance-reducing moieties (PEG) linked through an amine-bearing linker amino acid + oligo(ethylene glycol) spacer to one or more cyclic compstatin analog peptide units (SEQ ID NOs 3-36 in claim 1; SEQ ID NO 8 with specific substitutions in claim 9). The patent’s practical coverage is driven by four tightly coupled structural elements: cyclic peptide unit identity, terminal extension and spacer chemistry, PEG attachment architecture, and pharmacokinetic and dosing-dependent limitations (dose ranges for methods; plasma half-life and terminal half-life for compounds).
What does claim 1 cover and how broad is it? (Method of Treatment)
Independent claim 1 claims a method of treating a subject with a complement-mediated disorder using a long-acting compstatin analog that includes a specific modular architecture:
Core limitations in claim 1
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Treatment modality
- “administering a long-acting compstatin analog” to a subject in need of treatment for a complement-mediated disorder.
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Long-acting mechanism: clearance-reducing + cyclic peptide via spacer and amine-bearing amino acid
- “long-acting compstatin analog comprises one or more clearance reducing moieties attached to one or more compstatin analog moieties.”
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Compstatin analog moiety definition (SEQ ID NOs 3-36 with terminal extensions)
- Each compstatin analog moiety contains:
- a cyclic peptide having an amino acid sequence “as set forth in any of SEQ ID NOs: 3-36”
- extended by one or more terminal amino acids at N-terminus, C-terminus, or both
- at least one amino acid whose side chain comprises a primary or secondary amine
- the amine-bearing amino acid is separated from the cyclic peptide by a spacer
- spacer comprises oligo(ethylene glycol):
- (—(O—CH2CH2—)n), with n between 1 and 500
- linkage: cyclic peptide linked via its N-terminus or C-terminus to the spacer; spacer linked to the amine-bearing amino acid; amino acid linked to the clearance-reducing moiety.
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Clearance-reducing moiety definition (PEG)
- Each clearance-reducing moiety comprises polyethylene glycol (PEG).
- PEG is covalently attached via a linking moiety to the amine side chain.
- The linking moiety can be selected from a long open list:
- “unsaturated alkyl moiety,” “nonaromatic cyclic ring system,” “aromatic moiety,” “ether,” “amide,” “ester,” “carbonyl,” “imine,” “thioether,” or “amino acid residue.”
Breadth assessment for claim 1
- Peptide scope: “any of SEQ ID NOs 3-36” is broad across multiple cyclic compstatin analog sequences, but still constrained to cyclic peptide frameworks tied to those SEQs.
- Terminal extension: “one or more terminal amino acids” at either terminus gives flexibility, but the extension must include an amine-bearing side chain.
- Spacer polymerization degree: n up to 500 creates very broad PEG-like chain length tolerance for the oligo(ethylene glycol) spacer (not necessarily the PEG clearance-reducing moiety).
- Linking chemistry: claim 1 uses an “or” list that is structurally permissive while still requiring covalent attachment of PEG to an amine via a linking moiety.
- Open-ended moiety pairing: “one or more” compstatin analog moieties and “one or more” clearance reducing moieties enables multi-valent conjugates.
How does claim 1 narrow in dependent claims? (Disorder type, route, dosing)
Claims 2–4: complement condition and target biology
- Claim 2: complement disorder results in complement-mediated damage to red blood cells.
- Claim 3: disorder is Paroxysmal Nocturnal Hemoglobinuria (PNH).
- Claim 4: administration is intravascularly or subcutaneously.
These dependent claims tighten real-world applicability toward PNH and RBCD-mediated complement damage.
Claims 5–7: dosing and patient status
- Claim 5: method includes “one or more doses.”
- Claim 6: each dose comprises 5 mg/kg to 20 mg/kg of the long-acting compstatin analog.
- Claim 7: subject is transfusion-dependent.
These add specific clinical usage constraints.
What does claim 9 cover and how does it differ from claim 1? (Compound scope)
Independent claim 9 is a product-by-structure claim focused on a more specific compstatin peptide (SEQ ID NO 8) with substitution positions and explicit spacer substructure constraints, plus PEG attachment architecture.
Core limitations in claim 9
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One or more compstatin analog moieties
- each comprises:
- a cyclic peptide extended by one or more amino acids at N-terminus and/or C-terminus
- cyclic peptide sequence = SEQ ID NO: 8
- cyclic peptide has 2, 3, or 4 substitutions
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Tryptophan/analog substitution pattern at defined positions
- position 4 relative to SEQ ID NO 8: tryptophan analog selected from:
- 2-naphthylalanine (2-NaI)
- 1-naphthylalanine (1-NaI)
- 2-indanylglycine carboxylic acid (Ig1)
- dihydrotrpytophan (Dht)
- 4-benzoyl-L-phenylalanine
- β-3-benzothienyl-L-alanine
- 1-methyltryptophan
- 5-methyltryptophan
- position 7 relative to SEQ ID NO 8:
- tryptophan or 5-fluorotryptophan
- position 9 relative to SEQ ID NO 8:
- alanine or 2-aminobutyric acid (2-Abu)
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Amine-containing side chain + oligo(ethylene glycol) spacer
- one or more amino acids has side chain with primary/secondary amine
- separated from cyclic portion by spacer comprising oligo(ethylene glycol):
- (—(O—CH2—CH2—)n)
- n between 1 and 10 (more restrictive than claim 1)
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Clearance-reducing moiety = PEG
- each clearance-reducing moiety comprises PEG.
Breadth assessment for claim 9
- Claim 9 is narrower than claim 1 on peptide identity (fixed to SEQ ID NO 8) and spacer length (n 1-10 instead of 1-500).
- It compensates with substantial flexibility:
- substitution choice set for position 4
- optional tryptophan analogs at position 4
- Tryptophan/5-F substitution at position 7
- alanine or 2-Abu at position 9
- 2–4 total substitutions
What are the explicit compound subscopes in claims 10–35? (Structure and PK)
Below is the claim-level map of what increases or decreases coverage.
A. Peptide and spacer specifics
- Claim 10: amine-containing residue can be Lys.
- Claim 11: oligo(ethylene glycol) spacer has n between 1 and 10.
- Claim 12: spacer comprises —(CH2)m— and —(O—CH2—CH2—)n with m between 1 and 10 and n between 1 and 10.
- Claim 13: spacer can be AEEAc or 11-amino-3,6,9-trioxaundecanoic acid.
- Claim 16: PEG may be attached directly or via a linking moiety to compstatin analog moieties.
- Claim 17: if via linking moiety, that linking moiety includes the same broad list types (unsaturated alkyl, cyclic, aromatic, ether, amide, ester, carbonyl, imine, thioether, amino acid residue).
B. PEG size windows (clearance reducing moiety MW)
- Claim 14: clearance-reducing moiety MW ≥ 5 kD
- Claim 15: MW ≥ 10 kD
- Claim 18: MW between 20 kD and 100 kD
- Claim 19: MW ≥ 40 kD
This is a major land-grab because most competitive long-acting conjugates hinge on PEG size and valency to tune half-life.
C. PEG architecture (linear vs branched, multivalent anchoring)
- Claim 20: clearance reducing moiety is linear PEG
- Claim 21: clearance reducing moiety is branched PEG
- Claim 22: linear PEG with compstatin analog attached at each end
- Claim 23: branched PEG with 3 to 10 branches
- Claim 24: branched PEG with 3–10 branches where ≥50% branches have compstatin attached
- Claim 25: branched PEG with 3–10 branches where ≥75% branches have compstatin attached
D. Number of compstatin units per conjugate
- Claim 26: 2 to 10 compstatin analog moieties
- Claim 27: 2 to 100 compstatin analog moieties
The 2–100 range is extremely broad and covers many “PEG scaffold with multiple ligands” designs.
E. Pharmacokinetics (primate IV and half-life metrics)
- Claim 28: plasma half-life ≥ 2 days (IV into primate)
- Claim 29: plasma half-life ≥ 3 days (IV into primate)
- Claim 30: plasma half-life ≥ 4 days (IV into primate)
- Claim 34: terminal half-life ≥ 5-fold higher than corresponding compstatin analog without the clearance-reducing moiety (at comparable dose)
These PK claims create a functional barrier for entrants: even if structure matches, failure to achieve those thresholds can avoid infringement if claims are construed as requiring those properties.
F. Molar activity retention vs non-PEGylated analog
- Claim 31: molar activity ≥ 20% of corresponding compstatin analog without clearance-reducing moiety
- Claim 32: molar activity ≥ 30%
- Claim 33: with multiple compstatin moieties, molar activity ≥ 10% of the sum of activities of the individual compstatin analog moieties
This targets a common failure mode: PEG conjugation can reduce potency. The patent builds in potency retention requirements.
G. Dosing in the method (claim 6)
- method dosing per dose: 5 mg/kg to 20 mg/kg.
How is the patent positioned in the compstatin long-acting PEG landscape? (Inferred landscape logic from claim scope)
The claims describe a long-acting compstatin analog strategy built around:
- cyclic compstatin analog peptide cores with defined substitution chemistry,
- amine-containing terminal extension,
- a PEG-like spacer (oligo(ethylene glycol), n up to 500 in claim 1) between cyclic core and the PEG conjugation point,
- and a PEG clearance-reducing moiety (with size and branching rules) linked through a linking moiety to the amine.
From a patent-landscape standpoint, the most relevant infringement and clearance questions turn on:
- Is your peptide core in the claimed SEQ set?
- Claim 1: “any of SEQ ID NOs 3-36.”
- Claim 9: SEQ ID NO 8 only, with defined substitution pattern.
- Does your design use an amine-bearing linker amino acid separated by an oligo(ethylene glycol) spacer?
- Claim 1 and claim 9 require that structural spacing.
- Does your “clearance reducing moiety” actually equal PEG conjugated via a covalent linking moiety?
- Claim 1 requires PEG; claim 9 repeats PEG as clearance-reducing moiety.
- Do you meet PK thresholds and potency retention if you practice within those functional claim elements?
- IV primate half-life thresholds (2/3/4 days) and terminal half-life 5-fold.
- molar activity retention (20%/30% or 10% of sum for multi-mers).
This claim architecture typically concentrates the competitive set into conjugation chemistries that mirror PEGylated scaffolds and peptide-spacer-amine coupling.
What is the likely “scope of protection” shape? (Practical claim overlap boundaries)
Strongest overlap zones
- PEGylated compstatin analogs where:
- cyclic peptide is from the claimed SEQ set,
- linker uses primary/secondary amines,
- spacer is oligo(ethylene glycol) with specified n ranges (claim 9: 1–10; claim 1: 1–500),
- PEG MW falls into one or more claimed windows (≥5 kD, ≥10 kD, 20–100 kD, ≥40 kD),
- conjugate valency and PEG branching match 2–10 or 2–100 moiety counts,
- and PK meets at least 2–4 day plasma half-life (if asserted through claim 28–30).
Most plausible design-around pressure points
- Shift away from:
- the claimed cyclic peptide sequence set (SEQ ID NOs 3–36 or SEQ ID NO 8 with defined substitutions),
- the oligo(ethylene glycol) spacer requirement,
- or the PEG “clearance reducing moiety” definition,
- or fail the PK/potency functional limits if those are treated as essential claim requirements during enforcement.
Key Takeaways
- US 11,661,441 claims a long-acting compstatin analog built from PEG clearance-reduction plus a cyclic compstatin peptide linked through an amine-bearing terminal extension and an oligo(ethylene glycol) spacer.
- Claim 1 is broader on peptide identity (SEQ ID NOs 3–36) and spacer length (n 1–500) but still requires the same core modular architecture and PEG linkage scheme.
- Claim 9 is narrower on peptide identity (SEQ ID NO 8 only) but is broad on substitution options, PEG structure (linear/branched; branches 3–10), and conjugate valency (2–100).
- The patent adds enforceability through functional constraints: primate plasma half-life (≥2/3/4 days), terminal half-life (≥5-fold), and molar activity retention (≥20%/30% or ≥10% of sum).
- Coverage for clinical use tightens in dependent claims toward PNH, red blood cell complement damage, intravascular or subcutaneous administration, and a 5–20 mg/kg dosing window.
FAQs
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Does US 11,661,441 require PEG as the clearance-reducing moiety?
Yes. Both claim 1 and claim 9 define the clearance-reducing moiety as polyethylene glycol (PEG).
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What governs the linkage between the cyclic compstatin peptide and PEG?
The claims require an amine-bearing side chain separated from the cyclic peptide by an oligo(ethylene glycol) spacer, with PEG covalently attached via a linking moiety to that amine.
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Are the spacer lengths fixed?
No. Claim 1 allows n between 1 and 500 for the oligo(ethylene glycol) spacer; claim 9 limits n between 1 and 10.
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Do the compound claims include pharmacokinetic performance requirements?
Yes. Claims 28–30 require plasma half-life thresholds in primates after IV dosing, and claim 34 requires terminal half-life at least 5-fold higher than the non-clearance-reduced comparator.
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Does the patent cover PNH specifically?
Yes. Claim 3 specifies Paroxysmal Nocturnal Hemoglobinuria (PNH) within the method claim set.
References
[1] United States Patent 11,661,441.
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