US Patent 9,315,811: Scope, Claims, and Patent Landscape for HAE Prophylaxis Using KLKB1-Targeting Modified Oligonucleotides
What does US 9,315,811 claim cover at the highest level?
US Patent 9,315,811 is directed to prophylactic treatment of hereditary angioedema (HAE) by administering a modified oligonucleotide (12 to 30 linked nucleosides) that is at least 90% complementary to a KLKB1 nucleic acid, with dependent claim options that narrow the mechanism and specify KLKB1 sequence embodiments, nucleoside chemistry, route, and combination therapy.
The independent claim anchors the invention on three technical pillars:
- Indication: prophylaxis in an animal identified as having HAE.
- Target: KLKB1 nucleic acid complementarity (>=90%).
- Modality: a chemically modified oligonucleotide (12 to 30 nucleosides) administered therapeutically.
What is the claim 1 “scope core” and how broadly does it read?
Claim 1 (independent) breakdown
Claim 1 recites a method:
- Prophylactically treating hereditary angioedema (HAE)
- In an animal identified as having HAE
- By administering a therapeutically effective amount of a compound comprising a:
- Modified oligonucleotide
- 12 to 30 linked nucleosides
- At least 90% complementary to a KLKB1 nucleic acid
Practical scope implications
- Sequence latitude is wide: “at least 90% complementary” to KLKB1 includes numerous distinct oligonucleotide candidates (especially if KLKB1 target region is defined only by complementarity rather than exact length, position, or exact sequence match).
- Modality latitude exists: the claim calls it a “modified oligonucleotide” but does not specify which modifications are allowed at the independent-claim level. Specific chemistry appears in dependent claims.
- Method-of-treatment is device-free: no delivery system is mandated in claim 1; it later narrows to parenteral administration in claim 20.
Dependent claim chain expands narrowing points
From claim 2 onward, the patent uses typical dependent claim tightening levers:
- Clinical outcomes (claims 2-5)
- Human embodiment (claims 6-9)
- Exact KLKB1 nucleic acid identity (claim 8 and its SEQ ID NO set; claim 9 requires 100% complementarity)
- Oligonucleotide structural form (claims 10-12)
- Specific chemistries (claims 13-18)
- Combination therapy scope (claim 19)
- Route (claims 20-21)
- Conjugate option (claim 22)
What clinical and mechanistic limitations are included in claims 2–5?
Claims 2–5 do not add additional structural features to the oligonucleotide. They narrow the purpose/effect of prophylaxis:
- Claim 2: prophylactic administering prevents or ameliorates edema
- Claim 3: prophylaxis prevents or ameliorates vascular permeability
- Claim 4: prophylaxis prevents or ameliorates vascular leakage
- Claim 5: prophylaxis prevents or ameliorates inflammation
Scope impact
- These dependent claims are broad functionally. They do not require a specific validated biomarker, but they map prophylaxis to recognized HAE pathophysiology (edema, leakage/permeability, inflammation).
How does the patent narrow from animal to human and from KLKB1 general to specific sequences?
Human-specific narrowing
- Claim 6: animal is a human
- Claim 7: KLKB1 nucleic acid is human KLKB1
- Claim 8: human KLKB1 nucleic acid is SEQ ID NO: 1–9 or the complement of SEQ ID NO: 10
- Claim 9: modified oligonucleotide is 100% complementary to the human KLKB1 nucleic acid
Scope impact
- The independent claim allows “>=90% complementary” to KLKB1 generally.
- The later claims carve out a stricter regime: 100% complementarity to defined human KLKB1 sequences (SEQ ID set).
- That structure creates a two-tier landscape:
- Broader infringement risk under claim 1 for “>=90% complementarity”
- Higher certainty embodiments under claims 7–9 where full complementarity and specific SEQ ID anchors exist
What molecular and chemical limitations are imposed by the dependent claims?
Oligonucleotide physical form
- Claim 10: modified oligonucleotide is a single-stranded oligonucleotide
Internucleoside linkage chemistry
- Claim 11: at least one nucleoside has a modified internucleoside linkage
- Claim 12: modified internucleoside linkage is phosphorothioate
Sugar modifications
- Claim 13: at least one nucleoside has a modified sugar
- Claim 14: sugar is a bicyclic sugar
- Claim 15: bicyclic sugar comprises a 4′-CH(CH3)-O-2′ bridge
- Claim 16: modified sugar comprises a 2′-O-methoxyethyl group
Nucleobase modifications
- Claim 17: at least one nucleoside has a modified nucleobase
- Claim 18: modified nucleobase is 5-methylcytosine
Scope impact
- The dependent claims outline a chemistry “stack” consistent with advanced oligo chemistries used in antisense/oligonucleotide therapeutics:
- Single-stranded
- Phosphorothioate internucleoside linkages
- Bicyclic sugar and/or 2′-O-methoxyethyl
- 5-methylcytosine
- Whether claim coverage requires all these chemistries depends on whether a competitor’s candidate meets the dependent claim specifics. A product that uses different chemistry may still fall under claim 1’s broader “modified oligonucleotide” language if it meets length and complementarity thresholds, but it may avoid dependent-claim constraints.
What combination therapy does the patent explicitly cover?
- Claim 19: the method comprises co-administering the modified oligonucleotide compound with any agent from a defined group:
- Cl-INH recombinant protein (listed as “Cl-INH recombinant protein”)
- CINRYZE
- BERINERT
- KALBITOR
- Icatibant
- Ecallantide
- attenuated androgens
- anabolic steroids
- antifibrinolytic agents
- epsilon-aminocaproic acid
- tranexamic acid
Scope impact
- Claim 19 expands claim infringement exposure for combination regimens in the HAE standard-of-care space.
- It also makes the patent operationally relevant to product positioning: even if the oligo candidate is not used alone, claim 19 can capture co-therapy combinations.
What route of administration and conjugation options exist?
Route
- Claim 20: administering is parenteral
- Claim 21: parenteral is subcutaneous or intravenous
Conjugates
- Claim 22: compound comprises a conjugate
Scope impact
- Claim 20–21 restrict operational methods for downstream infringement analysis to injectable routes.
- Claim 22 keeps open the possibility of conjugated oligonucleotides (though the claim text does not specify conjugate type).
How would you map this to potential claim-coverage scenarios? (Infringement design space)
Below is a practical coverage map based strictly on the claim language:
| Candidate attribute |
Covered by claim 1 baseline |
Covered by narrower dependent claims |
| HAE prophylaxis method |
Yes |
Yes (claims 2–5 add effect) |
| Animal type |
Yes |
Human in claims 6–9 |
| Target |
KLKB1 nucleic acid with >=90% complementarity |
100% complementarity plus defined SEQ IDs in claims 7–9 |
| Oligo length |
12 to 30 nucleosides |
Same (dependent claims build on claim 1) |
| Single-stranded |
Not required in claim 1 |
Required in claim 10 |
| Phosphorothioate linkage |
Not required in claim 1 |
Required in claim 12 |
| Sugar chemistry (bicyclic, 2′-O-methoxyethyl) |
Not required in claim 1 |
Required in claims 13–16 |
| Nucleobase (5-methylcytosine) |
Not required in claim 1 |
Required in claims 17–18 |
| Combination with approved/standard HAE agents |
Not required |
Covered explicitly in claim 19 |
| Parenteral route (SC/IV) |
Not required in claim 1 |
Required in claims 20–21 |
| Conjugate |
Not required in claim 1 |
Covered in claim 22 |
What is the patent landscape logic around “KLKB1-targeting modified oligonucleotides”?
Given the claim set, the landscape naturally segments into three competitive zones:
-
KLKB1 antisense/targeting oligonucleotides for HAE prophylaxis
- This patent’s distinctive claim hook is the combination of HAE prophylaxis plus KLKB1 complementarity plus modified oligo length constraints.
-
Sequence-specific KLKB1 embodiments
- Claims 7–9 include exact SEQ ID references and full complementarity. That creates a stronger moat against close design-around attempts that still target the same KLKB1 region.
-
Chemistry-specific oligonucleotide embodiments
- Claims 11–18 impose common antisense/oligo chemistries (phosphorothioate linkages, bicyclic sugars/bridges, 2′-O-methoxyethyl, and 5-methylcytosine).
- Competitors using alternative chemistries may avoid dependent-claim coverage but still face claim 1 risk if they meet the “modified oligonucleotide” and >=90% complementarity and length requirements.
Where do design-arounds most likely fail against this patent?
Based on claim language alone, the likely failure modes are:
-
Targeting the same KLKB1 region with high complementarity
- “at least 90% complementary” is a broad capture net.
-
Using 12–30 linked nucleosides
- Many oligos for gene silencing/antisense fall within this window.
-
Using single-stranded modified oligos with common chemistries
- Phosphorothioate linkages and 2′ modifications are frequent in the modality space.
-
Practicing HAE prophylaxis via injectable co-therapy
- Claim 19 explicitly lists many standard-of-care HAE agents, reducing room for “no combination therapy” defenses if a regimen includes those agents.
How does the claims structure affect freedom-to-operate analysis?
This patent’s claim architecture is materially important:
- Claim 1 is broad on complementarity threshold (>=90%), moderate on oligo length (12–30), and only requires “modified” chemistry.
- Dependent claims add layered specificity (human KLKB1 SEQ IDs; 100% complementarity; phosphorothioate; bicyclic sugars; 2′-O-methoxyethyl; 5-methylcytosine; SC/IV; conjugates; co-therapy).
Business read-through
- If a candidate product hits claim 1 elements (length + >=90% complementary to KLKB1 + prophylaxis), it faces baseline risk even if it uses different chemistry from the dependent claims.
- If it also matches the dependent chemistry and SEQ ID-specific complementarity, risk concentrates on higher-likelihood enforceability pathways.
Key Takeaways
- US 9,315,811 claims HAE prophylaxis by administering a modified oligonucleotide (12–30 nucleosides) that is >=90% complementary to KLKB1.
- The claim set builds to human KLKB1 SEQ ID embodiments and requires 100% complementarity in narrower claims (claims 7–9).
- Dependent claims constrain oligo structure and chemistry (single-stranded; phosphorothioate linkages; bicyclic sugar with a 4′-CH(CH3)-O-2′ bridge; 2′-O-methoxyethyl; 5-methylcytosine).
- The patent also explicitly captures injectable prophylaxis (SC/IV) and co-administration with HAE standard-of-care agents (Cl-INH products, CINRYZE, BERINERT, KALBITOR, icatibant, ecallantide, and antifibrinolytics and hormones as listed).
- Patent landscape risk concentrates around KLKB1-targeted antisense/oligonucleotide approaches for HAE prophylaxis, with the strongest claim specificity in sequence-defined, fully complementary oligos and common antisense chemistries.
FAQs
1) Is claim 1 limited to a specific KLKB1 sequence?
No. Claim 1 only requires the modified oligonucleotide to be at least 90% complementary to a KLKB1 nucleic acid.
2) Which claims impose the strictest complementarity standard?
Claims 7–9. Claim 9 requires the modified oligonucleotide to be 100% complementary to the human KLKB1 nucleic acid defined by the SEQ ID set in claim 8.
3) What oligonucleotide length is required?
12 to 30 linked nucleosides (claim 1).
4) What route is specifically covered in dependent claims?
Parenteral, including subcutaneous or intravenous administration (claims 20–21).
5) Does the patent cover combination regimens?
Yes. Claim 19 requires co-administration with agents from a defined HAE treatment group (including Cl-INH products, icatibant, ecallantide, and antifibrinolytics/hormonal agents as listed).
References
[1] United States Patent No. 9,315,811. Claims text provided in the prompt.
