US Patent 8,809,292: What Is Claimed in PCSK9 dsRNA and Where the Patent Actually Lands
United States Patent 8,809,292 claims a specific class of double-stranded RNA (dsRNA) that inhibits human PCSK9 (proprotein convertase subtilisin kexin 9) expression, plus downstream claim sets covering (i) cells, (ii) formulations including lipid systems, and (iii) therapeutic methods based on administering the claimed dsRNA to humans or animals.
The patent’s enforceable scope is driven by three claim anchors:
- Sequence anchor: at least 15 contiguous nucleotides of SEQ ID NO:1228 in the antisense strand.
- Structural anchor: dsRNA duplex length between 15 and 30 base pairs, with dependent narrowing to 19 to 21 bp.
- Modification anchor: specific chemical modifications, including 2′-O-methyl and 5′-phosphorothioate, with broader coverage for many other modified nucleotides.
The patent is also mapped to commercially relevant embodiments through explicit recitation of sense/antisense sequence pairs (SEQ ID NO:1227/1228) and a concrete example duplex sequence set (SEQ ID NO:1229/1230), plus explicit lipid formulation language via ND-98.
What is the core independent claim scope (Claim 1)?
Claim 1 structure
Claim 1 is the independent spine:
- Object: a dsRNA for inhibiting expression of a human PCSK9 gene in a cell.
- Strands:
- sense strand (defined only by dependency in later claims),
- antisense strand containing at least 15 contiguous nucleotides of SEQ ID NO:1228.
- Duplex architecture:
- dsRNA forms a duplex structure between 15 and 30 base pairs in length.
- Functional requirement:
- The dsRNA is for inhibiting PCSK9 expression in a cell (the claims do not tie this to any particular assay in Claim 1, but later claims do).
Structural meaning for design-around
Any competitor dsRNA that:
- uses a different antisense region that fails to include 15 contiguous nucleotides from SEQ ID NO:1228, or
- uses a duplex length outside 15 to 30 bp, or
- targets PCSK9 without using dsRNA of this architecture (for example, uses siRNA with different duplex-length constraints or non-dsRNA modalities),
avoids the Claim 1 sequence/structure gates.
How do the dependent claims narrow the sequence and duplex geometry?
Dependent Claim 2: duplex length
- Claim 2 narrows duplex structure to 19 to 21 base pairs.
Implication: if an engineered dsRNA has the same antisense region but yields an effective duplex length outside 19–21 bp, it may still fall within Claim 1 (15–30) but not Claim 2.
Dependent Claims 3 and 4: exact sense/antisense sequences
- Claim 3: sense = SEQ ID NO:1227, antisense = SEQ ID NO:1228.
- Claim 4: “consists of” those exact strand sequences (stricter than Claim 3 because “consists of” limits additional nucleotides beyond those sequences).
Design consequence: if a competitor changes either strand sequence even slightly (outside the sequence definitions as recited), it may escape Claims 3/4 while still potentially meeting Claim 1 (because Claim 1 only requires contiguous 15 nt from SEQ ID NO:1228, not full exact-sequence matches).
What chemical modifications are claimed, and what is the practical risk?
Dependent Claim 5: specific modified sequences with explicit chemistry
Claim 5 is a high-value narrowing claim because it recites explicit modified strand sequences:
- sense strand consists of SEQ ID NO:1229:
5′-uucuAGAccuGuuuuGcuuTsT-3′
- antisense strand consists of SEQ ID NO:1230:
5′-AAGcAAAAcAGGUCuAGAATsT-3′
The claim language states that lower-case “c” or “u” indicates inclusion of a 2′-O-methyl ribonucleotide, and lower-case “s” indicates a phosphorothioate. The claim also states the strands include these modifications “as indicated.”
Risk posture: dsRNA products matching this exact modified sequence set are directly in-scope for Claim 5 (and its dependents).
Dependent Claim 6–8: modification breadth
- Claim 6: dsRNA comprises at least one modified nucleotide.
- Claim 7: dsRNA comprises at least one 2′-O-methyl and at least one 5′-phosphorothioate nucleotide.
- Claim 8: modified nucleotide is chosen from a long list, including:
- 2′-O-methyl
- 2′-deoxy-2′-fluoro
- 2′-deoxy
- locked nucleic acid (LNA)-type “locked”
- abasic nucleotide
- 2′-amino
- 2′-alkyl
- morpholino
- phosphoramidate
- 5′-phosphorothioate
- terminal nucleotide linked to cholesteryl derivative or dodecanoic acid bisdecylamide
- non-natural base nucleotides
Scope effect: Claim 8 expands the modification universe beyond the “2′-O-methyl + phosphorothioate” paradigm into many nucleotide chemistries. That makes the claim more difficult to avoid if a competitor keeps the same antisense sequence and duplex length but swaps chemistry.
What is claimed beyond the dsRNA: cells, vectors, compositions, and lipids?
Cells (Claim 9 and Claim 21/27/33)
- Claim 9: a cell comprising dsRNA of Claim 1.
- Claims 21/27/33: cells comprising dsRNA of Claims 3/4/5, respectively.
These are typical dependent “downstream use” claims. They can matter in enforcement if infringement is shown by uptake in target cells or in relevant ex vivo systems.
Pharmaceutical compositions (Claim 10, 22, 28, 34)
- Claim 10: dsRNA of Claim 1 + pharmaceutically acceptable carrier.
- Claims 22/28/34: the same structure but tied to dsRNA of Claims 3/4/5.
Lipid formulations (Claim 11, 23, 29, plus ND-98 in Claim 12)
- Claim 11: dsRNA of Claim 1 + lipid formulation.
- Claim 12: lipid formulation comprising cationic lipid comprising ND-98.
- Claims 23/29: lipid formulations tied to dsRNA of Claims 3 and 4.
Enforcement consequence: Claim 12 adds specificity. A formulation that does not use ND-98 could still infringe other composition claims if it uses a covered dsRNA and “a lipid formulation,” but the ND-98 claim tightens the evidentiary pathway for that embodiment.
Vectors (Claim 13–14)
- Claim 13: a vector with a regulatory sequence operably linked to nucleotide sequence encoding at least one dsRNA strand from Claim 1.
- Claim 14: a cell comprising that vector.
This is a separate infringement theory: genomic or episomal expression of strands that meet the dsRNA constraints.
What do the functional and method claims add?
In vitro inhibition thresholds (Claims 15–16)
Practical effect: these claims add performance metrics tied to specific dose ceilings and a specific cell model. They can strengthen infringement arguments if accused product data is available, but they also create an additional barrier if the accused dosing or potency regime differs.
Animal and patient therapeutic language (Claims 17, 19–20, 25–26, 31–32, 37–38)
- Claim 17: administering dsRNA to an animal decreases total serum cholesterol.
- Claim 19:
- treating or managing pathological processes “mediated by down regulating” PCSK9
- administering a therapeutically effective amount to a patient.
- Claim 20: treating PCSK9 gene-associated disorder with therapeutically effective amount.
Equivalent sets exist for dsRNA versions in Claims 3/4/5:
- Claims 25–26: for dsRNA of Claim 3
- Claims 31–32: for dsRNA of Claim 4
- Claims 37–38: for dsRNA of Claim 5
In-cell method claim (Claim 18 and Claim 24/30/36)
- Claim 18: contacting the cell with dsRNA of Claim 1 and maintaining sufficient time to degrade PCSK9 mRNA, inhibiting expression.
- Claims 24/30/36: same but tied to dsRNA of Claims 3/4/5.
What is the overall “claim map” coverage profile? (By embodiment type)
| Embodiment axis |
Where the patent lands |
What must match |
| Antisense sequence |
Claim 1 anchor |
Antisense contains at least 15 contiguous nt of SEQ ID NO:1228 |
| Full strand match |
Claims 3–5 |
Exact sequences SEQ ID NO:1227/1228 and/or explicit modified sequences SEQ ID NO:1229/1230 |
| Duplex length |
Claims 1–2 |
15–30 bp (Claim 1) and 19–21 bp (Claim 2) |
| Modification chemistry |
Claims 5–8 |
Explicit 2′-O-methyl + phosphorothioate sequencing in Claim 5; broad modification menu in Claim 8 |
| Delivery/formulation |
Claims 10–12 |
Carrier; lipid formulation; specific inclusion of ND-98 in Claim 12 |
| Biological system |
Claims 9, 13–14, 15–16, 18 |
Cell, vector, HepG2 potency and degradation thresholds |
| Therapeutic intent |
Claims 17, 19–20 |
Decrease serum cholesterol; treating disorders mediated by PCSK9 downregulation |
Patent landscape takeaways: where this patent fits relative to the PCSK9 RNA field
1) This patent is “sequence- and chemistry-governed,” not just target-governed
Many PCSK9 therapeutics define scope by target binding, target gene, or general oligonucleotide class. Here, the enforceability is tightly tied to:
- the SEQ ID NO:1228 antisense region (15 contiguous nucleotides),
- duplex length constraints,
- specific chemistry encoding (2′-O-methyl and phosphorothioate) and an expanded modification list.
This means a competitor cannot safely rely on “PCSK9 RNA” as an abstract category. They must map their construct to the specific gates.
2) Multiple claim tiers enable partial overlaps
- A competitor can be inside scope of Claim 1 without matching full exact strand sequences of Claims 3/4.
- A competitor can escape exact-sequence claims but still remain caught if they use antisense with at least 15 contiguous nucleotides matching SEQ ID NO:1228.
- A competitor can potentially avoid Claim 5 by using different explicit modified sequences, but still remain in-scope if their chemistry qualifies under Claim 6–8 and their antisense region + duplex length meet Claim 1.
3) Delivery does not fully define scope, but ND-98 does
If the competitor uses a lipid formulation that is not ND-98, they may avoid Claim 12 but not Claims 10–11 (composition) if dsRNA itself is in-scope. ND-98 is a specificity hook for one subset of product formats.
4) Potency thresholds and HepG2 are not universal, but they raise evidentiary value
Claims 15–16 introduce:
- a dose ceiling of 30 nM,
- a ≥20% inhibition benchmark in HepG2.
If the accused product’s data includes those conditions, infringement arguments become more direct. If data shows efficacy at higher doses or in other cell systems, the method tier may narrow, while the composition and dsRNA structure claims still matter.
Key Takeaways
- Claim 1 is broad enough to cover dsRNA where the antisense strand contains at least 15 contiguous nucleotides from SEQ ID NO:1228, with 15–30 bp duplex length, and functional intent to inhibit PCSK9 expression in cells.
- Dependent claims tighten the scope by locking in full strand sequences (SEQ ID NO:1227/1228), restricting duplex length to 19–21 bp, and specifying explicit modified sequences SEQ ID NO:1229/1230 with encoded 2′-O-methyl and 5′-phosphorothioate modifications.
- Modification coverage expands beyond 2′-O-methyl/phosphorothioate into a broad menu (Claim 8), reducing the protection value of swapping to alternative nucleotides if sequence/structure gates are still met.
- Delivery and downstream claims cover cells, vectors, compositions, and lipid formulations; ND-98 is specifically called out in a dependent composition claim.
- Method claims add functional potency constraints (≤30 nM; ≥20% inhibition in HepG2) and therapeutic outcomes (serum cholesterol reduction; treating PCSK9-mediated disorders).
FAQs
1) What is the minimum sequence requirement to fall under Claim 1?
The antisense strand must comprise at least 15 contiguous nucleotides of SEQ ID NO:1228.
2) What duplex lengths are covered?
Claim 1 covers dsRNA duplexes between 15 and 30 base pairs; Claim 2 narrows to 19 to 21 base pairs.
3) Do Claims 3 and 4 require the exact full strand sequences?
Yes. Claim 3 specifies sense = SEQ ID NO:1227 and antisense = SEQ ID NO:1228. Claim 4 uses “consists of,” limiting the strands to those exact sequences.
4) Is ND-98 required to infringe the lipid formulation claims?
No. ND-98 is specifically recited in Claim 12, but other lipid formulation composition claims exist without ND-98.
5) Do the therapeutic claims require animal data or specific cholesterol outcomes in the claim language?
No. The patent includes an animal cholesterol outcome claim (Claim 17), but the patient treatment claims are framed as administering a therapeutically effective amount for PCSK9-mediated pathological processes or PCSK9-associated disorders.
References
[1] United States Patent 8,809,292. Claims provided in prompt text.
