United States Patent 8,058,069: Scope, Claims, Expiration, and Nucleic Acid-Lipid Particle Patent Landscape

U.S. Patent No. 8,058,069 protects nucleic acid-lipid particles, including siRNA lipid nanoparticles, defined primarily by a narrow four-component lipid composition. The core composition contains 50-65 mol% cationic lipid, 4-10 mol% phospholipid, 30-40 mol% cholesterol or derivative, and 0.5-2 mol% aggregation-inhibiting conjugated lipid, typically a PEG-lipid.

The patent is commercially relevant because the claimed composition overlaps the general lipid ratio used in several siRNA and mRNA lipid nanoparticle platforms. Its strongest claim is claim 1, combined with the narrower formulation and performance limitations in claims 14 and 16-19. The patent does not claim a named drug, a specific siRNA sequence, a particular disease, or a manufacturing process.

The nominal 20-year patent term runs from the relevant 2006 nonprovisional or PCT filing date and points to expiration in 2026, subject to any patent-term adjustment or extension recorded by the USPTO. The patent is not, by itself, an FDA Orange Book listing or a regulatory exclusivity right.

What does U.S. Patent 8,058,069 protect?

The patent protects a nucleic acid-lipid particle defined by four required lipid categories:

Required component	Claim 1 range	Primary technical role
Cationic lipid	50-65 mol%	Associates with and encapsulates nucleic acid
Phospholipid	4-10 mol%	Provides structural membrane properties
Cholesterol or derivative	30-40 mol%	Stabilizes the lipid bilayer
Conjugated lipid that inhibits aggregation	0.5-2 mol%	Controls particle aggregation and circulation behavior

The claim is composition-based. It does not require a particular preparation method, administration route, therapeutic indication, nucleic acid sequence, or pharmaceutical dosage form.

A product is potentially within claim 1 if its total lipid composition falls within all four specified ranges and the particle contains nucleic acid. The use of "comprising" makes the claim open-ended as to additional elements, but the molar percentages must still be capable of satisfying the claimed composition as a whole.

The principal claim limitation is the combination of percentage ranges. A particle with the correct individual ingredients but a cationic-lipid concentration below 50 mol%, a phospholipid concentration above 10 mol%, or a PEG-lipid concentration above 2 mol% would not literally meet claim 1.

How do the dependent claims narrow the patent scope?

The dependent claims create several commercially important subgroups.

Claims	Added limitation	Scope
2-7	siRNA, length, modified nucleotides, 2'-O-methyl bases, 3' overhangs	siRNA-specific particles
8	Cationic lipid at 52-62 mol%	Narrower cationic-lipid range
9	DPPC, DSPC, or mixture	Defined phospholipid identity
10-13	PEG-lipid, PEG-DAG, PEG-DAA, PEG-DMA, PEG-DSA, approximately 2,000 Da PEG	Defined aggregation-inhibiting lipid
14	Approximately 57.1/7.1/34.3/1.4 mol% formulation	Specific nominal formulation
15	Conjugated lipid at 1-2 mol%	Higher PEG-lipid range
16	Nucleic acid substantially protected in serum	Functional stability limitation
17	Full nucleic acid encapsulation	Encapsulation-performance limitation
18	Lipid:nucleic acid mass ratio of approximately 5:1 to 15:1	Loading limitation
19	Median diameter of 40-150 nm	Particle-size limitation
20	Phospholipid at 5-9 mol%	Narrower phospholipid range
21	Cholesterol at 32-36 mol%	Narrower cholesterol range
22	Pharmaceutical composition with carrier	Drug-product format

Claims 2-7 are particularly important for siRNA products. They cover both unmodified and modified siRNA, including 2'-O-methyl modifications and conventional 3' overhangs. The claims do not limit the siRNA to a particular target gene or therapeutic indication.

What is the most important formulation in the patent?

Claim 14 recites approximately:

Lipid component	Claimed amount
Cationic lipid	57.1 mol%
Phospholipid	7.1 mol%
Cholesterol or derivative	34.3 mol%
PEG-lipid conjugate	1.4 mol%

The listed percentages total approximately 99.9 mol% because of rounding. This claim is narrower than claim 1 but may be easier to evaluate against a disclosed product composition.

Claim 14 is directed to a formulation profile rather than a specific named cationic lipid. It can therefore reach multiple lipid species if the product uses the required percentages and otherwise satisfies claim 1.

The lack of a named cationic lipid creates breadth but also creates potential validity and claim-construction issues. A competitor may argue that the specification does not adequately enable every lipid falling within the broad category of "cationic lipid," particularly if the patent disclosure focuses on a limited group of compounds.

Does the patent cover modern siRNA lipid nanoparticles?

It can. The claim architecture overlaps a standard four-component lipid nanoparticle design used for nucleic acid delivery:

An ionizable or cationic lipid.
DSPC or another phospholipid.
Cholesterol.
A PEG-lipid conjugate.

For example, the widely reported lipid composition of patisiran lipid nanoparticles is approximately 50 mol% DLin-MC3-DMA, 10 mol% DSPC, 38.5 mol% cholesterol, and 1.5 mol% PEG-lipid. That profile falls within the numerical ranges of claim 1 if DLin-MC3-DMA qualifies as the claimed cationic lipid under the applicable claim construction and the product otherwise satisfies the particle limitations.

The overlap does not establish infringement. A complete analysis would require:

The precise lipid identities.
The product's actual molar percentages.
Whether the cationic lipid is legally within the claim term.
Whether the nucleic acid is fully encapsulated.
Particle-size data.
Lipid:nucleic acid mass ratio.
Any relevant prosecution-history disclaimer.
The status of patent-term adjustments and claim validity.

How should "cationic lipid" be interpreted?

The claim uses "cationic lipid" rather than a narrower term such as "ionizable lipid" or a named lipid structure.

That wording potentially covers permanently charged cationic lipids and, depending on the specification and prosecution history, protonatable lipids that carry a positive charge under relevant formulation or physiological conditions. The distinction is commercially significant:

Lipid class	Typical behavior	Potential issue under claim 1
Permanently cationic lipid	Positively charged over a broad pH range	More straightforward fit if covered by specification
Ionizable lipid	Neutral near physiological pH and protonated under acidic formulation conditions	Scope depends on intrinsic disclosure and construction
Neutral helper lipid	Structural or membrane-supporting function	Usually fits phospholipid or other non-cationic category, not cationic category

The patent's claim language does not expressly require a particular pKa, charge state, chemical scaffold, or ionization profile. That increases potential reach across lipid platforms but leaves room for disputes concerning written description, enablement, and the technical meaning of "cationic."

What are the strongest claim elements for infringement analysis?

The most important elements are the percentage ranges and the PEG-lipid limitation.

Composition ranges

The product must satisfy all of the following:

Cationic lipid: 50-65 mol%.
Phospholipid: 4-10 mol%.
Cholesterol or derivative: 30-40 mol%.
Aggregation-inhibiting conjugated lipid: 0.5-2 mol%.

A product outside any one range is not literally within claim 1. For example:

49 mol% cationic lipid falls outside the claim.
11 mol% DSPC falls outside the claim.
2.1 mol% PEG-lipid falls outside the claim.
29 mol% cholesterol falls outside the claim.

The doctrine of equivalents could become relevant for small deviations, but numerical-range cases depend heavily on prosecution history, prior art, and the materiality of the difference.

PEG-lipid identity

Claims 10-13 narrow the aggregation-inhibiting lipid to PEG conjugates, including PEG-DAG and PEG-DAA species. Claims 11 and 12 identify PEG-DMA and PEG-DSA variants, while claim 13 targets approximately 2,000-dalton PEG.

A product using a different aggregation-control system, such as a non-PEG polymer or a different conjugated lipid, may avoid the narrower dependent claims even if it remains exposed under claim 1.

What are the principal validity vulnerabilities?

The patent has meaningful breadth but several predictable validity pressure points.

Anticipation

A prior-art lipid nanoparticle must disclose every claim element in a single reference, including the overlapping composition ranges and nucleic acid-particle structure. Earlier cationic lipid formulations, liposomes, siRNA particles, and PEGylated particles may be relevant, but a reference lacking the claimed percentage combination may not anticipate claim 1.

Obviousness

The most substantial challenge is likely obviousness. Prior art commonly disclosed combinations of cationic lipid, phospholipid, cholesterol, and PEG-lipid. The dispute would focus on whether selecting the claimed ranges was a routine optimization or produced an unexpected result.

The serum-stability, encapsulation, particle-size, and loading limitations in claims 16-19 could strengthen patentability if the specification demonstrates a technical correlation between the claimed ranges and those results.

Written description and enablement

The broad term "cationic lipid" may be challenged if the patent describes only a small number of lipid species. Claims that cover a large genus based mainly on functional or compositional language can face written-description and enablement scrutiny.

Indefiniteness

Terms such as "about," "substantially degraded," "fully encapsulated," and "conjugated lipid that inhibits aggregation" may require interpretation. The patent is stronger if the specification provides objective testing methods and numerical thresholds.

When does U.S. Patent 8,058,069 lose exclusivity?

The patent was issued on November 15, 2011. Its nominal term is calculated from the relevant 2006 filing date, producing an expected expiration in 2026. The exact expiration date depends on the USPTO's recorded patent-term adjustment and any applicable patent-term extension.

The patent is not a biologic patent and does not receive the 12-year reference-product exclusivity associated with biologics. It also does not receive Hatch-Waxman exclusivity merely because it covers a pharmaceutical composition.

Patent and regulatory exclusivity are separate

Right	Applies to this patent?
U.S. patent rights	Yes, during the enforceable term
FDA Orange Book listing	Not automatically
Five-year NCE exclusivity	No, based on the patent itself
Three-year FDA exclusivity	No, based on the patent itself
Seven-year orphan exclusivity	Product-specific, not created by this patent
Twelve-year biologic exclusivity	No

The patent's expiration does not automatically authorize a generic or follow-on product. Other composition, manufacturing, formulation, method-of-use, or product-specific patents may remain in force.

What is the Orange Book status of U.S. Patent 8,058,069?

A platform patent covering a class of nucleic acid-lipid particles is not automatically listed in the FDA Orange Book. Orange Book listing is tied to an approved drug application and patents that claim the approved drug, its formulation, or an approved method of use.

U.S. Patent 8,058,069 should therefore be treated as a standalone platform patent unless it appears in the patent listing for a particular approved product. The patent number alone does not establish an Orange Book listing for patisiran, givosiran, inclisiran, vutrisiran, or another nucleic acid therapy.

For products approved under an NDA, the relevant commercial analysis must separate:

Patent 8,058,069.
Orange Book-listed product patents.
Unlisted platform patents.
Regulatory exclusivity.
Trade-secret manufacturing rights.
Licenses and covenants not to sue.

Are there Paragraph IV challenges to this patent?

A Paragraph IV certification applies to patents listed in the Orange Book for an approved drug. It is not a general mechanism for challenging any pharmaceutical patent.

A generic applicant could file a Paragraph IV certification against a listed patent if the patent were associated with an approved NDA. A challenge to U.S. Patent 8,058,069 outside that context would ordinarily proceed through district-court litigation, an inter partes review petition, post-grant review where available, or another invalidity or noninfringement proceeding.

The patent's platform character reduces the likelihood that it would be the sole barrier identified in a generic filing. Commercial products may face a layered estate containing:

Active-lipid composition patents.
LNP formulation patents.
Nucleic acid sequence patents.
Therapeutic-use patents.
Manufacturing patents.
Product-specific Orange Book patents.

What litigation affects the patent landscape?

The principal LNP patent disputes have involved platform owners and developers of nucleic acid medicines, including disputes associated with Arbutus, Tekmira, Moderna, and Alnylam. Those cases have often focused on later-generation lipid nanoparticle patents, specific ionizable lipids, delivery systems, or mRNA products rather than relying solely on U.S. Patent 8,058,069.

The patent should not be treated as a standalone proxy for freedom to operate. A product can avoid claim 1 and still face infringement allegations under later patents covering:

A specific ionizable lipid.
A PEG-lipid structure.
A defined mRNA or siRNA delivery formulation.
A manufacturing or mixing process.
A lipid nanoparticle used for a particular therapeutic indication.

Conversely, a product that appears to fall within the numerical ranges may have defenses based on invalidity, claim construction, license rights, patent exhaustion, or the patent's expiration.

Which companies and products are most commercially relevant?

Company or product category	Relevance to Patent 8,058,069
Alnylam siRNA products	High relevance because several products use lipid nanoparticle delivery
Arbutus and former Tekmira platform rights	High relevance as historical and continuing LNP patent licensors
Moderna mRNA products	Compositionally relevant, but product-specific patent analysis is required
Ionis and partnered siRNA programs	Relevant where lipid nanoparticle delivery is used
Generic manufacturers	Relevant after patent and regulatory barriers are cleared
Biosimilar developers	Generally not applicable because siRNA products are not biologics in the conventional biosimilar pathway

The biosimilar framework is generally not the principal route for follow-on siRNA products. Depending on the reference product and dosage form, a competitor may pursue an ANDA, a 505(b)(2) application, or an alternative pathway. The regulatory pathway does not determine whether the product infringes the patent.

What manufacturing and IP barriers remain after expiration?

Expiration of this patent would remove only the rights created by this patent. Important barriers may remain in:

Ionizable-lipid synthesis.
PEG-lipid manufacture.
Controlled nanoprecipitation or mixing.
Particle-size control.
Encapsulation efficiency.
Sterile filtration.
Stability and cold-chain handling.
Analytical release testing.
Product-specific patents.
Trade secrets and know-how.
Licensing restrictions.

For a complex LNP product, manufacturing know-how can be commercially important even when the composition patent has expired. A competitor may need to reproduce particle size, encapsulation, potency, impurity profile, and release specifications without access to the originator's process controls.

How strong is the patent estate?

The patent is strongest against products that reproduce the claimed four-component formulation within the specified ranges, particularly where the product also uses siRNA, DSPC, cholesterol, a PEG-lipid, full encapsulation, and a 40-150 nm particle size.

Its principal strengths are:

Broad category language for the cationic lipid.
Direct coverage of siRNA particles.
Overlap with common LNP architecture.
Multiple dependent claims addressing commercial formulation characteristics.
Product-by-composition claim format, which does not require proof of manufacturing process.

Its principal weaknesses are:

Narrow percentage windows.
Potential prior art involving similar lipid combinations.
Uncertainty around the scope of "cationic lipid."
Functional limitations that may require objective testing.
Possible enablement and written-description challenges.
Limited remaining patent term.

What generic or follow-on launch scenarios exist?

Immediate composition-based launch after expiration

A competitor could launch after expiration if it avoids all enforceable later patents and satisfies FDA requirements. The competitor would still need to address product-specific regulatory protections.

Design-around launch before expiration

Possible design-around strategies include:

Reducing cationic lipid below 50 mol%.
Increasing phospholipid above 10 mol%.
Reducing cholesterol below 30 mol%.
Increasing PEG-lipid above 2 mol%.
Using a non-PEG aggregation-control lipid.
Using a particle size outside 40-150 nm.
Adopting a different lipid:nucleic acid ratio.

These changes may affect potency, tolerability, stability, and manufacturability. A design-around that avoids one dependent claim may remain within claim 1.

Licensed launch

Licensing may be more efficient than litigation where the product uses the claimed architecture and the patent owner controls related LNP rights. Historical licensing arrangements in the LNP sector have included rights from Tekmira and Arbutus to drug developers, although the scope of any license must be checked against the specific product, field, territory, and patent family.

Key Takeaways

U.S. Patent 8,058,069 claims nucleic acid-lipid particles with a defined four-component lipid ratio.
The core range is 50-65 mol% cationic lipid, 4-10 mol% phospholipid, 30-40 mol% cholesterol, and 0.5-2 mol% PEG or other aggregation-inhibiting conjugated lipid.
Claims 2-7 directly target siRNA particles, including modified siRNA and 2'-O-methyl nucleotides.
Claim 14 covers an approximately 57.1/7.1/34.3/1.4 mol% formulation.
The patent can overlap standard siRNA LNP formulations, including formulations using an ionizable lipid, DSPC, cholesterol, and PEG-lipid.
The nominal patent term points to expiration in 2026, subject to USPTO-recorded term adjustments.
The patent does not automatically create Orange Book protection, FDA exclusivity, or a biosimilar barrier.
A freedom-to-operate review must include later LNP patents, active-lipid patents, product patents, method-of-use patents, manufacturing rights, and licenses.
The main legal vulnerabilities are prior art, obviousness, enablement, written description, claim construction, and the precision of the claimed numerical ranges.

Frequently Asked Questions

Does Patent 8,058,069 cover patisiran?

It may overlap the reported lipid composition of patisiran nanoparticles, but coverage depends on the legally construed meaning of "cationic lipid," the product's verified composition, and other claim elements. Product overlap alone does not establish infringement.

Does the patent cover mRNA lipid nanoparticles?

The claims recite "nucleic acid" and are not limited to siRNA. The independent claim can therefore reach mRNA particles if the product satisfies the required lipid composition and particle limitations.

Can changing the PEG-lipid percentage avoid the patent?

It may avoid literal infringement of claim 1 if the PEG-lipid concentration is outside 0.5-2 mol%. The product must also be evaluated against the doctrine of equivalents and other patents.

Is U.S. Patent 8,058,069 a patent on a specific cationic lipid?

No. The claims use the broader category "cationic lipid." The patent does not limit claim 1 to a single named lipid, although the specification and prosecution history may affect the enforceable scope.

Does expiration eliminate all LNP patent risk?

No. Expiration removes the rights created by this patent only. Later patents may cover ionizable lipids, PEG-lipids, formulations, therapeutic uses, manufacturing methods, or approved products.

References

U.S. Patent No. 8,058,069, Nucleic acid-lipid particles. U.S. Patent and Trademark Office. Issued November 15, 2011.
U.S. Patent and Trademark Office. (n.d.). Patent Center. https://patentcenter.uspto.gov/
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
U.S. Food and Drug Administration. (2018). ONPATTRO (patisiran) injection, prescribing information. FDA.
U.S. Code, Title 35, §§ 154, 271, 282, and 284.
U.S. Code, Title 21, §§ 355 and 355(j).

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Alnylam Pharms Inc	ONPATTRO	patisiran sodium	SOLUTION;INTRAVENOUS	210922-001	Aug 10, 2018		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2008342535	⤷ Start Trial
Australia	2009238175	⤷ Start Trial
Canada	2710713	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,058,069

Which drugs does patent 8,058,069 protect, and when does it expire?

Summary for Patent: 8,058,069