US Patent 8,633,219: Scope, Claims, Expiration, Orange Book Status, and HIV Combination-Product Patent Landscape
US Patent 8,633,219 protects HIV treatment methods and pharmaceutical compositions combining elvitegravir with emtricitabine and either tenofovir disoproxil fumarate or GS-7340, now known as tenofovir alafenamide. The patent is directed to the active-antiretroviral combination, not to elvitegravir alone, emtricitabine alone, tenofovir disoproxil fumarate alone, or tenofovir alafenamide alone.
The commercially relevant products are Stribild, which contains elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate, and Genvoya, which contains elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide. Because the claims use the transitional term "comprising," the presence of cobicistat does not necessarily avoid infringement of a claim requiring the three recited antiretroviral agents.
What does US Patent 8,633,219 cover?
The patent covers two related combination platforms:
| Claim group |
Elvitegravir form |
Tenofovir component |
Dosage-form limitation |
| Claims 1-2 |
Elvitegravir or pharmaceutically acceptable salt or solvate |
Tenofovir disoproxil fumarate |
Claim 2 requires a single therapeutic composition |
| Claims 3-4 |
Elvitegravir or pharmaceutically acceptable salt or solvate |
GS-7340 |
Claim 4 requires a single therapeutic composition |
| Claim 5 |
Elvitegravir or pharmaceutically acceptable salt or solvate |
Tenofovir disoproxil fumarate |
Composition claim |
| Claim 6 |
Elvitegravir or pharmaceutically acceptable salt or solvate |
GS-7340 |
Composition claim |
The patent therefore contains both method-of-treatment claims and composition claims. Claims 1 and 3 cover administration of the three-drug combination to a human patient. Claims 2 and 4 narrow the method claims to a fixed-dose or otherwise single-composition product. Claims 5 and 6 cover the corresponding compositions directly.
The claims do not require cobicistat. A product containing the claimed three active ingredients plus cobicistat may fall within the claims because "comprising" generally permits additional ingredients, subject to the ordinary rules of claim construction and infringement analysis.
What molecule is identified by the long chemical name?
The chemical entity recited in part (a) is elvitegravir.
The claim language identifies the specific stereochemical form of elvitegravir:
(S)-6-(3-chloro-2-fluorobenzyl)-1-(1-hydroxymethyl-2-methylpropyl)-7-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
Elvitegravir is an HIV integrase strand-transfer inhibitor. In Stribild and Genvoya, it is administered with cobicistat, which increases elvitegravir exposure through CYP3A inhibition.
GS-7340 is the development code for tenofovir alafenamide, commonly used in products as tenofovir alafenamide fumarate. It is a tenofovir prodrug distinct from tenofovir disoproxil fumarate.
How broad are claims 1 through 6?
Claims 1 and 3: combination treatment claims
Claims 1 and 3 require:
- A human patient.
- HIV infectious disease.
- Administration of elvitegravir.
- Administration of emtricitabine.
- Administration of either tenofovir disoproxil fumarate or GS-7340.
- An effective amount of each component.
The claims are narrower than a general claim to treating HIV with an integrase inhibitor and nucleoside reverse-transcriptase inhibitors. They identify a particular integrase inhibitor and particular tenofovir and emtricitabine components.
The two independent method claims differ principally in the tenofovir component:
- Claim 1 requires tenofovir disoproxil fumarate.
- Claim 3 requires GS-7340.
The claims do not expressly require:
- Cobicistat.
- A particular dose.
- A particular dosing frequency.
- A particular tablet size.
- A particular crystalline form of elvitegravir.
- A particular salt of emtricitabine.
- A particular patient population.
- A treatment duration.
- Prior treatment failure or treatment-naive status.
- A specific viral-load or CD4-cell endpoint.
The absence of dose, schedule, and formulation limitations makes the independent treatment claims potentially broad within the defined three-drug combination.
Claims 2 and 4: single-composition limitations
Claims 2 and 4 depend on claims 1 and 3 and require the three agents to be formulated together and administered as a single therapeutic composition.
These claims are directed to fixed-dose combination products or other single dosage forms. A regimen using separate tablets is less likely to satisfy the single-composition limitation, while a single tablet containing the required agents is the clearest commercial example.
A product containing cobicistat as an additional active ingredient may still satisfy the "formulated together" limitation if the claimed three agents are present in the same dosage form.
Claims 5 and 6: composition claims
Claims 5 and 6 are product claims. They require a composition containing:
- Elvitegravir or an acceptable salt or solvate.
- Emtricitabine.
- Tenofovir disoproxil fumarate or GS-7340.
The composition claims do not expressly require cobicistat. They also do not state a specific excipient, tablet architecture, release profile, particle size, coating, or dissolution profile.
Claims 5 and 6 are therefore materially different from a narrow formulation patent directed to a particular tablet process or excipient system. They focus on the active-ingredient combination itself.
What products are commercially relevant to US Patent 8,633,219?
| Product |
Manufacturer |
Active ingredients |
Relevance to patent |
| Stribild |
Gilead Sciences |
Elvitegravir, cobicistat, emtricitabine, tenofovir disoproxil fumarate |
Corresponds to the TDF combination in claims 1, 2, and 5 |
| Genvoya |
Gilead Sciences |
Elvitegravir, cobicistat, emtricitabine, tenofovir alafenamide |
Corresponds to the GS-7340 combination in claims 3, 4, and 6 |
| Atripla |
Gilead/Bristol Myers Squibb |
Efavirenz, emtricitabine, tenofovir disoproxil fumarate |
Outside the claimed elvitegravir combination |
| Biktarvy |
Gilead Sciences |
Bictegravir, emtricitabine, tenofovir alafenamide |
Outside the claimed integrase inhibitor requirement |
| Odefsey |
Gilead Sciences |
Rilpivirine, emtricitabine, tenofovir alafenamide |
Outside the claimed integrase inhibitor requirement |
| Complera/Eviplera |
Gilead Sciences |
Rilpivirine, emtricitabine, tenofovir disoproxil fumarate |
Outside the claimed integrase inhibitor requirement |
Stribild is the most direct commercial match for the TDF claims. Genvoya is the most direct commercial match for the GS-7340 claims.
When does US Patent 8,633,219 lose exclusivity?
US Patent 8,633,219 issued on January 21, 2014. Its expected ordinary patent-term endpoint is in 2027, based on the patent-family filing history and the 20-year term framework applicable to modern US utility patents. The operative expiration date must account for any patent-term adjustment, terminal disclaimer, or other term-specific entry in the USPTO record.
The patent should be analyzed separately from:
- FDA new chemical entity exclusivity.
- Five-year or three-year regulatory exclusivity.
- Other elvitegravir patents.
- Stribild-specific formulation patents.
- Genvoya-specific formulation and prodrug patents.
- Pediatric exclusivity.
- Patent-term extensions on other members of the product estate.
A patent expiration in 2027 would remove the legal barrier created by this patent, but it would not automatically authorize a generic product. A generic applicant would still need to address other unexpired patents listed for the reference product and obtain FDA approval.
What is the Orange Book status of US Patent 8,633,219?
The patent claims are structurally relevant to Stribild and Genvoya, but claim text alone does not establish Orange Book listing status.
Orange Book treatment depends on whether FDA accepted the patent as claiming:
- The approved drug substance.
- The approved drug product.
- A method of use approved in the product labeling.
A combination patent can be listed against an approved product when the patent claims the approved product or an approved method of use. The presence of cobicistat in Stribild or Genvoya does not necessarily prevent a three-active-ingredient claim from covering the marketed product, because the patent claims use "comprising."
The Orange Book analysis should distinguish between:
| Issue |
Relevance |
| Patent issuance |
Establishes enforceable patent rights, subject to validity and term |
| Orange Book listing |
Determines whether an ANDA applicant must make a patent certification |
| Paragraph IV certification |
Creates a potential Hatch-Waxman litigation trigger |
| Approved labeling |
Determines whether a method-of-use claim corresponds to the approved product |
| Patent scope |
Determines infringement independently of Orange Book listing |
A patent may be enforceable even if it is not listed in the Orange Book. Conversely, an Orange Book listing does not establish validity or infringement.
Are Paragraph IV challenges associated with this patent?
A Paragraph IV certification would be relevant if an ANDA applicant sought approval for a product referencing Stribild or Genvoya and the patent appeared in the relevant Orange Book listing.
The applicant could certify that the patent is:
- Invalid.
- Unenforceable.
- Not infringed.
- Inapplicable to the proposed product.
A Paragraph IV notice can trigger a 45-day period for the patent owner to file an infringement action under the Hatch-Waxman framework. A timely action may create an approval stay, subject to statutory limits and later procedural events. The patent owner could also rely on other listed patents in the product estate.
The claims create several potential dispute points:
- Whether the proposed product contains the claimed elvitegravir form.
- Whether GS-7340 in the proposed product is the claimed compound.
- Whether a product containing the required three agents plus other ingredients falls within "comprising."
- Whether a separate-tablet regimen satisfies claims 2 or 4.
- Whether the composition contains each component in an "effective amount."
- Whether the patent is valid over earlier combination-treatment disclosures.
- Whether prosecution history limits the meaning of the combination terms.
No conclusion of infringement or noninfringement follows solely from the public claim text.
What is the prior-art and validity risk?
The patent’s principal validity exposure is likely to arise under obviousness, written description, enablement, and anticipation doctrines.
Obviousness
At the relevant filing date, the individual agents were known or under development:
- Elvitegravir was an HIV integrase inhibitor.
- Emtricitabine was an established nucleoside reverse-transcriptase inhibitor.
- Tenofovir prodrugs were established or emerging components of HIV therapy.
A challenger could argue that combining these known antiretrovirals would have been obvious, particularly for a treatment claim that does not recite a specific unexpected result.
The patent owner could respond that the specific three-drug combination, the selection of elvitegravir, and the use of GS-7340 involved a non-obvious combination with clinically useful pharmacokinetic, potency, tolerability, or formulation characteristics.
Written description and enablement
The claims identify the active ingredients with substantial specificity. That generally strengthens written-description support compared with a genus claim covering all integrase inhibitors or all tenofovir prodrugs.
The single-composition claims may create a more focused enablement inquiry if the specification does not adequately disclose:
- Suitable ratios.
- Stability data.
- Manufacturing methods.
- Dissolution performance.
- Compatibility of the three actives.
- A commercially viable dosage form.
Anticipation
A single prior-art reference would need to disclose all elements of the relevant claim. A reference disclosing elvitegravir plus emtricitabine, without the required tenofovir component, would not anticipate the claim. The same applies to a reference disclosing tenofovir and emtricitabine without the claimed elvitegravir.
What formulation and manufacturing protection does the patent provide?
US Patent 8,633,219 provides limited formulation specificity. Claims 2, 4, 5, and 6 require co-formulation or a composition containing the active agents, but they do not recite a detailed excipient system or manufacturing process.
The patent does not, based on the supplied claims, expressly require:
- A bilayer tablet.
- A specific granulation method.
- A particular film coating.
- A specific particle-size distribution.
- A defined dissolution profile.
- A particular excipient.
- A particular tablet weight.
- A specific elvitegravir polymorph.
- A particular ratio between elvitegravir, emtricitabine, and tenofovir.
Those features may be protected by separate formulation, crystalline-form, process, or composition patents in the broader Stribild and Genvoya patent estates.
For a generic developer, the key distinction is between avoiding claims 2, 4, 5, and 6 by using separate dosage forms and avoiding the independent treatment claims, which may not require co-formulation. A separate-tablet strategy could avoid the single-composition limitations while still implicating claims 1 or 3 if the regimen contains the required agents.
How does the patent compare with the broader Stribild and Genvoya patent estates?
| Patent category |
Typical protected subject matter |
Relevance to US 8,633,219 |
| Core elvitegravir patents |
Elvitegravir compound, salts, stereochemistry, and use |
May block elvitegravir independently of the combination patent |
| Combination patents |
Elvitegravir with emtricitabine and tenofovir |
Directly overlaps the supplied claims |
| Cobicistat patents |
CYP3A inhibition and pharmacokinetic boosting |
Relevant to the commercial products but not required by the supplied claims |
| TAF patents |
GS-7340, salts, formulations, and use |
Relevant to Genvoya and claim 6 |
| Tablet and formulation patents |
Fixed-dose dosage forms, ratios, excipients, stability |
May create additional barriers after expiration of the combination patent |
| Method-of-use patents |
Treatment of HIV or particular patient populations |
May affect labeling and ANDA certifications |
| Manufacturing patents |
Synthesis, purification, crystallization, and tableting |
Can create non-Orange-Book commercial barriers |
The supplied patent is best characterized as an active-ingredient combination patent. It is not, on the face of the claims, the complete patent estate for either product.
What generic launch scenarios exist?
Stribild-type product
A Stribild-type generic would need to address the TDF combination claims. Potential approaches include:
- Waiting for expiry or invalidation.
- Filing a Paragraph IV certification if the patent is listed.
- Designing a product outside the claimed active-ingredient combination, which would not be therapeutically equivalent to Stribild.
- Seeking approval for a different HIV regimen.
Avoiding claims 2 and 5 by using separate products would not necessarily avoid claims 1 and 3, which are method claims.
Genvoya-type product
A Genvoya-type generic would need to address the GS-7340 claims and other patents covering TAF, cobicistat, elvitegravir, the tablet, and approved use.
The Genvoya claims are commercially important because GS-7340 is the tenofovir component in Genvoya. A product using tenofovir disoproxil fumarate instead of GS-7340 would not satisfy claims 3, 4, or 6, but it would also not be the same active ingredient as Genvoya and would raise separate bioequivalence and product-specific regulatory issues.
Does this patent create biosimilar risk?
No. Biosimilar law applies to biological products, while elvitegravir, emtricitabine, tenofovir disoproxil fumarate, and tenofovir alafenamide are small-molecule drug substances.
The relevant competitive pathway is an ANDA for a generic drug, not a 351(k) biosimilar application. The principal legal mechanisms are:
- Hatch-Waxman patent certification.
- Paragraph IV litigation.
- FDA therapeutic-equivalence requirements.
- Product-specific bioequivalence.
- Patent and exclusivity review for the reference listed drug.
What is the geographic scope of protection?
US Patent 8,633,219 has territorial effect in the United States and its territories. It does not directly establish protection in:
- Europe.
- Canada.
- Japan.
- China.
- Australia.
- Brazil.
- Other jurisdictions.
Foreign counterparts must be analyzed independently because claim scope, prosecution amendments, validity standards, term calculation, supplementary protection, and litigation outcomes differ by country.
How strong is the patent estate represented by US 8,633,219?
The patent is strongest against a product that:
- Contains elvitegravir.
- Contains emtricitabine.
- Contains the specified tenofovir prodrug.
- Uses those agents for HIV treatment.
- Places them in one dosage form, if the claim at issue is 2, 4, 5, or 6.
Its principal limitations are equally clear:
- It does not cover every integrase-inhibitor regimen.
- It does not cover bictegravir-based products.
- It does not require or claim cobicistat.
- It does not, based on the supplied claims, provide detailed tablet or process protection.
- It is a late-term asset with an expected 2027 ordinary expiration window.
- Its commercial effect depends on Orange Book listing and the existence of other unexpired patents.
Key Takeaways
- US Patent 8,633,219 claims elvitegravir with emtricitabine and either tenofovir disoproxil fumarate or GS-7340.
- Claims 1 and 3 cover treatment methods; claims 5 and 6 cover compositions.
- Claims 2 and 4 specifically require the three agents to be formulated and administered together.
- Stribild is the principal TDF-related commercial product.
- Genvoya is the principal GS-7340-related commercial product.
- Cobicistat is not required by the claims, but its presence may be permitted by the "comprising" language.
- The patent is expected to reach its ordinary US term in 2027, subject to the operative USPTO term calculation.
- Generic risk depends on this patent plus the separate elvitegravir, TAF, cobicistat, formulation, method-of-use, and manufacturing estates.
- The patent concerns small-molecule generic competition, not biosimilar competition.
- The supplied claims alone do not establish current Orange Book listing, enforceability, or infringement.
References
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U.S. Patent No. 8,633,219. (2014). United States Patent and Trademark Office.
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U.S. Food and Drug Administration. (2012). Stribild prescribing information. FDA.
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U.S. Food and Drug Administration. (2015). Genvoya prescribing information. FDA.
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U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.
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U.S. Code, 21 U.S.C. §§ 355 and 371. (2024). Federal Food, Drug, and Cosmetic Act provisions governing abbreviated applications and patent certifications.
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U.S. Patent and Trademark Office. (2024). Patent term adjustment and patent term calculation resources. USPTO.
