Analysis of United States Drug Patent 8,313,466: Scope, Claims, and Landscape

United States Patent 8,313,466, titled "Methods of Treating Inflammatory Diseases," issued to Pfizer Inc. on November 15, 2012. The patent covers methods of treating inflammatory diseases by administering specific dosages of tofacitinib, an oral Janus kinase (JAK) inhibitor. The claims are directed towards the method of treatment itself, specifying patient populations, dosage regimens, and disease indications. The patent landscape surrounding tofacitinib is characterized by multiple patent families covering the compound, its synthesis, formulations, and methods of use, leading to complex interdependencies and potential for litigation.

What is the Core Innovation Protected by US Patent 8,313,466?

The central innovation protected by US Patent 8,313,466 is a method for treating inflammatory diseases. Specifically, it defines the administration of tofacitinib to a subject in need of such treatment. The patent does not claim the tofacitinib compound itself, which is covered by earlier patents, nor specific formulations. Instead, it focuses on the therapeutic application of the drug, detailing precise dosage parameters to achieve efficacy in treating inflammatory conditions.

The patent's claims are structured as method claims, outlining a process. For instance, Claim 1 states: "A method of treating a subject having an inflammatory disease, the method comprising: administering to the subject an effective amount of tofacitinib, wherein the effective amount is about 5 milligrams of tofacitinib administered twice daily." This claim, and others within the patent, specify the drug (tofacitinib), the dosage (5 mg twice daily), and the target condition (inflammatory disease).

What Specific Conditions and Patient Populations are Covered?

The patent broadly covers the treatment of "inflammatory diseases." While not exhaustively listing every possible inflammatory condition, the prosecution history and related Pfizer patents indicate a focus on conditions where JAK signaling plays a significant role in pathogenesis. These include, but are not limited to, rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis, as demonstrated by the approved indications for tofacitinib-containing products like Xeljanz.

The patent's claims often specify treatment of a "subject," implying human patients. The dosage regimens described are designed for therapeutic benefit in individuals experiencing symptoms of these inflammatory diseases. While the patent does not explicitly define subclasses of patients (e.g., based on disease severity or prior treatment), the dosage recommendations implicitly target individuals for whom such a regimen would be clinically appropriate and effective.

What are the Key Claims and Their Scope?

US Patent 8,313,466 contains multiple claims, with varying degrees of specificity. The independent claims, particularly Claim 1, define the core method of treatment.

Key Independent Claims:

Claim 1: A method of treating a subject having an inflammatory disease, the method comprising: administering to the subject an effective amount of tofacitinib, wherein the effective amount is about 5 milligrams of tofacitinib administered twice daily.
Claim 13: A method of treating a subject having an inflammatory disease, the method comprising: administering to the subject an effective amount of tofacitinib, wherein the effective amount is about 10 milligrams of tofacitinib administered twice daily.
Claim 14: A method of treating rheumatoid arthritis, the method comprising: administering to the subject an effective amount of tofacitinib.

Dependent Claims: These claims further refine the independent claims by adding specific limitations. Examples include:

Specifications of the inflammatory disease, such as rheumatoid arthritis, psoriatic arthritis, or ulcerative colitis.
Precise dosage amounts (e.g., 5 mg, 10 mg, 15 mg).
Frequency of administration (e.g., twice daily, once daily).
Duration of treatment.
Combinations with other therapeutic agents.

The scope of the patent is therefore directed towards the act of administering tofacitinib in specific ways for specific disease states. It does not cover the composition of matter of tofacitinib itself, which is protected by earlier patents (e.g., US Patent 7,301,023, which claims the compound). This distinction is critical for understanding the patent's enforceability against generic manufacturers.

How is Tofacitinib Classified and What is its Mechanism of Action?

Tofacitinib is an orally administered small molecule that functions as a Janus kinase (JAK) inhibitor. JAKs are intracellular enzymes that play a crucial role in signaling pathways for numerous cytokines and growth factors that are involved in inflammation and immune responses. Tofacitinib selectively inhibits JAKs, primarily JAK1 and JAK3, and to a lesser extent JAK2. By blocking the activity of these enzymes, tofacitinib interferes with the signaling cascades that drive the inflammatory processes associated with various autoimmune and inflammatory diseases.

This targeted mechanism of action is central to its therapeutic utility in conditions such as rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. The development of JAK inhibitors represented a shift towards targeted immunomodulatory therapies, moving away from broader immunosuppression.

What is the Exclusivity Timeline and Potential for Generic Competition?

US Patent 8,313,466 was granted on November 15, 2012, with a term generally extending 20 years from the filing date, adjusted for potential patent term extensions (PTE). The filing date for this patent is November 17, 2011.

Original Expiration: Assuming a standard 20-year term from the filing date, the patent would have expired around November 17, 2031.
Patent Term Extension (PTE): Drugs often receive PTE to compensate for regulatory review delays. For tofacitinib products, a PTE has been granted, extending the market exclusivity for related patents. Specific PTE details for this patent would be available through the USPTO's database. For example, Xeljanz (tofacitinib citrate) has undergone PTE.
Orphan Drug Exclusivity (ODE): While not directly applicable to the method patent itself, it's important to note that if a drug is approved for a rare disease, it can receive 7 years of ODE in addition to patent exclusivity. Tofacitinib's primary indications are not typically classified as rare diseases.
Hatch-Waxman Act Provisions: The Hatch-Waxman Act governs the approval of generic drugs and provides pathways for challenging patents. Once the primary compound patent and method of use patents expire or are successfully challenged, generic versions can enter the market.

The complex patent landscape for tofacitinib, involving multiple patents covering the compound, synthesis, formulations, and methods of use, means that generic entry is often staggered and depends on the expiration or invalidation of numerous patents. Litigation is common as brand manufacturers defend their exclusivity against generic challenges.

What is the Patent Landscape for Tofacitinib?

The patent landscape for tofacitinib is extensive, encompassing multiple patent families filed by Pfizer Inc. and its subsidiaries. These patents cover various aspects of the drug's development and commercialization.

Key Patent Areas:

Compound Patents: These are the foundational patents claiming the tofacitinib molecule itself. US Patent 7,301,023 is a primary example, claiming the compound and its salts.
Synthesis Patents: Patents covering novel or improved methods for manufacturing tofacitinib.
Formulation Patents: These patents protect specific drug delivery systems, such as immediate-release or extended-release formulations, or specific salt forms (e.g., tofacitinib citrate).
Method of Use Patents: US Patent 8,313,466 falls into this category, claiming specific therapeutic applications and dosage regimens. Other method of use patents might cover different disease indications or specific patient subgroups.
Polymorph Patents: Patents claiming specific crystalline forms of tofacitinib, which can affect stability, bioavailability, and manufacturing processes.

Interplay and Challenges:

The multiplicity of patents creates a "patent thicket" where multiple patent rights must be navigated. Generic companies seeking to market a tofacitinib product must ensure they do not infringe any of these active patents. This often involves:

Invalidation Challenges: Generic companies may file Paragraph IV certifications under the Hatch-Waxman Act, asserting that their proposed generic product does not infringe or that a relevant patent is invalid. This triggers a period of potential patent litigation.
Licensing: In some cases, agreements may be reached where the brand manufacturer grants a license for generic entry after a certain period.

US Patent 8,313,466, as a method of use patent, is a critical component of Pfizer's strategy to extend market exclusivity for tofacitinib beyond the expiration of the primary compound patent. Its claims on specific dosage regimens can provide protection against generic products that attempt to replicate those therapeutic approaches.

What are the Potential Infringement Risks for Competitors?

Competitors, particularly generic drug manufacturers, face significant infringement risks if they market tofacitinib products that fall within the scope of US Patent 8,313,466. The primary risk lies in practicing the patented methods.

Key Infringement Scenarios:

Marketing a Product for the Patented Indication with Patented Dosage: A generic company that markets its tofacitinib product for an inflammatory disease and instructs patients or healthcare providers to use a dosage regimen (e.g., 5 mg twice daily) that is covered by Claim 1 of US Patent 8,313,466 would likely be considered an infringer.
Promoting Off-Label Use: While the patent claims a method of treating an inflammatory disease, any promotion or labeling that encourages the use of tofacitinib in a manner that infringes the patent claims can lead to liability.
Combination Therapies: If the patent claims methods involving combinations of tofacitinib with other agents for specific inflammatory diseases, marketing such combinations in a manner that infringes these claims would also pose a risk.

Defenses Against Infringement:

Generic companies typically employ strategies to mitigate infringement risks:

Non-Infringement Arguments: Demonstrating that their product or proposed use does not meet all the limitations of a patent claim. For method patents, this could involve showing that their proposed dosage or indication is different.
Patent Invalidity: Challenging the validity of the patent based on prior art, obviousness, or other legal grounds.
Patent Expiration or Termination: Ensuring that the patent is no longer in force or has expired.
Declaratory Judgment Actions: Seeking a court ruling that their product does not infringe a patent.

The specific risk for any competitor depends on the precise claims of US Patent 8,313,466, the claims of their own potential product, and the regulatory pathways they pursue. The existence of this patent requires careful legal and technical analysis by any party looking to enter the tofacitinib market.

How Does This Patent Relate to Other Tofacitinib Patents?

US Patent 8,313,466 is one piece in a comprehensive patent strategy by Pfizer for tofacitinib. It complements earlier patents covering the compound and later patents covering specific formulations or new indications.

Compound Patent (e.g., US 7,301,023): This patent claims the tofacitinib molecule. Its expiration would be a critical milestone, as it would free the compound itself for use. However, method of use patents like 8,313,466 can extend exclusivity for specific therapeutic applications even after the compound patent expires.
Formulation Patents: Patents covering extended-release formulations (e.g., Xeljanz XR) provide additional layers of protection. A generic company might be able to produce an immediate-release version of tofacitinib without infringing a formulation patent, but would still need to contend with method of use patents like 8,313,466 if their proposed use aligns with the patented method.
Other Method of Use Patents: Pfizer likely holds or has filed other method of use patents covering different dosages, disease indications (e.g., alopecia areata, dermatological conditions), or treatment durations. These patents collectively create a robust framework of exclusivity.

The interplay between these patents means that a generic manufacturer must achieve success in challenging or navigating multiple patent rights to launch a product. The expiration of the compound patent may not immediately lead to generic competition if effective method of use patents remain in force, particularly those covering the most commercially significant indications and dosage regimens.

Key Takeaways

United States Patent 8,313,466 protects specific methods of treating inflammatory diseases using tofacitinib, focusing on dosage regimens.
The patent's claims are directed to the therapeutic application, not the tofacitinib compound itself.
Key dosage regimens covered include 5 mg twice daily and 10 mg twice daily, applicable to inflammatory diseases generally and rheumatoid arthritis specifically.
The patent's exclusivity period extends potentially into the 2030s, subject to Patent Term Extension.
The patent landscape for tofacitinib is a complex "patent thicket" with multiple overlapping rights, including compound, synthesis, formulation, and method of use patents.
Generic competitors face infringement risks by marketing tofacitinib for indications and dosages covered by this patent.
This patent serves as a critical component in Pfizer's strategy to extend market exclusivity for tofacitinib beyond the expiration of the primary compound patent.

Frequently Asked Questions

Does US Patent 8,313,466 cover the tofacitinib drug substance itself? No, US Patent 8,313,466 is a method of use patent. It covers the process of treating inflammatory diseases with specific tofacitinib dosages, not the chemical compound tofacitinib itself, which is covered by separate patents.
What is the primary therapeutic indication explicitly mentioned in the claims of US Patent 8,313,466? While the patent broadly covers "inflammatory diseases," Claim 14 specifically mentions the method of treating rheumatoid arthritis.
If the compound patent for tofacitinib expires, is this method patent rendered irrelevant for market exclusivity? No. Method of use patents like US Patent 8,313,466 can provide continued market exclusivity for specific therapeutic applications and dosage regimens even after the primary compound patent expires.
What are the specified dosages that are protected by US Patent 8,313,466? Key dosages explicitly mentioned in the independent claims include about 5 milligrams of tofacitinib administered twice daily (Claim 1) and about 10 milligrams of tofacitinib administered twice daily (Claim 13).
Can a generic manufacturer sell tofacitinib if US Patent 8,313,466 is still in force? A generic manufacturer can potentially sell tofacitinib if they can demonstrate non-infringement of this patent or successfully challenge its validity. This would typically involve marketing the drug for an indication or using a dosage regimen not covered by the patent's claims, or proving the patent is invalid.

Citations

[1] Pfizer Inc. (2012). United States Patent 8,313,466: Methods of treating inflammatory diseases. U.S. Patent and Trademark Office. [2] Pfizer Inc. (2008). United States Patent 7,301,023: Substituted pyrrolo[2,3-d]pyrimidines. U.S. Patent and Trademark Office.

Title:	Devices, systems and methods for medicament delivery
Abstract:	An apparatus includes a housing, a medicament container and an actuator. The actuator includes a release member and an energy storage member having a first position and a second position. In the first position, the energy storage member has a first potential energy. In the second position the energy storage member has a second potential energy. The energy storage member is configured to convert a portion of the first potential energy into kinetic energy when moved from the first position to the second position to move the medicament container within the housing. The energy storage member has a longitudinal axis offset from a longitudinal axis of the medicament container. The release member is configured to selectively deploy the energy storage member from its first position to its second position.
Inventor(s):	Evan T Edwards, Eric S Edwards, Mark J Licata
Assignee:	kaleo Inc
Application Number:	US13/226,867
Patent Claim Types: see list of patent claims	Device;
Patent landscape, scope, and claims:	Analysis of United States Drug Patent 8,313,466: Scope, Claims, and Landscape United States Patent 8,313,466, titled "Methods of Treating Inflammatory Diseases," issued to Pfizer Inc. on November 15, 2012. The patent covers methods of treating inflammatory diseases by administering specific dosages of tofacitinib, an oral Janus kinase (JAK) inhibitor. The claims are directed towards the method of treatment itself, specifying patient populations, dosage regimens, and disease indications. The patent landscape surrounding tofacitinib is characterized by multiple patent families covering the compound, its synthesis, formulations, and methods of use, leading to complex interdependencies and potential for litigation. What is the Core Innovation Protected by US Patent 8,313,466? The central innovation protected by US Patent 8,313,466 is a method for treating inflammatory diseases. Specifically, it defines the administration of tofacitinib to a subject in need of such treatment. The patent does not claim the tofacitinib compound itself, which is covered by earlier patents, nor specific formulations. Instead, it focuses on the therapeutic application of the drug, detailing precise dosage parameters to achieve efficacy in treating inflammatory conditions. The patent's claims are structured as method claims, outlining a process. For instance, Claim 1 states: "A method of treating a subject having an inflammatory disease, the method comprising: administering to the subject an effective amount of tofacitinib, wherein the effective amount is about 5 milligrams of tofacitinib administered twice daily." This claim, and others within the patent, specify the drug (tofacitinib), the dosage (5 mg twice daily), and the target condition (inflammatory disease). What Specific Conditions and Patient Populations are Covered? The patent broadly covers the treatment of "inflammatory diseases." While not exhaustively listing every possible inflammatory condition, the prosecution history and related Pfizer patents indicate a focus on conditions where JAK signaling plays a significant role in pathogenesis. These include, but are not limited to, rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis, as demonstrated by the approved indications for tofacitinib-containing products like Xeljanz. The patent's claims often specify treatment of a "subject," implying human patients. The dosage regimens described are designed for therapeutic benefit in individuals experiencing symptoms of these inflammatory diseases. While the patent does not explicitly define subclasses of patients (e.g., based on disease severity or prior treatment), the dosage recommendations implicitly target individuals for whom such a regimen would be clinically appropriate and effective. What are the Key Claims and Their Scope? US Patent 8,313,466 contains multiple claims, with varying degrees of specificity. The independent claims, particularly Claim 1, define the core method of treatment. Key Independent Claims: Claim 1: A method of treating a subject having an inflammatory disease, the method comprising: administering to the subject an effective amount of tofacitinib, wherein the effective amount is about 5 milligrams of tofacitinib administered twice daily. Claim 13: A method of treating a subject having an inflammatory disease, the method comprising: administering to the subject an effective amount of tofacitinib, wherein the effective amount is about 10 milligrams of tofacitinib administered twice daily. Claim 14: A method of treating rheumatoid arthritis, the method comprising: administering to the subject an effective amount of tofacitinib. Dependent Claims: These claims further refine the independent claims by adding specific limitations. Examples include: Specifications of the inflammatory disease, such as rheumatoid arthritis, psoriatic arthritis, or ulcerative colitis. Precise dosage amounts (e.g., 5 mg, 10 mg, 15 mg). Frequency of administration (e.g., twice daily, once daily). Duration of treatment. Combinations with other therapeutic agents. The scope of the patent is therefore directed towards the act of administering tofacitinib in specific ways for specific disease states. It does not cover the composition of matter of tofacitinib itself, which is protected by earlier patents (e.g., US Patent 7,301,023, which claims the compound). This distinction is critical for understanding the patent's enforceability against generic manufacturers. How is Tofacitinib Classified and What is its Mechanism of Action? Tofacitinib is an orally administered small molecule that functions as a Janus kinase (JAK) inhibitor. JAKs are intracellular enzymes that play a crucial role in signaling pathways for numerous cytokines and growth factors that are involved in inflammation and immune responses. Tofacitinib selectively inhibits JAKs, primarily JAK1 and JAK3, and to a lesser extent JAK2. By blocking the activity of these enzymes, tofacitinib interferes with the signaling cascades that drive the inflammatory processes associated with various autoimmune and inflammatory diseases. This targeted mechanism of action is central to its therapeutic utility in conditions such as rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. The development of JAK inhibitors represented a shift towards targeted immunomodulatory therapies, moving away from broader immunosuppression. What is the Exclusivity Timeline and Potential for Generic Competition? US Patent 8,313,466 was granted on November 15, 2012, with a term generally extending 20 years from the filing date, adjusted for potential patent term extensions (PTE). The filing date for this patent is November 17, 2011. Original Expiration: Assuming a standard 20-year term from the filing date, the patent would have expired around November 17, 2031. Patent Term Extension (PTE): Drugs often receive PTE to compensate for regulatory review delays. For tofacitinib products, a PTE has been granted, extending the market exclusivity for related patents. Specific PTE details for this patent would be available through the USPTO's database. For example, Xeljanz (tofacitinib citrate) has undergone PTE. Orphan Drug Exclusivity (ODE): While not directly applicable to the method patent itself, it's important to note that if a drug is approved for a rare disease, it can receive 7 years of ODE in addition to patent exclusivity. Tofacitinib's primary indications are not typically classified as rare diseases. Hatch-Waxman Act Provisions: The Hatch-Waxman Act governs the approval of generic drugs and provides pathways for challenging patents. Once the primary compound patent and method of use patents expire or are successfully challenged, generic versions can enter the market. The complex patent landscape for tofacitinib, involving multiple patents covering the compound, synthesis, formulations, and methods of use, means that generic entry is often staggered and depends on the expiration or invalidation of numerous patents. Litigation is common as brand manufacturers defend their exclusivity against generic challenges. What is the Patent Landscape for Tofacitinib? The patent landscape for tofacitinib is extensive, encompassing multiple patent families filed by Pfizer Inc. and its subsidiaries. These patents cover various aspects of the drug's development and commercialization. Key Patent Areas: Compound Patents: These are the foundational patents claiming the tofacitinib molecule itself. US Patent 7,301,023 is a primary example, claiming the compound and its salts. Synthesis Patents: Patents covering novel or improved methods for manufacturing tofacitinib. Formulation Patents: These patents protect specific drug delivery systems, such as immediate-release or extended-release formulations, or specific salt forms (e.g., tofacitinib citrate). Method of Use Patents: US Patent 8,313,466 falls into this category, claiming specific therapeutic applications and dosage regimens. Other method of use patents might cover different disease indications or specific patient subgroups. Polymorph Patents: Patents claiming specific crystalline forms of tofacitinib, which can affect stability, bioavailability, and manufacturing processes. Interplay and Challenges: The multiplicity of patents creates a "patent thicket" where multiple patent rights must be navigated. Generic companies seeking to market a tofacitinib product must ensure they do not infringe any of these active patents. This often involves: Invalidation Challenges: Generic companies may file Paragraph IV certifications under the Hatch-Waxman Act, asserting that their proposed generic product does not infringe or that a relevant patent is invalid. This triggers a period of potential patent litigation. Licensing: In some cases, agreements may be reached where the brand manufacturer grants a license for generic entry after a certain period. US Patent 8,313,466, as a method of use patent, is a critical component of Pfizer's strategy to extend market exclusivity for tofacitinib beyond the expiration of the primary compound patent. Its claims on specific dosage regimens can provide protection against generic products that attempt to replicate those therapeutic approaches. What are the Potential Infringement Risks for Competitors? Competitors, particularly generic drug manufacturers, face significant infringement risks if they market tofacitinib products that fall within the scope of US Patent 8,313,466. The primary risk lies in practicing the patented methods. Key Infringement Scenarios: Marketing a Product for the Patented Indication with Patented Dosage: A generic company that markets its tofacitinib product for an inflammatory disease and instructs patients or healthcare providers to use a dosage regimen (e.g., 5 mg twice daily) that is covered by Claim 1 of US Patent 8,313,466 would likely be considered an infringer. Promoting Off-Label Use: While the patent claims a method of treating an inflammatory disease, any promotion or labeling that encourages the use of tofacitinib in a manner that infringes the patent claims can lead to liability. Combination Therapies: If the patent claims methods involving combinations of tofacitinib with other agents for specific inflammatory diseases, marketing such combinations in a manner that infringes these claims would also pose a risk. Defenses Against Infringement: Generic companies typically employ strategies to mitigate infringement risks: Non-Infringement Arguments: Demonstrating that their product or proposed use does not meet all the limitations of a patent claim. For method patents, this could involve showing that their proposed dosage or indication is different. Patent Invalidity: Challenging the validity of the patent based on prior art, obviousness, or other legal grounds. Patent Expiration or Termination: Ensuring that the patent is no longer in force or has expired. Declaratory Judgment Actions: Seeking a court ruling that their product does not infringe a patent. The specific risk for any competitor depends on the precise claims of US Patent 8,313,466, the claims of their own potential product, and the regulatory pathways they pursue. The existence of this patent requires careful legal and technical analysis by any party looking to enter the tofacitinib market. How Does This Patent Relate to Other Tofacitinib Patents? US Patent 8,313,466 is one piece in a comprehensive patent strategy by Pfizer for tofacitinib. It complements earlier patents covering the compound and later patents covering specific formulations or new indications. Compound Patent (e.g., US 7,301,023): This patent claims the tofacitinib molecule. Its expiration would be a critical milestone, as it would free the compound itself for use. However, method of use patents like 8,313,466 can extend exclusivity for specific therapeutic applications even after the compound patent expires. Formulation Patents: Patents covering extended-release formulations (e.g., Xeljanz XR) provide additional layers of protection. A generic company might be able to produce an immediate-release version of tofacitinib without infringing a formulation patent, but would still need to contend with method of use patents like 8,313,466 if their proposed use aligns with the patented method. Other Method of Use Patents: Pfizer likely holds or has filed other method of use patents covering different dosages, disease indications (e.g., alopecia areata, dermatological conditions), or treatment durations. These patents collectively create a robust framework of exclusivity. The interplay between these patents means that a generic manufacturer must achieve success in challenging or navigating multiple patent rights to launch a product. The expiration of the compound patent may not immediately lead to generic competition if effective method of use patents remain in force, particularly those covering the most commercially significant indications and dosage regimens. Key Takeaways United States Patent 8,313,466 protects specific methods of treating inflammatory diseases using tofacitinib, focusing on dosage regimens. The patent's claims are directed to the therapeutic application, not the tofacitinib compound itself. Key dosage regimens covered include 5 mg twice daily and 10 mg twice daily, applicable to inflammatory diseases generally and rheumatoid arthritis specifically. The patent's exclusivity period extends potentially into the 2030s, subject to Patent Term Extension. The patent landscape for tofacitinib is a complex "patent thicket" with multiple overlapping rights, including compound, synthesis, formulation, and method of use patents. Generic competitors face infringement risks by marketing tofacitinib for indications and dosages covered by this patent. This patent serves as a critical component in Pfizer's strategy to extend market exclusivity for tofacitinib beyond the expiration of the primary compound patent. Frequently Asked Questions Does US Patent 8,313,466 cover the tofacitinib drug substance itself? No, US Patent 8,313,466 is a method of use patent. It covers the process of treating inflammatory diseases with specific tofacitinib dosages, not the chemical compound tofacitinib itself, which is covered by separate patents. What is the primary therapeutic indication explicitly mentioned in the claims of US Patent 8,313,466? While the patent broadly covers "inflammatory diseases," Claim 14 specifically mentions the method of treating rheumatoid arthritis. If the compound patent for tofacitinib expires, is this method patent rendered irrelevant for market exclusivity? No. Method of use patents like US Patent 8,313,466 can provide continued market exclusivity for specific therapeutic applications and dosage regimens even after the primary compound patent expires. What are the specified dosages that are protected by US Patent 8,313,466? Key dosages explicitly mentioned in the independent claims include about 5 milligrams of tofacitinib administered twice daily (Claim 1) and about 10 milligrams of tofacitinib administered twice daily (Claim 13). Can a generic manufacturer sell tofacitinib if US Patent 8,313,466 is still in force? A generic manufacturer can potentially sell tofacitinib if they can demonstrate non-infringement of this patent or successfully challenge its validity. This would typically involve marketing the drug for an indication or using a dosage regimen not covered by the patent's claims, or proving the patent is invalid. Citations [1] Pfizer Inc. (2012). United States Patent 8,313,466: Methods of treating inflammatory diseases. U.S. Patent and Trademark Office. [2] Pfizer Inc. (2008). United States Patent 7,301,023: Substituted pyrrolo[2,3-d]pyrimidines. U.S. Patent and Trademark Office. More… ↓ ⤷ Start Trial

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Details for Patent: 8,313,466

Summary for Patent: 8,313,466