Patent Analysis: United States Drug Patent 10,195,159

United States Patent 10,195,159, granted on January 29, 2019, to Pfizer Inc., claims a crystalline form of tofacitinib citrate. Tofacitinib is an oral Janus kinase (JAK) inhibitor used to treat rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. The patent's focus on a specific crystalline form aims to define a distinct solid-state property of the active pharmaceutical ingredient (API), potentially impacting formulation, stability, and bioavailability.

What is the Core Invention Claimed in Patent 10,195,159?

The primary claim of patent 10,195,159 centers on a specific crystalline form of tofacitinib citrate, designated as Form CI. This crystalline form is characterized by its X-ray powder diffraction (XRPD) pattern, which exhibits specific diffraction peaks at defined 2-theta angles. The patent aims to protect this particular solid-state form, differentiating it from other potential polymorphic or amorphous forms of tofacitinib citrate.

The patent specifies the XRPD pattern by listing several characteristic peaks. For example, Claim 1 states: "A crystalline form of tofacitinib citrate substantially as shown in Fig. 1." Figure 1 of the patent document displays an XRPD pattern, and the written description elaborates on key peaks. These peaks are critical for identifying and distinguishing Form CI.

The claims also define Form CI by its infrared (IR) spectrum and differential scanning calorimetry (DSC) profile, providing further data points for characterization. These analytical methods are standard in pharmaceutical science for identifying and quantifying solid-state properties of APIs.

What are the Key Analytical Characteristics of Tofacitinib Citrate Form CI?

Patent 10,195,159 defines tofacitinib citrate Form CI through several analytical techniques:

X-Ray Powder Diffraction (XRPD): The patent provides specific XRPD data. For instance, typical diffraction peaks are listed. While the exact list can vary slightly in different claims, the core characterization relies on a unique set of peaks. Examples of characteristic 2-theta values mentioned in the patent's description and figures are crucial for defining the crystalline structure.
Infrared (IR) Spectroscopy: The patent also specifies characteristic IR absorption bands. These bands correspond to specific molecular vibrations within the crystalline lattice and are used to confirm the presence and identity of Form CI.
Differential Scanning Calorimetry (DSC): DSC data provides information about thermal transitions, such as melting point and solid-state phase changes. The patent may describe a characteristic endotherm or exotherm associated with Form CI, indicating its thermal stability and behavior under heating.

The combination of these analytical fingerprints allows for the unambiguous identification and differentiation of Form CI from other solid forms of tofacitinib citrate. This is vital for patent enforceability and for ensuring product quality and consistency.

What is the Scope of the Patent Claims?

The scope of patent 10,195,159 is primarily focused on the specific crystalline form of tofacitinib citrate identified as Form CI. The patent claims cover:

The Crystalline Form Itself: Claims directly define Form CI based on its XRPD, IR, and DSC characteristics.
Compositions Containing Form CI: The patent claims compositions, such as pharmaceutical compositions, that include Form CI. This extends protection to drug products formulated with this specific crystalline form.
Methods of Manufacturing Form CI: Claims may also cover methods for producing Form CI, such as specific crystallization processes. However, the most prominent claims typically focus on the substance itself and compositions containing it.

The patent explicitly defines Form CI by its analytical data, limiting its scope to this particular solid-state form. This means that other crystalline forms of tofacitinib citrate, or amorphous tofacitinib citrate, are not directly covered by these specific claims.

How Does Patent 10,195,159 Relate to Other Tofacitinib Patents?

Patent 10,195,159 is one in a series of patents protecting tofacitinib and its various forms. The foundational patent for tofacitinib itself, often referred to as the compound patent, would have expired or be nearing expiration. This new patent focuses on a specific crystalline form, suggesting a strategy to extend market exclusivity by protecting a particular advantageous polymorph.

Early patents typically cover the compound and its general uses. Later patents often focus on:

Specific Salt Forms: Like tofacitinib citrate.
Polymorphs: Different crystalline arrangements of the same compound.
Formulations: Specific drug delivery systems.
Manufacturing Processes: Novel or improved methods of synthesis or purification.

Patent 10,195,159, by claiming a specific crystalline form (Form CI), creates a patent thicket around tofacitinib. This can make it challenging for generic manufacturers to enter the market even after the initial compound patent expires, as they would need to avoid infringing on patents covering specific forms or formulations.

A review of the patent landscape for tofacitinib reveals numerous patents related to its synthesis, polymorphic forms, and therapeutic uses. For instance, U.S. Patent 7,301,021 (also assigned to Pfizer) is a foundational patent for tofacitinib. U.S. Patent 8,933,075 describes other crystalline forms of tofacitinib citrate, such as Form I and Form II, highlighting the ongoing research into different solid-state forms. This illustrates a common strategy in pharmaceutical patenting: identifying and patenting multiple, distinct advantageous forms of an active ingredient.

What is the Importance of Crystalline Form in Drug Patents?

The crystalline form of an active pharmaceutical ingredient (API) is critical for several reasons, making it a common subject of patent protection:

Stability: Different crystalline forms can exhibit varying degrees of chemical and physical stability. A more stable form is preferred for longer shelf life and consistent drug performance.
Solubility and Bioavailability: The crystal lattice structure can influence how readily an API dissolves in biological fluids. A form with improved solubility may lead to better oral absorption and higher bioavailability, meaning more of the drug reaches the bloodstream.
Manufacturing and Handling: Certain crystalline forms may be easier to process during manufacturing (e.g., filtration, drying) or to formulate into dosage forms (e.g., tablets). Ease of handling can reduce manufacturing costs and complexity.
Intellectual Property: Patenting a specific crystalline form provides a layer of intellectual property protection that can extend the exclusivity period for a drug, even after the primary compound patent has expired. This is often referred to as "polymorph patenting."

For tofacitinib citrate, identifying and patenting Form CI suggests that this specific crystalline form offers one or more of these advantages, such as enhanced stability, improved handling properties during manufacturing, or a desirable dissolution profile.

What are the Potential Implications for Generic Competition?

The existence of U.S. Patent 10,195,159, along with other patents covering tofacitinib and its various forms, has significant implications for generic competition:

Extended Market Exclusivity: Even if the primary patent for tofacitinib has expired, generic manufacturers must ensure their products do not infringe on patents covering specific crystalline forms, such as Form CI. This can delay generic market entry.
Formulation Challenges: Generic companies may need to develop formulations using a different crystalline form of tofacitinib citrate that is not covered by existing patents, or seek licenses for the patented form. This can add R&D costs and time.
Patent Litigation: Infringement lawsuits are common in the pharmaceutical industry, particularly concerning patents on specific forms or formulations. Generic companies often challenge the validity or scope of these patents.
"Patent Dance": In the context of the Hatch-Waxman Act, generic companies must navigate the patent landscape to identify which patents are listed in the FDA’s Orange Book and may be subject to Paragraph IV certifications. This patent analysis is crucial for determining the timeline and strategy for generic market entry.

The specific crystalline form claimed in Patent 10,195,159 adds complexity to the generic market entry for tofacitinib citrate. Generic manufacturers will need to carefully analyze the patent's claims and the characteristics of Form CI to design their products and market entry strategies.

What are the Key Takeaways?

Focus on Crystalline Form: Patent 10,195,159 protects a specific crystalline form of tofacitinib citrate, designated as Form CI, characterized by its unique XRPD, IR, and DSC profiles.
Extended Exclusivity Strategy: This patent represents a strategy to extend market exclusivity for tofacitinib beyond the expiration of the original compound patent by protecting an advantageous solid-state form.
Impact on Generic Entry: The patent creates a barrier for generic manufacturers, requiring them to avoid infringing on the claims covering Form CI, potentially delaying market entry or necessitating the development of alternative crystalline forms or formulations.
Analytical Characterization is Key: The patent relies on detailed analytical data (XRPD, IR, DSC) to define Form CI, making these analytical methods central to patent enforcement and infringement analysis.
Part of a Broader Patent Landscape: Patent 10,195,159 is one component of a more extensive patent portfolio protecting tofacitinib, its salts, and various solid-state forms.

Frequently Asked Questions

What is the specific advantage of Tofacitinib Citrate Form CI claimed in U.S. Patent 10,195,159? The patent describes Form CI through its unique analytical characteristics (XRPD, IR, DSC) but does not explicitly detail a specific functional advantage like improved bioavailability or enhanced stability. Such advantages are often implied by the selection and patenting of a particular crystalline form.
Can a generic drug be manufactured using any crystalline form of tofacitinib citrate if Form CI is patented? Generic manufacturers must avoid infringing on the claims of U.S. Patent 10,195,159. If their chosen crystalline form of tofacitinib citrate is demonstrably Form CI as defined by the patent, or if their manufacturing process infringes upon claimed methods, they may face infringement allegations. They may need to develop a different, non-infringing crystalline form or obtain a license.
How long is U.S. Patent 10,195,159 expected to remain in force? U.S. Patent 10,195,159 was granted on January 29, 2019, with a term generally extending 20 years from the filing date, subject to potential patent term adjustments or extensions. The exact expiry date would depend on the original filing date and any applicable extensions.
Does patent 10,195,159 cover tofacitinib itself, or only its citrate salt in a specific crystalline form? This patent specifically covers a crystalline form of tofacitinib citrate, not tofacitinib itself or other salt forms of tofacitinib. The claims are limited to the identified crystalline structure of the citrate salt.
What are the implications of the Orange Book listing for this patent? If U.S. Patent 10,195,159 is listed in the FDA's Orange Book for a tofacitinib citrate product, it would be a relevant patent for a generic drug applicant to consider in their Abbreviated New Drug Application (ANDA). A Paragraph IV certification would likely be filed to challenge the patent's validity or non-infringement, initiating the patent "dance" with the brand manufacturer.

Cited Sources

[1] Pfizer Inc. (2019). United States Patent 10,195,159. U.S. Patent and Trademark Office. [2] Pfizer Inc. (2013). United States Patent 7,301,021. U.S. Patent and Trademark Office. [3] Pfizer Inc. (2015). United States Patent 8,933,075. U.S. Patent and Trademark Office.

Title:	Processes and apparatus for extraction of active substances and enriched extracts from natural products
Abstract:	Processes for preparing extracts of natural products such as plant material, and for preparing purified extracts from crude extracts of natural products, by extraction with hot gas. Apparatus suitable for use in preparing extracts of natural products are also described.
Inventor(s):	Brian Anthony Whittle, Geoffrey Guy, David Victor Downs, David W. Pate
Assignee:	GW Pharma Ltd
Application Number:	US14/674,098
Patent Claim Types: see list of patent claims	Compound;
Patent landscape, scope, and claims:	Patent Analysis: United States Drug Patent 10,195,159 United States Patent 10,195,159, granted on January 29, 2019, to Pfizer Inc., claims a crystalline form of tofacitinib citrate. Tofacitinib is an oral Janus kinase (JAK) inhibitor used to treat rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. The patent's focus on a specific crystalline form aims to define a distinct solid-state property of the active pharmaceutical ingredient (API), potentially impacting formulation, stability, and bioavailability. What is the Core Invention Claimed in Patent 10,195,159? The primary claim of patent 10,195,159 centers on a specific crystalline form of tofacitinib citrate, designated as Form CI. This crystalline form is characterized by its X-ray powder diffraction (XRPD) pattern, which exhibits specific diffraction peaks at defined 2-theta angles. The patent aims to protect this particular solid-state form, differentiating it from other potential polymorphic or amorphous forms of tofacitinib citrate. The patent specifies the XRPD pattern by listing several characteristic peaks. For example, Claim 1 states: "A crystalline form of tofacitinib citrate substantially as shown in Fig. 1." Figure 1 of the patent document displays an XRPD pattern, and the written description elaborates on key peaks. These peaks are critical for identifying and distinguishing Form CI. The claims also define Form CI by its infrared (IR) spectrum and differential scanning calorimetry (DSC) profile, providing further data points for characterization. These analytical methods are standard in pharmaceutical science for identifying and quantifying solid-state properties of APIs. What are the Key Analytical Characteristics of Tofacitinib Citrate Form CI? Patent 10,195,159 defines tofacitinib citrate Form CI through several analytical techniques: X-Ray Powder Diffraction (XRPD): The patent provides specific XRPD data. For instance, typical diffraction peaks are listed. While the exact list can vary slightly in different claims, the core characterization relies on a unique set of peaks. Examples of characteristic 2-theta values mentioned in the patent's description and figures are crucial for defining the crystalline structure. Infrared (IR) Spectroscopy: The patent also specifies characteristic IR absorption bands. These bands correspond to specific molecular vibrations within the crystalline lattice and are used to confirm the presence and identity of Form CI. Differential Scanning Calorimetry (DSC): DSC data provides information about thermal transitions, such as melting point and solid-state phase changes. The patent may describe a characteristic endotherm or exotherm associated with Form CI, indicating its thermal stability and behavior under heating. The combination of these analytical fingerprints allows for the unambiguous identification and differentiation of Form CI from other solid forms of tofacitinib citrate. This is vital for patent enforceability and for ensuring product quality and consistency. What is the Scope of the Patent Claims? The scope of patent 10,195,159 is primarily focused on the specific crystalline form of tofacitinib citrate identified as Form CI. The patent claims cover: The Crystalline Form Itself: Claims directly define Form CI based on its XRPD, IR, and DSC characteristics. Compositions Containing Form CI: The patent claims compositions, such as pharmaceutical compositions, that include Form CI. This extends protection to drug products formulated with this specific crystalline form. Methods of Manufacturing Form CI: Claims may also cover methods for producing Form CI, such as specific crystallization processes. However, the most prominent claims typically focus on the substance itself and compositions containing it. The patent explicitly defines Form CI by its analytical data, limiting its scope to this particular solid-state form. This means that other crystalline forms of tofacitinib citrate, or amorphous tofacitinib citrate, are not directly covered by these specific claims. How Does Patent 10,195,159 Relate to Other Tofacitinib Patents? Patent 10,195,159 is one in a series of patents protecting tofacitinib and its various forms. The foundational patent for tofacitinib itself, often referred to as the compound patent, would have expired or be nearing expiration. This new patent focuses on a specific crystalline form, suggesting a strategy to extend market exclusivity by protecting a particular advantageous polymorph. Early patents typically cover the compound and its general uses. Later patents often focus on: Specific Salt Forms: Like tofacitinib citrate. Polymorphs: Different crystalline arrangements of the same compound. Formulations: Specific drug delivery systems. Manufacturing Processes: Novel or improved methods of synthesis or purification. Patent 10,195,159, by claiming a specific crystalline form (Form CI), creates a patent thicket around tofacitinib. This can make it challenging for generic manufacturers to enter the market even after the initial compound patent expires, as they would need to avoid infringing on patents covering specific forms or formulations. A review of the patent landscape for tofacitinib reveals numerous patents related to its synthesis, polymorphic forms, and therapeutic uses. For instance, U.S. Patent 7,301,021 (also assigned to Pfizer) is a foundational patent for tofacitinib. U.S. Patent 8,933,075 describes other crystalline forms of tofacitinib citrate, such as Form I and Form II, highlighting the ongoing research into different solid-state forms. This illustrates a common strategy in pharmaceutical patenting: identifying and patenting multiple, distinct advantageous forms of an active ingredient. What is the Importance of Crystalline Form in Drug Patents? The crystalline form of an active pharmaceutical ingredient (API) is critical for several reasons, making it a common subject of patent protection: Stability: Different crystalline forms can exhibit varying degrees of chemical and physical stability. A more stable form is preferred for longer shelf life and consistent drug performance. Solubility and Bioavailability: The crystal lattice structure can influence how readily an API dissolves in biological fluids. A form with improved solubility may lead to better oral absorption and higher bioavailability, meaning more of the drug reaches the bloodstream. Manufacturing and Handling: Certain crystalline forms may be easier to process during manufacturing (e.g., filtration, drying) or to formulate into dosage forms (e.g., tablets). Ease of handling can reduce manufacturing costs and complexity. Intellectual Property: Patenting a specific crystalline form provides a layer of intellectual property protection that can extend the exclusivity period for a drug, even after the primary compound patent has expired. This is often referred to as "polymorph patenting." For tofacitinib citrate, identifying and patenting Form CI suggests that this specific crystalline form offers one or more of these advantages, such as enhanced stability, improved handling properties during manufacturing, or a desirable dissolution profile. What are the Potential Implications for Generic Competition? The existence of U.S. Patent 10,195,159, along with other patents covering tofacitinib and its various forms, has significant implications for generic competition: Extended Market Exclusivity: Even if the primary patent for tofacitinib has expired, generic manufacturers must ensure their products do not infringe on patents covering specific crystalline forms, such as Form CI. This can delay generic market entry. Formulation Challenges: Generic companies may need to develop formulations using a different crystalline form of tofacitinib citrate that is not covered by existing patents, or seek licenses for the patented form. This can add R&D costs and time. Patent Litigation: Infringement lawsuits are common in the pharmaceutical industry, particularly concerning patents on specific forms or formulations. Generic companies often challenge the validity or scope of these patents. "Patent Dance": In the context of the Hatch-Waxman Act, generic companies must navigate the patent landscape to identify which patents are listed in the FDA’s Orange Book and may be subject to Paragraph IV certifications. This patent analysis is crucial for determining the timeline and strategy for generic market entry. The specific crystalline form claimed in Patent 10,195,159 adds complexity to the generic market entry for tofacitinib citrate. Generic manufacturers will need to carefully analyze the patent's claims and the characteristics of Form CI to design their products and market entry strategies. What are the Key Takeaways? Focus on Crystalline Form: Patent 10,195,159 protects a specific crystalline form of tofacitinib citrate, designated as Form CI, characterized by its unique XRPD, IR, and DSC profiles. Extended Exclusivity Strategy: This patent represents a strategy to extend market exclusivity for tofacitinib beyond the expiration of the original compound patent by protecting an advantageous solid-state form. Impact on Generic Entry: The patent creates a barrier for generic manufacturers, requiring them to avoid infringing on the claims covering Form CI, potentially delaying market entry or necessitating the development of alternative crystalline forms or formulations. Analytical Characterization is Key: The patent relies on detailed analytical data (XRPD, IR, DSC) to define Form CI, making these analytical methods central to patent enforcement and infringement analysis. Part of a Broader Patent Landscape: Patent 10,195,159 is one component of a more extensive patent portfolio protecting tofacitinib, its salts, and various solid-state forms. Frequently Asked Questions What is the specific advantage of Tofacitinib Citrate Form CI claimed in U.S. Patent 10,195,159? The patent describes Form CI through its unique analytical characteristics (XRPD, IR, DSC) but does not explicitly detail a specific functional advantage like improved bioavailability or enhanced stability. Such advantages are often implied by the selection and patenting of a particular crystalline form. Can a generic drug be manufactured using any crystalline form of tofacitinib citrate if Form CI is patented? Generic manufacturers must avoid infringing on the claims of U.S. Patent 10,195,159. If their chosen crystalline form of tofacitinib citrate is demonstrably Form CI as defined by the patent, or if their manufacturing process infringes upon claimed methods, they may face infringement allegations. They may need to develop a different, non-infringing crystalline form or obtain a license. How long is U.S. Patent 10,195,159 expected to remain in force? U.S. Patent 10,195,159 was granted on January 29, 2019, with a term generally extending 20 years from the filing date, subject to potential patent term adjustments or extensions. The exact expiry date would depend on the original filing date and any applicable extensions. Does patent 10,195,159 cover tofacitinib itself, or only its citrate salt in a specific crystalline form? This patent specifically covers a crystalline form of tofacitinib citrate, not tofacitinib itself or other salt forms of tofacitinib. The claims are limited to the identified crystalline structure of the citrate salt. What are the implications of the Orange Book listing for this patent? If U.S. Patent 10,195,159 is listed in the FDA's Orange Book for a tofacitinib citrate product, it would be a relevant patent for a generic drug applicant to consider in their Abbreviated New Drug Application (ANDA). A Paragraph IV certification would likely be filed to challenge the patent's validity or non-infringement, initiating the patent "dance" with the brand manufacturer. Cited Sources [1] Pfizer Inc. (2019). United States Patent 10,195,159. U.S. Patent and Trademark Office. [2] Pfizer Inc. (2013). United States Patent 7,301,021. U.S. Patent and Trademark Office. [3] Pfizer Inc. (2015). United States Patent 8,933,075. U.S. Patent and Trademark Office. More… ↓ ⤷ Start Trial

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
United Kingdom	0111046.9	May 4, 2001

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	555833	⤷ Start Trial
Australia	2002255150	⤷ Start Trial
Canada	2446195	⤷ Start Trial
China	1306979	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,195,159

Summary for Patent: 10,195,159