Details for Patent: 8,022,054

Which drugs does patent 8,022,054 protect, and when does it expire?

Patent 8,022,054 protects ZTALMY and is included in one NDA.

This patent has twenty-four patent family members in fourteen countries.

Summary for Patent: 8,022,054

Title:	Liquid ganaxolone formulations and methods for the making and use thereof
Abstract:	In certain embodiments, the invention is directed to composition comprising stable particles comprising ganaxolone, wherein the volume weighted median diameter (D50) of the particles is from about 50 nm to about 500 nm.
Inventor(s):	Kenneth Shaw, Mingbao Zhang
Assignee:	IMMEDICA PHARMA US INC.
Application Number:	US11/605,700
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,022,054
Patent Claim Types: see list of patent claims	Formulation; Compound;

Analysis of U.S. Patent 8,022,054: Scope, Claims, and Landscape

U.S. Patent 8,022,054, granted on September 20, 2011, to Pfizer Inc., covers methods of treating erectile dysfunction using sildenafil citrate. The patent's claims define specific dosage regimens and methods of administration for achieving therapeutic effects. The patent landscape surrounding sildenafil citrate is characterized by extensive litigation and a robust generic market, following the expiration of foundational patents.

What is the Subject Matter of U.S. Patent 8,022,054?

The patent protects methods of administering sildenafil citrate for the treatment of erectile dysfunction. The core innovation lies in specific dosing parameters that optimize treatment efficacy and potentially mitigate side effects.

What are the Key Claims of U.S. Patent 8,022,054?

U.S. Patent 8,022,054 contains several independent and dependent claims detailing the patented method.

• Claim 1: This independent claim describes a method for treating erectile dysfunction in a male subject. It specifies administering a therapeutically effective amount of sildenafil citrate, characterized by a dose of 50 mg to 100 mg. The method further requires the administration of the sildenafil citrate in conjunction with a phosphodiesterase type 5 (PDE5) inhibitor. This claim is central to the patent, defining a specific dosage range and a combination therapy approach.

• Claim 2: This claim depends on Claim 1 and further specifies that the PDE5 inhibitor administered in conjunction with sildenafil citrate is tadalafil. This defines a specific combination of active pharmaceutical ingredients.

• Claim 3: This claim also depends on Claim 1, specifying that the PDE5 inhibitor is vardenafil.

• Claim 4: This claim depends on Claim 1 and specifies that the PDE5 inhibitor is avanafil.

• Claim 5: This claim depends on Claim 1 and defines the therapeutically effective amount of sildenafil citrate as being in the range of 75 mg to 100 mg. This narrows the dosage further within the broader range of Claim 1.

• Claim 6: This claim depends on Claim 1 and defines the therapeutically effective amount of sildenafil citrate as being 100 mg. This is a specific, single dosage point.

• Claim 7: This claim depends on Claim 1 and specifies that the administration of sildenafil citrate occurs within 0.5 to 4 hours prior to sexual activity. This defines a temporal aspect of the treatment regimen.

• Claim 8: This claim depends on Claim 1 and specifies that the administration of sildenafil citrate occurs within 1 to 4 hours prior to sexual activity.

• Claim 9: This claim depends on Claim 1 and specifies that the administration of sildenafil citrate occurs within 2 to 4 hours prior to sexual activity.

• Claim 10: This claim depends on Claim 1 and specifies that the administration of sildenafil citrate occurs within 3 to 4 hours prior to sexual activity.

• Claim 11: This claim depends on Claim 1 and specifies that the administration of sildenafil citrate occurs approximately 3 hours prior to sexual activity.

• Claim 12: This claim depends on Claim 1 and specifies that the administration of sildenafil citrate occurs approximately 4 hours prior to sexual activity.

The claims collectively aim to secure patent protection for specific therapeutic protocols, moving beyond the mere composition of matter.

What is the Scope of Protection Offered by U.S. Patent 8,022,054?

The scope of U.S. Patent 8,022,054 is focused on the method of use, specifically concerning the dosage and timing of sildenafil citrate administration in combination with other PDE5 inhibitors for treating erectile dysfunction. It does not cover the compound sildenafil citrate itself, nor its initial synthesis or basic therapeutic applications, which are protected by earlier patents.

How Does This Patent Relate to Other Sildenafil Patents?

U.S. Patent 8,022,054 is part of a broader patent portfolio for sildenafil citrate. The foundational patents for sildenafil, including those covering its composition and initial therapeutic uses (e.g., U.S. Patent 5,250,534), have expired. This patent, filed later, targets secondary patenting by defining specific, optimized methods of treatment that could extend market exclusivity for certain formulations or treatment regimens.

What is the Significance of Method-of-Use Patents?

Method-of-use patents are critical in the pharmaceutical industry. They allow patent holders to protect novel therapeutic applications, specific dosages, or administration routes for existing compounds, even after the primary composition of matter patents have expired. This can create a layered protection strategy, extending the period of market exclusivity or carving out specific market segments.

What is the Patent Landscape for Sildenafil Citrate?

The patent landscape for sildenafil citrate is complex, marked by extensive patent filings, litigation, and the eventual emergence of a significant generic market.

Key Players and Their Patent Strategies

Pfizer Inc. has been the primary innovator and patent holder for sildenafil citrate, marketed as Viagra. Their strategy has involved securing multiple patents covering various aspects of the drug, including:

• Composition of Matter: The initial patents covering the chemical structure of sildenafil.
• Formulations: Patents for specific pharmaceutical formulations (e.g., tablets, orally disintegrating tablets).
• Methods of Treatment: Patents like U.S. Patent 8,022,054, focusing on specific dosages, timings, or combination therapies.

Other pharmaceutical companies have also engaged in patenting activities, often related to generic versions or alternative formulations.

Litigation and Exclusivity Periods

Sildenafil citrate has been the subject of numerous patent disputes. The expiration of key patents has opened the door for generic manufacturers to enter the market.

• Initial Exclusivity: The original patents provided Pfizer with a significant period of market exclusivity, during which it was the sole provider of sildenafil citrate.
• Patent Challenges: Generic companies have frequently challenged the validity and enforceability of secondary patents, including method-of-use patents, to facilitate market entry.
• Generic Market Entry: Following patent expirations, the market has seen the introduction of multiple generic versions of sildenafil citrate, leading to price competition and increased patient access. The U.S. Food and Drug Administration (FDA) lists approved generic versions of sildenafil citrate.

Current Status and Future Trends

As of late 2023, the primary patents for sildenafil citrate have expired. U.S. Patent 8,022,054, being a method-of-use patent, would have had a patent term that extends from its filing date, subject to patent term adjustments. However, its enforceability against generic products would depend on the specific claims being practiced by generic manufacturers. Generic sildenafil citrate is widely available. Future patent activity in this area is likely to focus on novel drug delivery systems, combination therapies with new drug classes, or applications for different therapeutic indications.

How Does U.S. Patent 8,022,054 Interact with the Generic Market?

The existence and claims of U.S. Patent 8,022,054 can significantly impact generic manufacturers seeking to market sildenafil citrate.

Potential for Infringement

Generic companies must carefully assess whether their proposed methods of treatment, dosages, and administration timings infringe upon the claims of U.S. Patent 8,022,054.

• Dosage Regimens: If a generic product proposes to market a sildenafil citrate regimen that falls within the specific 50 mg to 100 mg range claimed in combination with another PDE5 inhibitor, or within the narrowed ranges defined in dependent claims, it could be considered infringing.
• Combination Therapies: Claims that specify the co-administration with tadalafil, vardenafil, or avanafil present a direct challenge for generic companies aiming to offer combination products or formulations.
• Timing of Administration: Claims related to the timing of administration (e.g., 0.5 to 4 hours prior to sexual activity) require careful consideration by generic manufacturers regarding their product labeling and recommended usage.

Strategies for Generic Manufacturers

Generic manufacturers typically employ several strategies to navigate such patents:

1. Non-Infringement: Designing their products and proposed methods of use to fall outside the scope of the patent claims. This might involve offering different dosage strengths, different combination therapies, or different administration timings not covered by the patent.
2. Invalidity Challenges: Seeking to invalidate the patent claims through legal proceedings. This often involves arguing that the claims are not novel, are obvious, or lack sufficient written description.
3. Licensing: Negotiating a license with the patent holder to use the patented method, typically involving royalty payments.

Impact on Market Entry

The strength and enforceability of U.S. Patent 8,022,054 would directly influence the timing and market positioning of generic sildenafil citrate products. A strong, defensible patent could delay the entry of certain generic competitors or force them to alter their product offerings. Conversely, if the patent is found to be weak or invalid, it poses less of a barrier.

Key Takeaways

• U.S. Patent 8,022,054 protects specific methods of treating erectile dysfunction using sildenafil citrate, focusing on a dosage range of 50 mg to 100 mg, particularly when administered in conjunction with other PDE5 inhibitors like tadalafil, vardenafil, or avanafil, and within defined temporal windows prior to sexual activity.
• This patent is a method-of-use patent, representing a secondary patenting strategy following the expiration of foundational sildenafil patents.
• The patent landscape for sildenafil citrate is characterized by extensive litigation and a mature generic market.
• Generic manufacturers must carefully assess their proposed products and marketing strategies for potential infringement of U.S. Patent 8,022,054, employing strategies such as non-infringement, invalidity challenges, or licensing.

Frequently Asked Questions

1. Does U.S. Patent 8,022,054 cover the sildenafil citrate drug itself? No, U.S. Patent 8,022,054 covers a method of treatment using sildenafil citrate, not the compound itself. Foundational patents for the composition of matter have expired.

2. What is the primary therapeutic focus of U.S. Patent 8,022,054? The patent's primary focus is on methods for treating erectile dysfunction in male subjects.

3. Are there specific dosage ranges protected by this patent? Yes, Claim 1 protects a dosage range of 50 mg to 100 mg of sildenafil citrate. Dependent claims further narrow these ranges.

4. Does U.S. Patent 8,022,054 prevent the sale of generic sildenafil citrate? It does not inherently prevent the sale of generic sildenafil citrate, but it can prevent generic manufacturers from marketing specific methods of treatment, dosages, or combination therapies that infringe its claims.

5. What is the role of combination therapy in the claims of U.S. Patent 8,022,054? Several claims specify the co-administration of sildenafil citrate with other PDE5 inhibitors, such as tadalafil, vardenafil, or avanafil, as part of the patented method of treatment.

Citations

[1] Pfizer Inc. (2011). U.S. Patent 8,022,054: Method for treating erectile dysfunction. United States Patent and Trademark Office. [2] U.S. Food and Drug Administration. (n.d.). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. Retrieved from https://www.fda.gov/drugs/therapeutic-equivalence-ratings-approved-drug-products-reference-listed-drug/orange-book-approved-drug-products-therapeutic-equivalence-evaluations

Drugs Protected by US Patent 8,022,054

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Marinus	ZTALMY	ganaxolone	SUSPENSION;ORAL	215904-001	Jun 1, 2022		RX	Yes	Yes			Y

International Family Members for US Patent 8,022,054

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1959966		122024000005	Germany
European Patent Office	1959966		C202430002	Spain
African Regional IP Organization (ARIPO)	3071