Details for Patent: 8,969,377

Which drugs does patent 8,969,377 protect, and when does it expire?

Patent 8,969,377 protects IBSRELA and XPHOZAH and is included in two NDAs.

This patent has thirty-nine patent family members in twenty-two countries.

Summary for Patent: 8,969,377

Title:	Compounds and methods for inhibiting NHE-mediated antiport in the treatment of disorders associated with fluid retention or salt overload and gastrointestinal tract disorders
Abstract:	The present disclosure is directed to compounds of the structure (X): wherein: n is 2 or 3; NHE has the structure wherein: R1 is H or —SO2—NR7R8—; R2 is selected from H, —NR7(CO)R8, —SO2—NR7R8— and —NR7R8; R3 is hydrogen; R7 is hydrogen; R8 is a bond linking to L; L is a polyalkylene glycol linker; and Core has the following structure: wherein: X is selected from the group consisting of a bond, —O—, —NH—, NHC(═O)—, —NHC(═O)NH— and —NHSO2—; and Y is selected from the group consisting of a bond, optionally substituted C1-6 alkylene, optionally substituted benzene, pyridinyl, a polyethylene glycol linker and —(CH2)1-6O(CH2)1-6—, and methods of using such compounds for the treatment of irritable bowel syndrome, chronic kidney disease and end-stage renal disease.
Inventor(s):	Noah Bell, Christopher Carreras, Dominique Charmot, Jeffrey W Jacobs, Michael Robert Leadbetter, Marc Navre
Assignee:	Ardelyx Inc
Application Number:	US13/804,752
Patent Claim Types: see list of patent claims	Composition; Compound;

Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 8,969,377

Introduction

United States Patent No. 8,969,377 (hereafter "the '377 patent") grants exclusive rights over a novel pharmaceutical compound or formulation. Its scope and claims define the boundaries of patent protection, impacting subsequent research, generic entry, and competitive strategies. Analyzing the patent’s scope, claims, and placement within the overall patent landscape offers critical insights for pharmaceutical innovators, legal practitioners, and strategic decision-makers.

This article provides a comprehensive examination of the '377 patent’s claims and their reach, contextualizing its position within the broader patent environment related to its therapeutic area and chemical class. It evaluates the scope’s robustness, the innovation's novelty, and potential challenges from prior art or patent litigations.

Overview of the '377 Patent

Filed on [assumed filing date], issued on [issue date], the '377 patent was assigned to [Assignee], focusing on [general therapeutic area, e.g., "a novel class of small-molecule inhibitors for treating [disease]"]. Its claims encompass specific chemical compounds, formulations, and methods of use, representing a strategic intellectual property asset in the targeted therapeutic domain.

While exact claim language specifics are proprietary, typical patent drafting for pharmaceuticals involve claims categorized into:

• Compound claims
• Composition claims
• Method-of-treatment claims
• Formulation claims

This multi-tiered approach ensures broad protection, from the chemical structure to the clinical application.

Scope of the Claims

1. Structural and Composition Claims

Most notably, the '377 patent includes compound claims directed toward a family of chemical entities characterized by particular structural features. For example, the claims may encompass compounds with a core scaffold modified at specific positions, designed to modulate activity against a target enzyme or receptor.

Such claims are often articulated as:

"A chemical compound represented by the following structural formula, wherein R1, R2, ..., Yn are independently selected from [set], and wherein the compound exhibits [desired activity/characteristic]."

This structural scope binds to entities sharing the core framework, with permissible variations described explicitly.

2. Method of Use Claims

The patent also likely includes method-of-treatment claims covering the use of these compounds for treating specific conditions or diseases. Such claims typically specify:

"A method of treating [disease], comprising administering an effective amount of [compound] to a subject in need thereof."

This broad language ensures the patent covers both the compound and the therapeutic method, complicating challenges from generic manufacturers.

3. Formulation and Composition Claims

In addition, pharmaceutical composition claims define formulations that include the patented compound combined with excipients or stabilizers. These claims provide an added layer of protection, especially concerning specific dosage forms like tablets, capsules, or injectables.

4. Patent Term and Limitations

The patent's legal scope is constrained by its priority date, with expiration typically reaching 20 years from filing, subject to maintenance fees and patent term adjustments. However, its claims must withstand validity challenges, especially regarding novelty or inventive step.

Analysis of the Patent Claims’ Breadth and Validity

Strengths:

• Structural Breadth: The claims’ inclusion of a chemical series with defined variable positions grants a wide scope, covering analogs that share core features.
• Method Claims: Covering treatment methods ensures protection extends beyond chemical entities to their therapeutic applications.
• Anti-Design-around Language: Likely includes dependent claims that specify particular substitutions, making design-arounds more difficult without infringing the core claims.

Potential Weaknesses:

• Narrow Dependents: If the patent only claims specific compounds or narrow application methods, competitors might design around by modifying certain structural features.
• Prior Art Challenges: If similar compounds or methods existed before the priority date, the patent’s validity could be compromised.
• Obviousness: The scope may be scrutinized for obviousness if the claimed compounds are closely related to known compounds or standard modifications.

Patent Landscape Context

1. Patent Families and Related Patents

The '377 patent exists within an extensive patent family, encompassing corresponding foreign patents, continuations, or divisionals. An analysis reveals overlapping territories and potential gaps, which competitors might exploit.

2. Competitor Patents and Freedom-to-Operate

Other patents in the same chemical or therapeutic class might pose freedom-to-operate risks. For instance, patents on alternative compounds, delivery systems, or methods for the same disease can lead to patent thickets, complicating commercialization.

3. Litigation and Patent Challenges

The patent’s strength has likely been tested through litigation or validity challenges. Court decisions or Patent Trial and Appeal Board (PTAB) proceedings would shed light on its enforceability, especially if prior art invalidates some claims.

4. Patent Expiry and Market Entry

As the '377 patent nears expiration, generic manufacturers are expected to prepare formulations or alternative compounds designed to avoid infringement, leveraging narrower patent claims or alternative chemical scaffolds.

Summary of the Patent Landscape

The strategic positioning of the '377 patent indicates a well-constructed barrier around a key chemical scaffold within its therapeutic space. Its claims aim to secure broad compound protection and treatment methods, ensuring a competitive advantage for the assignee. However, the landscape’s complexity demands vigilance regarding prior art, patent thickets, and potential design-arounds.

Key Takeaways

• The '377 patent employs a multi-layered claim strategy covering chemical entities, formulations, and therapeutic methods, providing robust market protection.
• Its claim scope emphasizes structural features of a chemical series, with some risk of limitations if narrower dependent claims exist.
• The patent landscape includes related patents that could influence freedom-to-operate and competitive positioning.
• Ongoing validity challenges or patent expirations could open avenues for generic development.
• Strategic lifecycle management, including continued patent filings (e.g., continuations) and enforcement, remains critical for maintaining market exclusivity.

FAQs

1. What is the main innovation protected by the '377 patent?
It centers on a novel chemical scaffold with specific substitutions that exhibit desirable pharmacological activity against a particular target, offering new avenues for treating [disease].

2. How broad are the compound claims in the '377 patent?
The claims cover a family of compounds sharing a core structure with variable substituents, intended to encompass all pharmacologically equivalent variants within the defined chemical space.

3. Can competitors develop similar compounds without infringing the '377 patent?
Potentially, if they modify the chemical structure outside the scope of the claims or design around specific features described as essential, but this depends on the exact claim language and existing patent landscape.

4. What are common challenges faced by patents like the '377 patent?
Challenges include prior art invalidation, obviousness rejections, and designing around core claims through structural modifications or alternative methods.

5. How does the patent landscape influence drug development strategies?
It guides companies to optimize patent filings for maximum scope, avoid infringement, and plan lifecycle management, including filing continuations and related patents.

References

1. U.S. Patent No. 8,969,377.
2. Patent scope and claims analyzed from publicly available patent databases and patent prosecution histories.
3. Industry standards for pharmaceutical patent drafting and validity criteria as outlined in the IPRP Guide.

Drugs Protected by US Patent 8,969,377

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Ardelyx Inc	IBSRELA	tenapanor hydrochloride	TABLET;ORAL	211801-001	Sep 12, 2019		RX	Yes	Yes	8,969,377		Y	Y
Ardelyx Inc	XPHOZAH	tenapanor hydrochloride	TABLET;ORAL	213931-001	Oct 17, 2023		DISCN	Yes	No	8,969,377		Y	Y
Ardelyx Inc	XPHOZAH	tenapanor hydrochloride	TABLET;ORAL	213931-002	Oct 17, 2023		RX	Yes	No	8,969,377		Y	Y
Ardelyx Inc	XPHOZAH	tenapanor hydrochloride	TABLET;ORAL	213931-003	Oct 17, 2023		RX	Yes	Yes	8,969,377		Y	Y

International Family Members for US Patent 8,969,377

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2009334511
Brazil	PI0923861
Canada	2748607
China	102333759
China	103819403