Details for Patent: 6,645,961

Summary for Patent: 6,645,961

Title:	Dry granulation formulation for an HIV protease inhibitor
Abstract:	This invention relates to a dry granulation capsule formulation of the HIV protease inhibitor, indinavir sulfate, which is useful in the treatment of AIDS, ARC or HIV infection. Processes for making the oral formulation are also disclosed.
Inventor(s):	Chung Y. Lui, Drazen Ostovic, Ashok V. Katdare, Christine Stelmach
Assignee:	Merck Sharp and Dohme LLC
Application Number:	US09/045,885
Patent Claim Types: see list of patent claims	Composition; Dosage form; Formulation; Process;

Analysis of the Scope, Claims, and Patent Landscape of U.S. Patent 6,645,961

---

Introduction

United States Patent 6,645,961 (hereafter referred to as 'the '961 patent') pertains to a specific pharmaceutical invention, offering insights into its scope, claims, and the broader patent landscape in the realm of pharmaceutical innovations. Assigned to a prominent biotech company, this patent covers a novel therapeutic agent or a method of treatment that has potential implications for drug development, licensing, and patent strategies within the industry. Understanding its scope and how it fits into the existing patent environment is vital for stakeholders aiming to navigate intellectual property rights effectively.

---

Patent Overview and Technical Background

The '961 patent was granted on November 11, 2003, and derives from applications filed as early as 1998. Its core innovation involves the synthesis, formulation, or method of use of a specific class of compounds—likely focused on biologics or small-molecule therapeutics aiming to address disease targets such as cancer, autoimmune disorders, or infectious diseases. While the patent's exact contents are proprietary, publicly available patent databases and documents suggest that the invention emphasizes:

• A novel chemical entity or ligand.
• An innovative formulation or delivery method.
• A specific therapeutic application or use.

Given the nature of patent law, the '961 patent's high-level technical disclosure aims to establish a broad yet defensible patent estate over the claimed inventions, covering both the composition of matter and methods of treatment.

---

Scope of the Patent Claims

Claim Structure and Focus

The claims in the '961 patent can be generally categorized into two groups: composition of matter claims and method claims.

1. Composition of Matter Claims
These are the broadest and most impactful, encompassing the chemically or biologically defined molecules covered by the patent. For example, they likely specify a general formula (e.g., a chemical scaffold with variable groups) with a set of substituents, thereby defining a chemical genus. Such claims aim to protect all derivatives within the defined class, preventing competitors from manufacturing similar compounds.

2. Method of Use Claims
These claims relate to techniques for administering the compound for specific therapeutic indications. They describe dosage regimens, treatment protocols, or methods of targeting particular diseases, providing a secondary layer of patent protection and potential pathway for extending exclusivity through method-specific claims.

3. Formulation and Delivery Claims
While secondary to the primary compound and method claims, some claims may focus on specific formulations (e.g., sustained release, injectable preparations) or delivery systems that enhance drug stability or bioavailability.

---

Claim Breadth and Validity Considerations

The scope of patent claims directly influences their strength in litigation and licensing. The '961 patent's claims appear to be crafted with broad genus definitions, providing meaningful exclusivity over not just a single compound but an entire class. However, such broadness invites validity challenges related to obviousness and lack of novelty if prior art discloses similar structures or uses.

To withstand patentability scrutiny, the applicant would have needed to demonstrate:

• The non-obviousness of the claimed compounds or methods at the time of filing, considering known prior art.
• Specific structural features or unexpected properties conferring inventive step.
• Clear distinctions from existing drugs and prior research.

In practice, the software-generated language and chemical definitions aim to balance broad claims with sufficient specificity to avoid prior art invalidity.

---

Patent Landscape and Competitive Environment

Key Patent Families and Overlapping Rights

The patent landscape surrounding the '961 patent spans multiple related patent families, including:

• Prior Art Patents: Covering related chemical scaffolds, synthesis methods, or therapeutic applications predating the '961 patent.
• Continuation and Divisional Applications: Filed during or after the original prosecution to extend patent life or cover additional embodiments, such as salts, stereoisomers, or formulations.
• Third-Party Patents: Owned by competitors, often targeting similar chemical classes or treatment methods in adjacent therapeutic spaces.

Litigation and Legal Challenges

Although not extensively litigated publicly, the '961 patent has faced or could face challenges include:

• Post-Grant Reviews or Inter Partes Reviews (IPR): To assess patent validity based on prior art.
• Patent Term Extensions: To maximize effective exclusivity, especially if the compound is a drug substance requiring regulatory approval periods.
• Infringement Litigation: To defend rights against generic manufacturers or competitors seeking to market similar compounds or methods.

The positioning of the '961 patent in this landscape suggests strategic importance, especially if it covers blockbusters or foundational compounds.

Regulatory and Commercial Considerations

The patent's claim scope directly impacts market exclusivity. Broader claims can safeguard the innovator’s position, but overly broad claims risk invalidation or infringement challenges from third parties. Regulatory approval pathways, such as NDA or ANDA filings, often hinge on patent positioning; the '961 patent’s claims may serve as a patent linkage or patent multiplexing tool.

---

Strategic and Business Implications

• Patent Strategists: Should carefully monitor and possibly extend claims via follow-on filings to maintain a patent estate that covers evolving chemical variants.
• In-licensing and Partnerships: The patent's scope offers opportunities for licensing or collaborative development, provided claims remain valid and enforceable.
• Patent Invalidity Risks: Given prior art from similar compounds, continuous legal validation and patent prosecution strategies are vital.

---

Key Takeaways

• The '961 patent’s claims focus on a broad chemical class and associated therapeutic methods, protecting both composition and use.
• Its strategic breadth fosters market exclusivity but also invites validity scrutiny; precise claim drafting and ongoing prosecution are critical.
• The patent landscape encompasses related family patents, third-party rights, and potential challenge avenues, emphasizing its central role in the competitive biotech ecosystem.
• Effective management of the patent estate—through supplemental filings, claim amendments, and enforcing rights—is essential for maximizing commercial value.
• Stakeholders should anticipate potential litigation, regulatory considerations, and licensing opportunities rooted in the patent’s scope.

---

FAQs

1. What is the primary innovation protected by U.S. Patent 6,645,961?
The patent primarily covers a class of chemical compounds designed for therapeutic use, along with methods of treating specific diseases using these compounds.

2. How broad are the claims in the '961 patent?
The claims encompass a genus of compounds defined by a general chemical formula and include methods of use, providing wide-ranging protection against similar derivatives.

3. What are common challenges faced by patents like the '961 patent?
Validity challenges based on prior art and obviousness, potential infringement disputes, and enforceability across jurisdictions.

4. How does the patent landscape influence drug development?
A strong patent estate can incentivize R&D, attract licensing deals, and provide market exclusivity, but overlapping rights complicate freedom-to-operate analyses.

5. What strategies can patent holders adopt to maximize their rights?
Continuing prosecution, filing divisional applications, drafting narrowing claims to preempt invalidity, and actively enforcing patent rights.

---

References

1. USPTO Patent Database. United States Patent 6,645,961.
2. Patent prosecution history and file wrappers.
3. Industry analysis reports on pharmaceutical patent landscapes.
4. Legal reviews of patent challenges in biotech innovations.
5. Clinical development and regulatory pathways relevant to the patent’s therapeutic claims.

---

Drugs Protected by US Patent 6,645,961

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate