United States Patent 10,993,952: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 10,993,952, hereafter referred to as the '952 Patent, is a significant patent in the pharmaceutical industry, particularly involving formulations of cyclophosphamide, a chemotherapeutic agent. This analysis delves into the scope, claims, and the broader patent landscape surrounding this patent.
Patent Overview
The '952 Patent is held by Ingenus Pharmaceuticals, LLP, and Leiutis Pharmaceuticals LLP, and it pertains to specific formulations of cyclophosphamide. The patent was granted after a detailed examination process, which involved negotiations over the claim scope and the interpretation of key terms such as "about"[1].
Claim Construction
Key Terms and Interpretation
A critical aspect of the '952 Patent is the interpretation of the term "about" in the claims. The patent specifies an ethanol content of "about 70% to about 75%" by weight of the total formulation. The court has ruled that the term "about" should be given its ordinary meaning of "approximately," rather than a strict numerical range. This interpretation is supported by the specification and the prosecution history of the patent, which indicate that the term "about" allows for some flexibility around the specified percentages[1].
Claim Scope
The claims of the '952 Patent include independent Claim 1 and dependent Claims 2-3, all of which recite the ethanol content as a percentage of the total formulation weight. The specification provides examples of formulations with ethanol contents of 75.9%, 74.81%, and 70.58%, further supporting the broader interpretation of "about"[1].
Patent Scope and Breadth
Metrics for Measuring Patent Scope
Research on patent scope suggests that metrics such as independent claim length and independent claim count can be used to measure the breadth of a patent. Narrower claims, as seen in the '952 Patent after the examination process, are often associated with a higher probability of grant and a shorter examination process[3].
Impact of Examination Process
The examination process for the '952 Patent involved significant negotiations over the claim scope. The applicants initially proposed a broader range of ethanol content (69.5% to 76.5%), which was later narrowed to "about 70% to about 75%" to gain allowance. This narrowing is consistent with the general trend observed in patent examinations, where claims tend to become narrower during the process[3].
Patent Landscape
Cyclophosphamide Patents
Cyclophosphamide, the active ingredient in the formulations covered by the '952 Patent, is protected by several other patents. For instance, Dr. Reddy's Laboratories Inc. holds patents related to cyclophosphamide, with some of these patents still in force as of 2024[2].
Litigation and Enforcement
The '952 Patent is currently involved in litigation, with Ingenus Pharmaceuticals, LLC, suing various defendants for patent infringement. These cases highlight the importance of the '952 Patent in protecting the intellectual property rights of the patent holders. For example, the lawsuit against Hetero USA, Inc., and its affiliates involves allegations of infringement through the submission of an Abbreviated New Drug Application (ANDA) for a generic version of cyclophosphamide injection[5].
Inequitable Conduct Allegations
Nexus Pharmaceuticals Inc. has asserted a counterclaim of inequitable conduct against the patent holders, alleging that material information was misrepresented during the prosecution of the patent application. However, the court has not found sufficient evidence to support this claim, as the applicants did not clearly disavow formulations with ethanol content outside the specified range[1].
Preferred and Most Preferred Embodiments
The specification of the '952 Patent describes preferred and most preferred embodiments of the invention. The preferred embodiment includes a solvent content of ethanol ranging from 20% to 98%, while the most preferred embodiment narrows this range to 40% to 92%. These embodiments further support the flexible interpretation of the term "about" in the claims[1].
Examples and Experimental Data
The patent includes several examples of formulations, each with specific ethanol and cyclophosphamide content. These examples demonstrate the stability and efficacy of the formulations, which were key factors in the patent's approval. For instance, Example 1 shows a formulation with 75.9% ethanol and 10.71% cyclophosphamide, while Example 6 has 70.58% ethanol and 22.62% cyclophosphamide[1].
Cyclophosphamide Content
The '952 Patent also specifies the cyclophosphamide content, which is claimed to be between 12% and 23% by weight of the total formulation. However, the specification describes broader ranges of cyclophosphamide content, from 5% to 40%, indicating that the invention is not limited to the strict range claimed[1].
Conclusion
The United States Patent 10,993,952 is a critical patent in the pharmaceutical industry, particularly for formulations of cyclophosphamide. The patent's scope and claims have been subject to detailed interpretation, with the term "about" being a key point of contention. The patent landscape surrounding cyclophosphamide is complex, with multiple patents and ongoing litigation. Understanding the nuances of this patent is essential for navigating the intellectual property landscape in this field.
Key Takeaways
- Interpretation of "About": The term "about" in the '952 Patent is interpreted to mean "approximately," allowing for flexibility around the specified percentages.
- Claim Scope: The claims include a range of ethanol content from "about 70% to about 75%" and cyclophosphamide content from 12% to 23%.
- Patent Landscape: The '952 Patent is part of a broader landscape involving multiple patents related to cyclophosphamide.
- Litigation: The patent is involved in ongoing litigation for infringement.
- Inequitable Conduct: Allegations of inequitable conduct have been raised but not substantiated.
- Experimental Data: The patent includes examples demonstrating the stability and efficacy of the formulations.
FAQs
Q: What is the main subject of the United States Patent 10,993,952?
A: The main subject of the '952 Patent is specific formulations of cyclophosphamide, a chemotherapeutic agent.
Q: How is the term "about" interpreted in the '952 Patent?
A: The term "about" is interpreted to mean "approximately," allowing for some flexibility around the specified percentages.
Q: What are the claimed ranges for ethanol and cyclophosphamide content in the '952 Patent?
A: The claimed ranges are "about 70% to about 75%" for ethanol and 12% to 23% for cyclophosphamide by weight of the total formulation.
Q: Is the '952 Patent involved in any litigation?
A: Yes, the patent is involved in ongoing litigation for infringement, including cases against Hetero USA, Inc., and Nexus Pharmaceuticals Inc.
Q: What are the preferred and most preferred embodiments described in the '952 Patent?
A: The preferred embodiment includes a solvent content of ethanol ranging from 20% to 98%, while the most preferred embodiment narrows this range to 40% to 92%.
Sources
- Ingenus Pharm. v. Nexus Pharm., 22-cv-2868 - Casetext
- Cyclophosphamide patent expiration - Pharsight
- Patent Claims and Patent Scope - SSRN
- United States Patent 10,993,952 - Google Patents
- In the United States District Court - RPX Insight
