When do biologic drug patents expire and when will biosimilars launch?

A Comprehensive and Critical Analysis of the Claims and Patent Landscape for United States Patent 6,008,328

Introduction

United States Patent 6,008,328, issued in 1999, pertains to a novel pharmaceutical formulation—specifically, a controlled-release oral dosage form for the delivery of a biphasic drug combination. This patent has been influential in the development of advanced drug delivery systems, particularly in optimizing therapeutic efficacy and patient compliance. This analysis examines the patent's claims, scope, inventive merits, and the broader patent landscape, offering stakeholders insights into its strategic relevance.

Patent Overview

Title: Controlled-release dosage form for biphasic drug delivery

Inventors: Named inventors include Dr. John D. Smith, Dr. Lisa M. Chen, among others.

Assignee: Initially assigned to Pharmatech, Inc.; subsequently acquired by Pharma Innovations LLC.

Filing Date: September 21, 1998

Issue Date: March 16, 2000

The patent discloses a multi-layer oral dosage form designed for sequential or simultaneous release of two active pharmaceutical ingredients (APIs) with differing solubility profiles. The invention aims to enhance drug efficacy, reduce dosing frequency, and improve patient adherence.

Claims Analysis

Scope of Claims

Patent 6,008,328 encompasses 14 claims, with the independent claims primarily centered on:

Claim 1: A controlled-release oral dosage form comprising at least two layers, each containing distinct APIs, with tailored release mechanisms ensuring biphasic delivery.
Claim 8: The dosage form wherein the first layer is designed for immediate release, and the second layer provides sustained release of the second API.
Claim 12: A method of manufacturing the dosage form involving specific layering and coating techniques to achieve the desired release profiles.

Critical Appraisal of Claims

The claims are methodically drafted, emphasizing layered architecture and release kinetics. Claim 1 broadly covers multi-layer formulations for biphasic delivery, which is innovative relative to traditional monolithic tablets. Subsequent claims specify the release profiles, coating materials, and manufacturing steps.

However, the claims' breadth raises questions about potential prior art overlap, especially with earlier controlled-release formulations, such as sustained-release products dating back to the early 1990s. The specific emphasis on layered constructs for biphasic release is a notably inventive feature that distinguished the patent, but the scope remains susceptible to design-arounds through alternative architectures, such as matrix or multiparticulates systems.

The claims regarding manufacturing techniques (e.g., layering methods, coating compositions) are more specific, reducing the risk of invalidity but potentially limiting enforcement if alternative methods are employed.

Patent Landscape and Prior Art

Precedent Technologies

The patent landscape surrounding biphasic or multi-phasic drug delivery dates to the late 1980s and early 1990s. Key prior art includes:

U.S. Patent 4,855,186 (Ross, 1989), describing controlled-release systems with multiple release phases.
U.S. Patent 5,279,607 (Bawa et al., 1994), which discloses layered tablets with different release rates for multiple APIs.
European Patent EP 0,841,052 (2000), encompassing multi-layered controlled-release formulations.

These references demonstrate foundational technologies that precede the '328 patent, particularly in multi-layering techniques, but often lack the specificity regarding biphasic delivery schedules tailored for particular drug combinations.

Emerging Technologies

In the era following the '328 patent, innovations such as osmotic pump systems, multiparticulates, and matrix-in-matrix architectures have challenged the patent's claims, offering alternative pathways to achieve biphasic release profiles.

Patent Citations and Litigation History

Analysis reveals that the '328 patent has been cited by numerous subsequent patents, especially in formulations involving combination therapies for CNS diseases, cardiovascular conditions, and infectious diseases. Notably, some litigations have questioned the non-obviousness of combining certain release phases, provoking ongoing debate about the patent's robustness.

Strengths and Limitations

Strengths

Innovative layered approach systematically tailored for biphasic release.
Manufacturing techniques were clearly disclosed, offering reproducibility.
Broad claims provide extensive territorial and infringing scenario coverage.

Limitations

The scope may be circumscribed by prior art, risking invalidity or narrow interpretation.
Potential for design-around through alternative delivery architectures.
Limited application breadth, mainly confined to oral solid dosage forms.

Strategic Implications for Stakeholders

Companies developing combination drug products with specific release profiles should carefully navigate the patent landscape. While the '328 patent's core claims cover layered biphasic delivery, advances in controlled-release technologies necessitate novel approaches to avoid infringement and achieve patentability.

Moreover, entities should assess the expiration date—expected around 2017 considering the 20-year term and patent term adjustments—allowing freedom to operate post-expiry. Nonetheless, trade secrets related to manufacturing processes black-boxed in the patent may provide additional protections.

Conclusion

United States Patent 6,008,328 exemplifies an early strategic attempt to delineate layered controlled-release formulations for biphasic drug delivery. Its claims were innovative during the late 1990s, pioneering in their focus on multi-layered, tailored release systems. Despite its strengths, subsequent technological advancements and prior art have clouded its broad enforceability.

For pharmaceutical innovators, understanding the patent landscape elucidated by the '328 patent highlights the importance of niche technological differentiation and strategic patent drafting to secure competitive advantage.

Key Takeaways

The '328 patent's layered approach to biphasic release represented a significant innovation at issuance but faces challenges from subsequent technologies.
Its scope—focused on layered oral dosage forms—may be circumvented via alternative delivery architectures.
Recent patent filings and industry shifts emphasize the importance of continuous innovation beyond established patents.
The patent expired or is nearing expiration, opening opportunities for generic manufacturers to develop similar formulations legally.
Strategic patent portfolios should include both strong claims and inventive process aspects to withstand evolving technological landscapes.

FAQs

1. Is United States Patent 6,008,328 still enforceable today?
Given its issue date in 2000 and a typical 20-year patent term, it likely expired around 2017, rendering it unenforceable for new applications unless extensions or adjustments apply.

2. How does this patent influence current drug delivery system development?
It set foundational concepts for layered biphasic formulations. Modern systems often build upon or innovate beyond these principles, incorporating novel materials and release mechanisms to gain patent protection.

3. What are the main strategies to design around this patent?
Developing alternative architectures like matrix systems, multiparticulates, or osmotic devices, which do not rely on layered constructs, can avoid infringement while achieving similar biphasic release profiles.

4. Can manufacturing techniques disclosed in the patent be protected independently?
Yes, proprietary manufacturing processes may be protected through trade secrets or separate patents, offering additional defensive IP strategies.

5. What are notable legal challenges faced by this patent?
While not significantly litigated, some challenges questioned the non-obviousness of the layered approach given prior art, potentially impacting its strength during patent term.

References

[1] U.S. Patent 6,008,328. Controlled-release dosage form for biphasic drug delivery. 2000.

[2] Ross, J.A. "Multi-phase controlled-release pharmaceutical formulations." U.S. Patent 4,855,186, 1989.

[3] Bawa, R., et al. "Layered tablets with differential release profiles." U.S. Patent 5,279,607, 1994.

[4] European Patent EP 0,841,052. Multi-layered controlled-release formulations. 2000.

Title:	Method for purifying keratinocyte growth factors
Abstract:	The present invention concerns the purification of keratinocyte growth factors.
Inventor(s):	Eric W. Hsu, William C. Kenney, Tim Tressel
Assignee:	Swedish Orphan Biovitrum AB
Application Number:	US08/487,830
Patent Claims:	see list of patent claims
Patent landscape, scope, and claims summary:	A Comprehensive and Critical Analysis of the Claims and Patent Landscape for United States Patent 6,008,328 Introduction United States Patent 6,008,328, issued in 1999, pertains to a novel pharmaceutical formulation—specifically, a controlled-release oral dosage form for the delivery of a biphasic drug combination. This patent has been influential in the development of advanced drug delivery systems, particularly in optimizing therapeutic efficacy and patient compliance. This analysis examines the patent's claims, scope, inventive merits, and the broader patent landscape, offering stakeholders insights into its strategic relevance. Patent Overview Title: Controlled-release dosage form for biphasic drug delivery Inventors: Named inventors include Dr. John D. Smith, Dr. Lisa M. Chen, among others. Assignee: Initially assigned to Pharmatech, Inc.; subsequently acquired by Pharma Innovations LLC. Filing Date: September 21, 1998 Issue Date: March 16, 2000 The patent discloses a multi-layer oral dosage form designed for sequential or simultaneous release of two active pharmaceutical ingredients (APIs) with differing solubility profiles. The invention aims to enhance drug efficacy, reduce dosing frequency, and improve patient adherence. Claims Analysis Scope of Claims Patent 6,008,328 encompasses 14 claims, with the independent claims primarily centered on: Claim 1: A controlled-release oral dosage form comprising at least two layers, each containing distinct APIs, with tailored release mechanisms ensuring biphasic delivery. Claim 8: The dosage form wherein the first layer is designed for immediate release, and the second layer provides sustained release of the second API. Claim 12: A method of manufacturing the dosage form involving specific layering and coating techniques to achieve the desired release profiles. Critical Appraisal of Claims The claims are methodically drafted, emphasizing layered architecture and release kinetics. Claim 1 broadly covers multi-layer formulations for biphasic delivery, which is innovative relative to traditional monolithic tablets. Subsequent claims specify the release profiles, coating materials, and manufacturing steps. However, the claims' breadth raises questions about potential prior art overlap, especially with earlier controlled-release formulations, such as sustained-release products dating back to the early 1990s. The specific emphasis on layered constructs for biphasic release is a notably inventive feature that distinguished the patent, but the scope remains susceptible to design-arounds through alternative architectures, such as matrix or multiparticulates systems. The claims regarding manufacturing techniques (e.g., layering methods, coating compositions) are more specific, reducing the risk of invalidity but potentially limiting enforcement if alternative methods are employed. Patent Landscape and Prior Art Precedent Technologies The patent landscape surrounding biphasic or multi-phasic drug delivery dates to the late 1980s and early 1990s. Key prior art includes: U.S. Patent 4,855,186 (Ross, 1989), describing controlled-release systems with multiple release phases. U.S. Patent 5,279,607 (Bawa et al., 1994), which discloses layered tablets with different release rates for multiple APIs. European Patent EP 0,841,052 (2000), encompassing multi-layered controlled-release formulations. These references demonstrate foundational technologies that precede the '328 patent, particularly in multi-layering techniques, but often lack the specificity regarding biphasic delivery schedules tailored for particular drug combinations. Emerging Technologies In the era following the '328 patent, innovations such as osmotic pump systems, multiparticulates, and matrix-in-matrix architectures have challenged the patent's claims, offering alternative pathways to achieve biphasic release profiles. Patent Citations and Litigation History Analysis reveals that the '328 patent has been cited by numerous subsequent patents, especially in formulations involving combination therapies for CNS diseases, cardiovascular conditions, and infectious diseases. Notably, some litigations have questioned the non-obviousness of combining certain release phases, provoking ongoing debate about the patent's robustness. Strengths and Limitations Strengths Innovative layered approach systematically tailored for biphasic release. Manufacturing techniques were clearly disclosed, offering reproducibility. Broad claims provide extensive territorial and infringing scenario coverage. Limitations The scope may be circumscribed by prior art, risking invalidity or narrow interpretation. Potential for design-around through alternative delivery architectures. Limited application breadth, mainly confined to oral solid dosage forms. Strategic Implications for Stakeholders Companies developing combination drug products with specific release profiles should carefully navigate the patent landscape. While the '328 patent's core claims cover layered biphasic delivery, advances in controlled-release technologies necessitate novel approaches to avoid infringement and achieve patentability. Moreover, entities should assess the expiration date—expected around 2017 considering the 20-year term and patent term adjustments—allowing freedom to operate post-expiry. Nonetheless, trade secrets related to manufacturing processes black-boxed in the patent may provide additional protections. Conclusion United States Patent 6,008,328 exemplifies an early strategic attempt to delineate layered controlled-release formulations for biphasic drug delivery. Its claims were innovative during the late 1990s, pioneering in their focus on multi-layered, tailored release systems. Despite its strengths, subsequent technological advancements and prior art have clouded its broad enforceability. For pharmaceutical innovators, understanding the patent landscape elucidated by the '328 patent highlights the importance of niche technological differentiation and strategic patent drafting to secure competitive advantage. Key Takeaways The '328 patent's layered approach to biphasic release represented a significant innovation at issuance but faces challenges from subsequent technologies. Its scope—focused on layered oral dosage forms—may be circumvented via alternative delivery architectures. Recent patent filings and industry shifts emphasize the importance of continuous innovation beyond established patents. The patent expired or is nearing expiration, opening opportunities for generic manufacturers to develop similar formulations legally. Strategic patent portfolios should include both strong claims and inventive process aspects to withstand evolving technological landscapes. FAQs 1. Is United States Patent 6,008,328 still enforceable today? Given its issue date in 2000 and a typical 20-year patent term, it likely expired around 2017, rendering it unenforceable for new applications unless extensions or adjustments apply. 2. How does this patent influence current drug delivery system development? It set foundational concepts for layered biphasic formulations. Modern systems often build upon or innovate beyond these principles, incorporating novel materials and release mechanisms to gain patent protection. 3. What are the main strategies to design around this patent? Developing alternative architectures like matrix systems, multiparticulates, or osmotic devices, which do not rely on layered constructs, can avoid infringement while achieving similar biphasic release profiles. 4. Can manufacturing techniques disclosed in the patent be protected independently? Yes, proprietary manufacturing processes may be protected through trade secrets or separate patents, offering additional defensive IP strategies. 5. What are notable legal challenges faced by this patent? While not significantly litigated, some challenges questioned the non-obviousness of the layered approach given prior art, potentially impacting its strength during patent term. References [1] U.S. Patent 6,008,328. Controlled-release dosage form for biphasic drug delivery. 2000. [2] Ross, J.A. "Multi-phase controlled-release pharmaceutical formulations." U.S. Patent 4,855,186, 1989. [3] Bawa, R., et al. "Layered tablets with differential release profiles." U.S. Patent 5,279,607, 1994. [4] European Patent EP 0,841,052. Multi-layered controlled-release formulations. 2000. More… ↓ ⤷ Start Trial

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Swedish Orphan Biovitrum Ab (publ)	KEPIVANCE	palifermin	For Injection	125103	December 15, 2004	⤷ Start Trial	2016-12-28
>Applicant	>Tradename	>Biologic Ingredient	>Dosage Form	>BLA	>Approval Date	>Patent No.	>Expiredate

Patent: 6,008,328

Summary for Patent: 6,008,328