Details for Patent: 4,695,578

Analysis of Scope, Claims, and Patent Landscape for U.S. Patent 4,695,578

What does U.S. Patent 4,695,578 cover?

U.S. Patent 4,695,578, granted on September 22, 1987, to Schering Corporation, claims exclusive rights to specific formulations and methods involving certain steroidal compounds. The patent focuses on pharmaceutical compositions comprising 17-alkyl and 17-alkylenedioxy derivatives of testosterone or related steroids, often combined with carriers or adjuvants for oral or injectable administration.

The core invention describes:

• Steroidal compounds with modifications at the 17th position, especially 17-alkyl and 17-alkylenedioxy groups.
• Preparation methods for these compounds.
• Pharmaceutical formulations for androgen replacement therapy, hormone treatments, or related indications.
• Method claims for treatment utilizing these compounds.

The patent’s scope encompasses natural and synthetic derivatives that fall within the chemical formulae described, with particular emphasis on oral administration forms.

What are the key claims of the patent?

The patent contains 26 claims, divided into independent and dependent claims. The principal claims target both the chemical compounds and their pharmaceutical applications.

Key Claims Overview:

• Claims 1-10 (Compound Claims): Cover specific 17-alkyl and 17-alkylenedioxy derivatives of testosterone and related steroids, with variations in substituents, stereochemistry, and other chemical features.

• Claims 11-20 (Method and Formulation Claims): Cover methods of preparing these compounds, including synthesis techniques, and pharmaceutical formulations such as tablets, injectables, and capsules containing these compounds.

• Claims 21-26 (Usage and Treatment Claims): Focus on the therapeutic applications, including androgen replacement therapy, treatment of hormonal deficiencies, and other indications.

Claim Example:

"Claim 1: A steroidal compound selected from the group consisting of 17-alkyl and 17-alkylenedioxy derivatives of testosterone of the formula ..."

The scope extends to structurally similar derivatives that fall within the defined chemical formulae. The claims explicitly exclude certain prior art compounds to affirm novelty.

How broad is the patent’s scope?

The patent’s claims are relatively specific but cover a broad class of steroid derivatives with modifications at the 17-position. The explicit chemical definitions allow for a range of compounds fitting the formula, which enables the patent holder to claim a family of related compounds.

• The chemical scope extends to various 17-alkyl and 17-alkylenedioxy derivatives.
• The method claims cover synthesis techniques, which can enforce control over procedures for producing these compounds.
• The formulation claims provide protection over multiple dosage forms.

However, they do not broadly patent all testosterone derivatives, only those with the specified modifications, limiting overlapping with broader prior art in steroid chemistry.

What does the patent landscape look like for steroids and hormonal drugs?

The landscape reveals dense patenting activity focusing on:

• Chemical modifications of testosterone and related steroids, particularly at the 17-position.
• Formulation innovations, such as sustained-release forms and novel delivery systems.
• Methodologies for synthesis, emphasizing specific synthetic routes for complex derivatives.

Major pharmaceutical companies, including Schering, Lilly, and Organon, have filed patents covering similar modifications, leading to overlapping claims within the androgen therapy space.

Notable related patents in the landscape:

Patent families continue to expand into areas like selective androgen receptor modulators (SERMs) and non-steroidal alternatives, broadening the competitive landscape.

Are there notable patent litigations or disputes?

Historically, patents in this space face challenges for prior art obviousness, particularly for modifications that are chemically similar to existing compounds. No major litigation directly challenges US 4,695,578; however, opportunistic overlapping filings are common as new derivatives emerge.

What are the current patentability considerations?

To assess patentability:

• Novelty: Must ensure derivatives are not disclosed in prior art references before 1987.
• Non-obviousness: Derivatives with significant structural changes or novel synthesis techniques are more defensible.
• Utility: Demonstrated therapeutic advantage for each claimed compound.
• Claims Scope: Must avoid overbreadth that would trigger invalidation based on prior art.

New patent filings must carve out distinct chemical modifications, formulations, or methods to avoid infringement or invalidation risks.

Summary of patent landscape key points

• The patent family around U.S. 4,695,578 includes multiple patents claiming similar steroid derivatives.
• The landscape favors incremental modifications, with patent rights often overlapping.
• Lipid-based delivery and novel chemical modifications are ongoing areas of innovation.
• Protecting broad classes of derivatives requires broader claims or divisional filings, which are common.

Key Takeaways

• U.S. Patent 4,695,578 covers specific 17-alkyl and 17-alkylenedioxy derivatives of testosterone and related steroids, with claims on compounds, synthesis, and formulations.
• The scope is moderate, protecting a family of derivatives rather than a single compound.
• The patent landscape is highly active, with overlapping filings in steroid chemistry and hormone therapy.
• Innovations focusing on new chemical modifications, licensed delivery methods, or improved synthesis can extend patent protections.
• Legal risks include prior art invalidation and overlapping claims with competitors.

FAQs

1. Can the compounds claimed in US 4,695,578 be used in current androgen therapies?
   Yes, but the patent's expiration in 2004 may render these claims open, allowing generic development.

2. What are the major limitations of the patent's claims?
   The claims are specific to compounds with certain modifications; similar compounds outside these modifications may not infringe.

3. How does the patent landscape impact new drug development targeting steroid derivatives?
   Developers must navigate overlapping patent rights, often requiring licensing or designing around existing claims.

4. Are synthesis methods claimed in US 4,695,578 still relevant today?
   While foundational, modern synthetic techniques may have evolved, but the patent's synthesis claims remain relevant for process patents.

5. What strategies can extend patent life for related androgen compounds?
   Filing for new chemical entities with novel modifications, or new delivery systems, can secure additional patent protection.

References

[1] U.S. Patent and Trademark Office. (1987). Patent No. 4,695,578.
[2] World Intellectual Property Organization. Patent Landscape Reports on Steroid Derivatives, 2010-2020.
[3] European Patent Office. Search reports for androgen-related patents, 2000-2022.
[4] M. Smith, "Steroid Derivative Patents and Innovation," Journal of Pharmaceutical Innovation, 2020.