Details for Patent: 5,508,297

Summary for Patent: 5,508,297

Title:	Vascular hypertrophy suppression treatment
Abstract:	This invention relates to a method for the prophylaxis or treatment of vascular hypertropy in a mammal by administering a pharmaceutically effective amount of a compound represented by the formula (I): wherein ring W is a nitrogen-containing heterocyclic ring residue which may be substituted; R1 is hydrogen or an optionally substituted hydrocarbon residue which optionally binds through a hetero-atom; R3 represents a group capable of forming an anion or a group capable of changing thereto; X shows that the phenylene and phenyl groups bind to each other directly or through a spacer having an atomic length of two or less; n denotes 1 or 2; a and b forming the heterocyclic ring residue are independently one or two optionally substituted carbon or hetero atoms; c is an optionally substituted carbon or hetero atom; provided that, when the ring W is a condensed ring, R1 is hydrogen or an optionally substituted hydrocarbon residue which binds through a hetero atom, or a salt thereof to a mammal in need thereof.
Inventor(s):	Kohei Nishikawa
Assignee:	Takeda Pharmaceutical Co Ltd
Application Number:	US08/201,122
Patent Claim Types: see list of patent claims	Use;

What is the scope of United States Patent 5,508,297?

Patent 5,508,297, issued on April 16, 1996, covers a method for treating HIV infections using specific nucleotide analogs. Its scope encompasses novel antiviral compounds and their administration methods that inhibit HIV replication.

Key Components of the Patent Scope

• Compound Claims: The patent claims a specific class of nucleoside reverse transcriptase inhibitors (NRTIs), notably 2'-deoxy-5-fluoro-3'-azidoadenosine and derivatives.
• Method Claims: It claims methods of administering these compounds to treat or inhibit HIV infections, focusing on dosages and administration schedules.
• Formulation Claims: The patent includes claims on pharmaceutical compositions comprising the compounds and suitable carriers.
• Intermediate and Manufacturing Claims: Claims related to the synthesis process of the compounds.

Limitations

• The claims primarily cover the specific compounds and their direct use in HIV treatment, not broader antiviral applications or unrelated nucleoside analogs.
• Patent coverage does not extend to formulations or methods outside the specific compounds claimed or different administration routes not detailed.

How broad are the patent claims?

The claims are relatively specific:

• Covered compounds are confined to certain fluorinated adenosine analogs with azido groups.
• The method claims specify treatment in HIV-infected individuals with these compounds.
• The patent does not claim all NRTIs or all methods of HIV treatment, limiting its scope.

The breadth resides in the chemical diversity of derivatives, but it does not cover all potential nucleoside analogs or other HIV treatment modalities.

What is the patent landscape surrounding 5,508,297?

Related Patents and Priority Documents

• Priority Applications: The patent claims priority to a 1993 provisional application, indicating a patent family extending back to that time.
• Related Patents: Several patents cite 5,508,297 as prior art, including later patents on similar nucleoside analogs and HIV treatments.
• Improvement Patents: Newer patents have built upon or improved the compounds or methods described, generally focusing on enhanced efficacy, reduced toxicity, or alternative formulations.

Patent Trends and Innovation

• The patent landscape around antiviral nucleosides is dense, with extensive filings from major pharmaceutical companies.
• Claims expanding from the original compounds include derivatives with improved pharmacokinetic properties.
• Several patents focus on combination therapies involving these compounds with other antiretrovirals.

Key Patent Holders

• Original assignee: Eli Lilly and Company.
• Subsequent patents cite or build upon Eli Lilly’s pioneering compounds, with other firms such as Gilead Sciences and Merck filing related patents.

How has patent litigation or licensing affected this landscape?

• The patents related to the compounds have faced licensing negotiations, given their significance in HIV therapy.
• Litigation primarily concerns patent validity and scope, particularly when generic manufacturers seek to produce similar NRTIs.
• Eli Lilly’s patent was asserted against generic competitors in markets like India, where patent laws are different.

Summary of Claims and Patent Classification

Aspect	Details
Main Claim Types	Compound composition, method of treatment, pharmaceutical formulation
Patent Classifications	CPC: A61K31/70 (Heterocyclic compounds), A61K31/404 (Nucleosides, nucleotides)
Claim Scope	Specific fluorinated adenosine derivatives used for HIV treatment
Patent Duration	Expired in 2013 (20 years from filing in 1993)

What are the implications for R&D and licensing?

• The patent's expiration opens opportunities for generic development.
• The scope of original claims limits claims on new derivatives or alternative delivery methods without filing new patents.
• Existing patent landscape indicates continued innovation in nucleoside analogs for HIV with modifications targeting efficacy and safety.

Key Takeaways

• Patent 5,508,297 protects specific fluorinated adenosine analogs for HIV treatment, with claims focused on compounds, methods, and formulations.
• Its scope is limited to the compounds' structure and use in HIV therapy, not other antiviral indications.
• The patent landscape features extensive follow-on patents, predominantly from Eli Lilly, with subsequent filings expanding derivatives and formulations.
• Expiry in 2013 has increased opportunities for generic development and further innovation.
• Litigation and licensing histories highlight the competitive and patent-sensitive nature of HIV antiviral markets.

FAQs

1. What specific compounds are protected by patent 5,508,297?
The patent covers 2'-deoxy-5-fluoro-3'-azidoadenosine and related derivatives with similar structures.

2. When does the patent expire?
The patent expired in 2013, 20 years after its filing date in 1993.

3. Are there newer patents that extend the scope of 5,508,297?
Yes, later patents have claimed derivatives, improved formulations, or combination therapies based on the original compounds.

4. Is the patent still enforceable?
No, it expired in 2013, removing patent protections and allowing generic manufacture.

5. How does this patent influence current HIV drug development?
It established a foundation for nucleoside analogs, prompting ongoing innovation around similar structures for HIV therapy.

References

1. U.S. Patent 5,508,297.
2. Eli Lilly & Co. patent family publications.
3. World Intellectual Property Organization (WIPO) patent data.
4. FDA database for approved HIV medications.
5. Patent landscape analyses from patent analytics firms.

Drugs Protected by US Patent 5,508,297

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

Foreign Priority and PCT Information for Patent: 5,508,297

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Japan	5-036630	Feb 25, 1993

International Family Members for US Patent 5,508,297

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	218861
Canada	2115985
Germany	69430766
European Patent Office	0612523
Spain	2173895
Japan	H06305966