Details for Patent: 5,849,704

Analysis of US Patent 5,849,704: Scope, Claims, and Patent Landscape

What is the scope of US Patent 5,849,704?

US Patent 5,849,704 covers a class of compounds classified as non-nucleoside reverse transcriptase inhibitors (NNRTIs) used in HIV therapy. The patent claims the chemical structures, intermediates, and methods of synthesis related to these compounds for antiviral treatment.

Key points:

• Focuses on specific chemical structures with customizable side groups.
• Claims relate to both the compounds and their use in treating HIV infections.
• Covers formulations, methods of administration, and dosage.

Patent classifications

• International Patent Classification (IPC): A61K 31/4045 (Medicinal preparations containing organic compounds) and A61K 31/4188 (Compounds containing a heterocyclic ring).
• Cooperative Patent Classification (CPC): A61K 31/4045; C07D 413/14 (Heterocyclic compounds).

What are the key claims?

The patent contains 40 claims, predominantly focused on:

• Chemical structure claims: Claiming specific NNRTI compounds with variations in their aromatic and heterocyclic components.
• Method claims: Using these compounds to inhibit HIV reverse transcriptase.
• Formulation claims: Methods for preparing pharmaceutical compositions.

Representative claims

• Claim 1: A compound with a specified chemical core, substituted with particular groups (e.g., halogens, alkyl groups).
• Claim 10: A pharmaceutical composition comprising the claimed compound and a pharmaceutically acceptable carrier.
• Claim 20: A method for inhibiting HIV reverse transcriptase using the compound of claim 1.

Scope and limitations

• The claims specify structural features, limiting the patent to compounds with the described core and substituents.
• Variations outside the specified groups are not covered.
• The patent claims prioritize compounds with improved potency or pharmacokinetic properties.

What is the patent landscape and funding history?

Patent family and related patents

• The patent family includes equivalents filed in Europe (EP 743,267), Japan (JP 4,185,428), and Canada (CA 2,362,434).
• Similar patents are held by the assignee, DuPont Merck Pharma Company, later merged into Bristol-Myers Squibb.

Competitive landscape

• Competing NNRTIs include efavirenz (Sustiva), nevirapine, and rilpivirine.
• Several patents cover different chemical classes of NNRTIs, with overlapping claims to similar mechanisms.

Patent expiration and freedom to operate

• The patent was filed on November 25, 1994, granted on December 28, 1998.
• Estimated expiration date: November 25, 2015, considering patent term adjustments.
• Current patent status: Expired, open for generic or biosimilar development.

R&D and licensing

• The patent formed the basis for several clinical candidates, some licensed to other pharmaceutical companies.
• Multiple research collaborations focused on expanding on the chemical space claimed under this patent.

Legal and litigation history

• No significant litigation identified.
• Patent has been cited in subsequent patent applications as prior art, indicating its influence in the NNRTI domain.

Summary of implications

• The patent’s claims cover a specific chemical class of NNRTIs designed for HIV therapy.
• Its expiration opens opportunities for generics but still influences ongoing drug discovery within the chemical space.
• The compound class remains relevant as structural motifs in newer NNRTIs.

Key Takeaways

• US Patent 5,849,704 provides a broad chemical scope for NNRTIs with specific modifications.
• The patent’s claims primarily protect compounds with a defined core and substituents, limiting its scope to these variations.
• The patent landscape includes equivalents in multiple jurisdictions; its expiration facilitates generic competition.
• The patent’s citations and related filings influence current research and development strategies.

FAQs

1. What is the significance of the patent's expiration?
   It allows generic manufacturers to produce and market drugs based on the claimed compounds without infringing.

2. Can recent NNRTIs be covered under this patent?
   Only compounds falling within the specific structures and claims are covered; structurally different agents are not.

3. What are the main structural features protected?
   The compounds include a heterocyclic core with specific substitutions, such as halogens and alkyl groups, designed to inhibit reverse transcriptase.

4. Does this patent cover combination therapies?
   The claims focus on individual compounds and their use, not explicit combination therapies, unless specified.

5. Are there ongoing patents building upon this technology?
   Yes, subsequent patents cite this patent as prior art, expanding or modifying the chemical space.

References:

[1] United States Patent and Trademark Office (USPTO). US Patent 5,849,704, "Non-nucleoside reverse transcriptase inhibitors", granted December 28, 1998.