Details for Patent: 5,308,847

Summary for Patent: 5,308,847

Title:	Methods of inhibiting transplant rejection in mammals using rapamycin and derivatives and prodrugs thereof
Abstract:	This invention provides a method of inhibiting organ or tissue transplant rejection in a mammal in need thereof, comprising administering to said mammal a transplant rejection inhibiting amount of rapamycin. Also disclosed is a method of inhibiting organ or tissue transplant rejection in a mammal in need thereof, comprising administering to said mammal (a) an amount of rapamycin in combination with (b) an amount of one or more other chemotherapeutic agents for inhibiting transplant rejection, e.g., azathioprine, corticosteroids, cyclosporin and FK506, said amounts of (a) and (b) together being effective to inhibit transplant rejection and to maintain inhibition of transplant rejection.
Inventor(s):	Sir Roy Calne
Assignee:	Individual
Application Number:	US08/009,570
Patent Claim Types: see list of patent claims	Use; Delivery;

Scope and Claims of U.S. Patent 5,308,847

U.S. Patent 5,308,847, granted to Eli Lilly and Company on May 3, 1994, covers a chemical compound class and related methods of use. The patent claims focus on a specific subclass of substituted benzamides with potential therapeutic applications, primarily targeting central nervous system disorders.

Key Claims:

• Compound Claims: Patent claims include a chemical structure characterized by a benzamide core with specific substitutions at designated positions. The core structure is para- or meta-substituted benzamides, with variations allowing different substituents (e.g., alkyl, halogen, hydroxy groups).

• Method Claims: Claims encompass methods of treating conditions such as schizophrenia, depression, and other CNS disorders using the compounds described. These methods specify administering a therapeutically effective amount of the compound.

• Scope: The patent's claims are limited to compounds with particular substituents on the benzamide ring, ensuring specificity yet covering a broad class within that chemical space. The patent also includes claims on pharmaceutical compositions containing these compounds.

Chemical Scope:

• The compounds primarily concern derivatives of 3,4-dihydro-2H-1-benzopyran, linked via various substituents to the benzamide core.
• Substitutions include alkoxy, halogen, or hydroxy groups at various positions, which influence pharmacological activity.
• The patent claims include species with potential activity as antipsychotics or antidepressants due to their affinity for dopaminergic and serotonergic receptors.

Claims Limitations:

• The claims are confined to specific chemical structures with detailed substituents.
• The patent excludes compounds not falling within the defined chemical space, typically through explicit structural limitations.

---

Patent Landscape Overview

1. Patent Family and Jurisdiction

• The patent family includes applications filed in multiple jurisdictions, including Europe, Japan, and Canada, with equivalents granted or pending.
• The patent is enforceable primarily in the United States until its expiration.

2. Duration and Expiry

• Expired on May 3, 2011, after 17 years from grant, due to patent term calculation (patents filed before 1995 in the U.S. have a 20-year term from earliest filing date).
• The expiration opens the covered chemical space for generic development.

3. Similar Patents and Related Innovations

• Several patents have cited or referenced U.S. 5,308,847, indicating ongoing innovation in the same chemical class.
• Derivations, formulations, and methods of use continue to evolve, with recent patents focusing on improved pharmacokinetics, delivery systems, or new indications.

4. Competitive Landscape

• Major pharmaceutical firms with interests in CNS drugs, such as Janssen, Pfizer, and Teva, hold or have filed patent applications on related compounds.
• Patent filings demonstrate active R&D efforts around benzamide derivatives with CNS activity, including potential new chemical entities aiming to improve selectivity or reduce side effects.

5. Legal and Patent Challenges

• The patent faced potential challenges related to novelty and obviousness, especially considering prior art disclosing benzamide derivatives.
• No significant recent litigation involving this patent has been documented, likely due to its expiry.

6. Patentability of Similar Compounds

• New compounds structurally similar but with different substituents may be eligible for patenting if they demonstrate non-obviousness and enhanced activity.
• The expiration of U.S. 5,308,847 broadens opportunities for generics and biosimilars targeting the same chemical class.

---

Implications for R&D and Business

• The expiration decreases barriers to developing and marketing drugs within the same chemical space.
• Patent landscape monitoring is essential to identify emerging patents that could block or elevate the value of new compounds.
• Companies should evaluate the scope of remaining patents for novel derivatives or formulations to secure overlapping or new protections.

---

Key Takeaways

• U.S. Patent 5,308,847 covers benzamide derivatives with CNS activity, specifically compounds with defined substitutions on a benzamide core.
• The patent, granted in 1994, expired in 2011, opening the market for generic competition.
• The patent landscape includes related filings and citations, indicating ongoing innovation but no recent legal disputes.
• Competition focuses on enhancing pharmacological profiles and expanding indications.
• Opportunities exist for new derivatives, especially with different substitutions or formulations, to avoid patent barriers.

---

FAQs

1. What is the main chemical scope of U.S. Patent 5,308,847?
It primarily covers substituted benzamides with specific substitutions around a benzamide core, linked to CNS activity, targeting disorders such as schizophrenia and depression.

2. When did the patent expire, and what does that imply?
It expired on May 3, 2011, enabling generic manufacturers to produce similar compounds without infringement.

3. Are there existing patents related to this compound class?
Yes, many patents have cited or built on this patent, including those focusing on formulations, new derivatives, or additional therapeutic uses.

4. Can companies now freely develop drugs similar to those claimed in the patent?
Yes; the patent's expiration removes patent barriers for compounds within its scope. However, care must be taken regarding newer patents filed after 2011.

5. Are there ongoing legal challenges related to this patent?
No recent known litigations are documented, likely due to its expiration and the age of the patent.

---

Sources

[1] U.S. Patent 5,308,847. Available at USPTO.gov.
[2] Patent landscape reports on benzamide derivatives.
[3] Market analyses on CNS drugs and patent expirations.

Drugs Protected by US Patent 5,308,847

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

International Family Members for US Patent 5,308,847

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0401747		CA 2001 00025	Denmark
European Patent Office	0401747		SPC/GB01/036	United Kingdom
European Patent Office	0401747		25/2001	Austria
Austria	135215