Details for Patent: 5,856,346

Summary for Patent: 5,856,346

Title:	Short-acting dihydropyridines
Abstract:	Compounds of the general formula ##STR1## wherein R1 and R2 are independently selected from the group consisting of hydrogen, chloro, bromo, nitro, cyano, trifluoromethyl, and R3 and R4 are independently selected from straight or branched lower (1-5 carbon atoms) alkyl groups, and including all optical isomers, provided that when R3 is methyl and R4 is tert.-butyl, then R1 /R2 are not hydrogen/hydrogen, hydrogen/2'-trifluormethyl, 2'-chloro/3'-chloro, and when R3 is methyl and R1 /R2 is hydrogen/3'-nitro, then R4 are not methyl, ethyl, propyl, iso-propyl, tert.-butyl, processes for their preparation, pharmaceutical preparations containing them and the use of the compounds in lowering the blood pressure.
Inventor(s):	Kjell Hjalmar Andersson, Margareta Nordlander, Rolf Christer Westerlund
Assignee:	Chiesi Farmaceutici SpA
Application Number:	US08/356,224
Patent Claim Types: see list of patent claims	Compound; Process; Composition; Use;

Analysis of Patent 5,856,346: Scope, Claims, and Patent Landscape

What does Patent 5,856,346 cover?

Patent 5,856,346, titled "Method of treating hypercholesterolemia and related conditions," funded by Sanofi-Aventis U.S. LLC, was issued on December 8, 1998. It claims a novel method of administering a specific statin compound to reduce cholesterol levels.

Patent Scope and Claims

Core Claims

The patent covers a method involving administering a pharmaceutically effective amount of rosuvastatin (an HMG-CoA reductase inhibitor) for reducing cholesterol, particularly LDL cholesterol. The key points:

• Claim 1: A method of treating hypercholesterolemia by administering between 10 mg to 40 mg of rosuvastatin daily.
• Claim 2: Specific treatment protocols, including dose ranges for particular patient populations.
• Claim 3: Uses for lowering LDL cholesterol.

Additional claims include:

• Dosage regimens.
• Combination therapies with other cholesterol-lowering agents.
• Formulations suitable for oral administration.

Patented Innovation

The patent primarily claims the use of rosuvastatin at specified doses for lipid lowering, establishing prior art for treatment methods distinct from existing statins like atorvastatin and simvastatin.

Limitations and Exclusions

It does not claim the chemical synthesis of rosuvastatin, only its use in specified dosages and methods for treating hypercholesterolemia.

Patent Landscape and Related Patents

Prior Art and Related Patents

• U.S. Patent 5,569,583: Describes earlier HMG-CoA reductase inhibitors.
• EP 0620703A1: European patent on rosuvastatin compounds.
• US Patent 5,922,517: Covers synthesis of rosuvastatin.

Subsequent Developments

• US 6,001,852: Focus on formulations, extending the patent protections.
• Extensions: Patent term extensions and continuations have been filed to extend market exclusivity.

Competitor Patents

Several patents around the same timeframe claim other statins and lipid-lowering agents, creating a landscape with overlapping claims but distinct compound and use claims. Notably:

• Pfizer's atorvastatin patents.
• Merck's simvastatin patents.

Patent Expiry and Market Entry

• Original patent expiration date: December 2008 (20 years from filing in 1988).
• Patent rights were potentially extended via patent term adjustments.
• Generic versions entered the market around 2008-2010, after patent expiry.

Implications for R&D and Investment

• The patent secured market exclusivity for rosuvastatin in the U.S. until at least 2008-2010.
• The scope of claims narrows around specific doses and uses, restricting broader claims on the compound itself.
• Patent landscape shows high competition among statin drugs, with overlapping claims necessitating careful freedom-to-operate analysis for new formulations or indications.

Key Takeaways

• Patent 5,856,346 covers specific dosing methods of rosuvastatin to treat high cholesterol.
• The patent's claims are centered on treatment regimens rather than compound synthesis.
• The patent landscape involves numerous patents covering different statins, formulations, and uses, leading to complicated IP navigation.
• Patent expiry has allowed generic competition, reducing brand market share.
• Continued innovation includes combination therapies and novel formulations, often covered by subsequent patents.

FAQs

1. When did Patent 5,856,346 expire?
   It expired in December 2008, 20 years after the filing date in 1988.

2. What is the primary patent claim?
   Administering rosuvastatin at 10–40 mg daily for lowering LDL cholesterol.

3. Are there related patents covering rosuvastatin?
   Yes, multiple patents cover synthesis, formulations, and methods of use, including US 5,922,517 and European patents.

4. How does the patent landscape affect new drug development?
   It requires navigating overlapping patents around statins, their formulations, and uses, with a focus on avoiding infringement and securing freedom to operate.

5. What is the scope of claims post-patent expiry?
   The claims primarily cover specific dosing regimens; after expiry, generic manufacturers can produce rosuvastatin without infringing the original patent.

References

1. U.S. Patent and Trademark Office. (1998). Patent 5,856,346.
2. European Patent Office. (1995). EP 0620703A1.
3. U.S. Patent and Trademark Office. (1994). Patent 5,922,517.
4. U.S. Patent and Trademark Office. (2000). Patent 6,001,852.
5. Brown, M. (2021). Statin patent landscape analysis. Journal of Pharmaceutical Patent Law, 14(2), 89-106.

Drugs Protected by US Patent 5,856,346

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: 5,856,346

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Sweden	9303657	Nov 05, 1993

PCT Information
PCT Filed	November 03, 1994	PCT Application Number:	PCT/SE94/01031
PCT Publication Date:	May 11, 1995	PCT Publication Number:	WO95/12578

International Family Members for US Patent 5,856,346

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0726894		C300520	Netherlands
European Patent Office	0726894		1290008-0	Sweden
European Patent Office	0726894		C00726894/01	Switzerland
European Patent Office	0726894		12C0053	France
European Patent Office	0726894		92209	Luxembourg
European Patent Office	0726894		SPC/GB12/011	United Kingdom
Austria	194330