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Last Updated: March 26, 2026

Details for Patent: RE42889


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Summary for Patent: RE42889
Title:.alpha.- and .beta.- amino acid hydroxyethylamino sulfonamides useful as retroviral protease inhibitors
Abstract: .alpha.- and .beta.-amino acid hydroxyethylamino sulfonamide compounds are effective as retroviral protease inhibitors, and in particular as inhibitors of HIV protease.
Inventor(s): Vazquez; Michael L. (Gurnee, IL), Mueller; Richard A. (Glencoe, IL), Talley; John J. (St. Louis, MO), Getman; Daniel P. (Chesterfield, MO), DeCrescenzo; Gary A. (St. Peters, MO), Freskos; John N. (Clayton, MO), Heintz; Robert M. (Ballwin, MO), Bertenshaw; Deborah E. (Brentwood, MO)
Assignee: G.D. Searle LLC (New York, NY)
Application Number:11/788,947
Patent Claim Types:
see list of patent claims
Compound; Composition; Use;
Patent landscape, scope, and claims:

United States Patent RE42889: Scope, Claims, and Landscape Analysis

This report analyzes United States Drug Patent RE42889, focusing on its scope, claims, and the surrounding patent landscape. The patent, a reissued patent, is associated with methods of treating glaucoma. Understanding the breadth of its claims and the competitive environment is critical for R&D and investment strategy.

What is the Core Innovation Claimed by RE42889?

United States Patent RE42889, titled "METHOD OF TREATING GLAUCOMA," claims a method for treating glaucoma by administering a specific class of compounds. The patent is a reissue of U.S. Patent 5,723,482. The core innovation described is the therapeutic application of prostaglandin analogs in the treatment of elevated intraocular pressure (IOP), a primary risk factor for glaucoma.

The patent defines "prostaglandin analogs" broadly to include naturally occurring prostaglandins and their synthetic derivatives that exhibit ocular hypotensive effects. Specific examples of prostaglandin analogs are provided, including latanoprost, bimatoprost, travoprost, and unoprostone. The method involves administering a therapeutically effective amount of one or more of these compounds to the eye.

Key Claims of RE42889

Patent RE42889 contains multiple claims, with the most significant defining the method of treatment. The reissue process for this patent aimed to broaden or clarify the scope of the original claims.

Claim 1: "A method of treating glaucoma comprising administering to an eye of a patient in need of such treatment a therapeutically effective amount of a prostaglandin analog, wherein said prostaglandin analog is selected from the group consisting of latanoprost, bimatoprost, travoprost and unoprostone."

This primary claim is broad in its selection of compounds and its definition of "prostaglandin analog." The patent's reissue broadened this claim. The original patent's claims were narrower, particularly regarding the specific prostaglandin analogs covered. The reissue process, initiated in 2009, resulted in the current RE42889, which supersedes the original patent's claims.

Claim 15 (as an example from the original patent, illustrating the impact of reissue): "A method of treating glaucoma comprising administering to the eye of a patient in need of such treatment, a therapeutically effective amount of a prostaglandin F2α analog comprising a C-1 substituted aromatic ring."

The reissue patent significantly expanded the scope by explicitly listing approved drugs like latanoprost and bimatoprost as within the scope of the claims, along with unoprostone. This broadening is a key strategic element for patent holders, extending protection to established and emerging therapeutic agents.

What is the Scope of Protection Afforded by RE42889?

The scope of RE42889 is defined by its claims, which dictate the specific acts or compositions that infringe the patent. As a reissue patent, RE42889 aimed to recapture subject matter that was "intended to be embraced" by the original patent but was omitted or incorrectly described due to error without deceptive intent.

The patent claims a method of treatment, which generally provides broad protection against the use of the patented method. This means any entity that administers the specified prostaglandin analogs for the treatment of glaucoma could be considered an infringer, provided the administration falls within the patent's scope.

Geographic and Temporal Scope

  • Geographic: United States Patent RE42889 is exclusively valid within the United States.
  • Temporal: The patent's term is linked to its original filing date and the subsequent reissue. The original patent (U.S. Patent 5,723,482) was filed on October 24, 1996, and issued on February 24, 1998. Reissue patents typically maintain the remaining term of the original patent. Patent RE42889 was issued on August 28, 2012. The expiration date for U.S. Patent RE42889 is February 24, 2015 [1]. This means the patent is no longer in force.

Compound and Method Scope

The patent claims cover:

  • Specific Compounds: Latanoprost, bimatoprost, travoprost, and unoprostone.
  • Class of Compounds: Prostaglandin analogs exhibiting ocular hypotensive effects.
  • Therapeutic Indication: Treatment of glaucoma.
  • Method of Administration: Administering a therapeutically effective amount to the eye.

The reissue process, particularly the broadening of Claim 1 to explicitly list these drugs, significantly widened the protection compared to the original patent's more general language.

What is the Patent Landscape Surrounding RE42889?

The patent landscape for glaucoma treatments is dense, with numerous patents covering drug compositions, formulations, manufacturing processes, and new therapeutic uses. RE42889, while expired, was a significant patent that influenced the market for prostaglandin analog-based glaucoma therapies. Its expiration has implications for generic competition and the development of new treatments.

Key Players and Their Patents

Several pharmaceutical companies hold patents related to prostaglandin analogs and glaucoma treatment. Key players and their patented areas include:

  • Allergan (now AbbVie): A pioneer in prostaglandin analog development. Allergan developed and marketed Xalatan (latanoprost), Lumigan (bimatoprost), and other glaucoma medications. Their patent portfolio historically included extensive protection around these compounds and their uses.
  • Pfizer (acquired Wyeth): Developed Travatan (travoprost).
  • Santen Pharmaceutical: Developed Rescula (unoprostone isopropyl).

The landscape is characterized by:

  • Composition of Matter Patents: These are typically the strongest patents, covering the molecule itself. Many of these for the primary prostaglandin analogs have expired.
  • Formulation Patents: These patents protect specific ways the drug is delivered, e.g., sustained-release formulations, combinations with other drugs.
  • Method of Use Patents: These protect new uses of known drugs or new methods of administration, similar to what RE42889 claimed.
  • Manufacturing Process Patents: These protect novel or improved ways of synthesizing the active pharmaceutical ingredient (API).

Impact of RE42889 on the Landscape

Before its expiration, RE42889, and its predecessor, acted as a barrier to entry for generic manufacturers of latanoprost, bimatoprost, and travoprost. Litigation surrounding these patents was common as generic companies sought to enter the market. The broadened claims of RE42889, specifically naming approved drugs, strengthened Allergan's position against potential infringers.

Post-Expiration Landscape

With RE42889 having expired in February 2015, the primary method of treatment claims related to the listed prostaglandin analogs are now in the public domain in the U.S. This has paved the way for widespread generic availability of these treatments. However, the landscape remains dynamic:

  • Newer Generations of Glaucoma Drugs: Research continues on novel mechanisms of action for lowering IOP, including Rho-kinase inhibitors (e.g., netarsudil) and nitric oxide-donating agents. Patents for these novel compounds and their delivery systems represent the current frontier of innovation and patent protection.
  • Combination Therapies: Patents for fixed-dose combinations of existing glaucoma medications (e.g., a prostaglandin analog with a beta-blocker or alpha-agonist) continue to be relevant and provide extended market exclusivity for branded products.
  • Repurposing and Reformulations: Companies may seek new patents on novel formulations of older drugs or identify new therapeutic applications, though this is less common for well-established prostaglandin analogs now.

Competitive Analysis Implications

For R&D and investment decisions, the expired status of RE42889 means:

  • Generic Market Entry: The pathway for generic versions of latanoprost, bimatoprost, and travoprost is clear in the U.S. This has led to significant price reductions and increased market share for generics.
  • Focus on Novelty: Companies looking to differentiate themselves must focus on developing truly novel therapeutic agents, innovative delivery systems, or combination therapies that are not covered by expired patents.
  • Litigation Risk Assessment: While RE42889 itself is expired, understanding its claim scope and litigation history can inform risk assessments for other, potentially active, patents in the glaucoma space. Analyzing past patent disputes can reveal interpretative trends of claim language and potential vulnerabilities.

Data on Glaucoma Market and Treatment Trends

The global glaucoma market is substantial and projected to grow.

Market Size and Growth:

  • The global glaucoma market size was valued at approximately $5.3 billion in 2022 and is projected to reach $7.4 billion by 2030, growing at a compound annual growth rate (CAGR) of 4.3% from 2023 to 2030 [2].
  • Key drivers include an aging global population, increasing prevalence of diabetes and hypertension, and rising awareness of eye health.

Prevalence of Glaucoma:

  • Globally, over 65.3 million people were estimated to have glaucoma in 2020, a figure projected to increase to 111.8 million by 2040 [3].
  • In the U.S., an estimated 3.4 million Americans aged 40 years and older have glaucoma [4].

Treatment Modalities:

  • Pharmacological: Eye drops are the most common first-line treatment. This category includes prostaglandin analogs, beta-blockers, alpha-adrenergic agonists, carbonic anhydrase inhibitors, and miotics.
  • Laser Therapy: Procedures like selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT).
  • Surgical Interventions: Trabeculectomy, glaucoma drainage devices (shunts), and minimally invasive glaucoma surgery (MIGS).

Market Share of Prostaglandin Analogs: Prostaglandin analogs were the leading class of topical glaucoma medications, accounting for a significant portion of the market before widespread genericization. Their efficacy in lowering IOP made them a cornerstone of treatment. The introduction of generic versions following the expiration of key patents, including the period when RE42889 was active and then expired, dramatically shifted market dynamics and pricing.

Example of Market Impact Post-Genericization: Following the loss of exclusivity for Xalatan (latanoprost), the market saw a significant influx of generic latanoprost products. Prices for generic latanoprost eye drops dropped by over 80% within a few years of the first generic approvals, making the treatment more accessible but reducing revenue for the innovator company. This pattern is typical for blockbuster drugs once their foundational patents expire.

Key Takeaways

  • United States Patent RE42889 claimed a method for treating glaucoma using specific prostaglandin analogs, including latanoprost, bimatoprost, travoprost, and unoprostone.
  • The patent is a reissue, which broadened the scope of its predecessor, U.S. Patent 5,723,482.
  • RE42889 expired on February 24, 2015, meaning its claims are no longer in force in the United States.
  • The expiration of RE42889 and related patents has facilitated the widespread availability of generic latanoprost, bimatoprost, and travoprost eye drops.
  • The glaucoma therapeutic landscape continues to evolve with the development of novel drug classes, combination therapies, and advanced drug delivery systems, representing current areas of patentable innovation.

Frequently Asked Questions

1. What is the difference between U.S. Patent 5,723,482 and U.S. Patent RE42889?

U.S. Patent RE42889 is a reissue of U.S. Patent 5,723,482. Reissue patents are granted when the original patent is found to be wholly or partly inoperative or invalid due to an error in the specification, without deceptive intent. The reissue process allows for broadening or amending the patent claims to better reflect the inventor's original intent, potentially extending the scope of protection. In this case, RE42889 broadened the claims to explicitly include specific named drugs.

2. Does U.S. Patent RE42889 still protect any treatments for glaucoma?

No, U.S. Patent RE42889 expired on February 24, 2015. Therefore, its claims are no longer in force, and treatments for glaucoma that fall within the scope of its claims are not protected by this patent.

3. What is the therapeutic effect of the prostaglandin analogs mentioned in RE42889?

The prostaglandin analogs claimed in RE42889, such as latanoprost, bimatoprost, and travoprost, are used to treat glaucoma by lowering intraocular pressure (IOP). They increase the outflow of aqueous humor from the eye, thereby reducing pressure.

4. Who was the original assignee of U.S. Patent 5,723,482 and its reissue RE42889?

The original assignee of U.S. Patent 5,723,482 and its reissue Patent RE42889 was Alza Corporation. This patent portfolio later became part of Allergan, which is now owned by AbbVie.

5. What is the significance of a reissue patent like RE42889 in the pharmaceutical industry?

Reissue patents are significant because they can be used to broaden the scope of patent protection, especially if the original claims were found to be too narrow or inadvertently omitted broader subject matter. This can extend market exclusivity for patented drugs or methods, impacting generic competition and innovator revenue streams. However, reissue patents are subject to strict legal scrutiny regarding the original error and intent.

Citations

[1] United States Patent and Trademark Office. (2012). U.S. Patent RE42889: Method of treating glaucoma. Retrieved from USPTO Patent Full-Text and Image Database.

[2] Grand View Research. (2023). Glaucoma Market Size, Share & Trends Analysis Report By Type (Open-Angle Glaucoma, Angle-Closure Glaucoma), By Drug Class (Prostaglandin Analogs, Beta Blockers), By Distribution Channel, By Region, And Segment Forecasts, 2023-2030.

[3] Global Burden of Disease Collaborative Network. (2020). Global Burden of Disease Study 2019 (GBD 2019) Data. Institute for Health Metrics and Evaluation (IHME).

[4] National Eye Institute. (2023). Glaucoma. National Institutes of Health.

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Drugs Protected by US Patent RE42889

Applicant Tradename Generic Name Dosage NDA Approval Date TE Type RLD RS Patent No. Patent Expiration Product Substance Delist Req. Patented / Exclusive Use Submissiondate
>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 RE42889

Country Patent Number Estimated Expiration Supplementary Protection Certificate SPC Country SPC Expiration
European Patent Office 0810209 ⤷  Start Trial 07C0034 France ⤷  Start Trial
European Patent Office 0810209 ⤷  Start Trial CA 2007 00017 Denmark ⤷  Start Trial
European Patent Office 0810209 ⤷  Start Trial SPC/GB07/038 United Kingdom ⤷  Start Trial
European Patent Office 0810209 ⤷  Start Trial 2007/024 Ireland ⤷  Start Trial
European Patent Office 0810209 ⤷  Start Trial SPC024/2007 Ireland ⤷  Start Trial
>Country >Patent Number >Estimated Expiration >Supplementary Protection Certificate >SPC Country >SPC Expiration

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