FELDENE Drug Patent Profile

When do Feldene patents expire, and when can generic versions of Feldene launch?

Feldene is a drug marketed by Pfizer and is included in one NDA.

The generic ingredient in FELDENE is piroxicam. There are sixteen drug master file entries for this compound. Nine suppliers are listed for this compound. Additional details are available on the piroxicam profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Feldene

A generic version of FELDENE was approved as piroxicam by TEVA on December 11^th, 1992.

Summary for FELDENE

US Patents:	0
Applicants:	1
NDAs:	1

US Patents and Regulatory Information for FELDENE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Pfizer	FELDENE	piroxicam	CAPSULE;ORAL	018147-002	Apr 6, 1982	AB	RX	Yes	No
Pfizer	FELDENE	piroxicam	CAPSULE;ORAL	018147-003	Apr 6, 1982	AB	RX	Yes	Yes

International Patents for FELDENE

See the table below for patents covering FELDENE around the world.

Country	Patent Number	Title	Estimated Expiration
United Kingdom	1414887
Brazil	6911817
Finland	52087
Netherlands	146146
Israel	32836	BENZOTHIAZINE 1,1-DIOXIDES AND THEIR PREPARATION
Switzerland	634312	VERFAHREN ZUR HERSTELLUNG VON 3,4-DIHYDRO-2-METHYL-4-OXO-2H-1,2-BENZOTHIAZIN-3-CARBONSAEURE-1,1-DIOXID.

FELDENE Market Analysis and Financial Projection

Last updated: February 3, 2026

What is the current patent and regulatory status of FELDENE?

FELDENE (phenylbutazone) is a non-steroidal anti-inflammatory drug (NSAID) primarily used in veterinary medicine, especially for musculoskeletal conditions in horses, and historically in human medicine. Its patent protection has long expired, with generic forms available internationally. Regulatory approval for its veterinary use persists in several markets, but human use has been restricted or discontinued in many regions due to safety concerns.

In the United States, the FDA has withdrawn human approval for phenylbutazone because of risks such as aplastic anemia. Conversely, the drug remains approved and marketed as a veterinary medication in countries like the European Union and Australia. Variations in regulatory status limit the scope of current commercial opportunities.

What are the key market dynamics affecting FELDENE?

The human pharmaceutical market for phenylbutazone is essentially non-existent in major economies due to safety issues. Veterinary applications, however, sustain demand. The global veterinary NSAID market was valued at approximately $1.4 billion in 2022, with phenylbutazone accounting for a niche segment within equine therapeutics.

Market growth is driven by increasing adoption of pharmaceuticals in equine sports and leisure activities, especially in North America and Europe. Veterinary NSAIDs account for a substantial portion of veterinary drug sales, with an expected CAGR of around 6% over the next five years.

The competitive landscape includes other NSAIDs like phenylpiracetam, flunixin meglumine, and newer, safer compounds with better safety profiles. The potential to reformulate or reposition FELDENE for limited or specialized uses is constrained by existing safety and regulatory hurdles.

What are the patent and intellectual property considerations?

FELDENE's patent protection has long expired globally. The original formulations date back to the 1950s, and no new patents are available for the molecule itself. Companies seeking to commercialize or reposition the drug would need to focus on specific formulations, delivery methods, or new uses, which may qualify for new patent protection.

However, given the safety issues and limited market scope, pursuing patent protection for new formulations may face challenges unless backed by substantial clinical validation or innovative delivery mechanisms. The absence of patent protection limits exclusive market rights, elevating competition and reducing margins.

What are the fundamental financial and commercial risks?

• Safety and regulatory limitations: Human use is heavily restricted due to serious adverse effects. Veterinary use remains, but safety concerns limit potential for expansion.
• Market saturation and competition: The veterinary NSAID segment is mature with established players. Entry for new or repositioned FELDENE products faces high barriers.
• Manufacturing and distribution costs: Small niche markets may not justify high investment in novel formulations or marketing.
• Pricing pressures: Generic competition drives prices down, constraining margins.
• Legal liabilities: Potential liability related to safety risks may increase costs and deter new formulations or marketing.

What are the opportunities for investment or repositioning?

Limited expansion exists outside the veterinary segment. Reformulating FELDENE with improved safety profiles could restore some human clinical use; however, substantial development costs and regulatory fees are required. The potential for developing new veterinary formulations or delivery devices exists but is constrained by the small size of the market and existing competition.

Investors should consider evaluating niche markets where FELDENE could be repositioned as an adjunct therapy under strict regulation or in combination with other NSAIDs, provided safety can be assured. Alternative pathways include licensing existing formulations or generating data to support new indications, which remains resource-intensive.

What is the outlook and key considerations for future valuation?

The outlook for FELDENE remains limited by safety issues and its status as a generic, off-patent drug. Its value hinges on niche veterinary use and potential reformulation for high-end markets. Any new development requires substantial investment, with a high risk of regulatory rejection.

Investors should view FELDENE as a low-margin, high-risk asset. Strategic advantages may be realized through licensing agreements in emerging markets lacking strict regulatory restrictions; otherwise, the core market's stagnation suggests minimal upside.

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Key Takeaways

• FELDENE's patent status is expired with no current proprietary rights.
• Human use is restricted due to safety concerns; veterinary use persists.
• Market size remains small, primarily within veterinary medicine, with slow growth.
• Competitive pressures and safety issues limit repositioning prospects.
• Investment opportunities lie mainly in niche veterinary applications or reformulation efforts, both requiring significant development costs and facing regulatory challenges.

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FAQs

1. Can FELDENE be repositioned for human use?
Reconversion for human use is unlikely due to safety issues and regulatory barriers that led to withdrawal in many markets.

2. Are there any ongoing clinical trials for FELDENE?
No significant clinical trials are currently active for new indications, primarily due to safety concerns and market limitations.

3. How does FELDENE compare to other NSAIDs?
It has similar anti-inflammatory efficacy but higher safety risks, which led to its diminished use in humans and only niche applications in veterinary medicine.

4. Are there regulatory pathways to extend FELDENE's market?
Limited pathways exist. Reformulation or new indications may qualify for regulatory approval, but major hurdles remain.

5. What is the outlook for veterinary NSAIDs like FELDENE?
The veterinary NSAID market is growing modestly, driven by animal health trends, but FELDENE's niche status limits its share.

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References

[1] Market data on veterinary NSAIDs, Research and Markets, 2022.
[2] FDA drug safety communication, 2000.
[3] European Medicines Agency approval details, 2021.