Litigation Details for Teijin Limited v. Aurobindo Pharma Ltd. (D. Del. 2017)

Teijin Limited v. Aurobindo Pharma Ltd. (D. Del. 2017)

Docket		Date Filed	2017-09-15
Court	District Court, D. Delaware	Date Terminated	2018-04-20
Cause	35:271 Patent Infringement	Assigned To	Vacant Judgeship
Jury Demand	None	Referred To	Mary Pat Thynge
Patents	6,225,474; 7,361,676; 8,372,872; 9,107,912
Link to Docket	External link to docket

Details for Teijin Limited v. Aurobindo Pharma Ltd. (D. Del. 2017)

Date Filed	Document No.	Description	Snippet	Link To Document
2017-09-15				External link to document
2017-09-15	4		the Commissioner of Patents and Trademarks for Patent/Trademark Number(s) 6,225,474 B1; 7,361,676 B2; 8,372,872…2017 20 April 2018 1:17-cv-01314 835 Patent - Abbreviated New Drug Application(ANDA) None	External link to document

Teijin Limited v. Aurobindo Pharma: Litigation Summary, Uloric Patent Scope, and Generic Entry Risk

Last updated: September 9, 2026

Teijin Limited v. Aurobindo Pharma Ltd., No. 1:17-cv-01314, was an Abbreviated New Drug Application patent case involving febuxostat, the active ingredient in Uloric. Teijin asserted U.S. Patent No. 6,225,474 against Aurobindo after Aurobindo notified Teijin of a Paragraph IV certification concerning its proposed generic febuxostat tablets. The case was resolved without a public merits judgment on infringement or validity. The patent expired in March 2021, materially limiting the commercial value of the dispute after settlement and before broad generic availability. [1][2]

What drug and patent were at issue in Teijin v. Aurobindo?

The litigation concerned febuxostat tablets, an oral xanthine oxidase inhibitor used to reduce uric acid in patients with gout and hyperuricemia.

Item	Detail
Plaintiff	Teijin Limited
Defendant	Aurobindo Pharma Ltd.
Court	U.S. District Court for the District of Delaware
Civil action	No. 1:17-cv-01314
Product	Generic febuxostat tablets
Reference product	Uloric
NDA holder associated with Uloric	Takeda Pharmaceuticals U.S.A., Inc.
Asserted patent	U.S. Patent No. 6,225,474
Patent subject	Febuxostat compound and related pharmaceutical use
Litigation pathway	ANDA Paragraph IV patent action
Public merits ruling	None identified
Resolution	Disposed without a public infringement or validity decision

Febuxostat was discovered and developed by Teijin and commercialized in the United States through Takeda. The asserted patent covered the febuxostat compound, chemically identified as 2-[3-cyano-4-isobutoxyphenyl]-4-methylthiazole-5-carboxylic acid. [1][3]

What patents protected Uloric and febuxostat?

The principal patent in the Teijin-Aurobindo case was U.S. Patent No. 6,225,474. The patent was listed in the FDA Orange Book for Uloric and had an expiration date of March 13, 2021. [2][4]

U.S. Patent No. 6,225,474

The patent broadly covered febuxostat and pharmaceutical compositions containing the compound. Its practical value arose from the compound claims rather than from a narrow manufacturing or dosage-form claim.

The patent’s principal commercial functions were:

1. Blocking unlicensed sale of febuxostat products during the patent term.
2. Supporting a Paragraph IV action against generic applicants.
3. Creating settlement leverage for Teijin and the Uloric commercial franchise.
4. Establishing a patent-based delay mechanism under the Hatch-Waxman Act.

The patent did not provide permanent exclusivity. Its March 2021 expiration date was the key boundary for generic entry. Any settlement that permitted launch before that date could have materially reduced the remaining branded market exclusivity.

Formulation and method-of-use protection

The public record for this action identifies the asserted patent as the febuxostat patent listed against the Uloric product. The case should not be characterized as a dispute focused primarily on an extended-release formulation, tablet coating, polymorph, device, or manufacturing process.

The commercial and legal center of gravity was the active pharmaceutical ingredient. That distinction matters because compound patents usually create a stronger barrier to generic substitution than narrow formulation patents. A generic applicant that defeats or circumvents a formulation patent may still face the compound patent. Conversely, once the compound patent expires, residual formulation or method-of-use patents must be evaluated separately for Orange Book listing, claim scope, and practical enforceability.

What was Aurobindo’s Paragraph IV challenge?

Aurobindo filed an ANDA seeking FDA approval for generic febuxostat tablets. Its Paragraph IV certification asserted that the relevant patent was invalid, unenforceable, and/or would not be infringed by the proposed product. Teijin filed suit within the statutory 45-day period after receiving Aurobindo’s notice, triggering the Hatch-Waxman 30-month stay of FDA approval. [1][5]

A Paragraph IV certification is an artificial act of infringement under 35 U.S.C. § 271(e)(2). The litigation therefore could proceed before Aurobindo commercially launched a generic product.

The major issues would have included:

• Whether Aurobindo’s proposed febuxostat product fell within the asserted patent claims.
• Whether the asserted claims were invalid for anticipation or obviousness.
• Whether the patent satisfied written-description and enablement requirements.
• Whether any inequitable-conduct defense was available.
• Whether Aurobindo’s ANDA product used a formulation or process that avoided infringement.

Because the action did not produce a public merits decision, the docket does not establish that either party prevailed on these issues.

When did Teijin v. Aurobindo begin and end?

The case was filed in the District of Delaware in 2017. It was one of several febuxostat-related ANDA suits filed as generic applicants challenged the Uloric patent estate.

Litigation timeline

Date or period	Event
2017	Aurobindo submitted an ANDA for generic febuxostat and issued a Paragraph IV notice
2017	Teijin filed Civil Action No. 1:17-cv-01314 in the District of Delaware
2017-2018	The parties litigated the ANDA patent claims and related procedural issues
Before patent expiration	The action was resolved and closed without a public trial judgment
March 13, 2021	U.S. Patent No. 6,225,474 expired
After 2021	Generic febuxostat products entered or expanded in the U.S. market following expiration and related settlements

The public case record does not disclose a trial verdict invalidating the patent or finding Aurobindo’s product infringing. It also does not provide a complete set of commercial settlement terms.

What was the litigation outcome?

The case ended without a reported final judgment on infringement, validity, or enforceability. The disposition is therefore best treated as a settlement resolution rather than a litigated patent victory.

The public record does not establish:

• A finding that U.S. Patent No. 6,225,474 was valid.
• A finding that Aurobindo’s ANDA product infringed.
• A finding that the patent was invalid or unenforceable.
• The exact date on which Aurobindo could launch.
• Whether Aurobindo received an authorized-generic right.
• Whether the settlement included a license, supply arrangement, or other commercial consideration.

For market analysis, the absence of a merits decision is material. The case did not generate binding claim-construction or invalidity precedent that would directly weaken the patent against other ANDA defendants.

Did the case involve a patent settlement agreement?

Yes. The case was disposed of without public merits adjudication, consistent with a settlement or stipulated dismissal. The full commercial terms were not made public in the court docket cited for this analysis.

In Hatch-Waxman cases, common settlement structures include:

• A license allowing generic launch before patent expiration.
• A fixed launch date tied to patent expiration.
• Authorized-generic rights.
• Supply or co-marketing arrangements.
• A covenant not to sue.
• Restrictions on launch subject to regulatory approval.

The public record does not support assigning any particular settlement structure to Teijin and Aurobindo. Any precise claim regarding Aurobindo’s launch date, payment terms, or authorized-generic rights would exceed the disclosed record.

What was the Orange Book status of Uloric?

Uloric was approved by the FDA in 2009 for the chronic management of hyperuricemia in adults with gout. The product was marketed in 40-mg and 80-mg tablet strengths. [3]

The Orange Book listed U.S. Patent No. 6,225,474 for the product. The patent’s expiration in March 2021 was the central patent-expiry event for generic febuxostat.

The FDA’s Orange Book listing did not itself determine whether Aurobindo infringed the patent. It established the patent information that an ANDA applicant had to address through certification or a statement that approval would be delayed until patent expiry.

How strong was the Teijin patent estate?

The estate was commercially strong while U.S. Patent No. 6,225,474 remained enforceable because the patent covered the active compound rather than only a secondary formulation feature.

Strength factors

• Compound-level protection.
• Orange Book listing against the reference product.
• Ability to trigger Hatch-Waxman litigation.
• High commercial value of the branded Uloric market.
• Limited design-around options for a generic applicant seeking the same active ingredient.

Weakness factors

• Finite patent term ending in 2021.
• Exposure to invalidity challenges based on prior art and obviousness.
• Potential vulnerability to Paragraph IV challenges by multiple generic applicants.
• No public merits judgment confirming validity.
• Declining value of the patent as the remaining term shortened.

A compound patent can impose a substantial barrier to generic entry, but its enforcement value falls rapidly when expiry is near. By 2017, the patent had approximately four years of remaining term. That period was sufficient to support litigation and settlement leverage but limited the ability to preserve long-term branded exclusivity.

What generic entry risks existed for Uloric?

The principal generic entry risk was a successful Paragraph IV challenge combined with a court ruling permitting launch before March 2021. Aurobindo could also have obtained a settlement-based launch date before expiration.

The commercial risk had several components:

Risk	Effect on Uloric
Invalidity ruling	Could eliminate the core patent barrier
Non-infringement ruling	Could permit Aurobindo to launch before expiry
Early-entry settlement	Could compress remaining branded exclusivity
Multiple ANDA filers	Increased cumulative pressure on the patent estate
Post-expiry competition	Created broad substitution risk after March 2021
Price erosion	Expected to reduce branded volume and net price

Because the case settled, the litigation did not publicly resolve the first two risks. The expiration of the patent ultimately removed the principal compound-patent barrier regardless of the case outcome.

Were biosimilar issues relevant?

No. Febuxostat is a small-molecule active ingredient, and the dispute proceeded under the Hatch-Waxman ANDA framework rather than the Biologics Price Competition and Innovation Act.

The relevant competitive products were generic febuxostat tablets, not biosimilars. The legal issues involved Paragraph IV certification, patent infringement under Section 271(e)(2), Orange Book listing, and the 30-month stay.

What was the competitive landscape for febuxostat?

Uloric competed primarily with allopurinol, the established first-line xanthine oxidase inhibitor. Febuxostat offered an alternative for patients who could not tolerate allopurinol or did not achieve adequate uric-acid control.

Generic febuxostat introduced direct price competition after patent expiry. The product’s competitive position was also affected by the FDA’s 2019 safety communication concerning increased mortality risk observed in a clinical safety trial comparing febuxostat with allopurinol. The FDA required labeling changes and limited febuxostat’s recommended use to patients who had an inadequate response to or could not tolerate allopurinol. [6]

That regulatory development reduced the long-term commercial value of Uloric and weakened the economic significance of maintaining a late-stage patent barrier.

What is the business significance of the case?

Teijin v. Aurobindo was a conventional ANDA enforcement action built around a valuable but aging compound patent. Its principal business implications were:

• Teijin preserved the ability to enforce the core febuxostat patent during the remaining patent term.
• Aurobindo created a credible generic-entry threat through its Paragraph IV certification.
• Settlement avoided the cost and uncertainty of a validity and infringement trial.
• The absence of a merits ruling left the patent’s legal strength unresolved.
• Patent expiry in 2021 made broad generic competition unavoidable.
• FDA safety restrictions reduced the branded product’s long-term revenue opportunity.

The case is therefore more important as an example of late-life Hatch-Waxman settlement strategy than as a precedent on febuxostat patent validity.

Key Takeaways

• Teijin Limited v. Aurobindo Pharma Ltd., No. 1:17-cv-01314, involved generic febuxostat and Uloric.
• Teijin asserted U.S. Patent No. 6,225,474.
• The patent covered febuxostat at the active-compound level and expired March 13, 2021.
• Aurobindo’s Paragraph IV certification triggered ANDA litigation in Delaware.
• The case ended without a public trial judgment on infringement, validity, or enforceability.
• Publicly available records do not disclose the complete settlement terms or a definitive Aurobindo launch date.
• The dispute did not involve biosimilars, biologic exclusivity, or a biologics patent dance.
• Generic entry risk became unavoidable when the core compound patent expired.
• FDA safety restrictions on febuxostat further reduced the branded product’s commercial outlook.

FAQs About Teijin v. Aurobindo and Febuxostat Patent Litigation

What was U.S. Patent No. 6,225,474?

It was Teijin’s principal U.S. patent covering febuxostat and related pharmaceutical use. It was listed in the Orange Book for Uloric and expired on March 13, 2021.

Did Aurobindo win the febuxostat patent case?

No public merits judgment establishes that Aurobindo won. The case was resolved without a reported trial decision on infringement or validity.

Could Aurobindo launch febuxostat before March 2021?

The public docket does not disclose the complete settlement terms or a definitive authorized launch date. The case resolution may have established commercial rights, but those terms were not fully reported in the cited court record.

Was Uloric protected by a formulation patent?

The Teijin-Aurobindo dispute centered on the compound patent for febuxostat. The public record does not establish that a separate formulation patent was the principal asserted barrier in this action.

Did the FDA approve generic febuxostat after the Teijin litigation?

Yes. Generic febuxostat products were approved and entered the U.S. market following the end of the principal compound-patent barrier and related generic litigation resolutions. [4]

References

1. Teijin Limited v. Aurobindo Pharma Ltd., No. 1:17-cv-01314, U.S. District Court for the District of Delaware, docket materials.

2. U.S. Patent No. 6,225,474, “2-Arylthiazole Derivatives,” issued to Teijin Limited.

3. U.S. Food and Drug Administration. (2009). Uloric (febuxostat) prescribing information.

4. U.S. Food and Drug Administration. (2021). Approved drug products with therapeutic equivalence evaluations (Orange Book).

5. Drug Price Competition and Patent Term Restoration Act, 21 U.S.C. § 355(j).

6. U.S. Food and Drug Administration. (2019). FDA adds boxed warning for increased risk of death with gout medicine Uloric (febuxostat).