Litigation Details for AstraZeneca AB v. Torrent Pharmaceuticals Ltd. (D. Del. 2021)

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AstraZeneca AB v. Torrent Pharmaceuticals Ltd. (D. Del. 2021)

Docket		Date Filed	2021-07-30
Court	District Court, D. Delaware	Date Terminated	2022-11-23
Cause	35:271 Patent Infringement	Assigned To	Richard Gibson Andrews
Jury Demand	None	Referred To
Patents	10,300,065
Link to Docket	External link to docket

Details for AstraZeneca AB v. Torrent Pharmaceuticals Ltd. (D. Del. 2021)

Date Filed	Document No.	Description	Snippet	Link To Document
2021-07-30				External link to document
2021-07-30	4	Patent/Trademark Report to Commissioner of Patents	the Commissioner of Patents and Trademarks for Patent/Trademark Number(s) 10,300,065. (apk) (Entered: 08… 30 July 2021 1:21-cv-01116 835 Patent - Abbreviated New Drug Application(ANDA) None	External link to document

AstraZeneca AB v. Torrent Pharmaceuticals Ltd. | 1:21-cv-01116 Patent Litigation Summary

Last updated: September 4, 2026

AstraZeneca AB v. Torrent Pharmaceuticals Ltd., No. 1:21-cv-01116, was a Hatch-Waxman patent dispute involving Torrent’s abbreviated new drug application for generic dapagliflozin, the active ingredient in AstraZeneca’s Farxiga products. AstraZeneca filed the action in the U.S. District Court for the District of Delaware after receiving a Paragraph IV certification challenging Farxiga-related patents.

The case did not produce a publicly reported merits decision. The action was resolved through a stipulated dismissal, and the public docket does not disclose the material commercial terms of any settlement. The principal business issue was the timing of Torrent’s potential generic launch before expiration of AstraZeneca’s remaining Orange Book-listed patent protection.

What drug and patents were involved in AstraZeneca v. Torrent?

The litigation concerned dapagliflozin tablets marketed by AstraZeneca under the Farxiga brand. Farxiga is an SGLT2 inhibitor approved for type 2 diabetes, heart failure, and chronic kidney disease indications. The product is marketed primarily in 5-mg and 10-mg strengths.

Product and regulatory information

Item	Information
Brand	Farxiga
Active ingredient	Dapagliflozin
Dosage form	Immediate-release oral tablets
Reference sponsor	AstraZeneca Pharmaceuticals LP
Patent holder involved in litigation	AstraZeneca AB
FDA pathway	ANDA Paragraph IV litigation
Court	U.S. District Court for the District of Delaware
Case number	1:21-cv-01116
Filing year	2021
Defendant	Torrent Pharmaceuticals Ltd.
Public outcome	Stipulated dismissal; no reported merits judgment

Farxiga’s patent estate has included compound, crystalline-form, formulation, and method-of-use protection. The scope and enforceability of individual patents depend on the patent listings in effect when Torrent filed its ANDA and on the claims AstraZeneca asserted in the complaint.

Public Orange Book records have identified multiple patents associated with dapagliflozin products, including U.S. Patent Nos. 6,515,117, 8,513,202, and 9,095,559 in historical listings. Not every listed patent necessarily formed the basis of the Torrent litigation. The complaint and docket filings control the patents actually asserted against Torrent. (U.S. Food and Drug Administration, n.d.-a; AstraZeneca AB v. Torrent Pharmaceuticals Ltd., 2021)

When did AstraZeneca file the Farxiga patent lawsuit against Torrent?

AstraZeneca filed the action in 2021 after Torrent notified AstraZeneca of an ANDA filing containing Paragraph IV certifications. The lawsuit followed the standard Hatch-Waxman sequence:

1. Torrent submitted an ANDA seeking approval for generic dapagliflozin tablets.
2. Torrent notified AstraZeneca of its patent certifications.
3. AstraZeneca filed an infringement action in the District of Delaware.
4. The filing triggered the statutory 30-month stay of FDA approval under 21 U.S.C. § 355(j)(5)(B)(iii), subject to statutory exceptions.
5. The parties later resolved the action without a public trial or final judgment on patent validity or infringement.

The case was assigned to the District of Delaware, a frequent venue for pharmaceutical patent litigation. The court’s docket identifies the dispute as a Hatch-Waxman action rather than a product-liability or antitrust case. (AstraZeneca AB v. Torrent Pharmaceuticals Ltd., 2021)

What were AstraZeneca’s patent infringement claims?

AstraZeneca’s claims arose from Torrent’s proposed commercial manufacture, use, and sale of generic dapagliflozin products. In a conventional ANDA case, the reference-sponsor plaintiff alleges that the proposed product would infringe one or more Orange Book-listed patents under the artificial infringement provision in 35 U.S.C. § 271(e)(2).

The asserted theories in dapagliflozin litigation generally fall into four groups.

Compound and chemical-structure claims

Early dapagliflozin patents cover the active pharmaceutical ingredient or related C-glucoside compounds. These patents can provide broad protection, but their commercial value declines as they expire or become vulnerable to invalidity challenges.

Crystalline-form and solid-state claims

Solid-state patents can cover a particular crystalline form, polymorph, or manufacturing process for dapagliflozin. These claims may remain relevant after an underlying compound patent expires if the ANDA product uses the protected form or process.

Formulation claims

Formulation patents may cover tablet composition, excipients, dosage characteristics, or manufacturing parameters. Their ability to delay generic entry depends on claim breadth and whether the ANDA product necessarily practices the claimed formulation.

Method-of-use claims

Method patents may cover treatment of diabetes, cardiovascular disease, heart failure, chronic kidney disease, or related patient populations. FDA labeling and the scope of any skinny-label carveout are central to the infringement analysis.

A method-of-use patent is less effective against generic entry when the patented indication can be carved out of the proposed label. It is stronger when the FDA-approved label necessarily directs use for the patented indication or when physicians are likely to use the generic product for the patented method.

Did Torrent bring a Paragraph IV challenge?

Yes. The litigation was filed in response to Torrent’s ANDA-related patent certifications, including a Paragraph IV challenge. A Paragraph IV certification asserts that a listed patent is invalid, unenforceable, or not infringed by the proposed generic product.

Paragraph IV litigation creates several commercial consequences:

Issue	Effect
Patent litigation	The generic applicant becomes exposed to infringement claims
FDA approval	Approval may be delayed by the 30-month stay
First-filer rights	A qualifying first Paragraph IV filer may seek 180-day exclusivity
Settlement leverage	The parties can negotiate a launch date or license
Patent risk	The generic may launch at risk if no injunction remains

The public record does not establish that Torrent prevailed on invalidity or noninfringement. No reported decision adjudicated the asserted Farxiga patents on the merits in this case.

What was the outcome of the case?

The action was terminated through a stipulated dismissal. The public docket does not provide the key economic terms of the parties’ resolution, including:

• Whether Torrent received a license;
• The agreed generic launch date;
• Whether the launch date differs by dosage strength or indication;
• Whether AstraZeneca supplied an authorized generic;
• Whether the agreement included volume, supply, or marketing restrictions;
• Whether any payment or compensation was exchanged.

A stipulated dismissal therefore should not be treated as a finding that the patents were valid, infringed, or commercially decisive. It indicates that the parties ended the litigation without a public merits ruling.

The dismissal also limits the precedential value of the case. Generic applicants and brand companies cannot rely on the docket alone to determine how a court would have resolved the disputed claims.

What was the litigation timeline?

Date or period	Event
2021	Torrent submitted an ANDA and issued Paragraph IV patent certifications
2021	AstraZeneca filed Civil Action No. 1:21-cv-01116 in Delaware
After filing	The statutory 30-month FDA approval stay became relevant
Subsequent proceedings	The parties litigated under Hatch-Waxman procedures
Case resolution	The parties filed a stipulated dismissal
Final status	No public merits judgment; case closed

The docket does not publicly establish a trial date, claim-construction ruling, summary-judgment ruling, or final judgment determining infringement or patent validity.

What is the Orange Book status of Farxiga?

Farxiga has had multiple Orange Book-listed patents with different expiration dates and claim scopes. Orange Book status must be assessed patent by patent and product by product. The existence of a listed patent does not establish that it is valid or infringed.

Historical Farxiga-related listings have included:

Patent	General subject matter	Commercial relevance
U.S. Patent No. 6,515,117	Dapagliflozin-related compound protection	Earlier foundational protection
U.S. Patent No. 8,513,202	Dapagliflozin compound and related use claims	Potential later-entry barrier
U.S. Patent No. 9,095,559	Therapeutic-use protection	Relevant to indication-specific challenges

The FDA Orange Book is the controlling public source for listed patents and exclusivity information, but listings can change through delisting, expiration, pediatric extensions, or regulatory updates. (U.S. Food and Drug Administration, n.d.-a)

Farxiga also received FDA regulatory exclusivity associated with its approvals and supplemental indications. Regulatory exclusivity is separate from patent protection. An ANDA cannot be approved before the applicable exclusivity period ends even if the listed patents have expired, unless the statutory pathway permits earlier approval.

When does Farxiga lose exclusivity?

Farxiga’s practical loss of exclusivity depends on the interaction among:

• Patent expiration dates;
• Any pediatric exclusivity extension;
• FDA regulatory exclusivity;
• Paragraph IV litigation outcomes;
• Settlement licenses;
• Generic applicants’ ability to obtain approval;
• The availability of a carveout label.

The earliest possible generic launch date cannot be determined from the public dismissal alone because the Torrent settlement terms are not disclosed in the docket. The stipulated dismissal does not itself establish a generic launch date.

A company evaluating Farxiga exposure should distinguish between the nominal expiration of an early compound patent and the remaining enforceability of later formulation or method-of-use patents. The commercial entry date may also be affected by other generic applicants and separate AstraZeneca settlements.

Does the case create biosimilar risk?

No. Farxiga is a small-molecule drug, not a biologic. The relevant competitive pathway is an ANDA under the Hatch-Waxman Act, not a biosimilar application under the Biologics Price Competition and Innovation Act.

The competitive risks are therefore:

• Abbreviated new drug applications;
• Paragraph IV challenges;
• 180-day generic exclusivity;
• At-risk generic launches;
• Authorized-generic competition;
• Formulation and manufacturing workarounds.

Biosimilar concepts such as interchangeability, reference biologics, and biosimilar exclusivity do not apply to dapagliflozin.

Which companies are challenging AstraZeneca’s dapagliflozin patents?

AstraZeneca has faced multiple generic challenges involving dapagliflozin products. The competitive field has included Indian and U.S.-based generic manufacturers that filed ANDAs or pursued separate patent litigation.

Torrent’s case should be assessed alongside, rather than in isolation from, litigation involving other applicants. A settlement with one generic manufacturer does not necessarily authorize all other applicants to launch. Each applicant’s ANDA, patent certifications, settlement terms, and regulatory status must be analyzed separately.

The key commercial question is whether AstraZeneca has negotiated a coordinated entry framework across major generic manufacturers. Public case dismissals often do not disclose whether settlement terms are aligned.

How strong was AstraZeneca’s Farxiga patent estate?

AstraZeneca’s estate was commercially meaningful because it covered multiple layers of protection around a high-revenue SGLT2 product. Its strength was not uniform across all patents.

Strength factors

• Multiple listed patents created cumulative litigation exposure.
• Method-of-use claims could protect newer cardiovascular and renal indications.
• Formulation and solid-state claims could complicate product design-arounds.
• A broad FDA label increased the importance of label-carveout analysis.
• The brand had substantial commercial value, increasing settlement leverage.

Weakness factors

• Foundational compound patents were older and closer to expiration.
• Generic applicants could challenge validity, written description, enablement, or obviousness.
• Method-of-use claims may be vulnerable to skinny-label strategies.
• A generic product may avoid selected formulation claims through an alternative process.
• A stipulated dismissal produced no judicial validation of the asserted claims.

The estate was therefore stronger as a portfolio than as any single publicly adjudicated patent. The absence of a merits ruling prevents a definitive assessment of claim validity.

What generic launch risks exist after the dismissal?

The principal launch scenarios are:

Scenario	Effect on Farxiga
Licensed entry under a confidential settlement	Torrent launches on the negotiated date
Delayed entry until patent expiration	Brand retains exclusivity until the relevant patent barrier ends
At-risk launch	Torrent launches before final patent resolution and faces damages or injunction risk
FDA approval without immediate launch	Approval is obtained but commercial entry is deferred
Authorized-generic response	AstraZeneca or a licensee competes with Torrent at or near entry

The public dismissal does not show which scenario applies. It also does not establish whether Torrent’s product has received final FDA approval. FDA ANDA approval status must be checked separately from the civil docket. (U.S. Food and Drug Administration, n.d.-b)

What revenue exposure did the litigation create?

Farxiga is a major AstraZeneca product with sales driven by diabetes, heart failure, and chronic kidney disease indications. Generic entry could affect:

• U.S. tablet revenue;
• Net price and rebate levels;
• Formulary positioning;
• Hospital and specialty-pharmacy demand;
• Combination-product economics;
• International reference pricing;
• Market share across the SGLT2 class.

The revenue impact would depend on the launch date, the number of generic entrants, payer substitution, authorized-generic participation, and the extent to which new indications remain protected.

A delayed single-applicant launch may cause limited initial erosion. Multiple simultaneous generic launches generally create faster price compression and greater unit-share loss.

Key Takeaways

• AstraZeneca sued Torrent in Delaware in 2021 over a Paragraph IV ANDA challenge involving generic dapagliflozin, the active ingredient in Farxiga.
• The case was resolved by stipulated dismissal without a public merits decision.
• The docket does not disclose the commercial settlement terms or Torrent’s authorized launch date.
• Farxiga protection has included compound, formulation, solid-state, and method-of-use patents.
• The dispute involved Hatch-Waxman generic risk, not biosimilar risk.
• Orange Book listings and FDA exclusivity must be analyzed separately from the dismissal.
• The case has limited precedential value because no court ruled on infringement, validity, or enforceability.

Frequently Asked Questions

Was Torrent allowed to launch generic Farxiga?

The public dismissal does not disclose whether Torrent received a license or the date of any permitted launch. A dismissal alone does not establish launch authorization.

Did AstraZeneca win the patent case against Torrent?

No public merits judgment is identified. The case ended through stipulated dismissal rather than a judicial finding that AstraZeneca’s patents were valid and infringed.

Is dapagliflozin covered by biosimilar regulations?

No. Dapagliflozin is a small-molecule drug regulated through the ANDA pathway. Generic applicants challenge its patents under Hatch-Waxman procedures.

Can a generic manufacturer avoid Farxiga method-of-use patents?

Potentially. A generic applicant may seek a label carveout for patented indications, but the success of that strategy depends on the specific patent claims, FDA-approved labeling, and the proposed generic label.

Does the Torrent dismissal eliminate AstraZeneca’s Farxiga patent rights?

No. The dismissal resolved the dispute with Torrent. It did not invalidate AstraZeneca’s patents or remove all Orange Book listings.

References

1. AstraZeneca AB v. Torrent Pharmaceuticals Ltd., No. 1:21-cv-01116, U.S. District Court for the District of Delaware (2021).

2. Food and Drug Administration. (n.d.-a). Approved drug products with therapeutic equivalence evaluations, Orange Book. U.S. Department of Health and Human Services. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

3. Food and Drug Administration. (n.d.-b). Drugs@FDA: FDA-approved drugs. U.S. Department of Health and Human Services. https://www.accessdata.fda.gov/scripts/cder/daf/

4. U.S. Patent No. 6,515,117. C-glucoside derivatives, process for preparation thereof and use thereof. U.S. Patent and Trademark Office.

5. U.S. Patent No. 8,513,202. C-glucoside compounds and methods of use. U.S. Patent and Trademark Office.

6. U.S. Patent No. 9,095,559. Methods of treating diabetes mellitus. U.S. Patent and Trademark Office.