Last updated: August 3, 2026
AstraZeneca AB v. Torrent Pharma Inc., No. 3:15-cv-03375, was a Hatch-Waxman patent infringement action in the U.S. District Court for the District of New Jersey concerning Torrent’s proposed generic version of Farxiga, the dapagliflozin product marketed by AstraZeneca. AstraZeneca asserted patents covering dapagliflozin and related pharmaceutical use. The case was filed after Torrent submitted an Abbreviated New Drug Application with a Paragraph IV certification. The action was resolved without a reported merits judgment, and the public docket does not disclose the commercial terms of the parties’ resolution. [1]
What drug and ANDA were at issue in AstraZeneca v. Torrent?
The case involved Farxiga, whose active ingredient is dapagliflozin. Dapagliflozin is a sodium-glucose cotransporter 2 inhibitor used to treat type 2 diabetes and, under later regulatory approvals, heart failure and chronic kidney disease.
AstraZeneca’s complaint challenged Torrent’s proposed generic dapagliflozin product under 35 U.S.C. § 271(e)(2). The statutory infringement theory was based on Torrent’s submission of an ANDA containing a Paragraph IV certification that listed AstraZeneca patents were invalid, unenforceable, or would not be infringed by Torrent’s proposed product. [1]
| Item |
Case detail |
| Plaintiff |
AstraZeneca AB |
| Defendant |
Torrent Pharma Inc. |
| Court |
U.S. District Court for the District of New Jersey |
| Civil action |
No. 3:15-cv-03375 |
| Filing year |
2015 |
| Product |
Farxiga |
| Active ingredient |
Dapagliflozin |
| Regulatory pathway |
ANDA |
| Certification |
Paragraph IV |
| Legal basis |
Hatch-Waxman patent infringement |
| Case outcome |
Resolved without a reported merits determination |
What patents protected Farxiga in the Torrent litigation?
The principal patent issues centered on AstraZeneca’s dapagliflozin patent estate. The key early patents associated with Farxiga included U.S. Patent Nos. 6,414,126 and 6,515,117. Both patents concerned compounds in the dapagliflozin class and related pharmaceutical applications. [2]
The scope of asserted claims generally mattered more than the patent titles. In a Paragraph IV case, Torrent’s proposed product could create infringement exposure through the drug substance, formulation, manufacturing process, or labeled method of use. The litigation therefore required analysis of both the ANDA product and the use instructions proposed to FDA.
Core Farxiga patent estate
| Patent |
General subject matter |
Commercial relevance |
| U.S. Patent No. 6,414,126 |
Dapagliflozin-related compounds and pharmaceutical applications |
Core compound protection |
| U.S. Patent No. 6,515,117 |
Dapagliflozin-related compounds and uses |
Core compound and use protection |
| Later Farxiga patents |
Formulations, dosing, combinations, and therapeutic uses |
Potentially extended market protection beyond core compound patents |
The Orange Book listing for Farxiga has changed over time as AstraZeneca obtained additional patents and regulatory approvals. The applicable patent set therefore depends on the date of the ANDA certification and the specific Farxiga strength, indication, formulation, and labeling at issue. [3]
When did AstraZeneca file the case against Torrent?
AstraZeneca filed the action in 2015 after receiving notice of Torrent’s Paragraph IV certification. The case number, 3:15-cv-03375, identifies the matter as a District of New Jersey action filed during the 2015 docket year. [1]
The filing triggered the statutory 30-month stay under 21 U.S.C. § 355(j)(5)(B)(iii), subject to the statutory rules governing the timing of the infringement action and the regulatory status of the ANDA. The stay prevented FDA from granting final approval to the challenged ANDA during the applicable period unless the court issued an earlier decision or another statutory event ended the stay.
What was AstraZeneca’s infringement theory?
AstraZeneca’s case presented the standard legal theories used in a pharmaceutical Paragraph IV action:
- Torrent’s ANDA submission constituted an artificial act of infringement under 35 U.S.C. § 271(e)(2).
- The proposed dapagliflozin product would infringe asserted patent claims if commercially manufactured, used, or sold.
- The proposed labeling could induce infringement of method-of-use claims.
- Torrent’s Paragraph IV certification placed validity and infringement in dispute before FDA approval.
The central factual questions would have included the composition of Torrent’s proposed tablets, the manufacturing process disclosed in the ANDA, the proposed labeling, and the claim construction applicable to the asserted patents.
Did the case involve formulation patents or method-of-use patents?
The public case identification connects the action to AstraZeneca’s Farxiga patent program, which included compound, formulation, dosing, and method-of-use protection. The core dispute was not limited to a single patent category.
Formulation protection
Formulation patents can protect tablet composition, excipients, dosage uniformity, dissolution properties, or combinations of active and inactive ingredients. For an ANDA applicant, a formulation claim can create infringement risk even when the applicant contests the validity or expiration of the compound patent.
The practical strength of formulation patents depends on whether the claims cover commercially necessary features or optional design choices. A generic applicant may avoid some formulation claims by using a different excipient system or manufacturing process. That strategy is less effective where the claimed formulation is closely tied to the drug’s bioavailability or required dosage form.
Method-of-use protection
Method-of-use claims can cover the treatment of diabetes, heart failure, renal disease, or other indications. Their commercial value depends on the scope of the approved label and the availability of a carve-out under FDA regulations.
A generic applicant may seek approval for a label that omits a patented indication. If the remaining label still encourages use covered by an asserted claim, AstraZeneca can pursue induced-infringement arguments. The analysis is fact-specific and turns on the actual label, physician use, promotional conduct, and claim language.
What was the litigation outcome?
The case did not produce a reported trial judgment or appellate decision resolving the validity of the asserted Farxiga patents. The public docket indicates that the matter was resolved and closed without a published merits opinion. [1]
The settlement terms were not publicly disclosed in the docket materials commonly available for the case. The record therefore does not establish a public generic launch date, an authorized-generic arrangement, a royalty rate, or a specific license scope.
| Issue |
Publicly established result |
| Patent validity |
No reported merits ruling in this case |
| Infringement |
No reported merits ruling in this case |
| Claim construction |
No reported published decision identified |
| Settlement |
Case resolved without public commercial terms |
| Generic launch date |
Not established by the reported docket |
| Authorized generic |
No public term establishing one |
| Appeal |
No reported merits appeal |
The absence of a final judgment means the case cannot be used as precedent on the validity or scope of the asserted Farxiga patents. Its principal commercial effect was the resolution of Torrent’s specific ANDA challenge.
Did Torrent file a Paragraph IV challenge?
Yes. The action was a Paragraph IV Hatch-Waxman case. Torrent’s certification put AstraZeneca’s listed Farxiga patents directly at issue and created the statutory basis for litigation before generic approval. [1]
A Paragraph IV certification is not a finding that a patent is invalid. It is a regulatory and litigation position taken by the ANDA applicant. The applicant asserts that the listed patent is invalid, unenforceable, or not infringed. The brand company then decides whether to sue within the statutory period.
What was the Orange Book status of Farxiga?
Farxiga was listed in FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book. The listing included patents associated with dapagliflozin products and, over time, additional approved uses and product configurations. [3]
Orange Book analysis must distinguish among:
- patents listed against the original NDA;
- later-listed patents covering new indications or dosing regimens;
- pediatric exclusivity;
- patents applying to specific fixed-dose combinations;
- patents that may remain listed but have different practical relevance to a particular ANDA.
For Farxiga, the core compound patents were the principal early barrier to generic entry. Later patents could affect specific indications, combinations, or labeling even after expiration of the earliest compound protection.
When did Farxiga lose exclusivity?
Farxiga’s commercial exclusivity did not depend on a single date. The relevant barriers included FDA regulatory exclusivity, core compound patents, pediatric exclusivity, and later patents covering approved uses or formulations.
The early dapagliflozin patents associated with Farxiga had expiration dates around 2020, subject to any applicable patent-term adjustment or pediatric extension. The effective generic-entry date could therefore differ from the nominal patent expiration date. Later-listed patents could create additional entry restrictions for particular indications or combinations. [2,3]
| Protection type |
Effect on entry |
| New chemical entity exclusivity |
Delayed certain ANDA submissions after initial approval |
| Core compound patent |
Broadest early protection for dapagliflozin |
| Pediatric exclusivity |
Could add six months to eligible protections |
| Formulation patent |
Could block or complicate a particular tablet design |
| Method-of-use patent |
Could restrict labeled indications |
| Fixed-dose combination patent |
Applies to combination products rather than all dapagliflozin products |
How strong was AstraZeneca’s patent estate?
AstraZeneca’s estate was strong during the early Farxiga commercialization period because the core patents covered the active pharmaceutical ingredient and had a broad relationship to the marketed product. That structure increased the cost of a Paragraph IV challenge and reduced the value of a design-around limited to excipients or tablet manufacture.
Its later strength was more segmented. Formulation and method-of-use patents generally provide narrower protection than a compound patent. They can still delay a full-label generic launch, but an ANDA applicant may pursue a section viii statement or label carve-out for a patented indication.
The absence of a merits decision in the Torrent case leaves the judicial strength of the asserted claims unresolved. No invalidity holding, noninfringement finding, or claim-construction ruling from this docket materially weakened the estate.
Which companies challenged Farxiga patents?
Farxiga faced generic competition from multiple ANDA applicants over time. The competitive field included major generic manufacturers and regional producers that pursued dapagliflozin approval through Paragraph IV certifications or other patent strategies.
The relevant competitive question is not simply whether a company challenged a patent. It is whether the applicant obtained approval, secured a settlement license, avoided particular indications, or launched after the applicable patent and regulatory barriers ended.
| Competitive pathway |
Commercial consequence |
| Paragraph IV challenge |
Potential early entry after litigation or settlement |
| Paragraph III certification |
Entry after listed patent expiration |
| Section viii statement |
Approval for non-patented indications |
| Label carve-out |
Limited indication or use profile |
| Settlement license |
Entry date and conditions depend on confidential or disclosed terms |
| Post-expiration launch |
Broadest generic labeling opportunity |
What generic-entry risks did AstraZeneca face?
AstraZeneca faced three principal risks.
First, an adverse Paragraph IV judgment could have invalidated or narrowed the core patents before their scheduled expiration.
Second, a settlement could have licensed Torrent to enter before the full expiration of AstraZeneca’s commercial protection. The lack of public settlement terms prevents assigning a specific entry date to Torrent from the docket alone.
Third, later generic applicants could use different regulatory strategies. A competitor might initially launch a limited-label dapagliflozin product, then expand after method-of-use patents expired or became less commercially significant.
For revenue forecasting, the material exposure was Farxiga’s diabetes revenue and, as the product obtained additional indications, revenue from heart failure and chronic kidney disease. Generic erosion would likely depend on whether an entrant could market the full label, whether multiple manufacturers entered simultaneously, and whether AstraZeneca used an authorized generic or other defensive strategy.
Does biosimilar risk apply to Farxiga?
No. Farxiga is a small-molecule drug, not a biologic. The relevant competitive pathway is an ANDA generic, not a biosimilar application under the Public Health Service Act.
The principal regulatory risks are therefore Paragraph IV litigation, patent-term timing, label carve-outs, bioequivalence, manufacturing approval, and commercial launch strategy. Biosimilar interchangeability, reference-product exclusivity under the biologics statute, and patent dance procedures do not apply to dapagliflozin.
What does this case mean for licensing and business strategy?
The case illustrates the commercial value of resolving an ANDA challenge without a public merits ruling. AstraZeneca preserved control over the timing and conditions of Torrent’s potential entry, while Torrent avoided the cost and risk of a full patent trial.
For licensing analysis, the key limitation is the absence of disclosed settlement terms. The docket does not establish:
- an authorized generic arrangement;
- a royalty-bearing license;
- a permitted launch date;
- geographic restrictions;
- supply obligations;
- restrictions on challenging later patents; or
- a covenant covering future dapagliflozin products.
Any transaction or litigation model that assigns Torrent a specific launch date or market-share profile from this case alone would exceed the public record.
Key Takeaways
- AstraZeneca AB v. Torrent Pharma Inc., No. 3:15-cv-03375, was a District of New Jersey Hatch-Waxman case involving generic dapagliflozin, marketed as Farxiga.
- Torrent’s Paragraph IV certification triggered AstraZeneca’s patent infringement action.
- The dispute implicated AstraZeneca’s core dapagliflozin patent estate, including U.S. Patent Nos. 6,414,126 and 6,515,117.
- The case ended without a reported validity, infringement, or claim-construction ruling.
- Public docket materials do not disclose the settlement’s commercial terms or establish Torrent’s launch date.
- Farxiga’s generic risk depends on the interaction of compound patents, later formulation and method-of-use patents, FDA label strategy, and the number of approved entrants.
- Biosimilar law is not relevant because dapagliflozin is a small-molecule drug.
FAQs About AstraZeneca v. Torrent Pharma
Was AstraZeneca v. Torrent a patent infringement case?
Yes. It was a Hatch-Waxman action alleging infringement under 35 U.S.C. § 271(e)(2) based on Torrent’s Paragraph IV ANDA certification for generic dapagliflozin.
Did Torrent win the Farxiga patent litigation?
The public record does not show a merits victory for Torrent. The case was resolved without a reported judgment holding the asserted patents invalid or not infringed.
Did the case determine when Torrent could launch generic Farxiga?
No public merits opinion or docketed settlement term establishes a definitive Torrent launch date.
Are Farxiga patents listed in the Orange Book?
Yes. FDA listed patents associated with Farxiga and related dapagliflozin products. The relevant patents and expiration dates depend on the product, indication, and date of review.
Could a dapagliflozin generic avoid Farxiga method-of-use patents?
Potentially. An ANDA applicant may pursue a label carve-out or section viii statement for certain patented uses. That strategy does not automatically eliminate infringement risk and depends on the proposed label and the specific patent claims.
References
-
U.S. District Court for the District of New Jersey. (2015). AstraZeneca AB v. Torrent Pharma Inc., No. 3:15-cv-03375, docket materials.
-
U.S. Patent and Trademark Office. (2002). U.S. Patent No. 6,414,126, C-glucoside derivatives, process for their preparation and pharmaceutical compositions containing them.
-
U.S. Food and Drug Administration. (n.d.). Approved Drug Products with Therapeutic Equivalence Evaluations: Farxiga, NDA 202293. FDA Orange Book.
