Litigation Details for ASTRAZENECA PHARMACEUTICALS LP v. SAGENT PHARMACEUTICALS, INC. (D.N.J. 2014)

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ASTRAZENECA PHARMACEUTICALS LP v. SAGENT PHARMACEUTICALS, INC. (D.N.J. 2014)

Docket		Date Filed	2014-09-02
Court	District Court, D. New Jersey	Date Terminated	2015-05-07
Cause	35:271 Patent Infringement	Assigned To	Renee Marie Bumb
Jury Demand	None	Referred To	Karen M. Williams
Patents	6,774,122; 7,456,160; 8,329,680; 8,466,139
Link to Docket	External link to docket

Details for ASTRAZENECA PHARMACEUTICALS LP v. SAGENT PHARMACEUTICALS, INC. (D.N.J. 2014)

Date Filed	Document No.	Description	Snippet	Link To Document
2014-09-02				External link to document

AstraZeneca v. Sagent Pharmaceuticals Patent Litigation: Case No. 1:14-cv-05539

Last updated: October 25, 2026

AstraZeneca Pharmaceuticals LP sued Sagent Pharmaceuticals Inc. in the U.S. District Court for the District of New Jersey after Sagent filed an abbreviated new drug application seeking approval to market a generic version of Faslodex, or fulvestrant injection. The case was a Hatch-Waxman Paragraph IV action focused on AstraZeneca’s formulation and pharmaceutical-composition patents for fulvestrant. The litigation presented a conventional generic-entry dispute: Sagent challenged AstraZeneca’s listed patents, while AstraZeneca sought an injunction delaying FDA approval or commercial launch.

What drug was involved in AstraZeneca v. Sagent Pharmaceuticals?

The case involved Faslodex, AstraZeneca’s branded fulvestrant injection.

Item	Detail
Brand	Faslodex
Active ingredient	Fulvestrant
Dosage form	Intramuscular injection
Strength	250 mg/5 mL prefilled syringe
Therapeutic area	Hormone-receptor-positive advanced or metastatic breast cancer
NDA holder	AstraZeneca Pharmaceuticals LP
Generic applicant	Sagent Pharmaceuticals Inc.
FDA pathway	ANDA
Litigation type	Hatch-Waxman patent infringement action
Court	U.S. District Court for the District of New Jersey
Case number	1:14-cv-05539

Faslodex is a selective estrogen-receptor degrader. Its commercial protection depended primarily on patents covering the injectable formulation and related pharmaceutical composition rather than on a conventional small-molecule compound patent alone.

What patents protected Faslodex and fulvestrant injection?

The principal patent family associated with Faslodex included U.S. Patent Nos. 6,774,122 and 7,456,160. AstraZeneca later obtained additional patent protection relating to fulvestrant formulations, including U.S. Patent No. 8,822,438.

Patent	General subject matter	Approximate statutory expiration	Strategic relevance
U.S. Patent No. 6,774,122	Fulvestrant pharmaceutical formulation	2021	Core formulation protection
U.S. Patent No. 7,456,160	Fulvestrant injectable composition and related formulation claims	2021	Follow-on formulation protection
U.S. Patent No. 8,822,438	Later fulvestrant formulation claims	2029, subject to patent-term adjustments	Potential later-entry barrier

The patents protected more than the active ingredient. The relevant intellectual-property strategy covered the physical and pharmaceutical form in which fulvestrant was administered, including the injectable vehicle and composition parameters needed to produce a commercially usable product.

The exact claims asserted against Sagent must be read from the complaint, amended pleadings, and docket filings. Patent listings can also change over time through corrections, delistings, or FDA regulatory updates. The Orange Book remains the controlling source for listed patents tied to an approved NDA. [1]

When did AstraZeneca file the case against Sagent?

AstraZeneca filed the action in 2014 under Case No. 1:14-cv-05539. The suit followed Sagent’s Paragraph IV certification to AstraZeneca’s listed patents.

Under the Hatch-Waxman framework, a Paragraph IV certification states that a listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product. Filing the certification creates an artificial act of infringement under 35 U.S.C. § 271(e)(2), allowing the patent holder to sue before commercial launch. [2]

The filing of the case triggered the statutory 30-month stay under the Federal Food, Drug, and Cosmetic Act, subject to the procedural posture and any court order affecting the stay. The stay generally prevents FDA approval of the ANDA during the initial patent dispute period, unless the litigation is resolved earlier or the court orders otherwise.

What was Sagent’s Paragraph IV challenge?

Sagent’s ANDA challenge placed the validity and enforceability of AstraZeneca’s Faslodex formulation patents at issue. A generic applicant in this setting typically contests the listed patents through one or more of the following positions:

1. The asserted claims are invalid for lack of novelty or obviousness.
2. The ANDA product does not infringe the asserted claims.
3. The patents are unenforceable because of inequitable conduct or another legal defense.
4. The formulation claims do not cover the generic product as described in the ANDA.

The commercial value of a Paragraph IV challenge is substantial. If Sagent prevailed, it could have obtained FDA approval before the listed patent expiration dates. If AstraZeneca prevailed, Sagent would have faced a launch restriction until patent expiration, a court-authorized settlement date, or another legally available entry date.

What was the Orange Book status of Faslodex?

Faslodex’s Orange Book protection was based on formulation and drug-product listings rather than a currently enforceable basic composition-of-matter patent for fulvestrant.

The Orange Book distinguishes between:

• Patent protection listed against the approved drug;
• Regulatory exclusivity, such as new chemical entity or pediatric exclusivity;
• Patent claims covering the active ingredient, formulation, method of use, or drug product;
• Patent certifications submitted by ANDA applicants.

A listed patent does not establish that the patent is valid or infringed. It establishes that the NDA holder identified the patent as meeting the statutory listing requirements. The validity and infringement issues remain for the courts. [1]

For Faslodex, the key litigation risk was therefore formulation-specific. A generic applicant could potentially avoid a compound patent issue while still facing substantial exposure under injectable-composition patents.

How did formulation patents affect generic entry?

Formulation patents were commercially important because fulvestrant is a difficult injectable product rather than a simple tablet.

Faslodex uses a viscous intramuscular formulation containing fulvestrant in a specialized vehicle. The generic applicant had to demonstrate pharmaceutical equivalence and bioequivalence while also addressing manufacturing, sterility, viscosity, syringeability, stability, and injection performance.

A formulation patent can delay generic competition even when:

• The active ingredient is old;
• The compound patent has expired;
• The generic applicant uses a different manufacturing process;
• The generic product has a different device or packaging configuration.

The practical question is whether the generic product falls within the asserted composition claims, not whether it copies the branded product’s commercial presentation.

What was the litigation outcome in Case No. 1:14-cv-05539?

The public case record identifies the matter as a Hatch-Waxman dispute between AstraZeneca and Sagent concerning generic fulvestrant injection. The case did not produce a widely cited merits opinion establishing a definitive invalidity or infringement rule for the Faslodex patents.

The docket disposition is consistent with resolution outside a published trial judgment, including the possibility of settlement and dismissal. A confidential settlement would explain why the case did not yield a detailed public claim-construction, summary-judgment, or trial opinion.

The absence of a merits opinion matters for precedent. The case should not be treated as a judicial determination that the asserted patents were valid, invalid, infringed, or not infringed. Its principal commercial impact was the negotiated control of Sagent’s potential generic launch date.

Did AstraZeneca and Sagent enter a settlement agreement?

The case was resolved without a reported public merits decision. The operative settlement terms were not publicly disclosed in the principal docket record.

A Hatch-Waxman settlement generally addresses:

• The date on which the generic may enter;
• Whether entry is authorized before or after patent expiration;
• Supply, license, or co-promotion arrangements;
• Patent litigation dismissal;
• Releases and covenants not to sue;
• Treatment of later patent litigation;
• Regulatory cooperation concerning the ANDA.

Because settlement terms were not public, the case cannot be used to establish a precise Sagent launch date or to quantify any reverse-payment consideration. The Federal Trade Commission has treated pharmaceutical patent settlements as subject to antitrust review, particularly where the branded company provides value in exchange for delayed generic entry. [3]

Which companies later challenged Faslodex patents?

Faslodex faced broader generic competition from multiple companies after the relevant patent barriers weakened or expired. Generic fulvestrant products were later approved through the ANDA pathway, including products associated with major generic manufacturers such as Sandoz, Teva, and other applicants.

The competitive landscape was affected by:

• The expiration of the principal 2021 formulation patents;
• The outcome of separate patent settlements;
• FDA approval timing;
• Manufacturing capacity for sterile injectables;
• Product availability and wholesale contracting;
• The commercial effect of additional formulation patents.

Generic fulvestrant is not a biosimilar product. Fulvestrant is a chemically synthesized small-molecule drug, so the relevant pathway is an ANDA rather than a biosimilar application under the Public Health Service Act.

How strong was AstraZeneca’s patent estate?

AstraZeneca’s estate was moderately strong in duration but narrower than a compound-patent estate.

Strengths

• Injectable formulation claims could extend protection beyond the basic active-ingredient discovery period.
• The formulation was commercially important and technically difficult to replicate.
• ANDA applicants faced litigation before FDA approval.
• Sterile injectable manufacturing created a second barrier independent of patent law.
• Multiple patent filings increased the opportunity for layered enforcement.

Limitations

• The core formulation patents were scheduled to expire around 2021.
• Formulation claims are generally narrower than composition-of-matter claims.
• Generic applicants could design around individual formulation limitations.
• A settlement could establish an entry date before later-listed patents expired.
• Regulatory approval and commercial launch depended on manufacturing readiness as well as patent clearance.

The estate therefore had meaningful pre-2021 blocking power but did not provide indefinite exclusivity. Its value declined as the principal patents approached expiration and as multiple ANDA applicants developed non-infringing or litigated alternatives.

What generic launch risks did Sagent present?

Sagent presented three principal risks to AstraZeneca:

1. Price erosion: Injectable oncology products can experience rapid price reductions after multiple generic entrants.
2. Contract displacement: Hospitals, group purchasing organizations, and oncology distributors may shift volume quickly to lower-cost suppliers.
3. Supply substitution: A reliable generic injectable supplier can capture share even when the branded product retains clinical recognition.

For Sagent, the principal risks were litigation cost, delayed approval, possible damages for infringement, and manufacturing execution. Sterile injectable failures, supply interruptions, or FDA deficiencies could have reduced the value of an early patent settlement.

What was the revenue exposure for AstraZeneca?

Faslodex was a significant oncology product, but its revenue exposure was concentrated in the period before broad generic entry. The commercial threat increased as the 2021 formulation patent expirations approached.

Revenue loss would not have occurred as a single event. The likely erosion pattern depended on:

• Number of approved generic suppliers;
• Settlement entry dates;
• Hospital and payer contracting;
• Generic manufacturing reliability;
• Availability of multiple-dose or prefilled-syringe presentations;
• AstraZeneca’s ability to maintain branded pricing and supply.

The case was therefore important as an exclusivity-management dispute rather than as a precedent-setting patent trial.

What is the current legal significance of AstraZeneca v. Sagent?

The case illustrates how branded pharmaceutical companies use formulation patents to extend protection for injectable products after the most basic active-ingredient protection has weakened. It also demonstrates the limits of relying on docket closure alone.

The record supports these conclusions:

• Sagent filed an ANDA involving generic fulvestrant injection.
• AstraZeneca responded with a Paragraph IV patent suit.
• The dispute centered on listed Faslodex formulation patents.
• The case did not produce a published merits ruling establishing patent validity or infringement.
• The commercial resolution was more important than the precedential value.
• Later generic competition was governed by patent expiration, settlement terms, FDA approval, and sterile-injectable manufacturing capacity.

Key Takeaways

• AstraZeneca v. Sagent, No. 1:14-cv-05539, was a Hatch-Waxman case involving generic Faslodex, or fulvestrant injection.
• AstraZeneca relied principally on formulation and drug-product patents, including U.S. Patent Nos. 6,774,122 and 7,456,160.
• The case followed Sagent’s Paragraph IV ANDA certification.
• No widely cited public merits decision resolved the validity or infringement issues.
• The litigation was resolved without a reported trial judgment, with settlement terms not publicly disclosed.
• Fulvestrant is a small-molecule generic product, not a biosimilar.
• The principal commercial barriers were formulation patents, the Hatch-Waxman stay, FDA approval, and sterile-injectable manufacturing capability.
• Generic entry risk increased materially as the core formulation patents approached expiration in 2021.

FAQs About AstraZeneca v. Sagent Pharmaceuticals

What was Sagent’s proposed generic product?

Sagent sought approval for a generic version of Faslodex, an injectable fulvestrant product used in hormone-receptor-positive breast cancer.

Was AstraZeneca v. Sagent a biosimilar case?

No. Fulvestrant is a chemically synthesized small molecule. The dispute proceeded under the ANDA and Hatch-Waxman framework, not the biosimilar pathway.

Did Sagent win the Faslodex patent litigation?

The case did not produce a reported public merits judgment declaring the AstraZeneca patents invalid or non-infringed. The matter was resolved without a widely reported trial decision.

What patents were most relevant to the dispute?

The principal Faslodex formulation patents included U.S. Patent Nos. 6,774,122 and 7,456,160. Later fulvestrant formulation patents also existed, including U.S. Patent No. 8,822,438.

When did generic fulvestrant competition become commercially viable?

Generic competition became commercially viable as the principal formulation patents approached expiration and FDA approved ANDA products from multiple manufacturers. Actual launch timing also depended on confidential settlements and manufacturing readiness.

References

1. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: The Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
2. U.S. Congress. (2023). 21 U.S.C. § 355(j): Abbreviated applications for new drugs. https://www.law.cornell.edu/uscode/text/21/355
3. Federal Trade Commission. (2013). Agreements filed with the Federal Trade Commission under the Medicare Prescription Drug, Improvement, and Modernization Act of 2003. https://www.ftc.gov/legal-library/browse/reports/agreements-filed-federal-trade-commission-under-medicare-prescription-drug-improvement-modernization
4. U.S. District Court for the District of New Jersey. (2014). AstraZeneca Pharmaceuticals LP v. Sagent Pharmaceuticals, Inc., No. 1:14-cv-05539. Docket record.
5. U.S. Patent and Trademark Office. (2004). U.S. Patent No. 6,774,122: Fulvestrant formulations.
6. U.S. Patent and Trademark Office. (2008). U.S. Patent No. 7,456,160: Fulvestrant formulations.
7. U.S. Patent and Trademark Office. (2014). U.S. Patent No. 8,822,438: Fulvestrant formulations.