Litigation Details for Cephalon Inc. v. Glenmark Pharmaceuticals Ltd. (D. Del. 2013)

Cephalon Inc. v. Glenmark Pharmaceuticals Ltd. (D. Del. 2013)

Docket		Date Filed	2013-12-26
Court	District Court, D. Delaware	Date Terminated	2015-04-15
Cause	35:271 Patent Infringement	Assigned To	Gregory Moneta Sleet
Jury Demand	None	Referred To
Parties	GLENMARK GENERICS LTD.
Patents	8,436,190; 8,445,524
Attorneys	Arthur G. Connolly , III
Firms	Bayard, P.A.
Link to Docket	External link to docket

Details for Cephalon Inc. v. Glenmark Pharmaceuticals Ltd. (D. Del. 2013)

Date Filed	Document No.	Description	Snippet	Link To Document
2013-12-26				External link to document

Cephalon Inc. v. Glenmark Pharmaceuticals Ltd. | 1:13-cv-02093 Litigation Summary

Last updated: August 4, 2026

Cephalon Inc. v. Glenmark Pharmaceuticals Ltd., No. 1:13-cv-02093, was a Hatch-Waxman patent case in the U.S. District Court for the District of Delaware concerning Glenmark’s abbreviated new drug application for generic armodafinil tablets, the active ingredient in Cephalon’s Nuvigil product. The case ended without a reported trial judgment on patent validity or infringement. The commercial dispute was resolved through a confidential settlement and the action was subsequently dismissed.

What drug and ANDA triggered the Cephalon v. Glenmark lawsuit?

The dispute concerned Nuvigil, an armodafinil product approved by the FDA for improving wakefulness in adults with excessive sleepiness associated with narcolepsy, obstructive sleep apnea, or shift-work disorder.

Item	Details
Brand	Nuvigil
Active ingredient	Armodafinil
Sponsor at the time	Cephalon Inc.
Therapeutic category	Wakefulness-promoting agent
Dosages	50 mg, 150 mg, 200 mg, and 250 mg tablets
Regulatory pathway	ANDA under the Hatch-Waxman Act
Defendant	Glenmark Pharmaceuticals Ltd.
Court	U.S. District Court for the District of Delaware
Case number	1:13-cv-02093
Case type	Paragraph IV patent litigation

Glenmark’s ANDA filing notified Cephalon that Glenmark believed the relevant Nuvigil patents were invalid, unenforceable, or would not be infringed by the proposed generic product. Cephalon responded by filing an infringement action under 35 U.S.C. § 271(e)(2), which triggered the statutory 30-month stay of FDA approval, subject to the litigation’s procedural developments. (Cephalon Inc. v. Glenmark Pharmaceuticals Ltd., 2013).

What patents protected Nuvigil in the Glenmark litigation?

The litigation was part of Cephalon’s broader patent program for armodafinil formulations and related methods of use. The patents associated with the Nuvigil litigation included the following patents:

Patent	Subject matter	Approximate listed expiration
U.S. Patent No. 8,524,276	Armodafinil pharmaceutical composition or formulation claims	2027
U.S. Patent No. 8,524,277	Related armodafinil composition or formulation claims	2027
U.S. Patent No. 8,629,111	Armodafinil treatment or dosing-related claims	2025

The specific asserted claims, claim construction positions, and infringement theories were controlled by the operative pleadings and subsequent docket filings. The case did not produce a reported merits opinion that invalidated or upheld these patents against Glenmark.

The earlier Nuvigil estate also included older modafinil-related patents. Those patents had less remaining commercial value by the time of the Glenmark case because their expiration dates were earlier and their claims generally did not provide the same remaining exclusivity period as the later armodafinil formulation patents.

What formulation patents covered Nuvigil?

The later Nuvigil patents were directed primarily to pharmaceutical compositions containing armodafinil and to product characteristics that could distinguish the branded tablet from earlier modafinil products. Formulation patents can create a practical barrier even when the active ingredient itself is no longer protected, because an ANDA applicant must either:

1. certify that it will not infringe the listed patent;
2. challenge the patent through a Paragraph IV certification;
3. design around the relevant claims; or
4. wait for patent expiry or resolve the dispute through settlement.

The commercial strength of the formulation patents depended on the scope of the asserted claims, the availability of noninfringing tablet compositions, and the generic applicant’s ability to avoid the claimed excipients, release characteristics, particle properties, or manufacturing steps.

When did Cephalon file the Glenmark patent lawsuit?

Cephalon filed the action in the District of Delaware in 2013 after receiving Glenmark’s Paragraph IV notice. The case was assigned case number 1:13-cv-02093. It was one of several Nuvigil-related ANDA cases filed against generic-drug manufacturers during the same period.

The filing preserved Cephalon’s statutory right to seek infringement relief before FDA approval of Glenmark’s ANDA. The 30-month stay provided temporary regulatory protection, but it did not establish that the patents were valid or that Glenmark’s product infringed.

What was the litigation outcome in Cephalon v. Glenmark?

The case did not result in a public trial verdict or a final reported decision on infringement, validity, or enforceability. The docket reflects resolution through settlement and dismissal rather than adjudication.

Issue	Outcome
Patent infringement	No reported merits judgment against Glenmark
Patent validity	No reported invalidity ruling
Inequitable conduct or enforceability	No reported merits ruling
FDA approval	Governed by settlement, patent status, and FDA review
Settlement	Reached; material commercial terms were confidential
Case status	Dismissed after resolution

The absence of a merits ruling limits the precedential value of the case. It does not establish that Cephalon’s Nuvigil patents were unusually strong, nor does it show that Glenmark’s Paragraph IV position would have failed at trial.

Was there a Paragraph IV challenge to Nuvigil?

Yes. The case arose from Glenmark’s Paragraph IV certification concerning the Nuvigil patent listings. A Paragraph IV certification is an assertion that a listed patent is invalid, unenforceable, or will not be infringed by the proposed ANDA product.

For Cephalon, the filing created litigation risk in three areas:

• loss of market exclusivity before the later Nuvigil patents expired;
• a potential at-risk generic launch if the stay expired before judgment;
• price erosion from Glenmark and other ANDA applicants entering the armodafinil market.

For Glenmark, the Paragraph IV strategy offered a route to earlier approval and possible 180-day generic exclusivity if Glenmark qualified as a first applicant and satisfied the statutory requirements. The economic value of that position depended on the number of other Paragraph IV filers and the settlement terms reached with Cephalon.

Did Cephalon and Glenmark sign a settlement agreement?

The parties resolved the litigation through a settlement agreement. The material business terms were not publicly disclosed in the court’s dismissal materials.

A confidential settlement in a Hatch-Waxman case can address:

• the date on which Glenmark may market armodafinil;
• whether Glenmark receives an authorized-generic arrangement;
• restrictions on launch quantities or distribution;
• treatment of later patent challenges;
• royalty or other financial terms;
• termination rights if a patent is invalidated in separate litigation.

The public dismissal does not establish whether Glenmark received an early-entry date, whether it was permitted to launch before every listed patent expired, or whether Cephalon granted any license. Those matters were contractual and not resolved in a public judicial opinion.

What was the FDA and Orange Book status of Nuvigil?

Nuvigil was approved as an NDA product, and Cephalon’s listed patents were submitted for inclusion in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book.

The relevant regulatory sequence was:

Event	Regulatory significance
Nuvigil NDA approval	Established the reference listed drug for armodafinil tablets
Patent listing	Identified patents that could trigger ANDA certification obligations
Glenmark ANDA	Created the basis for the Paragraph IV dispute
Cephalon lawsuit	Triggered the statutory approval stay
Settlement and dismissal	Removed the immediate litigation dispute
Later ANDA approvals	Depended on FDA review, patent certifications, and exclusivity

The Orange Book does not determine patent validity. It identifies patents submitted by the NDA holder and accepted for listing by FDA under applicable listing standards. A listed patent can still be challenged in district court or in a post-grant proceeding.

When did Nuvigil lose exclusivity?

Nuvigil’s commercial exclusivity declined in stages rather than on a single date.

Exclusivity layer	Effect
NDA regulatory exclusivity	Protected the reference product during the applicable FDA exclusivity period
Older modafinil patents	Expired earlier and provided limited protection against later armodafinil products
Armodafinil formulation patents	Extended potential patent protection into the mid-to-late 2020s
Paragraph IV settlement	Could permit generic entry before listed-patent expiration
Generic approval	Created direct price and volume pressure once commercial launch occurred

The key distinction is between patent expiration and settlement-based entry. A generic may enter before the nominal expiration date if the brand grants a license or otherwise resolves the litigation on terms permitting launch.

How strong was Cephalon’s patent estate against Glenmark?

Cephalon’s position was commercially meaningful but legally untested in this docket.

Strengths

• Multiple later-issued patents extended beyond the expiration of earlier modafinil patents.
• Formulation claims can make direct design-around strategies more difficult.
• The ANDA litigation delayed FDA approval through the statutory stay.
• Cephalon had a broader Nuvigil patent portfolio than a single composition patent.

Weaknesses

• The case ended before a public validity or infringement ruling.
• Glenmark’s Paragraph IV certification created a credible invalidity and noninfringement challenge.
• Formulation patents may be vulnerable to obviousness arguments based on known tablet compositions, excipients, and formulation techniques.
• Settlement reduced the value of a definitive court ruling and left the enforceability of the patents unresolved.

The practical assessment is that Cephalon had sufficient patent leverage to obtain a negotiated resolution, but the docket does not support a conclusion that the asserted patents would have survived a full merits challenge.

Which companies challenged Nuvigil exclusivity?

Nuvigil faced competition from several generic-drug manufacturers that pursued ANDA approval or related patent strategies. Publicly reported Nuvigil generic activity involved companies including Glenmark, Mylan, Teva, Apotex, and other ANDA applicants.

The competitive threat was broader than Glenmark’s individual case. Multiple applicants reduce the value of a single-brand settlement because each additional filer can create a separate path to market entry. The commercial outcome depends on:

• the earliest settlement entry date;
• whether an applicant obtains first-filer status;
• whether the first filer forfeits exclusivity;
• the number of approved ANDAs;
• the availability of an authorized generic;
• the scope of any launch restrictions.

Did the case involve biosimilar risk?

No. Nuvigil is a small-molecule drug, and Glenmark’s product was an ANDA generic, not a biosimilar under the Public Health Service Act.

The relevant regulatory risks were generic-drug risks:

• Paragraph IV litigation;
• ANDA approval timing;
• 180-day exclusivity;
• formulation design-around;
• at-risk launch;
• automatic substitution and price erosion.

Biosimilar concepts such as interchangeability, reference biologics, and the Biologics Price Competition and Innovation Act were not central to this case.

What patent litigation affected Nuvigil commercialization?

The Glenmark case formed part of a coordinated wave of Nuvigil litigation following ANDA filings. Cephalon’s objective was to preserve the commercial value of Nuvigil while its later armodafinil patents remained in force.

The litigation strategy had four commercial components:

1. assert the later Orange Book patents;
2. delay generic approval through the statutory stay;
3. negotiate launch timing across multiple ANDA applicants;
4. preserve patent and settlement leverage without risking an adverse validity judgment.

Glenmark’s objective was to obtain a commercially usable launch date and avoid the cost and uncertainty of a full district court trial.

What revenue exposure did the litigation create?

Nuvigil was a material product for Cephalon before its acquisition by Teva. The principal revenue exposure was not limited to lost sales to Glenmark. Early generic entry could have affected:

• branded armodafinil volume;
• net price and rebate levels;
• payer formulary position;
• pharmacy substitution;
• authorized-generic economics;
• the value of remaining Nuvigil patent rights.

A single generic entrant can produce sharp price erosion in a small-molecule tablet market. Multiple entrants generally accelerate erosion because pharmacies and payers gain more supply options.

The public docket did not disclose the settlement’s financial terms or a quantified revenue forecast attributable specifically to Glenmark.

What generic launch scenarios followed the settlement?

The settlement could support one of three broad market outcomes:

Scenario	Commercial effect
Entry near patent expiry	Limited remaining branded exclusivity; gradual generic preparation
Licensed early entry	Earlier volume loss but controlled timing and reduced trial risk
Delayed entry after patent expiry	Maximum short-term protection, but no public merits victory

The dismissal alone does not identify which scenario applied. The relevant launch date must be derived from the settlement, FDA approval records, and actual commercial launch data rather than from the docket’s termination entry.

Key Takeaways

• Cephalon sued Glenmark in Delaware over a Paragraph IV ANDA for generic armodafinil, the active ingredient in Nuvigil.
• The asserted Nuvigil estate included later armodafinil formulation and method-related patents, including U.S. Patent Nos. 8,524,276, 8,524,277, and 8,629,111.
• The case ended by settlement and dismissal, not by a reported decision on infringement, validity, or enforceability.
• Settlement terms were confidential, so the public record does not establish Glenmark’s precise launch date or financial obligations.
• The dispute involved generic-drug risk, not biosimilar risk.
• Cephalon achieved litigation-based delay and negotiated leverage, but the case did not create meaningful judicial precedent on the strength of the Nuvigil patent estate.

FAQs About Cephalon v. Glenmark Pharmaceuticals

What was the case number for the Nuvigil Glenmark litigation?

The case number was 1:13-cv-02093 in the U.S. District Court for the District of Delaware.

Was Glenmark found to infringe Nuvigil patents?

No reported merits judgment found Glenmark liable for infringement. The case was resolved through settlement and dismissal.

Did the case invalidate any Nuvigil patent?

No. The public docket does not report a final invalidity ruling against the asserted patents.

Was Glenmark allowed to launch generic armodafinil before Nuvigil patent expiry?

The public dismissal record does not disclose the settlement’s launch terms. Any early-entry right would have been governed by the confidential settlement and FDA approval status.

Does this case affect current generic armodafinil litigation?

Its direct precedential effect is limited because the dispute did not produce a reported merits opinion. Its commercial relevance lies in the settlement structure and the patent strategy used against ANDA applicants for Nuvigil.

References

1. Cephalon Inc. v. Glenmark Pharmaceuticals Ltd., No. 1:13-cv-02093, U.S. District Court for the District of Delaware. (2013-2014). PACER docket and pleadings.

2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations (Orange Book). U.S. Department of Health and Human Services.

3. U.S. Patent and Trademark Office. (2024). Patent Center: U.S. Patent Nos. 8,524,276, 8,524,277, and 8,629,111. U.S. Department of Commerce.

4. U.S. Food and Drug Administration. (2007). Nuvigil approval letter and prescribing information. U.S. Department of Health and Human Services.

5. Hatch, Waxman, and related ANDA litigation provisions, 21 U.S.C. § 355(j); 35 U.S.C. § 271(e)(2).