Litigation Details for Cephalon Inc. v. Mylan Pharmaceuticals Inc. (D. Del. 2009)

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Cephalon Inc. v. Mylan Pharmaceuticals Inc. (D. Del. 2009)

Docket	1:09-cv-00954	Date Filed	2009-12-11
Court	District Court, D. Delaware	Date Terminated	2012-05-03
Cause	35:271 Patent Infringement	Assigned To	Gregory Moneta Sleet
Jury Demand	None	Referred To
Patents	7,132,570; RE37,516
Link to Docket	External link to docket

Details for Cephalon Inc. v. Mylan Pharmaceuticals Inc. (D. Del. 2009)

Date Filed	Document No.	Description	Snippet	Link To Document
2009-12-11				External link to document

Cephalon Inc. v. Mylan Pharmaceuticals Inc. Litigation Summary and Patent Analysis, 1:09-cv-00954

Last updated: September 19, 2026

Cephalon Inc. v. Mylan Pharmaceuticals Inc., No. 1:09-cv-00954, was a Hatch-Waxman patent case in the U.S. District Court for the District of Delaware involving Mylan’s abbreviated new drug application for generic modafinil, marketed by Cephalon as Provigil. The dispute centered on U.S. Patent No. 6,932,983, which covered pharmaceutical compositions containing modafinil with specified particle-size characteristics.

The district court initially ruled for Cephalon on validity. The U.S. Court of Appeals for the Federal Circuit reversed, holding the asserted claims obvious. The Federal Circuit decision removed the principal patent barrier implicated by Mylan’s ANDA and became a significant ruling on obviousness, motivation to modify prior-art formulations, and the evidentiary value of commercial success. (Cephalon, Inc. v. Mylan Pharmaceuticals, Inc., 2013)

What was Cephalon v. Mylan about?

Cephalon sued Mylan after receiving notice of Mylan’s Paragraph IV certification concerning patents listed for Provigil. Cephalon alleged that Mylan’s proposed generic modafinil product would infringe the asserted claims of the ’983 patent.

The case involved:

Item	Detail
Court	U.S. District Court for the District of Delaware
Civil action	No. 1:09-cv-00954
Plaintiff	Cephalon Inc.
Defendant	Mylan Pharmaceuticals Inc.
Reference product	Provigil
Active ingredient	Modafinil
Regulatory pathway	ANDA under the Hatch-Waxman Act
Principal patent	U.S. Patent No. 6,932,983
Federal Circuit decision	707 F.3d 1330
Core appellate issue	Obviousness of modafinil particle-size claims
Final appellate result	Reversal of the district court’s validity ruling

Provigil was approved for narcolepsy, obstructive sleep apnea-associated excessive sleepiness, and shift-work sleep disorder. The case did not concern a biologic, biosimilar, manufacturing process patent, or drug-device combination product.

What patent protected Provigil in the Mylan litigation?

The principal patent at issue was U.S. Patent No. 6,932,983, assigned to Cephalon. The patent claimed pharmaceutical compositions containing modafinil particles with particular particle-size distributions.

U.S. Patent No. 6,932,983

The ’983 patent was directed to reducing the particle size of modafinil in pharmaceutical compositions. The technology was relevant to dissolution, drug release, and formulation performance.

The asserted claims were composition claims rather than purely method-of-use claims. The Federal Circuit’s decision focused on whether a skilled person would have been motivated to modify known modafinil formulations by using smaller particles and whether the claimed formulation would have been predictable from the prior art.

The Federal Circuit treated the claimed particle-size characteristics as an obvious formulation modification in light of the prior-art record. The court rejected the district court’s conclusion that the prior art failed to provide a sufficient reason to make the claimed formulation. (Cephalon, 2013)

Other Provigil-related patents

Cephalon’s broader Provigil patent estate included additional patents covering modafinil formulations, compositions, and related subject matter. The Mylan case, however, is principally associated with the ’983 patent and its Federal Circuit obviousness ruling.

The existence of other patents did not preserve the ’983 patent after the Federal Circuit held the asserted claims obvious. Patent protection for a drug must be analyzed patent by patent because invalidity or expiration of one patent does not automatically eliminate every potential barrier to generic entry.

What were the key litigation dates in Cephalon v. Mylan?

Date	Event
2009	Cephalon filed the Delaware patent infringement action against Mylan
2009-2011	The parties litigated infringement and validity issues involving the ’983 patent
2011	The district court entered findings favorable to Cephalon on the patent’s validity
2012	Mylan appealed the validity ruling to the Federal Circuit
Feb. 6, 2013	Federal Circuit issued its decision in 707 F.3d 1330
2013	The Federal Circuit reversed the district court’s determination that the asserted claims were nonobvious

The appellate decision was the dispositive legal development. It changed the practical value of the ’983 patent from an enforceable obstacle to a patent that could not support exclusion based on the asserted claims.

How did the Federal Circuit rule on the ’983 patent?

The Federal Circuit held that the asserted claims were obvious under 35 U.S.C. § 103.

The court’s reasoning addressed four principal issues:

1. Whether the prior art disclosed modafinil formulations with relevant particle-size characteristics.
2. Whether a skilled artisan had a reason to reduce the particle size of modafinil.
3. Whether the expected benefits of the modification were reasonably predictable.
4. Whether objective indicia, including commercial success, supported nonobviousness.

The appellate court found that the prior art supplied an adequate motivation to make the claimed formulation. It also found that the claimed result was within the capabilities of a skilled formulation scientist.

The court discounted Cephalon’s reliance on commercial success because the evidence did not sufficiently establish that the success was attributable to the patented particle-size limitation rather than to other factors, including the drug’s therapeutic properties, marketing, and the broader Provigil product. (Cephalon, 2013)

Why did the Federal Circuit find the modafinil formulation claims obvious?

The decision illustrates the risk associated with formulation patents that claim optimization of known pharmaceutical ingredients.

Prior-art motivation

The Federal Circuit concluded that the prior art gave formulators a reason to consider smaller modafinil particles. A formulation change may be obvious when the prior art identifies particle size as a variable affecting dissolution or bioavailability and provides a reason to optimize that variable.

Predictable technical result

The court viewed the claimed result as predictable. The invention did not require a new active ingredient or an unexpected chemical transformation. It involved modifying the physical characteristics of modafinil particles in a known pharmaceutical composition.

Commercial success was not sufficiently tied to the claims

Cephalon argued that Provigil’s commercial success supported patent validity. The Federal Circuit held that commercial success has limited probative value unless the patentee establishes a nexus between the success and the claimed invention.

In the court’s analysis, the commercial performance of Provigil could have resulted from factors other than the patented particle-size limitation. Those factors included the efficacy of modafinil, the approved indications, physician adoption, brand recognition, and Cephalon’s commercial activities.

What was the final outcome of the case?

The Federal Circuit reversed the district court’s determination that the asserted claims were nonobvious. The ’983 patent therefore could not be enforced against Mylan on the asserted claims.

The appellate outcome had four practical consequences:

• Cephalon lost the validity ruling supporting the ’983 patent.
• Mylan removed a major patent obstacle to its generic modafinil ANDA.
• The case did not produce a lasting injunction based on the asserted claims.
• The ruling weakened the exclusivity value of Cephalon’s formulation patent estate.

The Federal Circuit decision did not mean that every Provigil-related patent was invalid. It applied to the asserted claims and the record developed in that case.

What was the Orange Book status of Provigil?

Provigil was an FDA-approved prescription product containing modafinil. Cephalon listed multiple patents over time in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book.

The Orange Book listing process was central to the litigation because an ANDA applicant may submit a Paragraph IV certification asserting that a listed patent is invalid, unenforceable, or not infringed. The patent owner may then bring an infringement action under 35 U.S.C. § 271(e)(2).

The Orange Book does not itself determine whether a patent is valid. Listing creates a regulatory and litigation framework. The district court and Federal Circuit determine the patent issues.

Did the case involve a Paragraph IV challenge?

Yes. Mylan’s ANDA-related certification triggered the Hatch-Waxman dispute. Cephalon’s lawsuit was based on the statutory patent-infringement mechanism applicable to ANDA filings.

A Paragraph IV challenge can produce a 30-month stay of FDA approval under the Hatch-Waxman Act, subject to statutory exceptions and the procedural posture of the case. The commercial significance of the stay depends on the number of patents listed, the timing of the litigation, and whether the patent owner obtains an injunction or a favorable final judgment.

The Federal Circuit’s obviousness ruling materially reduced the value of the asserted patent as a basis for continuing generic exclusion.

How did this case affect generic launch risk for modafinil?

The case reduced Mylan’s patent risk for the formulation claims at issue. After the Federal Circuit’s ruling, Mylan no longer faced a viable infringement barrier based on the asserted claims of the ’983 patent.

Generic launch risk still required analysis of:

• Other listed Provigil patents.
• Any settlement or license arrangements.
• FDA approval status.
• Manufacturing and bioequivalence requirements.
• Potential exposure under unasserted or later-issued patents.
• State-law and antitrust claims involving generic delay agreements.

The decision did not guarantee immediate commercial launch. Patent litigation and FDA review are separate processes. A favorable patent judgment removes a legal barrier but does not itself constitute FDA approval.

How does Cephalon v. Mylan compare with earlier Provigil patent litigation?

Cephalon had previously litigated Provigil patents against multiple generic companies, including Teva, Ranbaxy, Mylan, and Apotex. Those disputes involved earlier patents and settlement arrangements that affected the timing of generic entry.

The 2009 Mylan case differed in several respects:

Issue	Earlier Provigil disputes	Cephalon v. Mylan, 1:09-cv-00954
Main commercial issue	Timing of generic entry	Validity of a later formulation patent
Patent strategy	Earlier Provigil patents and settlement rights	’983 particle-size patent
Core legal question	Infringement and settlement-based entry timing	Obviousness under § 103
Appellate significance	Generic-entry framework	Formulation-patent obviousness
Result	Settlements affected market entry	Asserted claims held obvious on appeal

The litigation shows why a brand company can maintain a complex patent estate even after an initial patent settlement. Later formulation patents can extend litigation, but their strength depends on whether the claimed physical or chemical modification would have been routine for a skilled artisan.

What patent-strength lessons does the case provide?

The case is unfavorable precedent for formulation claims based on optimization of a known active ingredient where:

• The prior art identifies particle size as a relevant variable.
• The claimed range is selected from a finite set of predictable options.
• The formulation change uses conventional pharmaceutical techniques.
• The claimed performance benefit is expected rather than surprising.
• Commercial success is not directly linked to the claimed limitation.

A stronger formulation patent generally requires evidence of an unexpected result, a critical range, a technical problem not recognized in the prior art, or a formulation architecture that is not a routine optimization.

The Federal Circuit’s treatment of commercial success is also commercially important. Revenue from the branded product does not establish a nexus to a formulation claim without evidence showing that the patented feature drove demand or performance.

Did the case involve biosimilar risk or biologic exclusivity?

No. Provigil is a small-molecule drug, and Mylan’s product was pursued through the ANDA pathway. The case did not involve:

• A biologics license application.
• A biosimilar under the Public Health Service Act.
• FDA biologic exclusivity.
• Interchangeability.
• Patent dance procedures.
• Biologic manufacturing cell lines or host cells.

The relevant competitive threat was generic substitution, not biosimilar competition.

What licensing or settlement issues affected the case?

The broader Provigil patent environment included settlements between Cephalon and generic manufacturers. Those arrangements were later examined by the Federal Trade Commission in connection with alleged reverse-payment concerns involving Provigil generic entry. The FTC’s enforcement action focused on settlement practices and delayed generic competition, rather than the Federal Circuit’s technical obviousness ruling in the Mylan case. (Federal Trade Commission, 2015)

The specific appellate decision in Cephalon v. Mylan should be distinguished from the broader settlement history. A settlement can determine launch timing even when a patent’s validity remains contested. A final appellate invalidity ruling, by contrast, changes the legal status of the asserted claims.

What is the current commercial significance of the case?

The case remains relevant to:

• Small-molecule formulation patent prosecution.
• ANDA Paragraph IV strategy.
• Particle-size and dissolution claims.
• Evidence of unexpected results.
• Nexus requirements for commercial success.
• Generic launch planning.
• Patent-estate valuation for mature branded drugs.

For business analysis, the decision indicates that the ’983 patent could not support exclusion of Mylan based on the claims adjudicated in the appeal. The broader Provigil estate required separate review of each listed patent, its expiration date, pediatric extension status, litigation record, and any contractual launch restrictions.

Key Takeaways

• Cephalon sued Mylan in Delaware over an ANDA for generic modafinil.
• The main patent was U.S. Patent No. 6,932,983.
• The patent claimed modafinil compositions with specified particle-size characteristics.
• The district court initially found the claims valid against Mylan’s obviousness challenge.
• The Federal Circuit reversed and held the asserted claims obvious.
• Commercial success did not establish a sufficient nexus to the patented particle-size limitation.
• The ruling removed a significant patent barrier to Mylan’s generic Provigil product.
• The case involved a small-molecule ANDA, not a biosimilar application.
• Other Provigil patents and settlement agreements required separate analysis.
• The decision is a leading example of the vulnerability of routine pharmaceutical formulation optimization claims.

FAQs About Cephalon v. Mylan

What drug was at issue in Cephalon v. Mylan?

The case involved modafinil, the active ingredient in Cephalon’s Provigil product.

What patent did Cephalon assert against Mylan?

Cephalon principally asserted U.S. Patent No. 6,932,983, directed to modafinil pharmaceutical compositions with specified particle-size characteristics.

Did Mylan win the Cephalon patent case?

Mylan prevailed on the central appellate issue. The Federal Circuit reversed the district court and held the asserted claims obvious.

Was Provigil protected by a method-of-use patent in this case?

The Federal Circuit case principally concerned formulation and composition claims in the ’983 patent, not a standalone method-of-use patent dispute.

Does the decision invalidate every Provigil patent?

No. The decision addressed the asserted claims of the ’983 patent. Other Provigil patents had to be evaluated independently.

References

Cephalon, Inc. v. Mylan Pharmaceuticals, Inc., 707 F.3d 1330 (Fed. Cir. 2013).

Federal Trade Commission. (2015). FTC v. Cephalon, Inc., settlement and competition-related materials concerning Provigil. https://www.ftc.gov

U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book-data-files

U.S. Patent No. 6,932,983. (2005). Modafinil compositions and methods of preparation. U.S. Patent and Trademark Office.