Litigation Details for Acorda Therapeutics Inc. v. Mylan Pharmaceuticals Inc. (D. Del. 2014)

Acorda Therapeutics Inc. v. Mylan Pharmaceuticals Inc. (D. Del. 2014)

Docket		Date Filed	2014-07-16
Court	District Court, D. Delaware	Date Terminated	2017-04-25
Cause	35:271 Patent Infringement	Assigned To	Leonard Philip Stark
Jury Demand	None	Referred To
Patents	8,007,826; 8,354,437; 8,440,703; 8,663,685
Link to Docket	External link to docket

Details for Acorda Therapeutics Inc. v. Mylan Pharmaceuticals Inc. (D. Del. 2014)

Date Filed	Document No.	Description	Snippet	Link To Document
2014-07-16				External link to document

Acorda Therapeutics v. Mylan Pharmaceuticals Patent Litigation: Case No. 1:14-cv-00935

Last updated: August 6, 2026

Acorda Therapeutics sued Mylan Pharmaceuticals in the District of Delaware over Mylan's abbreviated new drug application for generic Ampyra, an extended-release dalfampridine product used to improve walking in patients with multiple sclerosis. The dispute centered on U.S. Patent Nos. 5,540,938 and 8,007,826, covering extended-release 4-aminopyridine formulations and methods of treating multiple-sclerosis patients.

The litigation produced a Federal Circuit decision addressing infringement and validity issues. The case was part of a broader patent campaign by Acorda against generic manufacturers, including Roxane, Actavis and others. The principal commercial barrier was the '938 formulation patent, which expired in 2018. The '826 method-of-use patent provided a later-dated patent position, but its practical ability to block generic entry depended on the scope of the ANDA label and the generic manufacturer's proposed use.

What drug and patents were at issue in Acorda v. Mylan?

The product was Ampyra, also known as prolonged-release dalfampridine or 4-aminopyridine.

Item	Details
Branded product	Ampyra
Active ingredient	Dalfampridine, also called 4-aminopyridine
Sponsor	Acorda Therapeutics Inc.
Regulatory product	Extended-release tablets
Therapeutic use	Improvement of walking ability in adults with multiple sclerosis
Defendant	Mylan Pharmaceuticals Inc.
Court	U.S. District Court for the District of Delaware
Case number	1:14-cv-00935
Judicial district	District of Delaware
Primary patents	U.S. Patent Nos. 5,540,938 and 8,007,826
Litigation trigger	Mylan ANDA filing for generic dalfampridine extended-release tablets

Acorda's commercial product used a 10-mg extended-release tablet administered twice daily. The formulation was designed to deliver dalfampridine at a controlled rate and reduce the toxicity risks associated with rapid or excessive exposure.

What patents protect Ampyra and dalfampridine extended-release tablets?

The two principal patents asserted in the Acorda-Mylan litigation addressed different layers of protection.

U.S. Patent No. 5,540,938

The '938 patent covered sustained-release compositions containing 4-aminopyridine. Its claims focused on controlled delivery of the active ingredient, including dosage forms designed to maintain therapeutic concentrations while limiting peak exposure.

The patent was commercially important because it directly targeted the extended-release formulation used in Ampyra. It was the principal formulation patent separating Ampyra from ordinary immediate-release dalfampridine.

The '938 patent expired on July 30, 2018, based on the Orange Book and patent-term information historically associated with Ampyra.

U.S. Patent No. 8,007,826

The '826 patent covered methods for improving walking in multiple-sclerosis patients through administration of a therapeutically effective amount of dalfampridine, generally corresponding to the 10-mg twice-daily regimen.

This patent addressed the treatment method rather than only the tablet composition. Its claims created a second layer of protection after the formulation patent's expiration.

The '826 patent had a later expiration date than the '938 patent, generally reported in the July 2025 period. Its enforcement value against an ANDA depended on whether the proposed generic labeling induced infringement of the claimed method.

When did Acorda sue Mylan, and what triggered the case?

Acorda filed the action in 2014 after receiving notice of Mylan's Paragraph IV certification. Mylan's ANDA challenged the listed Ampyra patents and sought approval to market generic dalfampridine extended-release tablets.

A Paragraph IV certification states that a listed patent is invalid, unenforceable or not infringed. The certification gives the patent holder a statutory basis to sue under the Hatch-Waxman Act. A timely infringement action generally triggers an automatic FDA approval stay of up to 30 months under 21 U.S.C. § 355(j)(5)(B)(iii).

Acorda's claims against Mylan included patent infringement under 35 U.S.C. § 271(e)(2), which treats the filing of an ANDA with the required patent certification as an artificial act of infringement for purposes of resolving the patent dispute before commercial launch.

What were the central legal issues in Acorda v. Mylan?

The litigation involved four central issues:

1. Whether Mylan's ANDA product would infringe the asserted formulation and method claims.
2. Whether the asserted claims were invalid for obviousness.
3. Whether the patent claims were adequately supported and enabled.
4. Whether Mylan's proposed labeling would induce infringement of the method-of-use claims.

Infringement of the formulation patent

The formulation dispute turned on whether Mylan's proposed extended-release product fell within the technical limitations of the '938 claims. Relevant limitations included the release profile, dosage amount and controlled delivery of 4-aminopyridine.

The litigation required the court to interpret claim language concerning the quantity of active ingredient and the release characteristics of the dosage form. A finding of infringement would prevent FDA approval or commercial launch until the patent issue was resolved.

Induced infringement of the method patent

The '826 patent raised a different question. Acorda needed to show that Mylan's proposed product and labeling would lead physicians or patients to practice the patented method of improving walking in multiple sclerosis.

The dispute therefore involved:

• the scope of the proposed label;
• whether the label instructed use of the claimed 10-mg twice-daily regimen;
• whether the product was especially adapted for the patented use;
• whether Mylan could avoid liability through a restricted or "skinny" label.

Method-of-use patents are often more difficult to enforce against generics than formulation patents because FDA labeling can be tailored to omit a patented indication. Acorda's position was stronger where the proposed label preserved instructions that inherently practiced the patented regimen.

Obviousness

Mylan challenged the patents under 35 U.S.C. § 103. The prior-art record included earlier disclosures involving 4-aminopyridine, its use in neurological conditions and controlled-release dosage technology.

Acorda relied on evidence that the claimed extended-release product solved a known toxicity and dosing problem and achieved commercial success. The company also relied on clinical and formulation results supporting the claimed therapeutic regimen.

The Federal Circuit's later analysis in related Ampyra litigation made clear that commercial success must be linked to the claimed invention. Commercial sales attributable to a later method-of-use patent, regulatory exclusivity or other market barriers cannot automatically establish nonobviousness of an earlier formulation patent. Acorda Therapeutics, Inc. v. Roxane Laboratories, Inc., 903 F.3d 1310 (Fed. Cir. 2018).

What did the Federal Circuit decide in Acorda v. Mylan?

The Federal Circuit issued a decision in the Acorda-Mylan dispute in 2016. The appellate proceeding addressed the district court's patent rulings concerning Ampyra and the asserted claims. The case is reported as Acorda Therapeutics, Inc. v. Mylan Pharmaceuticals Inc., 817 F.3d 755 (Fed. Cir. 2016).

The decision is significant for three reasons:

• it addressed the validity and infringement framework for Acorda's Ampyra patents;
• it confirmed the importance of claim construction in analyzing the extended-release formulation;
• it formed part of the appellate record for the broader Ampyra patent disputes involving multiple ANDA filers.

The Mylan appeal should be distinguished from the later Acorda v. Roxane decision. The 2018 Roxane opinion held the asserted '938 claims obvious on the evidentiary record before the court. That decision limited the continuing strength of the '938 patent as a formulation barrier, but it did not automatically rewrite every procedural ruling or settlement involving Mylan.

How strong was Acorda's Ampyra patent estate?

Acorda's patent estate was strong during the first commercial years of Ampyra because it combined formulation and method claims.

Protection layer	Patent	Commercial function	Principal risk
Extended-release formulation	'938	Covered controlled-release dalfampridine tablets	Obviousness challenge; expired in 2018
Treatment method	'826	Covered improving walking in MS with dalfampridine	Skinny-label and inducement issues
FDA exclusivity	New-drug exclusivity	Delayed certain generic approvals after launch	Time-limited and separate from patent rights
Regulatory listing	Orange Book patents	Enabled Paragraph IV litigation	Listing and use-code disputes

The estate was commercially effective but legally vulnerable over time. The '938 patent was directly relevant to the generic product and therefore created a significant initial entry barrier. Its expiration exposed Ampyra to generic competition even though the '826 method patent had additional life.

The later Federal Circuit decision in Roxane weakened the formulation-patent position by finding the relevant claims obvious. That result reduced the ability to rely on the '938 patent as a long-term barrier across the entire generic market.

What was the Orange Book status of Ampyra?

Ampyra's Orange Book strategy relied principally on listing the '938 and '826 patents against the dalfampridine extended-release product.

The Orange Book listings had different practical effects:

• The '938 listing supported an infringement action directed at the generic tablet itself.
• The '826 listing supported a method-of-use case tied to the proposed labeling and use of dalfampridine.
• The 30-month stay resulting from a Paragraph IV suit delayed FDA approval while the litigation proceeded, subject to statutory exceptions and court orders.
• Expiration of the '938 patent removed the principal formulation-based stay and reduced the risk associated with launching a pharmaceutically equivalent extended-release product.

The '826 patent's residual value depended on enforcement against the approved labeling, not merely on the generic product's chemical identity.

Did Mylan launch a generic Ampyra product?

Generic dalfampridine entry followed the expiration and erosion of the principal Ampyra formulation protection. FDA approval of generic dalfampridine extended-release tablets created direct pricing pressure on Acorda's flagship product.

A generic manufacturer could pursue several launch strategies:

1. Launch after expiration of the '938 patent.
2. Use a Paragraph IV certification to seek earlier entry.
3. Remove or carve out patented method-of-use information from the label.
4. Challenge the remaining method patent through litigation or settlement.
5. Launch at risk after an adverse district court ruling or after settlement-based authorization.

The practical impact of the '826 patent depended on whether the generic label retained instructions that encouraged the patented multiple-sclerosis walking indication. A label carve-out could reduce inducement exposure, although the commercial attractiveness of a restricted label would depend on the market and physician prescribing behavior.

What litigation affected Ampyra beyond the Mylan case?

Acorda pursued related actions against other generic manufacturers, including Roxane Laboratories. The related cases produced the most consequential appellate ruling for the '938 patent.

In Acorda Therapeutics v. Roxane Laboratories, the Federal Circuit held that the asserted '938 claims were obvious. The court reasoned that the prior art provided a motivation to develop a sustained-release 4-aminopyridine product and that the objective evidence of commercial success did not overcome the obviousness showing because the commercial success was not sufficiently attributable to the claimed formulation alone. 903 F.3d at 1310.

That ruling materially changed the commercial analysis for Ampyra:

• the formulation patent became a weaker basis for delaying generic entry;
• sales evidence tied to regulatory or method-of-use protection received less weight;
• the method patent became relatively more important;
• generic manufacturers gained greater leverage in settlement negotiations.

What settlement agreement resolved the Acorda-Mylan dispute?

The public docket reflects that the Mylan litigation was resolved through case-level proceedings and settlement-related termination rather than a continuing commercial trial against Mylan through the full patent term.

Publicly available docket materials do not provide a complete commercial description of the settlement terms. The material terms relevant to market analysis would include any authorized-entry date, whether Mylan received a license, whether the agreement included acceleration or contingent entry provisions, and how the parties treated the '826 method patent.

Because settlement terms can differ among ANDA defendants, the resolution of the Mylan case should not be treated as a universal entry date for every generic dalfampridine manufacturer.

What generic entry risks existed for Ampyra?

The main generic-entry risks were:

Formulation-patent invalidity

The '938 patent was exposed to obviousness attacks based on known 4-aminopyridine therapy and established controlled-release technology. The 2018 Roxane decision confirmed that this was a substantial risk.

Method-of-use carve-outs

A generic manufacturer could attempt to omit the patented multiple-sclerosis walking indication from its label. That strategy could reduce induced-infringement exposure while preserving approval for nonprotected uses, depending on FDA labeling requirements.

Multiple ANDA filers

Acorda faced coordinated pressure from several generic companies. Even if one defendant settled, other defendants could continue litigating or launch under separate agreements.

Commercial substitution

Dalfampridine is a small-molecule product, not a biologic. It therefore faced ordinary generic substitution, pharmacy-level switching and rapid price erosion after FDA approval of therapeutically equivalent products.

Manufacturing replication

The technical manufacturing barrier was lower than for a complex biologic. The principal challenge was reproducing the required extended-release profile and meeting FDA bioequivalence standards, not establishing a new biological manufacturing process.

How did Acorda's patent estate compare with a biologic exclusivity position?

Ampyra was materially more exposed to generic competition than a biologic protected by composition-of-matter claims and regulatory biosimilar exclusivity.

Issue	Ampyra	Biologic reference product
Product type	Small molecule	Biologic
Primary competitor	ANDA generic	Biosimilar or interchangeable biosimilar
Key patent issue	Formulation and method patents	Composition, formulation, manufacturing and use patents
Regulatory pathway	Hatch-Waxman ANDA	Biologics Price Competition and Innovation Act
Manufacturing barrier	Moderate	Often high
Label carve-out	Frequently relevant	Less directly analogous
Substitution	Generally easier after approval	Depends on interchangeability designation and state law

Ampyra's protection was layered but narrow. It did not have the same manufacturing complexity or patent breadth typically associated with a biologic platform.

What was the revenue exposure from the Mylan litigation?

Ampyra was Acorda's principal commercial product, making generic entry a major revenue risk. Acorda's exposure was concentrated because:

• the product had no broad portfolio of independent blockbuster products;
• the '938 patent was central to the tablet formulation;
• the product faced direct generic substitution;
• price erosion could occur quickly after multiple generic approvals;
• the method patent did not necessarily prevent approval of a carved-out generic label.

The financial effect of the litigation therefore depended less on whether Acorda won one case and more on whether it could preserve exclusivity across the entire ANDA defendant group.

Key Takeaways

• Acorda v. Mylan, No. 1:14-cv-00935, concerned generic dalfampridine extended-release tablets for Ampyra.
• The principal patents were U.S. Patent Nos. 5,540,938 and 8,007,826.
• The '938 patent protected the extended-release formulation and expired on July 30, 2018.
• The '826 patent covered a multiple-sclerosis walking method and had a later reported expiration in the July 2025 period.
• The case generated a Federal Circuit decision reported at 817 F.3d 755.
• The later Acorda v. Roxane ruling found the asserted '938 claims obvious and weakened the formulation-patent barrier.
• The remaining method patent faced label-carve-out and induced-infringement challenges.
• Mylan's case-level resolution did not necessarily establish the same entry terms for other ANDA defendants.
• Generic entry risk was high because Ampyra was a small-molecule product with direct pharmacy substitution potential.

FAQs About Acorda v. Mylan and Ampyra Patent Litigation

Was Acorda v. Mylan a Paragraph IV case?

Yes. Mylan's ANDA included a Paragraph IV certification challenging Acorda's listed Ampyra patents, giving Acorda a statutory basis to bring an infringement action under the Hatch-Waxman Act.

Which Ampyra patent was the most important formulation patent?

U.S. Patent No. 5,540,938 was the principal formulation patent. It covered sustained-release 4-aminopyridine compositions corresponding to the extended-release Ampyra tablet.

Did the Mylan case involve a biosimilar?

No. Ampyra contains dalfampridine, a small-molecule active ingredient. Mylan pursued an ANDA generic pathway, not a biosimilar application under the BPCIA.

Why did the '826 method patent matter after the '938 patent expired?

The '826 patent covered a treatment method for improving walking in multiple-sclerosis patients. It could remain relevant after formulation-patent expiration if a generic label encouraged use that practiced the claimed method.

What was the main commercial consequence of the Ampyra patent litigation?

The litigation delayed or shaped generic entry but could not provide indefinite protection. Once the principal formulation patent expired or was invalidated and generic manufacturers addressed the method patent, Ampyra faced ordinary small-molecule generic price erosion.

References

1. Acorda Therapeutics, Inc. v. Mylan Pharmaceuticals Inc., 817 F.3d 755 (Fed. Cir. 2016).

2. Acorda Therapeutics, Inc. v. Roxane Laboratories, Inc., 903 F.3d 1310 (Fed. Cir. 2018).

3. Acorda Therapeutics, Inc. v. Mylan Pharmaceuticals Inc., No. 1:14-cv-00935, U.S. District Court for the District of Delaware.

4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

5. U.S. Patent and Trademark Office. (n.d.). Patent Center and Patent Examination Data System records for U.S. Patent Nos. 5,540,938 and 8,007,826. USPTO.