Litigation Details for Acorda Therapeutics Inc. v. Alkem Laboratories Ltd. (D. Del. 2014)

Acorda Therapeutics Inc. v. Alkem Laboratories Ltd. (D. Del. 2014)

Docket		Date Filed	2014-07-11
Court	District Court, D. Delaware	Date Terminated	2016-08-05
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. Alkem Laboratories Ltd. (D. Del. 2014)

Date Filed	Document No.	Description	Snippet	Link To Document
2014-07-11				External link to document

Acorda Therapeutics v. Alkem Laboratories: Litigation Summary, Patent Analysis, and Generic Entry Risk

Last updated: August 20, 2026

Acorda Therapeutics sued Alkem Laboratories in the District of Delaware after Alkem filed an abbreviated new drug application seeking approval for generic dalfampridine extended-release tablets, the generic equivalent of Ampyra. The case, C.A. No. 14-917-RGA, was an ANDA patent-infringement action under 35 U.S.C. § 271(e)(2). The litigation ended without a reported trial judgment or Federal Circuit merits decision. The public docket reflects resolution by stipulated dismissal following settlement.

The dispute centered on Acorda’s patents covering the 10-mg extended-release dalfampridine product and its use in improving walking ability in patients with multiple sclerosis. The principal commercial issue was whether Alkem could launch before the July 2025 expiration of Acorda’s core Ampyra patent protection.

What was Acorda Therapeutics v. Alkem Laboratories about?

Acorda alleged that Alkem’s ANDA filing constituted an artificial act of infringement because the proposed generic product would infringe patents listed for Ampyra. Alkem’s ANDA product was intended to contain dalfampridine, also known as 4-aminopyridine, in a controlled-release oral tablet.

Case element	Detail
Court	U.S. District Court for the District of Delaware
Civil action	C.A. No. 14-917-RGA; docket identifier 1:14-cv-00917
Plaintiff	Acorda Therapeutics Inc.
Defendant	Alkem Laboratories Ltd.
Judge	Richard G. Andrews
Legal basis	Hatch-Waxman ANDA litigation under 35 U.S.C. § 271(e)(2)
Reference product	Ampyra, dalfampridine extended-release tablets
Dosage strength	10 mg
Therapeutic area	Multiple sclerosis and walking impairment
Disposition	Stipulated dismissal following settlement
Trial or merits judgment	None reported

The action was part of a broader wave of Ampyra patent cases filed after generic manufacturers submitted ANDAs for dalfampridine extended-release tablets.

What patents protected Ampyra in the Alkem litigation?

The litigation involved Acorda’s core extended-release dalfampridine patents. The most commercially important patents in the Ampyra estate were U.S. Patent Nos. 8,007,826 and 8,663,685.

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

The ’826 patent covered sustained-release aminopyridine formulations and dosing regimens. Its claims were directed to maintaining controlled dalfampridine exposure through an extended-release oral dosage form.

The patent was central to the commercial protection for Ampyra because it addressed the product’s release profile and dosing interval rather than merely claiming dalfampridine as a chemical compound.

U.S. Patent No. 8,663,685

The ’685 patent covered methods associated with the use of sustained-release aminopyridine formulations, including treatment of walking impairment in multiple sclerosis patients.

Its method-of-use claims created a separate litigation pathway from the formulation claims in the ’826 patent. A generic applicant could challenge the patents through Paragraph IV certifications, a Section viii statement carving out a patented indication, or a combination of both depending on the proposed labeling.

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

The ’938 patent covered earlier aspects of aminopyridine treatment. By the time of the later Ampyra ANDA disputes, its remaining term was shorter than that of the ’826 and ’685 patents. It was not the principal long-term barrier to generic entry.

Patent	General subject matter	Commercial relevance
5,540,938	Earlier aminopyridine treatment technology	Historical protection; shorter remaining term
8,007,826	Sustained-release dalfampridine formulation and dosing	Core formulation barrier
8,663,685	Therapeutic use and method-of-treatment claims	Core method-of-use barrier

The precise claims asserted against Alkem should be determined from the operative complaint and claim charts. The case did not produce a reported judicial opinion that adjudicated the scope or validity of those claims.

What was the procedural history of the Alkem patent case?

Acorda filed the action in 2014 after receiving notice of Alkem’s Paragraph IV position. The complaint triggered the Hatch-Waxman 30-month stay of FDA approval, subject to statutory exceptions and any later court order.

The case did not proceed to a reported trial decision. It was resolved through settlement and stipulated dismissal. The publicly available docket does not establish a judicial finding that Alkem infringed, that the asserted claims were valid, or that Alkem’s ANDA product was noninfringing.

This distinction matters. A stipulated dismissal preserves the commercial effect of a settlement but does not create a binding merits precedent on claim construction, anticipation, obviousness, enablement, written description, or infringement.

Procedural significance

The settlement likely provided Acorda with control over the timing of Alkem’s potential generic launch while avoiding litigation risk. Alkem obtained a path to eventual market entry, but the public docket does not disclose the economic terms or the exact licensed-entry date.

Because the settlement agreement was not publicly detailed in the reported docket materials, the following points cannot be treated as established terms:

• A specific authorized launch date;
• A royalty or payment arrangement;
• Any supply or manufacturing obligation;
• A no-challenge clause;
• The scope of any covenant not to sue;
• Whether Alkem’s launch depended on the resolution of other Ampyra cases.

Was there a Paragraph IV challenge to Ampyra?

Yes. The case arose from an ANDA filing and Acorda’s response to Alkem’s patent certifications. The Paragraph IV mechanism allowed Alkem to argue that the listed Ampyra patents were invalid, unenforceable, or would not be infringed by its proposed generic product.

A Paragraph IV filing is not itself proof that a patent is invalid. It creates a statutory controversy and permits the patent owner to sue before commercial launch.

Alkem’s potential defenses would have included:

1. Noninfringement based on the formulation, release profile, or labeling of its proposed product.
2. Invalidity based on anticipation or obviousness.
3. Lack of adequate written description or enablement.
4. Limits on method-of-use enforcement if the proposed label omitted a patented indication.
5. Challenges to the scope or enforceability of the asserted claims.

No reported merits opinion in the Alkem action resolved those issues.

What was the Orange Book status of Ampyra?

Ampyra was listed in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book. The listed patents included the core formulation and method-of-use patents associated with the product.

The key Orange Book timing was as follows:

Event	Timing
Ampyra approval	2010
Original listed patent protection	Included earlier ’938 patent
Core ’826 and ’685 patent expiration	July 30, 2025
Regulatory exclusivity	Separate from patent term and largely expired before the Alkem case
Generic approval pathway	ANDA approval subject to patent certifications and statutory stays

Patent expiration and FDA exclusivity are separate legal protections. Ampyra’s generic-entry risk was driven primarily by the ’826 and ’685 patents, not by remaining new-drug exclusivity.

The FDA Orange Book identifies listed patents and expiration information, but it does not disclose settlement terms between a brand company and an ANDA filer.[1]

When did Ampyra lose exclusivity?

Acorda’s core patent protection for Ampyra expired on July 30, 2025, based on the expiration dates associated with U.S. Patent Nos. 8,007,826 and 8,663,685. The earlier ’938 patent expired before that date and therefore did not provide the principal barrier to post-2025 generic entry.

The practical loss of exclusivity depended on three separate events:

1. The expiration or judicial invalidation of the relevant patents.
2. FDA approval of one or more dalfampridine ANDAs.
3. Any private settlement restrictions governing individual applicants.

An applicant could have an FDA-approved product before the patent expiration date but remain contractually restricted from launching under a settlement.

How strong was Acorda’s Ampyra patent estate?

Acorda’s estate was commercially significant but legally exposed. Its strength came from layering formulation and method-of-use claims around a drug whose active ingredient was known before Ampyra’s approval.

Strengths

The estate had several advantages:

• It protected the controlled-release delivery system rather than only the active ingredient.
• It included both formulation and method-of-use claims.
• It covered the commercial 10-mg dosing regimen.
• It supported ANDA litigation before generic launch.
• Multiple listed patents increased settlement leverage.

Weaknesses

The estate also faced material validity and enforcement risks:

• Aminopyridine was an established pharmacologic class.
• Controlled-release formulation technology was a familiar field of pharmaceutical development.
• The patents had to distinguish the claimed release profile from prior art.
• Method-of-use claims could face labeling and induced-infringement defenses.
• Patent term ended in 2025, limiting the value of prolonged litigation.

In related Ampyra litigation, the Federal Circuit upheld the validity of key Acorda patents in Acorda Therapeutics Inc. v. Mylan Pharmaceuticals Inc., 817 F.3d 755 (Fed. Cir. 2016). The court later addressed related obviousness issues in Acorda Therapeutics Inc. v. Roxane Laboratories Inc., 903 F.3d 1310 (Fed. Cir. 2018). Those decisions materially affected the negotiating environment for other ANDA defendants, including Alkem.[2][3]

The Alkem case itself did not produce a reported merits ruling. Its patent strength therefore must be assessed through the broader Ampyra litigation record rather than from a judgment against Alkem.

Which companies challenged Acorda’s Ampyra patents?

Acorda faced multiple ANDA challenges involving generic dalfampridine. Publicly reported litigation included cases against Mylan, Roxane, Actavis and other generic manufacturers.

Challenger	Relevance
Mylan	Key Federal Circuit validity decision involving the ’826 and ’685 patents
Roxane	Related Federal Circuit litigation addressing obviousness and patentability
Actavis	ANDA litigation concerning generic dalfampridine
Alkem	Delaware ANDA case resolved by settlement and dismissal

The Mylan and Roxane decisions were more important for legal precedent than the Alkem docket because they generated appellate opinions. The Alkem settlement, by contrast, primarily affected commercial launch timing.

Did the Alkem settlement permit early generic launch?

The public record does not provide a reported judicial order establishing an early launch date or publishing the settlement’s economic terms. The case ended by stipulated dismissal, which is consistent with a private resolution.

The commercial possibilities in an Ampyra settlement would have included:

• Launch on or after July 30, 2025;
• An earlier licensed launch date;
• A royalty-bearing license;
• An acceleration clause tied to another generic entrant;
• A launch contingent on patent invalidation in separate litigation.

No such term should be attributed to Alkem without the settlement agreement or a public regulatory filing that confirms it.

What generic launch risks existed after the Alkem case?

The principal risk to Acorda was not limited to Alkem. Acorda had to manage cumulative exposure from multiple ANDA filers. Once one applicant obtained a favorable judgment, entered under a license, or launched at risk, other applicants could rely on the resulting market conditions.

Legal launch risk

The main legal risks were:

• Invalidity findings against the ’826 or ’685 patents;
• A noninfringement ruling based on a generic formulation;
• An adverse claim construction;
• A Paragraph IV settlement permitting early entry;
• At-risk launch by a generic company;
• Loss of effective market exclusivity after July 30, 2025.

Commercial launch risk

Ampyra’s generic exposure was amplified by the product’s relatively straightforward oral solid dosage form. The product did not require biosimilar development, complex biologic manufacturing, or device-platform replication.

A generic applicant still had to demonstrate bioequivalence and satisfy FDA requirements for the extended-release formulation. Those requirements created regulatory work but did not create the same manufacturing barriers associated with injectable biologics.

Was biosimilar risk relevant to Ampyra?

No. Ampyra is a small-molecule oral drug, not a biologic. The relevant competitors were ANDA-based generics, not biosimilars under the Biologics Price Competition and Innovation Act.

The competitive analysis should therefore focus on:

• Paragraph IV certifications;
• Orange Book-listed patents;
• FDA ANDA approvals;
• Authorized or licensed generic entry;
• Paragraph IV litigation settlements;
• Post-expiration price erosion.

What was the revenue exposure from the Alkem case?

The Alkem case exposed Acorda’s Ampyra franchise to the same erosion risk associated with any approved generic dalfampridine product. Acorda historically depended heavily on Ampyra revenue, making the product’s patent expiry strategically important to the company.

The exact revenue attributable to Alkem cannot be determined from the litigation docket. Revenue exposure depended on whether Alkem entered before or after July 30, 2025, the number of competing generics, launch discounts, pharmacy substitution, and the extent of any authorized-generic strategy.

After core patent expiration, the likely commercial pattern was rapid price and share erosion typical of an oral small-molecule product with multiple ANDA competitors. The degree of erosion would depend on the number of FDA-approved competitors and the timing of their launches.

What patent litigation affects Ampyra after the Alkem case?

The broader Ampyra patent record is more important than the Alkem dismissal. The Mylan and Roxane Federal Circuit decisions established appellate precedent concerning the validity and obviousness of Acorda’s core patents.[2][3]

That precedent reduced the value of relitigating identical validity theories, but it did not eliminate all noninfringement or formulation-specific defenses. Each ANDA product still required analysis of:

• Its release-control technology;
• Dissolution profile;
• Excipient composition;
• Tablet structure;
• Proposed labeling;
• Manufacturing process;
• Claims actually listed in the Orange Book.

A generic formulation that used a materially different release mechanism could create a noninfringement position even if it remained therapeutically equivalent to Ampyra.

Key Takeaways

• Acorda sued Alkem in Delaware over an ANDA for generic dalfampridine extended-release tablets.
• The case was C.A. No. 14-917-RGA, docket number 1:14-cv-00917.
• The principal Ampyra patents were U.S. Patent Nos. 8,007,826 and 8,663,685.
• The action ended by stipulated dismissal following settlement.
• No reported Alkem judgment determined infringement, validity, claim construction, or damages.
• The public record does not establish the settlement’s launch date or economic terms.
• Acorda’s core patent protection expired July 30, 2025.
• Ampyra faced generic, not biosimilar, competition.
• The Mylan and Roxane Federal Circuit decisions provide the principal appellate context for assessing Acorda’s patent position.
• Post-expiration risk centers on rapid generic entry, price erosion and loss of Ampyra revenue.

FAQs About Acorda v. Alkem Laboratories

Did Alkem win the Ampyra patent lawsuit?

No merits victory was reported. The case ended through stipulated dismissal following settlement. The docket does not establish that either side prevailed on infringement or patent validity.

What drug was Alkem trying to copy?

Alkem sought approval for generic dalfampridine extended-release tablets, the generic equivalent of Acorda’s Ampyra 10-mg product.

Did Acorda have orphan-drug exclusivity for Ampyra?

FDA orphan-drug exclusivity is separate from the patents at issue. The Alkem litigation principally concerned patent rights and the ANDA approval pathway, not a remaining orphan-exclusivity period.

Could Alkem launch before July 30, 2025?

An early launch would have required a settlement authorization, a successful patent challenge, or another legal basis for entry. The public Alkem docket does not disclose an authorized early-launch date.

Are dalfampridine generics approved by the FDA?

FDA approval of generic dalfampridine depends on individual ANDA determinations and applicable patent certifications. The relevant regulatory record is the FDA’s Orange Book and product-approval database, rather than the civil docket alone.

References

1. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations (Orange Book). https://www.accessdata.fda.gov/scripts/cder/ob/
2. Acorda Therapeutics Inc. v. Mylan Pharmaceuticals Inc., 817 F.3d 755 (Fed. Cir. 2016).
3. Acorda Therapeutics Inc. v. Roxane Laboratories Inc., 903 F.3d 1310 (Fed. Cir. 2018).
4. Acorda Therapeutics Inc. v. Alkem Laboratories Ltd., No. 1:14-cv-00917, U.S. District Court for the District of Delaware.
5. U.S. Food and Drug Administration. (2024). Approved drug product information for Ampyra (dalfampridine). FDA Drugs@FDA database. https://www.accessdata.fda.gov/scripts/cder/daf/