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	2014-07-07
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
Parties	MYLAN PHARMACEUTICALS INC.
Patents	8,007,826; 8,354,437; 8,440,703; 8,663,685
Attorneys	Micheal L. Binns
Firms	Smith, Katzenstein, & Jenkins LLP
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
2014-07-07				External link to document

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

Last updated: August 27, 2026

Acorda Therapeutics sued Alkem Laboratories in the Southern District of New York after Alkem filed an abbreviated new drug application seeking approval for a generic version of Ampyra, Acorda's extended-release dalfampridine product. The case, No. 1:14-cv-00882, was a Hatch-Waxman patent infringement action based on Alkem's Paragraph IV certifications.

The dispute centered on patents covering dalfampridine extended-release tablets and their use in patients with multiple sclerosis. The case did not produce a publicly reported merits judgment establishing infringement or invalidity. The public docket reflects a negotiated resolution and dismissal rather than a trial verdict. The settlement terms, including any authorized generic launch date or restrictions on Alkem's entry, were not publicly disclosed in the court record.[1]

What was Acorda Therapeutics v. Alkem Laboratories about?

Acorda commercialized Ampyra, also known as dalfampridine extended-release tablets, for improving walking ability in adults with multiple sclerosis. Alkem's ANDA sought FDA approval to market a competing dalfampridine extended-release product before the asserted patents' stated expiration dates.

Acorda treated Alkem's ANDA filing as an act of infringement under 35 U.S.C. § 271(e)(2). The filing triggered the Hatch-Waxman litigation framework and an automatic FDA approval stay of up to 30 months, subject to statutory exceptions.

Case element	Detail
Plaintiff	Acorda Therapeutics Inc.
Defendant	Alkem Laboratories Ltd.
Court	U.S. District Court for the Southern District of New York
Case number	1:14-cv-00882
Litigation type	Hatch-Waxman patent infringement
Reference product	Ampyra, dalfampridine extended-release tablets
Therapeutic area	Multiple sclerosis
Filing period	2014
Public disposition	Dismissed pursuant to settlement or negotiated resolution
Public merits ruling	No reported final infringement or validity judgment
Settlement terms	Not publicly disclosed in the docket

What patents protected Ampyra in the Alkem litigation?

The Alkem case involved Acorda's patent estate for dalfampridine extended-release products. The central Ampyra patents during this period included U.S. Patent No. 5,540,938 and U.S. Patent No. 8,007,826. Later Ampyra litigation also involved U.S. Patent No. 8,663,685 and related patents.[2]

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

The '938 patent covered sustained-release aminopyridine compositions. Its claims addressed the formulation architecture used to provide prolonged delivery of 4-aminopyridine, the active pharmaceutical ingredient later known as dalfampridine.

The patent had a 20-year term measured from its effective filing date and was approaching expiration when the Alkem action was filed. Its commercial significance was therefore greater in the near term than in the long-term Ampyra patent portfolio.

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

The '826 patent covered methods of treating multiple sclerosis with sustained-release 4-aminopyridine or dalfampridine. It was a method-of-use patent rather than a simple composition patent.

Method-of-use claims can create a meaningful Hatch-Waxman barrier when an ANDA applicant's proposed labeling directs or encourages the patented use. Their practical value depends on claim scope, the wording of the generic label, induced-infringement theories, and whether the claims survive validity challenges.

U.S. Patent No. 8,663,685 and related patents

Acorda's later Ampyra litigation involved additional method-of-use and formulation patents. Those patents expanded the estate beyond the original sustained-release composition claims, but the broader portfolio did not prevent generic entry after key patents were invalidated or otherwise became ineffective against generic competition.

The Alkem complaint and subsequent docket history should be distinguished from later Federal Circuit litigation involving other ANDA defendants. A decision in litigation against Roxane or another generic defendant did not automatically resolve every legal issue in the Alkem case, although it materially affected the negotiating position of the parties.

When did Ampyra patents lose exclusivity?

Ampyra's commercial exclusivity eroded in stages rather than on a single date.

Exclusivity component	Relevant timing or status
FDA approval of Ampyra	2010
New chemical entity exclusivity	Expired before the Alkem litigation
Original formulation patent, U.S. 5,540,938	Expiration approached in 2018, subject to any applicable pediatric extension
Method-of-use patent, U.S. 8,007,826	Listed expiration generally extended into the mid-2020s
Later Ampyra patents	Included additional terms into the mid-2020s
Generic dalfampridine approvals	FDA approvals began in 2018
Practical market exclusivity	Ended when approved generic products entered or became commercially available

The Orange Book listed patents associated with Ampyra, but Orange Book listing did not guarantee that each patent would remain enforceable through its listed expiration date. Patent invalidity decisions, settlements, claim construction, non-infringement findings, and authorized launches could all reduce the practical value of the listed terms.[3]

What was Alkem's Paragraph IV challenge?

Alkem's ANDA filing included Paragraph IV certifications against one or more patents listed for Ampyra. A Paragraph IV certification asserts that a listed patent is invalid, unenforceable, or would not be infringed by the proposed generic product.

Acorda's response was to file suit within the statutory 45-day period. That filing created the statutory stay delaying FDA approval of Alkem's ANDA for up to 30 months, unless the court resolved the case earlier or another statutory event terminated the stay.

The publicly available case history does not show a final judicial determination that Alkem infringed the asserted claims. Nor does it show a final determination that the claims were invalid in the Alkem action. The case therefore should be classified as a settled Paragraph IV dispute, not as a litigated invalidity win for either party.

What was the litigation timeline?

2014: Complaint and Hatch-Waxman stay

Acorda filed the complaint in the Southern District of New York in 2014. The complaint alleged that Alkem's ANDA filing infringed Ampyra-related patents.

The asserted theories likely included infringement based on Alkem's proposed product and labeling. In a Hatch-Waxman action, the relevant conduct is the ANDA submission itself, not commercial sale of the generic product.

2014-2015: Patent and claim disputes

The parties litigated the scope of the asserted formulation and method-of-use claims. The case was positioned against a wider group of Ampyra patent cases involving other ANDA applicants.

The central commercial issue was whether Alkem would receive a negotiated launch date. A settlement could preserve Acorda's near-term revenue while granting Alkem a defined future entry right, but the court docket did not disclose the economic or operational terms.

Final disposition: settlement and dismissal

The case ended without a reported trial verdict or final written opinion deciding infringement, validity, or enforceability. The dismissal means the Alkem docket cannot be used as a merits precedent concerning the validity of the Ampyra patents.

The settlement also does not establish that Alkem was barred from the market until patent expiration. Generic settlements commonly provide a license or agreed entry date that can precede the nominal expiration of listed patents.

What was the impact of later Ampyra patent litigation?

The most important later development was the Federal Circuit's decision in Acorda Therapeutics, Inc. v. Roxane Laboratories, Inc. The Federal Circuit held the asserted claims of the '826 and related Ampyra patents invalid for obviousness, reversing the district court's contrary conclusion.[4]

The Federal Circuit's reasoning addressed the interaction between a known active ingredient and the claimed sustained-release dosing regimen. The court also rejected Acorda's reliance on commercial success where a blocking patent had restricted competitors from entering the market. The decision weakened Acorda's ability to rely on the broader Ampyra patent estate to prevent generic competition through the mid-2020s.

That later decision did not convert the Alkem case into an adjudicated invalidity case. It did, however, reduce the value of any settlement protection that depended on the continued enforceability of the same or closely related claims.

How strong was Acorda's patent estate?

Acorda's estate had meaningful initial strength but declining long-term durability.

Formulation protection

The '938 patent addressed the extended-release delivery system. Formulation patents can be commercially valuable because they may cover the product architecture rather than only a therapeutic use. Their weakness in this case was timing: the principal formulation patent was already near the end of its term when Alkem filed suit.

Method-of-use protection

The '826 and related patents extended the nominal patent horizon by claiming treatment of multiple sclerosis with specific dalfampridine dosing. These patents gave Acorda additional leverage against ANDA applicants.

Their legal vulnerability was obviousness. The Federal Circuit later found that the claimed regimen was obvious in light of the prior art and the known pharmacology of 4-aminopyridine.[4]

Portfolio assessment

Factor	Assessment
Near-term litigation leverage	High at the time of the 2014 filing
Formulation patent life	Limited
Method-of-use patent duration	Longer nominal term
Validity risk	Material after later Federal Circuit decisions
Design-around risk	Depended on formulation and labeling differences
Settlement leverage	Stronger before adverse appellate precedent
Long-term exclusionary value	Limited after generic approvals and invalidity rulings

What was the commercial impact on Ampyra?

Ampyra was Acorda's core commercial product. Generic entry therefore created direct revenue exposure rather than a secondary portfolio issue.

Acorda's annual reports described Ampyra as the company's principal revenue source before generic competition. After generic dalfampridine products entered the market, Acorda reported a significant decline in Ampyra net revenue and reduced expectations for the product's future contribution.[5]

The Alkem settlement may have included a delayed-entry or launch arrangement, but the public record does not disclose whether Alkem actually launched, licensed its product to another company, or remained commercially inactive. FDA approval of an ANDA does not establish that the applicant launched at risk or generated material sales.

Did the case involve biosimilar risk?

No. Ampyra is a small-molecule drug, not a biologic. The relevant pathway was an ANDA under the Hatch-Waxman Act, not a biosimilar application under the Biologics Price Competition and Innovation Act.

The competitive risks were:

• Paragraph IV generic challenges;
• formulation design-around products;
• labeling-based non-infringement strategies;
• settlements with authorized entry dates;
• commercial launch after patent invalidity or expiration.

Biosimilar interchangeability, reference-product exclusivity under the Public Health Service Act, and biologic manufacturing comparability were not relevant to this case.

What was the Orange Book status of Ampyra?

Ampyra was listed in the FDA Orange Book with patents covering the approved product. Orange Book listings informed ANDA certification obligations and triggered the Hatch-Waxman litigation process.

The listing of a patent did not prevent an ANDA applicant from filing a Paragraph IV certification. It also did not establish that the patent was valid or infringed. The practical value of the listing depended on the outcome of litigation or settlement and on whether the generic applicant could obtain approval after the statutory stay.

The Orange Book status should therefore be analyzed together with:

1. the exact patent claims;
2. the applicant's certification;
3. the date of the 30-month stay;
4. any court order or settlement;
5. later appellate validity decisions; and
6. FDA approval and commercial launch records.

What generic entry risks existed after the Alkem settlement?

The principal risks were:

1. Alkem could obtain a license to enter before nominal patent expiration.
2. Other ANDA applicants could prevail in separate litigation.
3. A generic defendant could invalidate claims that Acorda had not yet adjudicated against Alkem.
4. A court could find non-infringement based on a different formulation or label.
5. The FDA could approve multiple generic products after patent barriers fell.
6. Price competition could begin rapidly once several suppliers entered.

The later Federal Circuit decision and FDA approvals confirmed that Ampyra's practical exclusivity was materially shorter than the listed patent terms suggested.

Key Takeaways

• Acorda sued Alkem in 2014 after a Paragraph IV ANDA filing for generic dalfampridine extended-release tablets.
• The case involved Ampyra formulation and method-of-use patents, including U.S. Patent Nos. 5,540,938 and 8,007,826.
• The public docket reflects settlement and dismissal, not a final infringement or invalidity judgment.
• Settlement terms and any agreed generic entry date were not publicly disclosed.
• Later Federal Circuit litigation invalidated key Ampyra method-of-use claims, weakening Acorda's broader patent position.
• Ampyra faced small-molecule generic competition, not biosimilar competition.
• Generic entry began in 2018, materially reducing Acorda's Ampyra revenue exposure.
• The Alkem case is best characterized as a settled Hatch-Waxman action whose commercial importance was later overtaken by broader Ampyra patent invalidity rulings.

FAQs

Did Alkem win the Acorda Ampyra patent case?

No public merits judgment shows that Alkem won on infringement or validity. The case ended through settlement-related dismissal.

Did Alkem launch a generic version of Ampyra?

The public case docket does not establish a commercial launch by Alkem. FDA approval, if granted, would not by itself prove that Alkem marketed the product.

Which Ampyra patent was most important in later litigation?

U.S. Patent No. 8,007,826 was central to later litigation over the method of treating multiple sclerosis with sustained-release dalfampridine. The Federal Circuit later held related asserted claims invalid for obviousness.

Was the Acorda-Alkem settlement an authorized generic agreement?

The publicly available docket does not disclose enough detail to classify the settlement as an authorized generic arrangement. A license, delayed-entry settlement, or other commercial structure could have been used.

Why did Ampyra lose exclusivity before all listed patents expired?

Patent listing dates were not the only determinant of market exclusivity. Generic approvals, Paragraph IV litigation, invalidity rulings, settlements, and appellate decisions reduced the practical force of the listed patents.

References

1. U.S. District Court for the Southern District of New York. (2014). Acorda Therapeutics Inc. v. Alkem Laboratories Ltd., No. 1:14-cv-00882. Public docket records.
2. U.S. Patent and Trademark Office. (1996). U.S. Patent No. 5,540,938, Sustained release aminopyridine compositions.
3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Ampyra, dalfampridine extended-release tablets. Orange Book.
4. United States Court of Appeals for the Federal Circuit. (2018). Acorda Therapeutics, Inc. v. Roxane Laboratories, Inc., 903 F.3d 1310.
5. Acorda Therapeutics, Inc. (2018-2020). Annual reports on Form 10-K. U.S. Securities and Exchange Commission.