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

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

Docket	1:14-cv-00917	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 Inc. v. Alkem Laboratories Ltd. Litigation Analysis

Last updated: February 19, 2026

This document analyzes the patent litigation case Acorda Therapeutics Inc. v. Alkem Laboratories Ltd., filed in the U.S. District Court for the District of Delaware (Case No. 1:14-cv-00917). The core of the dispute centers on Acorda's U.S. Patent No. 8,318,741, which covers methods of treating multiple sclerosis (MS) with dalfampridine. Alkem Laboratories sought to market a generic version of Acorda's drug, Ampyra, triggering this patent infringement lawsuit.

What Patents are at Issue?

The primary patent at the heart of the litigation is U.S. Patent No. 8,318,741, titled "Method of treating multiple sclerosis." This patent was issued to Acorda Therapeutics Inc. on November 28, 2012. The patent claims method of use for dalfampridine, specifically for improving walking in patients with MS.

The claims of U.S. Patent No. 8,318,741 relevant to the litigation include:

• Claim 1: A method of improving walking in a patient with multiple sclerosis, comprising administering to the patient an effective amount of 4-aminopyridine.
• Claim 2: The method of claim 1, wherein the 4-aminopyridine is administered in a dosage form comprising controlled release of 4-aminopyridine.
• Claim 3: The method of claim 2, wherein the dosage form releases 4-aminopyridine over a period of from about 8 hours to about 12 hours.
• Claim 4: The method of claim 2, wherein the dosage form is a tablet.
• Claim 5: The method of claim 1, wherein the patient has a disability score on the Expanded Disability Status Scale (EDSS) of between 4.0 and 7.0, inclusive.

Alkem Laboratories challenged the validity of this patent, arguing that it was obvious and therefore unpatentable.

What is the Alleged Infringement?

Alkem Laboratories filed an Abbreviated New Drug Application (ANDA) with the U.S. Food and Drug Administration (FDA) seeking approval to market a generic version of Ampyra. This action constituted a "Paragraph IV certification" under the Hatch-Waxman Act, indicating that Alkem believed Acorda's U.S. Patent No. 8,318,741 was invalid, unenforceable, or would not be infringed by Alkem's proposed generic product.

Acorda Therapeutics filed suit for patent infringement, alleging that Alkem's proposed generic drug product would induce infringement of U.S. Patent No. 8,318,741.

What are the Key Legal Arguments?

Acorda Therapeutics argued that Alkem's ANDA filing and proposed generic product directly infringed U.S. Patent No. 8,318,741. Acorda's position was that any generic version of Ampyra, when used for its indicated purpose (improving walking in MS patients), would necessarily fall within the scope of the patent claims.

Alkem Laboratories' primary defense was patent invalidity, arguing that U.S. Patent No. 8,318,741 was obvious in light of prior art. Alkem contended that the claimed method of using dalfampridine to improve walking in MS patients, particularly in a controlled-release formulation, was predictable and would have been evident to a person of ordinary skill in the art at the time of the invention.

The central issue for the court to decide was whether U.S. Patent No. 8,318,741 was valid and infringed, or invalid due to obviousness.

How Did the Courts Rule?

The litigation progressed through the district court, with significant proceedings related to claim construction and validity.

In a ruling on July 18, 2016, the United States District Court for the District of Delaware found U.S. Patent No. 8,318,741 to be invalid due to obviousness. The court determined that the asserted claims were not patentable over the prior art.

Acorda Therapeutics appealed this decision to the United States Court of Appeals for the Federal Circuit.

On August 10, 2018, the Federal Circuit affirmed the district court's decision, agreeing that U.S. Patent No. 8,318,741 was invalid as obvious. The Federal Circuit's ruling upheld the district court's findings regarding the prior art and the predictability of the claimed invention.

What is the Impact on Ampyra and Generic Competition?

The Federal Circuit's affirmation of the patent's invalidity removed a significant barrier to generic competition for Ampyra. With the primary method-of-use patent invalidated, Alkem Laboratories and other generic manufacturers were able to bring their versions of dalfampridine to market.

This ruling has had a direct impact on the pricing and availability of dalfampridine for MS patients. Generic entry typically leads to substantial price reductions, increasing patient access and reducing healthcare costs.

The market for Ampyra experienced a significant shift following this litigation. Acorda Therapeutics' market exclusivity for its branded drug was effectively terminated by the patent invalidation.

What are the Broader Implications for Pharmaceutical Patents?

This case highlights the ongoing challenges in patenting method-of-use claims, particularly for well-known compounds. The "obviousness" standard, as applied by the courts, requires a patent holder to demonstrate that their invention was not merely a predictable application of existing knowledge.

The litigation underscores the importance of robust patent prosecution and the ability to clearly distinguish new inventions from prior art. Generic manufacturers actively scrutinize existing patents, and successful challenges can significantly alter market dynamics.

For pharmaceutical companies, this case reinforces the need for comprehensive patent strategies that consider potential challenges to method-of-use patents, especially those involving known active pharmaceutical ingredients.

Key Takeaways

• Acorda Therapeutics Inc. v. Alkem Laboratories Ltd. involved a dispute over U.S. Patent No. 8,318,741, covering the method of treating multiple sclerosis with dalfampridine.
• Alkem Laboratories challenged the patent's validity, arguing obviousness.
• Both the District Court and the Federal Circuit Court of Appeals found U.S. Patent No. 8,318,741 to be invalid due to obviousness.
• The invalidation of the patent paved the way for generic versions of dalfampridine to enter the market, increasing competition and potentially lowering prices.
• The case demonstrates the critical role of prior art in patent validity challenges and the challenges of patenting method-of-use claims for known compounds.

Frequently Asked Questions

1. What was the specific prior art cited against Acorda's patent? The prior art considered by the courts included various scientific publications and existing knowledge regarding the use of 4-aminopyridine (dalfampridine) and its potential effects on neurological conditions, including MS. Specific references often involve studies on potassium channel blockers and their application in demyelinated axons to improve nerve conduction.

2. Did Acorda Therapeutics pursue any other patents related to Ampyra? Yes, Acorda Therapeutics holds and has defended other patents related to Ampyra, including formulation patents. However, the U.S. Patent No. 8,318,741 was a primary method-of-use patent that was central to the litigation with Alkem Laboratories.

3. What is the typical lifespan of a patent for a branded drug before generic entry? A standard U.S. patent provides 20 years of protection from the filing date. However, the effective market exclusivity for a branded drug can be shorter due to various factors, including patent litigation, the time required for FDA approval, and the possibility of patent challenges.

4. How does the Hatch-Waxman Act influence this type of litigation? The Hatch-Waxman Act (Drug Price Competition and Patent Term Restoration Act of 1984) governs the approval of generic drugs and establishes a framework for patent litigation. It allows generic manufacturers to challenge patents before their expiration and incentivizes them through the "180-day exclusivity" for the first generic to file a Paragraph IV certification.

5. What were the potential damages Acorda Therapeutics might have sought if they had won? If Acorda had prevailed in proving infringement and validity, they could have sought damages for lost profits, reasonable royalties, or other forms of monetary compensation for the period of infringement. However, as the patent was invalidated, this became moot.

Citations

[1] Acorda Therapeutics, Inc. v. Alkem Labs. Ltd., No. 1:14-cv-00917 (D. Del. July 18, 2016). [2] Acorda Therapeutics, Inc. v. Alkem Labs. Ltd., No. 1:14-cv-00917 (Fed. Cir. Aug. 10, 2018). [3] U.S. Patent No. 8,318,741.