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

Acorda Therapeutics Inc. v. Teva Pharmaceuticals USA Inc. (D. Del. 2014)

Docket		Date Filed	2014-07-17
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. Teva Pharmaceuticals USA Inc. (D. Del. 2014)

Date Filed	Document No.	Description	Snippet	Link To Document
2014-07-17				External link to document

Acorda Therapeutics v. Teva Pharmaceuticals USA: Litigation Summary, Patent Analysis, and Generic Entry Risk

Last updated: October 1, 2026

Acorda Therapeutics Inc. v. Teva Pharmaceuticals USA Inc., No. 1:14-cv-00941, was a Hatch-Waxman case concerning Teva's abbreviated new drug application for generic Ampyra, an extended-release dalfampridine product approved to improve walking in patients with multiple sclerosis. Acorda asserted U.S. Patent Nos. 5,540,938 and 8,007,826 in the District of Delaware.

The district court initially found the asserted claims valid and infringed. The Federal Circuit later reversed, holding the asserted claims obvious in view of prior art and the known pharmacologic properties of 4-aminopyridine. The decision removed the principal patent barrier to generic dalfampridine entry and contributed to FDA approvals of generic products in 2018. (Acorda Therapeutics Inc. v. Roxane Laboratories, Inc., 903 F.3d 1310 (Fed. Cir. 2018)).

What drug and FDA product were at issue in Acorda v. Teva?

The case involved Ampyra, also known as dalfampridine extended-release tablets.

Product	Information
Brand	Ampyra
Active ingredient	Dalfampridine, also called 4-aminopyridine
Dosage form	Extended-release oral tablet
Strength	10 mg
NDA	NDA 022250
Sponsor	Acorda Therapeutics Inc.
FDA approval	January 2010
Indication	Improvement of walking in adults with multiple sclerosis
Regulatory pathway for Teva	ANDA under the Hatch-Waxman Act

The product was commercially important because Acorda developed a controlled-release formulation intended to provide therapeutic exposure while limiting peak concentrations associated with toxicity. The FDA-approved dosing regimen was one 10 mg extended-release tablet twice daily, approximately 12 hours apart. (FDA, 2010).

Dalfampridine is a small molecule. Biosimilar analysis therefore does not apply. The relevant competitive threat was generic substitution through the ANDA pathway, not a 351(k) biosimilar application.

Which patents did Acorda assert against Teva?

Acorda asserted two principal patents.

Patent	General subject matter	Role in litigation	Stated expiration
U.S. Patent No. 5,540,938	Use of 4-aminopyridine to improve walking in multiple sclerosis	Method-of-use patent	April 2018
U.S. Patent No. 8,007,826	Sustained-release 4-aminopyridine formulations and dosing	Formulation and dosing patent	July 2025

The '938 patent covered the therapeutic use of 4-aminopyridine to improve walking in patients with multiple sclerosis. The '826 patent focused on sustained-release formulations and administration parameters designed to maintain efficacy while reducing adverse effects.

Acorda's patent strategy depended on the combination of the two patents. The '938 patent covered the clinical use but was near expiration when the case was filed. The '826 patent provided a later-dated formulation barrier and was the more commercially significant patent because it potentially extended protection for the Ampyra product through 2025.

The patents were listed in the FDA's Orange Book for Ampyra. Orange Book listing enabled Acorda to receive a Paragraph IV notice from Teva and file patent litigation that triggered a statutory stay of ANDA approval. (FDA, Approved Drug Products with Therapeutic Equivalence Evaluations).

What triggered the Acorda v. Teva lawsuit?

Teva submitted an ANDA seeking approval to market generic dalfampridine extended-release tablets. Teva's Paragraph IV certification asserted that the relevant Acorda patents were invalid, unenforceable, or would not be infringed by Teva's proposed product.

Acorda filed suit in the U.S. District Court for the District of Delaware under docket No. 1:14-cv-00941. The filing triggered the Hatch-Waxman 30-month stay of FDA approval, subject to earlier termination or court resolution.

The dispute was part of broader Ampyra patent litigation involving several generic applicants. Related cases included actions against Roxane Laboratories, Mylan Pharmaceuticals, and other ANDA filers. The Federal Circuit addressed the common patent issues in a consolidated appeal framework, with the leading opinion issued in Acorda Therapeutics Inc. v. Roxane Laboratories Inc.

What did the District of Delaware decide?

The district court conducted a bench trial and initially ruled for Acorda on the principal validity and infringement issues. The court rejected Teva's obviousness arguments and found that the asserted claims were infringed by the proposed generic product.

The district court's analysis treated the claimed formulation and dosing parameters as more than a predictable application of known 4-aminopyridine science. The court also considered evidence concerning clinical development, formulation development, safety limitations, and commercial success.

The ruling preserved Acorda's ability to block generic entry until expiration of the asserted patents, subject to appeal. The decision did not produce a final damages award of lasting effect because the Federal Circuit later reversed the validity determinations.

Why did the Federal Circuit invalidate the Ampyra patent claims?

The Federal Circuit reversed on obviousness grounds. It held that the asserted claims would have been obvious to a person of ordinary skill based on prior art describing:

• 4-aminopyridine as a treatment for multiple sclerosis-related symptoms;
• the relationship between dose, blood concentration, efficacy, and toxicity;
• sustained-release delivery as a known solution for controlling drug exposure; and
• the use of routine formulation and dosing experimentation to identify suitable parameters.

The appellate court found that the prior art supplied a reason to pursue the claimed formulation and dosing approach. It rejected the district court's treatment of the development path as sufficiently unpredictable to support nonobviousness.

The Federal Circuit also gave limited weight to Acorda's evidence of commercial success. Ampyra sales were substantial, but the court held that commercial success was not adequately linked to the claimed features because regulatory approval, marketing, and other product attributes contributed to demand. The court concluded that the commercial evidence did not overcome the strong prima facie case of obviousness. (Acorda, 903 F.3d at 1310).

This reasoning was important beyond Ampyra. The decision addressed the risk that a branded company could obtain a later-expiring formulation patent for a drug whose active ingredient and therapeutic use were already known. The court's analysis limited the ability to rely on routine controlled-release development as a basis for long-term patent exclusivity.

What was the final litigation outcome?

The ultimate result favored Teva and the generic defendants.

Event	Outcome
2014	Acorda filed Hatch-Waxman litigation after Teva's Paragraph IV certification
2017	District court found the asserted claims valid and infringed
August 2018	Federal Circuit reversed on obviousness
After appellate reversal	Acorda could no longer rely on the asserted patents to block generic entry
2018	FDA approved generic dalfampridine products
Current status	The case is closed; the principal asserted patent claims did not remain an effective barrier to market entry

The Federal Circuit's decision vacated the district court's judgment to the extent it rested on validity of the asserted claims. The decision also removed the basis for maintaining a prospective injunction against generic launch.

The litigation did not result in a durable settlement-based entry date that controlled the market. The material outcome was appellate invalidation and the resulting loss of patent-based exclusivity.

When did Ampyra lose exclusivity?

Ampyra lost effective patent protection earlier than the nominal 2025 expiration date of the '826 patent because the Federal Circuit held the relevant claims obvious.

The exclusivity timeline was:

Date	Exclusivity event
January 2010	FDA approved Ampyra
April 2018	The '938 method-of-use patent reached its stated expiration
August 2018	Federal Circuit invalidated the key asserted claims of the '826 patent on obviousness grounds
2018	FDA approved generic dalfampridine products
July 2025	Nominal expiration date associated with the '826 patent, subject to the appellate invalidity ruling

The distinction between nominal expiration and effective exclusivity is material. A patent may remain listed or have an unexpired term while no longer blocking competitors if a court invalidates the asserted claims.

Ampyra also received regulatory exclusivity associated with FDA approval. That exclusivity did not preserve market control after the statutory period ended and did not prevent generic applicants from relying on the ANDA pathway once the patent obstacle was removed.

What was the Orange Book status of Ampyra?

Ampyra's patents were listed in the Orange Book, making them relevant to ANDA certifications and Hatch-Waxman litigation. The principal listed patents asserted against Teva were the '938 and '826 patents.

Orange Book listing created procedural leverage but did not guarantee that the patents would survive validity challenges. Teva's Paragraph IV certification shifted the dispute into federal court and forced Acorda to defend the patents before generic approval.

The case illustrates the difference between:

1. Orange Book listing, which identifies patents associated with an approved drug;
2. patent validity, which determines whether the claims can be enforced;
3. patent infringement, which determines whether the proposed generic falls within valid claims; and
4. regulatory exclusivity, which operates independently of patent validity.

What generic entry risks existed for Teva and Acorda?

Teva's risk profile

Teva faced the ordinary risks of a Paragraph IV launch:

• a 30-month FDA approval stay;
• an injunction if Acorda prevailed;
• potential damages for at-risk launch;
• exposure to infringement liability during appellate proceedings; and
• formulation and manufacturing challenges in reproducing the extended-release profile.

The appellate ruling materially reduced those risks. Once the asserted claims were held obvious, Teva's principal legal barrier to approval was removed.

Acorda's risk profile

Acorda faced a concentrated loss of revenue because Ampyra had limited product diversification and depended on patent-based protection. The invalidation of the '826 claims exposed the product to generic substitution shortly after the '938 patent expired.

Generic entry created several commercial effects:

• lower net pricing;
• pharmacy substitution;
• loss of market share;
• increased payer pressure;
• reduced branded prescriptions; and
• rapid erosion of Ampyra revenue.

Acorda reported that generic competition materially affected Ampyra sales following 2018 approvals and launches. (Acorda Therapeutics, 2019).

How strong was Acorda's Ampyra patent estate?

The estate was commercially meaningful but vulnerable on obviousness.

Strengths

• The '938 patent protected an approved clinical use.
• The '826 patent covered the extended-release product architecture.
• The patents supported an Orange Book listing.
• Acorda had clinical and commercial evidence supporting the product's value.
• The formulation patent appeared to extend nominal protection beyond the method-of-use patent.

Weaknesses

• The active ingredient and therapeutic concept were known before the asserted patents.
• Prior art disclosed 4-aminopyridine for multiple sclerosis-related symptoms.
• Controlled-release technology was established.
• Dose and exposure optimization were vulnerable to routine-experimentation arguments.
• Commercial success was difficult to attribute exclusively to the claimed technical features.
• The patent estate was concentrated in a small number of claims.

The Federal Circuit's ruling shows that a successful formulation product does not necessarily support a strong patent position. The patent must distinguish the claimed formulation or dosing regimen from predictable development using known ingredients, delivery technologies, and pharmacologic relationships.

Did formulation patents, method-of-use patents, or manufacturing patents remain relevant?

The litigation centered on formulation and method-of-use protection.

The '938 patent was a method-of-use patent. It covered treatment-related use of 4-aminopyridine to improve walking in multiple sclerosis.

The '826 patent was the primary formulation and dosing patent. Its importance arose from the extended-release dosage form and the claimed exposure parameters.

Manufacturing patents were not the principal basis for the Teva judgment. Manufacturing or process patents can create separate infringement risks, but they did not preserve the core Ampyra market after the Federal Circuit invalidated the asserted claims.

The case therefore reduced the value of the product's principal formulation barrier without necessarily eliminating every conceivable patent claim associated with dalfampridine. For generic applicants, the relevant question was whether any remaining valid and enforceable claims could support an injunction against the proposed commercial product.

Did Acorda have licensing or settlement protection against Teva?

The reported appellate outcome was not based on a settlement that granted Teva a delayed entry date. The principal resolution was judicial: the Federal Circuit reversed the validity ruling and held the asserted claims obvious.

There is no basis in the reported decision to treat the case as a conventional authorized generic or negotiated-entry settlement. Teva's commercial position improved through the invalidity ruling, not through a publicly controlling settlement term.

What does the case mean for generic launch strategy?

The case supports several generic launch conclusions.

First, a Paragraph IV challenge is particularly valuable when the brand's later-expiring patent claims depend on routine formulation optimization. Second, appellate reversal can eliminate a market barrier even after a branded company wins at trial. Third, commercial success evidence has limited force when sales may result from regulatory approval, marketing, or the overall product rather than the claimed technical advance.

For branded companies, the case demonstrates the risk of relying on a single extended-release patent to replace an expiring method-of-use patent. Stronger protection generally requires differentiated claims supported by unexpected results, technical distinctions, or manufacturing barriers that are not predictable from the prior art.

Key Takeaways

• Acorda sued Teva in the District of Delaware over generic Ampyra.
• The case involved dalfampridine extended-release 10 mg tablets.
• The principal patents were U.S. Patent Nos. 5,540,938 and 8,007,826.
• The district court initially found the patents valid and infringed.
• The Federal Circuit reversed and held the asserted claims obvious.
• The '938 patent expired in April 2018.
• The '826 patent had a nominal expiration in July 2025, but its asserted claims were invalidated before that date.
• The ruling removed the principal patent barrier to generic dalfampridine.
• FDA approvals of generic products followed in 2018.
• The case involved generic competition, not biosimilar substitution.
• Acorda's commercial success evidence did not overcome the obviousness case.
• No controlling settlement-based delayed-entry outcome defined the final result.

FAQs About Acorda Therapeutics v. Teva Pharmaceuticals

What was Teva's generic product in the Acorda litigation?

Teva sought approval for generic dalfampridine extended-release tablets corresponding to Ampyra 10 mg tablets.

Was Ampyra's active ingredient itself patented?

The core active ingredient, 4-aminopyridine or dalfampridine, was not the principal surviving barrier in this litigation. Acorda relied on method-of-use and extended-release formulation patents.

Did the Federal Circuit find Ampyra ineffective?

No. The decision concerned patent obviousness and infringement. It did not withdraw FDA approval or determine that Ampyra lacked clinical efficacy.

Did the ruling apply only to Teva?

The Federal Circuit's legal reasoning affected related Ampyra patent cases involving other ANDA applicants. The specific judgment and procedural consequences depended on each defendant's case.

Could Acorda use a new patent to block generic dalfampridine after the decision?

A later patent could create a separate enforcement issue if it covered a valid, enforceable, and infringed feature of the approved product. The invalidation of the asserted claims did not automatically invalidate every patent ever associated with dalfampridine.

References

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

Acorda Therapeutics Inc. v. Teva Pharmaceuticals USA Inc., No. 1:14-cv-00941, U.S. District Court for the District of Delaware.

Acorda Therapeutics, Inc. (2019). Annual report on Form 10-K for the fiscal year ended December 31, 2018. U.S. Securities and Exchange Commission.

Food and Drug Administration. (2010). Ampyra (dalfampridine) extended-release tablets, NDA 022250: Approval letter and prescribing information. U.S. Department of Health and Human Services.

Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. U.S. Department of Health and Human Services.