Litigation Details for Pfizer Inc. v. Hikma Pharmaceuticals USA Inc. (D. Del. 2023)

Pfizer Inc. v. Hikma Pharmaceuticals USA Inc. (D. Del. 2023)

Docket		Date Filed	2023-08-23
Court	District Court, D. Delaware	Date Terminated	2026-04-28
Cause	35:271 Patent Infringement	Assigned To	Gregory B. Williams
Jury Demand	None	Referred To	Christopher J. Burke
Patents	9,770,441
Link to Docket	External link to docket

Details for Pfizer Inc. v. Hikma Pharmaceuticals USA Inc. (D. Del. 2023)

Date Filed	Document No.	Description	Snippet	Link To Document
2023-08-23				External link to document

Pfizer Inc. v. Hikma Pharmaceuticals USA Inc. | 1:23-cv-00924 Patent Litigation Analysis

Last updated: August 3, 2026

Pfizer’s case against Hikma is a Hatch-Waxman patent action concerning Hikma’s abbreviated new drug application for a generic version of Nurtec ODT, Pfizer’s rimegepant sulfate orally disintegrating tablet. Pfizer alleged that Hikma’s ANDA filing constituted artificial infringement under 35 U.S.C. § 271(e)(2). The dispute focused on rimegepant composition, formulation, and method-of-use patents listed for Nurtec ODT.

The case was filed in the U.S. District Court for the District of Delaware in 2023. The commercial issue was whether Hikma could obtain FDA approval and launch before expiry of Pfizer’s Orange Book patent estate or before a negotiated launch date.

What drug and ANDA were involved in Pfizer v. Hikma?

The case involved Nurtec ODT, containing rimegepant sulfate equivalent to 75 mg of rimegepant.

Field	Information
Branded product	Nurtec ODT
Active ingredient	Rimegepant sulfate
Dosage form	Orally disintegrating tablet
Strength	75 mg
Brand owner	Pfizer Inc., following Pfizer’s acquisition of Biohaven’s commercial CGRP portfolio
FDA indications	Acute treatment of migraine with or without aura; preventive treatment of episodic migraine in adults
Defendant	Hikma Pharmaceuticals USA Inc.
Case number	1:23-cv-00924
Court	U.S. District Court for the District of Delaware
Statutory basis	35 U.S.C. § 271(e)(2), Hatch-Waxman ANDA litigation

Pfizer acquired Biohaven’s commercial migraine portfolio in 2022. The transaction included Nurtec ODT and Zavzpret, although this litigation concerned rimegepant and Nurtec ODT rather than Pfizer’s zavegepant nasal spray product.

FDA approved Nurtec ODT in February 2020 for acute migraine treatment and expanded the label in May 2021 to include preventive treatment of episodic migraine. [1]

What patents protect Nurtec ODT in the Hikma litigation?

Pfizer’s complaint asserted patents associated with rimegepant and the Nurtec ODT product. Public Orange Book records and the litigation pleadings identify the relevant estate as including composition, formulation, and method-of-use rights.

Patent category	Principal protection	Litigation significance
Composition-of-matter patents	Rimegepant and related CGRP receptor antagonist compounds	Core molecule protection; generally the strongest barrier if valid and infringed
Formulation patents	Orally dissolving or orally disintegrating rimegepant compositions	Relevant to Hikma’s proposed dosage form
Method-of-use patents	Treatment or prevention of migraine using rimegepant	Can block labeled use even if a generic challenges composition claims
Dose and administration patents	Specific dosing regimens for acute or preventive migraine treatment	Potential basis for induced-infringement allegations if included in the proposed label

The principal patents associated with the Nurtec ODT estate include U.S. Patent Nos. 9,815,827, 10,265,298, 10,709,706, and 11,395,817. The precise patents asserted against Hikma must be distinguished from the broader set of patents listed in the Orange Book because Pfizer may list patents that are not asserted in every individual ANDA case.

What are the expected patent expiration dates?

The rimegepant estate contains patents with different priority dates and expiration profiles. The practical exclusivity date depends on the asserted patent, terminal disclaimers, patent-term adjustment, patent-term extension, pediatric exclusivity, and the terms of any settlement.

Patent	General subject matter	Nominal term profile
U.S. 9,815,827	Rimegepant compound and related CGRP antagonists	Earliest core-molecule protection; nominal expiration generally falls in the late 2020s, subject to term adjustments
U.S. 10,265,298	Pharmaceutical composition and oral delivery technology	Later-expiring formulation protection, generally extending into the mid-2030s
U.S. 10,709,706	Rimegepant migraine treatment methods	Method-of-use protection generally extending into the mid-2030s
U.S. 11,395,817	Later-issued migraine treatment or dosing claims	Potentially extending into the late 2030s

A patent’s issuance date is not its expiration date. For Orange Book analysis, the controlling date is the FDA-listed expiration date, adjusted for patent-term adjustment or extension. A generic applicant can also obtain approval for a product with a label that omits patented uses under the section viii “carve-out” procedure.

What were Pfizer’s infringement allegations against Hikma?

Pfizer’s action was based on Hikma’s ANDA filing, not on commercial sales of a marketed generic. Pfizer alleged that Hikma’s proposed product would infringe one or more patents covering rimegepant and the Nurtec ODT dosage form.

The principal theories in an ANDA case of this type are:

1. Hikma’s proposed rimegepant product would practice patented composition claims.
2. The proposed orally disintegrating tablet would fall within patented formulation claims.
3. Hikma’s proposed labeling would encourage or induce use for patented migraine indications.
4. Filing the ANDA before patent expiry created statutory infringement under section 271(e)(2).

Pfizer’s strongest claims would be formulation and composition claims that read directly on Hikma’s proposed product. Method-of-use claims are more dependent on Hikma’s proposed label and any carve-outs accepted by FDA.

How does the Hatch-Waxman 30-month stay affect Hikma?

A Paragraph IV certification triggers a patent dispute when the ANDA applicant asserts that an Orange Book-listed patent is invalid, unenforceable, or will not be infringed. If the brand company files suit within the statutory period, FDA approval is generally stayed for up to 30 months, subject to court decisions and statutory exceptions. [2]

For Hikma, the filing created three immediate commercial constraints:

• FDA could not ordinarily give final approval during the applicable statutory stay.
• Pfizer could seek an injunction or judgment barring launch before patent expiry.
• Hikma’s ANDA could proceed through FDA review while the patent case remained pending.

The 30-month stay does not determine patent validity. It is a regulatory timing mechanism. A judgment of invalidity or noninfringement can end the effective barrier earlier.

What was the Paragraph IV risk in this case?

Hikma’s ANDA certification exposed Pfizer’s Nurtec ODT patents to validity and infringement challenges. The likely defenses in a rimegepant case include:

• lack of infringement because the proposed product or label does not meet every claim limitation;
• obviousness based on CGRP antagonist, migraine, and oral dosage-form references;
• lack of written description or enablement for broad genus or dosing claims;
• indefiniteness for formulation or method claims;
• unenforceability based on inequitable conduct, if supported by the record;
• section viii label carve-outs for patented uses.

Pfizer’s commercial position was strongest where the asserted claims covered the active ingredient or the exact orally disintegrating formulation. Hikma’s position was stronger against claims dependent on a specific indication, dose, or label language that could be omitted without destroying the product’s principal noninfringing use.

What is the Orange Book status of Nurtec ODT?

Nurtec ODT is an FDA-approved prescription drug with Orange Book-listed patents. The Orange Book gives generic applicants notice of patents that Pfizer identifies as covering the drug, its formulation, or an approved method of use. [3]

Orange Book listing does not establish that a patent is valid or infringed. It does, however, determine which certifications a later ANDA applicant must make and can trigger litigation under the Hatch-Waxman framework.

The key regulatory distinction is:

Regulatory path	Effect
Paragraph IV certification	Challenges validity, enforceability, or infringement and can trigger patent litigation
Section viii statement	Omits a patented method of use from the generic label
Paragraph III certification	Accepts patent validity and waits for patent expiry
ANDA approval after litigation	Depends on judgment, settlement terms, and statutory exclusivity rules

What formulation patents protect Nurtec ODT?

Nurtec ODT’s formulation is commercially important because it is designed for oral administration without water. Formulation claims may cover the active ingredient, excipients, dosage-unit architecture, dissolution characteristics, and manufacturing process.

Formulation patents can remain relevant after a composition patent expires. A generic applicant may avoid infringement by changing excipients or tablet construction, but that strategy can create FDA comparability, bioequivalence, stability, or manufacturability issues.

For Hikma, the central technical question was whether its proposed orally disintegrating tablet used the same formulation features claimed by Pfizer. A different excipient profile would not automatically avoid infringement if the asserted claims were written broadly enough to cover the proposed formulation.

What method-of-use patents affect generic rimegepant launch?

Nurtec ODT has two commercially important uses:

• acute treatment of migraine; and
• preventive treatment of episodic migraine.

Method-of-use patents can delay a fully labeled generic even when the generic applicant avoids composition or formulation claims. Hikma could seek approval with a label that excludes a patented indication, but a carve-out would reduce the scope of the approved label and could create separate inducement-of-infringement issues.

The practical value of a method patent depends on:

• whether the patented indication is commercially significant;
• whether the label can be carved out cleanly;
• whether physicians are likely to prescribe the generic for the patented use;
• whether Pfizer can prove that the generic label or promotional conduct encourages infringement.

What was the litigation status and settlement position?

The action was a Delaware ANDA case rather than a post-launch damages action. The public record should be evaluated through the docket for any dismissal, consent judgment, settlement filing, or amended complaint. No reported merits opinion establishing invalidity or noninfringement is associated with the case.

In pharmaceutical patent cases, a settlement can resolve the lawsuit without a trial and provide the generic company with a defined launch date, often before the latest patent expiry but after the earliest asserted patents. A settlement may also include:

• a licensed launch date;
• an authorized-generic arrangement;
• no-challenge provisions;
• supply or manufacturing restrictions;
• covenants not to sue;
• treatment of future patents;
• acceleration provisions if another generic enters.

A docket dismissal alone does not disclose the economic terms of a settlement. The FTC’s review of brand-generic patent settlements may provide additional information where the parties submit the agreement or required certification. [4]

Which companies were challenging Nurtec ODT exclusivity?

Nurtec ODT faced the standard competitive threat from ANDA applicants seeking generic rimegepant approval. The relevant competitive group includes generic manufacturers pursuing rimegepant tablets and other CGRP therapies, including:

• Hikma;
• Teva;
• Sandoz;
• other ANDA applicants whose filings may not produce public litigation immediately.

The competitive threat is not limited to generic rimegepant. Pfizer also competes with branded CGRP products, including Ubrelvy, Qulipta, Aimovig, Emgality, Ajovy, and Zavzpret. Nurtec ODT’s dual acute and preventive label gives it a broader commercial position than products approved for only one migraine-use category.

How strong is Pfizer’s Nurtec ODT patent estate?

Pfizer’s estate is commercially strong because it is layered. The molecule, dosage form, and approved uses are protected by different patent categories with staggered terms.

Strength factor	Assessment
Core molecule	High value, but vulnerable to prior-art and obviousness attacks
Orally disintegrating formulation	Material barrier to an identical generic dosage form
Acute migraine use	Commercially important and potentially protectable through method claims
Preventive migraine use	Adds label value and method-of-use leverage
Multiple patent vintages	Reduces the effect of invalidating one patent
Design-around potential	Higher for formulation and method claims than for composition claims
Biosimilar risk	Not applicable; rimegepant is a small molecule, not a biologic

The estate is stronger than a single-patent portfolio but remains exposed to claim construction, obviousness, written-description, and label-carve-out defenses.

What generic launch scenarios exist for rimegepant?

Three launch outcomes are commercially plausible within the Hatch-Waxman framework:

1. Launch after final judgment. Hikma prevails on all blocking claims or obtains a judgment that its product does not infringe.
2. Launch after patent expiry. Hikma receives approval but waits for the last enforceable blocking patent.
3. Agreed early launch. Pfizer grants Hikma a license or settles for a specified launch date and other contractual restrictions.

A first-filer 180-day exclusivity period could affect later ANDA applicants if Hikma made a qualifying first Paragraph IV filing. That issue depends on FDA’s determination of first-filer status, forfeiture events, and whether other applicants also qualified.

What revenue exposure does generic Nurtec ODT create for Pfizer?

Nurtec ODT is a strategic migraine product with revenue exposure from both acute and preventive use. Generic entry would affect:

• net price and rebate levels;
• pharmacy benefit formulary positioning;
• patient copay support;
• prescription volume;
• conversion from branded Nurtec ODT;
• Pfizer’s broader CGRP franchise.

An authorized generic or staggered settlement launch could reduce abrupt price erosion. A full-label generic launch would create greater pressure because the generic could compete across both approved indications.

Key Takeaways

• Pfizer v. Hikma, 1:23-cv-00924, is a Delaware Hatch-Waxman case involving generic rimegepant for Nurtec ODT.
• The dispute concerns Pfizer patents covering rimegepant, the orally disintegrating formulation, and migraine treatment methods.
• The case was triggered by Hikma’s Paragraph IV ANDA certification.
• Formulation and composition claims represent Pfizer’s principal direct-product barriers.
• Method-of-use patents may be limited by section viii label carve-outs.
• Biosimilar substitution is not relevant because rimegepant is a small-molecule drug.
• Generic entry depends on the asserted patent set, FDA’s 30-month stay, any judgment, and any settlement license.
• The commercial risk is substantial because Nurtec ODT has both acute and preventive migraine indications.

FAQs

When can a generic Nurtec ODT product launch?

A generic can launch after Pfizer’s blocking patents expire, after a court ruling permits launch, or on an earlier date established by a settlement or license.

Does a Nurtec ODT patent listing prove infringement?

No. Orange Book listing creates certification and litigation consequences but does not establish patent validity or infringement.

Can a generic rimegepant product omit preventive migraine treatment?

Yes. An ANDA applicant may seek a section viii carve-out for a patented use if FDA accepts the proposed labeling and the remaining label is approvable.

Are rimegepant patents eligible for biosimilar litigation?

No. Rimegepant is a chemically synthesized small molecule regulated through the ANDA pathway, not a biologic regulated through the biosimilar pathway.

What is the most important patent risk for Hikma?

The highest-risk claims are those that read directly on the active ingredient or the proposed orally disintegrating formulation. Method-of-use claims generally present greater opportunities for label carve-outs and noninfringement defenses.

References

1. U.S. Food and Drug Administration. (2020). FDA approves new treatment for patients with migraine. https://www.fda.gov/news-events/press-announcements/fda-approves-new-treatment-patients-migraine
2. U.S. Congress. (2023). Drug Price Competition and Patent Term Restoration Act, 21 U.S.C. § 355; 35 U.S.C. § 271(e)(2).
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
4. Federal Trade Commission. (2024). Agreements filed with the Federal Trade Commission under the Medicare Prescription Drug, Improvement, and Modernization Act of 2003. https://www.ftc.gov/legal-library/browse/competition-policy-guidance/agreements-filed-federal-trade-commission-under-medicare-prescription-drug-improvement-modernization-act-2003
5. Pfizer Inc. v. Hikma Pharmaceuticals USA Inc., No. 1:23-cv-00924, U.S. District Court for the District of Delaware, complaint and docket.