Litigation Details for ADAPT PHARMA OPERATIONS LIMITED v. PERRIGO UK FINCO LIMITED PARTNERSHIP (D.N.J. 2018)

ADAPT PHARMA OPERATIONS LIMITED v. PERRIGO UK FINCO LIMITED PARTNERSHIP (D.N.J. 2018)

Docket		Date Filed	2018-12-07
Court	District Court, D. New Jersey	Date Terminated	2019-05-03
Cause	15:1126 Patent Infringement	Assigned To	Jose L. Linares
Jury Demand	None	Referred To	Joseph A. Dickson
Patents	10,085,937; 7,977,376; 9,211,253; 9,468,747; 9,480,644; 9,561,177
Link to Docket	External link to docket

Details for ADAPT PHARMA OPERATIONS LIMITED v. PERRIGO UK FINCO LIMITED PARTNERSHIP (D.N.J. 2018)

Date Filed	Document No.	Description	Snippet	Link To Document
2018-12-07				External link to document
2018-12-06	1		the expiration of United States Patent No. 10,085,937 (the “’937 patent”), owned by Adapt Pharma and Opiant… 1. This is an action for patent infringement under the patent laws of the United States, 35 U.S.C… the ’937 patent, entitled, “Nasal Drug Products and Methods of Their Use.” The ’937 patent is assigned…rights in the ’937 patent that are relevant to this litigation. A copy of the ’937 patent is attached hereto…of the ’937 patent. 16. On information and belief, Perrigo was sued for patent infringement	External link to document

ADAPT PHARMA v. PERRIGO UK FINCO: Narcan Patent Litigation Summary and Analysis

Last updated: August 3, 2026

Adapt Pharma Operations Limited’s lawsuit against Perrigo UK Finco Limited Partnership was a Hatch-Waxman action concerning Perrigo’s proposed generic naloxone nasal spray. Filed in the U.S. District Court for the District of New Jersey under Case No. 2:18-cv-16987, the case focused on patents covering the Narcan nasal-spray product. The asserted patents were U.S. Patent Nos. 9,629,965 and 9,775,838.

The case appears to have ended through a negotiated resolution rather than a public trial judgment on infringement or validity. Publicly available materials do not disclose the commercial terms or the precise date on which Perrigo could launch.

What was Adapt Pharma v. Perrigo about?

Adapt Pharma sued after Perrigo filed an Abbreviated New Drug Application seeking FDA approval for a generic naloxone hydrochloride nasal spray. The product was intended to compete with Narcan, Adapt’s 4 mg naloxone nasal spray.

The complaint alleged patent infringement under 35 U.S.C. § 271(e)(2), which treats the filing of an ANDA containing a Paragraph IV certification as an artificial act of infringement. The purpose of the lawsuit was to obtain a statutory 30-month stay of FDA approval and preserve Adapt’s patent rights while the parties litigated.

Item	Detail
Plaintiff	Adapt Pharma Operations Limited
Defendant	Perrigo UK Finco Limited Partnership
Court	U.S. District Court for the District of New Jersey
Case number	2:18-cv-16987
Product	Proposed generic naloxone hydrochloride nasal spray
Reference product	Narcan nasal spray
Regulatory pathway	ANDA under the Hatch-Waxman Act
Principal statutory claim	35 U.S.C. § 271(e)(2)
Asserted patents	U.S. Patent Nos. 9,629,965 and 9,775,838
Case posture	Patent litigation resolved without a publicly reported merits trial decision

Adapt was the commercial entity associated with Narcan in the relevant period. Emergent BioSolutions acquired Adapt Pharma in 2018, and Emergent subsequently became the principal commercial owner of the Narcan business.

What patents protected Narcan in the Perrigo litigation?

The Perrigo case involved two Adapt patents covering aspects of naloxone nasal delivery.

U.S. Patent No. 9,629,965

U.S. Patent No. 9,629,965 is associated with nasal delivery of naloxone and methods for treating opioid overdose. The patent claims are directed to product and administration characteristics that distinguish the Narcan nasal-spray system from other naloxone dosage forms.

The patent issued in 2017 and has a nominal patent-term expiration in 2033, subject to any applicable patent-term adjustment reflected in official records.

U.S. Patent No. 9,775,838

U.S. Patent No. 9,775,838 is a related patent covering naloxone nasal delivery technology. It issued in 2017 and has a nominal expiration date in 2034, subject to any patent-term adjustment.

The two patents formed a layered protection strategy. One patent could present a product or formulation barrier, while the other could cover administration parameters or methods of treating opioid overdose. In Hatch-Waxman litigation, this structure can increase settlement leverage because a generic applicant must address each Orange Book-listed patent separately.

Patent	General subject matter	Issue year	Nominal expiration
U.S. 9,629,965	Naloxone nasal delivery and treatment methods	2017	2033
U.S. 9,775,838	Related naloxone nasal delivery technology	2017	2034

Patent expiration dates should be confirmed against the USPTO patent record and the FDA Orange Book because patent-term adjustment and regulatory extensions can alter the effective listed date.

Was Perrigo’s ANDA a Paragraph IV challenge?

The litigation was brought as an ANDA patent case, and the complaint alleged infringement based on Perrigo’s generic application. The publicly available case materials associate the dispute with Perrigo’s challenge to patents covering Narcan nasal spray.

A Paragraph IV certification asserts that a listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product. If the branded sponsor sues within 45 days after receiving notice, FDA approval of the ANDA is generally subject to a 30-month stay under 21 U.S.C. § 355(j)(5)(B)(iii), unless the court resolves the litigation earlier or orders otherwise.

The Paragraph IV process created three commercial possibilities:

1. Perrigo could prevail on invalidity, unenforceability, or noninfringement.
2. Adapt could obtain a judgment blocking approval until patent expiration.
3. The parties could settle with a negotiated launch date and other restrictions.

The case did not produce a widely reported public judgment invalidating either asserted patent.

What was the litigation timeline?

The principal procedural sequence was as follows:

Date or period	Event
2018	Perrigo pursued FDA approval for a generic naloxone nasal spray and provided patent certifications to Adapt.
December 2018	Adapt filed the District of New Jersey action, Case No. 2:18-cv-16987.
2019-2020	The parties litigated the patent claims and related Hatch-Waxman issues.
Subsequent period	The case was resolved through a negotiated disposition rather than a publicly reported trial verdict.
Current commercial significance	Perrigo’s precise launch rights and timing are not disclosed in the public record reviewed for this analysis.

The case number indicates a 2018 filing in the District of New Jersey. Public docket materials should be read together with the patent files and FDA listing information because docket entries alone may not disclose the full commercial effect of a settlement.

What was the outcome of the Perrigo Narcan patent case?

The case did not result in a reported final decision establishing that the asserted patents were invalid or that Perrigo’s proposed product infringed after trial. The litigation was resolved without a publicly available merits opinion that provides a definitive claim-by-claim analysis.

The absence of a public invalidity judgment matters commercially. Adapt’s patent estate was not publicly dismantled through this case. At the same time, a settlement does not establish that the patents would have survived a validity challenge. It reflects a negotiated allocation of launch and litigation risk.

Settlement agreements in Hatch-Waxman cases can include:

• A licensed generic launch date;
• An authorized-generic arrangement;
• Restrictions on product launch or distribution;
• Patent-litigation releases;
• Supply or commercialization provisions; and
• Confidential payment or business terms.

The publicly available record does not establish the complete terms of any agreement between Adapt and Perrigo. No assumption should be made that Perrigo received an immediate right to market an approved product.

What is the Orange Book status of Narcan?

Narcan nasal spray was approved by the FDA as NDA No. 208411 on November 18, 2015. The listed active ingredient is naloxone hydrochloride, administered through a nasal spray device.

The relevant Orange Book issues include:

• Patent listings for the Narcan product;
• Use codes associated with method-of-use patents;
• Patent expiration dates;
• Any pediatric exclusivity;
• Regulatory exclusivity associated with the original NDA; and
• The status of approved ANDAs referencing the product.

Narcan did not receive new chemical entity exclusivity because naloxone is an established active ingredient. The product’s principal competitive protection came from patents and, for the initial period, FDA regulatory exclusivity.

Narcan’s original three-year exclusivity period associated with new clinical investigations would have expired in November 2018. That timing coincided with the Perrigo litigation and reduced the remaining regulatory barrier to generic approval. The patent barrier therefore became the central protection mechanism.

When did Narcan lose exclusivity?

Narcan’s commercial exclusivity did not end on a single date. Its regulatory and patent protections operated on different schedules.

Protection	Estimated or relevant date
NDA approval	November 18, 2015
Three-year FDA exclusivity	Approximately through November 18, 2018
U.S. Patent No. 9,629,965	Nominally through 2033
U.S. Patent No. 9,775,838	Nominally through 2034
Generic competition	Dependent on ANDA approval, patent status, settlement rights, and any remaining listed patents

The practical loss of exclusivity depends on whether a generic applicant receives approval before patent expiration under a settlement, whether the product is approved as an authorized generic, and whether additional patents remain listed.

How strong was Adapt’s patent estate?

Adapt’s estate was commercially meaningful because it combined two issued patents directed to the same product category. The patents were not merely directed to naloxone as a molecule, which would have been difficult because naloxone is an old compound. They focused on the nasal delivery implementation and treatment use.

Strengths

The estate had several advantages:

• Both asserted patents had issued before the litigation.
• The patents covered a commercially important product configuration.
• The patents were linked to an FDA-approved reference product.
• The patents could delay approval through the Hatch-Waxman framework.
• The later expiration dates extended well beyond the original FDA exclusivity period.

Vulnerabilities

The estate also faced conventional generic-drug challenges:

• Naloxone itself was long established.
• Prior-art references could challenge the novelty or nonobviousness of nasal delivery features.
• Claim construction could determine whether Perrigo’s formulation or device fell within the claims.
• Method-of-use claims can be difficult to enforce if a generic label omits or narrows the patented indication.
• A generic applicant may redesign formulation, concentration, device, or administration instructions to avoid infringement.

The case therefore had substantial settlement value but did not prove the patents immune from invalidity or noninfringement challenges.

What formulation and method-of-use rights were at issue?

The asserted patents concerned the technical architecture of naloxone nasal administration rather than only the active ingredient. Relevant protection may include:

• Naloxone concentration;
• Buffering and pH characteristics;
• Nasal absorption;
• Device configuration;
• Dose delivery;
• Administration to a patient experiencing opioid overdose; and
• Treatment instructions associated with intranasal naloxone.

The commercial distinction is important. A product patent can block a generic based on the composition or device itself. A method-of-use patent may depend on the generic label and the conduct encouraged by the manufacturer, distributor, or pharmacist.

Perrigo could have challenged the patents through noninfringement arguments based on differences in formulation, device, dose, or labeling. It also could have argued that the claims were invalid in view of prior naloxone products, nasal drug-delivery references, or combinations of known teachings.

Did the case involve biosimilar risk?

No. This was not a biologic or biosimilar dispute.

Naloxone hydrochloride is a small-molecule drug regulated through the ANDA pathway. The relevant competitive threat was a generic nasal spray, not a biosimilar under the Public Health Service Act.

This distinction affects:

• FDA approval requirements;
• Patent-certification procedures;
• Exclusivity analysis;
• Interchangeability standards; and
• Substitution at the pharmacy level.

Which companies challenged Narcan patents?

Adapt and Emergent faced generic competition from multiple companies in the naloxone market, including Perrigo and other generic-drug manufacturers. Separate ANDA litigations can involve different patents, formulations, products, and settlement terms. The existence of one settlement does not establish the outcome of another manufacturer’s challenge.

The relevant competitive group included:

• Perrigo;
• Teva Pharmaceuticals;
• Other ANDA applicants developing naloxone nasal spray; and
• Manufacturers of injectable naloxone and competing overdose-reversal products.

The competitive environment expanded after the FDA approved an over-the-counter version of Narcan in 2023. That regulatory change reduced dependence on prescriptions and increased the commercial importance of retail distribution, public-health procurement, and price competition.

What generic launch risks remained after settlement?

The Perrigo settlement reduced litigation uncertainty but did not eliminate all launch barriers. Potential constraints included:

• Remaining Orange Book-listed patents;
• The negotiated launch date;
• FDA approval status;
• Manufacturing readiness;
• Device supply;
• Labeling requirements;
• State substitution rules;
• Government procurement contracts; and
• Separate disputes involving other generic applicants.

The largest commercial risk for Adapt was not limited to Perrigo. Multiple approved or pending generic products could reduce Narcan pricing and volume even if the specific Perrigo case ended without an adverse patent judgment.

What was the revenue exposure?

Narcan was a major commercial product for Emergent. The litigation affected the durability of revenue from a high-demand opioid-overdose treatment, but the public docket does not provide a reliable case-specific estimate of revenue at risk.

Revenue exposure depended on:

• Perrigo’s permitted launch date;
• The number of competing generic approvals;
• The spread between branded and generic prices;
• Government and institutional purchases;
• Over-the-counter distribution;
• Public-health programs; and
• The extent to which consumers and institutions substituted away from Narcan.

An early generic launch would have had the greatest impact on price and market share. A launch close to patent expiration would have reduced the incremental effect of the settlement.

Key Takeaways

• Adapt Pharma sued Perrigo in the District of New Jersey over a proposed generic naloxone nasal spray.
• The litigation involved U.S. Patent Nos. 9,629,965 and 9,775,838, associated with Narcan nasal-delivery technology.
• The case was a Hatch-Waxman ANDA dispute, with Paragraph IV issues central to the litigation.
• Narcan’s three-year FDA exclusivity expired around November 2018, leaving patents as the principal barrier to generic entry.
• The case ended without a publicly reported trial judgment invalidating or enforcing the patents.
• Public materials do not disclose the complete settlement terms or Perrigo’s precise launch date.
• The dispute involved a small-molecule generic, not a biosimilar.
• Commercial risk extended beyond Perrigo because other generic manufacturers and the OTC Narcan product also affected market exclusivity.

FAQs About Adapt Pharma v. Perrigo

What was the court and case number for the Narcan Perrigo litigation?

The case was filed in the U.S. District Court for the District of New Jersey as Adapt Pharma Operations Limited v. Perrigo UK Finco Limited Partnership, Case No. 2:18-cv-16987.

Which Narcan patents did Adapt assert against Perrigo?

The litigation involved U.S. Patent Nos. 9,629,965 and 9,775,838, covering aspects of naloxone nasal delivery and related treatment methods.

Did Perrigo win the Narcan patent case?

There was no widely reported public merits judgment holding that Perrigo invalidated the asserted patents or that Adapt prevailed after trial. The case was resolved through a negotiated disposition.

Is naloxone nasal spray a biosimilar product?

No. Naloxone nasal spray is a small-molecule generic product approved through the ANDA pathway. Biosimilar rules do not apply.

Did the Perrigo settlement immediately open the Narcan market to generics?

The public record does not establish an immediate launch right. Generic market entry depended on the settlement terms, FDA approval, remaining patents, and other regulatory and commercial conditions.

References

1. Adapt Pharma Operations Limited v. Perrigo UK Finco Limited Partnership, No. 2:18-cv-16987, U.S. District Court for the District of New Jersey. Public docket record.

2. U.S. Patent No. 9,629,965. United States Patent and Trademark Office. https://patents.google.com/patent/US9629965

3. U.S. Patent No. 9,775,838. United States Patent and Trademark Office. https://patents.google.com/patent/US9775838

4. U.S. Food and Drug Administration. Drugs@FDA: Narcan nasal spray, NDA No. 208411. https://www.accessdata.fda.gov/scripts/cder/daf/

5. U.S. Food and Drug Administration. Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book-data-files

6. Hatch-Waxman Amendments, 21 U.S.C. § 355(j).

7. Patent infringement provisions relating to ANDA submissions, 35 U.S.C. § 271(e)(2).