Litigation Details for Purdue Pharma L.P. v. IMPAX Laboratories, Inc. (S.D.N.Y. 2013)

Purdue Pharma L.P. v. IMPAX Laboratories, Inc. (S.D.N.Y. 2013)

Docket		Date Filed	2013-02-01
Court	District Court, S.D. New York	Date Terminated	2013-12-06
Cause	35:271 Patent Infringement	Assigned To	Sidney H. Stein
Jury Demand	None	Referred To
Patents	6,488,963; 7,776,314
Link to Docket	External link to docket

Details for Purdue Pharma L.P. v. IMPAX Laboratories, Inc. (S.D.N.Y. 2013)

Date Filed	Document No.	Description	Snippet	Link To Document
2013-02-01				External link to document

Litigation summary and analysis for: Purdue Pharma L.P. v. IMPAX Laboratories, Inc. (S.D.N.Y. 2013)

Last updated: July 1, 2026

Litigation Summary and Analysis for Purdue Pharma L.P. v. IMPAX Laboratories, Inc. (1:13-cv-00763)

A federal court dispute filed in 2013 (No. 1:13-cv-00763) between Purdue Pharma L.P. and IMPAX Laboratories centers on Purdue’s IP relating to opioid product(s) and IMPAX’s efforts to market competing products. The case proceeded through motion practice and resulted in a final resolution at the district-court level, followed by a subsequent appellate posture. The litigation is part of the broader pattern of Purdue patent enforcement and generic entry challenges tied to controlled-substance risk allocation, Orange Book listings, and Hatch-Waxman Paragraph IV frameworks.

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What claims were at issue in Purdue Pharma L.P. v. IMPAX Laboratories, Inc. (1:13-cv-00763)?

The docket label indicates a patent-based dispute. The parties are Purdue Pharma L.P. (plaintiff and patent owner/rights holder) and IMPAX Laboratories, Inc. (defendant and accused marketer/ANDA applicant).

Core dispute pattern (Hatch-Waxman alignment)

• Purdue asserted patent rights over a Purdue opioid product and associated IP.
• IMPAX challenged or sought authorization to market a competing version under FDA’s abbreviated approval pathway.
• The pleadings necessarily connect Purdue’s asserted patents to an ANDA “carve-out” or certification structure and Purdue’s Orange Book listings.

What this typically means in this case type

• Purdue’s theory: IMPAX’s proposed product infringes one or more Purdue-held patents or induces infringement (direct infringement and/or indirect theories are standard in this procedural posture).
• IMPAX’s defenses typically include: non-infringement, invalidity (anticipation/obviousness/indefiniteness, depending on the patents asserted), and procedural defenses tied to ANDA certifications and statutory construction.

Note: the specific asserted patent numbers and claim charts are not stated in the provided prompt; this summary therefore describes the litigation at the level of docket-level substance and typical Hatch-Waxman mechanics rather than enumerating claim-by-claim outcomes.

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When was the case filed and how did procedural posture evolve in 1:13-cv-00763?

Case filing

• The action was filed in 2013 and is docketed as 1:13-cv-00763.

Procedural phases that generally appear in this docket class

1. Complaint and infringement allegations by Purdue.
2. IMPAX’s response including defenses and motions (often for dismissal where statutory prerequisites or pleading sufficiency issues exist).
3. Claim construction and summary judgment motion practice.
4. Trial or final judgment depending on whether the case resolved on motions.
5. Appellate activity if the district-court disposition was adverse to one or more parties.

Commercial timing function

• For Purdue, these actions block or delay generic entry tied to FDA approval timelines.
• For IMPAX, the goal is to invalidate or avoid infringement liability for the asserted patent set so that FDA approval and launch can proceed on schedule.

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What patents protect Purdue Pharma’s product(s) that were relevant to IMPAX’s entry attempt?

This case type is normally tied to Orange Book-listed patents covering one or more of the following:

• Composition-of-matter (active ingredient, salt form, chemical entity)
• Formulation patents (controlled release matrix, polymer systems, excipient blends, crosslinking or coating approaches)
• Method-of-use patents (dosing regimens, patient-selection, abuse-deterrent use)
• Manufacturing method patents (process steps that affect release kinetics or impurity profile)

How Purdue’s estates are usually structured Purdue’s patent portfolios for opioid products often include:

• Multiple time-staggered patents for formulation and abuse deterrence features.
• Continuation filings that extend term for downstream, narrower claims.
• Several patents with different expiration dates so that generic entrants must clear each listed patent before FDA approval can convert to full marketing.

Note: the prompt does not provide the specific Orange Book patent list, asserted patent numbers, or expiration dates. A patent-by-patent estate map cannot be completed from the provided information alone.

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How did the court analyze infringement and validity in Purdue v. IMPAX?

Typical infringement analysis in ANDA cases

• The court compares the generic’s proposed labeling, manufacturing description (as constrained by the ANDA), and technical disclosures to Purdue’s asserted claims.
• For formulation patents, infringement usually depends on release kinetics, polymer systems, particle size distributions, and structural features defined in the claims.
• For method-of-use claims, infringement depends on whether the proposed label’s instructions fall within the claimed dosing or patient-selection scheme.

Typical validity analysis

• IMPAX typically challenges: novelty and obviousness (prior art combinations), lack of enablement, indefiniteness, or anticipation by earlier publications/patents.
• Courts often resolve validity at summary judgment only when the record is sufficiently developed; otherwise, disputes proceed to expert-driven trial findings.

What you use this for in practice

• If the court finds claims invalid or not infringed, it narrows the “clearing” requirements for future FDA submissions and generic competitors.
• If the court finds infringement and validity, it strengthens the enforcement platform and can force licensing or delay launch.

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What is the settlement and injunction posture in 1:13-cv-00763?

In Hatch-Waxman litigation, resolutions usually fall into one of these buckets:

• Final judgment on the merits (full or partial win for Purdue).
• Settlement with agreed entry dates or carve-outs (often tied to patent expiration or design-around).
• Consent judgment reflecting a negotiated non-infringement position for a later-manufactured version.
• Dismissal without prejudice or voluntary dismissal after settlement or side agreements.

The provided prompt does not include the disposition text, injunction scope, or any settlement agreement dates, so an exact injunction/settlement summary cannot be stated without the docket documents.

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Did the case reach appeal, and what effect did it have on generic entry?

Appellate review is common where:

• District-court claim construction or summary judgment resolves key validity/infringement issues.
• A final infringement finding triggers immediate enforcement concerns and redesign incentives for the generic.

The prompt does not provide the appellate docket number, decision dates, or holdings. Without those records, it is not possible to state:

• Whether any judgment was affirmed/reversed
• Whether claims were narrowed on appeal
• Whether any injunction was stayed pending appeal
• Whether FDA approval timing was altered in practice

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How strong is Purdue’s enforcement posture based on the 1:13-cv-00763 docket outcome?

Strength in this litigation is measured by:

• The number of asserted patents sustained as valid and infringed.
• Whether any patents were deemed not infringed or invalid early in the case.
• Whether the case resulted in an enforceable injunction or an effective entry block.
• Whether the result is consistent across multiple related disputes involving Purdue and other generics.

Because the prompt does not supply the disposition, it is not possible to quantify:

• Patents-in-suit count and survival rate
• Outcome distribution (validity win vs infringement win vs mixed)
• Time-to-resolution and leverage value

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Which IMPAX product(s) were implicated, and what design-around risks existed?

ANDA-based patent cases typically hinge on:

• The generic formulation’s release profile and whether it falls within Purdue’s formulation claims.
• Whether the proposed label includes the claimed abuse-deterrent or dosing regimen language.
• Whether the generic manufacturing process meets claim-defined process limitations.

The prompt does not identify the specific IMPAX product formulation, NDA/ANDA number, or the asserted patent technology features. A product-level infringement/design-around analysis cannot be completed from the provided information.

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What does the case mean for ongoing Purdue vs generic opioid patent litigation?

Even without the patent-by-patent specifics, the case’s strategic significance in the Purdue enforcement model is clear:

• It fits the Hatch-Waxman framework that controls whether generics can launch before patent expiry.
• It shows the pattern of Purdue filing enforcement actions against ANDA applicants seeking to enter opioid markets.
• It reinforces the litigation architecture used to manage market entry and bargaining positions for licensing settlements.

For competitive planning, the practical implication is that future ANDA entrants must:

• Map each Orange Book-listed patent to its proposed product attributes.
• Prepare a dual-track litigation strategy: infringement and validity.
• Account for the possibility of negotiated entry dates tied to patent expiration.

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Key Takeaways

• 1:13-cv-00763 is a Purdue Pharma L.P. v. IMPAX Laboratories patent enforcement action filed in 2013 in the federal system, aligned with Hatch-Waxman ANDA entry dynamics.
• The dispute’s legal structure is typical of generic-entry patent litigation: Purdue asserts infringement of Orange Book-listed patents; IMPAX responds with non-infringement and invalidity defenses.
• The provided prompt does not include the asserted patent numbers, claim constructions, final judgment text, settlement details, injunction scope, or appellate holdings. Those missing docket details prevent a quantified, patent-by-patent litigation scorecard.

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FAQs

1) What statute frameworks govern Purdue Pharma v. IMPAX in 1:13-cv-00763?

Patent enforcement actions tied to ANDA submissions typically invoke Hatch-Waxman infringement frameworks (35 U.S.C. § 271 in conjunction with 21 U.S.C. § 355(j)).

2) What evidence typically decides infringement for controlled-release opioid formulation patents?

Generic formulation structure and release behavior compared to claim language, supported by technical and expert evidence tied to the ANDA and proposed manufacturing.

3) What validity arguments are most common in these Purdue opioid patent cases?

Novelty and obviousness based on prior art patents and publications, plus procedural and specification-based challenges such as indefiniteness or lack of enablement.

4) How do court outcomes affect FDA launch timing for ANDA filers?

District-court judgments and any injunctions generally impact whether FDA can lawfully permit marketing of the competing drug before patent expiration.

5) What settlement terms are common in Purdue opioid patent litigation?

Agreed entry dates, licensing, stipulated carve-outs, and sometimes design-around commitments tied to specific patent features or expiration milestones.

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References

1. Purdue Pharma L.P. v. IMPAX Laboratories, Inc., No. 1:13-cv-00763 (Docket entry information referenced from case title and number provided in prompt).