DCT
1:25-cv-00387
InfoRLife SA v. Sagent Pharmaceuticals
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: InfoRLife SA (Switzerland)
- Defendant: Sagent Pharmaceuticals (Inc.) (Wyoming)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP; Rothwell, Figg, Ernst & Manbeck, P.C.
- Case Identification: 1:25-cv-00387, D. Del., 03/28/2025
- Venue Allegations: Defendant Sagent has agreed not to contest venue in the District of Delaware for the purposes of this litigation.
- Core Dispute: Plaintiff alleges that Defendant’s submission of an Abbreviated New Drug Application (ANDA) for a generic norepinephrine solution infringes a patent related to a storage-stable, ready-to-use pharmaceutical formulation.
- Technical Context: The technology concerns ready-to-use intravenous solutions of norepinephrine, a drug used to restore blood pressure, which are formulated for long-term stability at room temperature without requiring antioxidants.
- Key Procedural History: This action arises under the Hatch-Waxman Act, triggered by Defendant’s submission of an ANDA with a Paragraph IV certification against the patent-in-suit. Defendant sent a notice letter to Plaintiff on February 14, 2025, asserting that the patent is invalid, unenforceable, or will not be infringed by its proposed generic product.
Case Timeline
| Date | Event |
|---|---|
| 2019-04-26 | '534 Patent Priority Date |
| 2021-01-12 | U.S. Patent No. 10,888,534 Issued |
| 2025-02-14 | Sagent sends ANDA Notice Letter to InfoRLife |
| 2025-02-18 | InfoRLife receives Sagent's Notice Letter |
| 2025-03-27 | Sagent confirms it will not contest venue |
| 2025-03-28 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,888,534 - "Storage stable ready-to-use norepinephrine aqueous solutions in flexible plastic bags", Issued January 12, 2021
The Invention Explained
- Problem Addressed: The patent’s background section describes challenges with then-current norepinephrine solutions, which were supplied in concentrated form requiring dilution prior to use. This process introduced risks of microbial contamination and dosing errors, and the formulations typically contained antioxidants like sulfites, which could pose health risks to patients. (’534 Patent, col. 1:15-32).
- The Patented Solution: The invention is a ready-to-use, diluted norepinephrine IV solution that is stable for long-term storage (12 to 24 months) at room temperature without antioxidants. This stability is achieved by packaging the solution in a flexible plastic bag, which is then sealed in a secondary, low-oxygen-permeability over-wrap pouch that also contains an oxygen absorber to prevent oxidative degradation of the drug. (’534 Patent, Abstract; col. 2:60-65; FIG. 1).
- Technical Importance: This approach provides a safer and more convenient product for intensive care and emergency settings by eliminating the risks associated with on-site dilution and avoiding the use of potentially harmful antioxidants. (’534 Patent, col. 1:45-58).
Key Claims at a Glance
- The complaint asserts infringement of at least independent claim 1. (Compl. ¶31).
- The essential elements of independent claim 1 include:
- A sterile, antioxidant-free aqueous norepinephrine solution packaged in a flexible plastic container within a sealed over-wrap pouch containing an oxygen absorber.
- The solution "consisting essentially of" specific concentrations of norepinephrine, a tonicity adjusting agent for a specific osmolality range (260-320 mosm/kg), an acid/base for a specific pH range (3.6-3.8), and water.
- A negative process limitation, wherein dissolved oxygen "has not been removed" from the solution before filling the container.
- A stability requirement, wherein after 12-24 months of storage at room temperature, the solution remains clear and colorless and/or retains at least 90% of its initial norepinephrine amount.
- The complaint alleges infringement of "one or more claims," suggesting a reservation of the right to assert dependent claims. (Compl. ¶37).
III. The Accused Instrumentality
- Product Identification: The accused instrumentality is "Sagent’s ANDA Product," a proposed generic version of InfoRLife's norepinephrine bitartrate solution in 0.9% sodium chloride, intended for intravenous use in three strengths: 4 mg/250 ml, 8 mg/250 ml, and 16 mg/250 ml. (Compl. ¶¶ 1, 18).
- Functionality and Market Context:
- The product is described as a solution for restoring blood pressure in patients with acute hypotensive states, supplied in single-dose infusion bags. (Compl. ¶¶ 16, 28).
- By filing an ANDA, Sagent represents that its product has the same active ingredient, dosage form, route of administration, and strength as Plaintiff's approved product and is bioequivalent. (Compl. ¶29). The complaint alleges, based on a review of confidential ANDA materials, that the accused product is a sterile, antioxidant-free solution packaged in a flexible container inside a sealed over-wrap containing an oxygen absorber. (Compl. ¶¶ 17, 33).
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
'534 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A sterile, antioxidant-free aqueous norepinephrine solution packaged in a flexible plastic container in a sealed over-wrap pouch containing an oxygen absorber | Sagent's ANDA Product is alleged to be a sterile, antioxidant-free aqueous norepinephrine solution packaged in a flexible plastic container in a sealed over-wrap pouch containing an oxygen absorber. | ¶33 | col. 4:11-20 |
| consisting essentially of between about 0.010 and 0.2 mg/ml of norepinephrine concentration as free base, a tonicity adjusting agent to provide an osmolality of from 260 and 320 mosm/kg, and... | The product is alleged to consist essentially of norepinephrine within the claimed concentration range (0.016, 0.032, and 0.064 mg/ml), a tonicity agent providing the required osmolality, and other specified components. | ¶33 | col. 2:47-50 |
| sufficient acid and optionally a base to provide a pH of from about 3.6 to 3.8, with the remainder water | The product is alleged to contain sufficient acid and/or base to provide a pH within the claimed range of 3.6 to 3.8. | ¶33 | col. 3:1-2 |
| wherein dissolved oxygen in the solution has not been removed before filling the flexible plastic container with the solution | The complaint alleges that dissolved oxygen has not been removed from the solution before filling the container for Sagent's ANDA Product. | ¶33 | col. 5:40-52 |
| wherein, after storage for from 12 months to about 24 months at room temperature of about 25° C., the solution remains clear and colorless and/or the solution contains 90% or more of an initial amount of norepinephrine. | The product is alleged to meet the claimed stability requirements, remaining clear and colorless and/or containing 90% or more of the initial norepinephrine amount after storage. | ¶33 | col. 6:3-9 |
- Identified Points of Contention:
- Scope Questions: A potential dispute may arise over the term "consisting essentially of." The infringement analysis will turn on whether Sagent's formulation, as specified in its ANDA, contains any unlisted ingredients that materially affect the invention's basic and novel properties, namely its long-term stability without antioxidants.
- Technical Questions: The complaint alleges infringement of a negative process limitation ("dissolved oxygen... has not been removed") and a long-term stability profile. (Compl. ¶33). A key question for the court will be what Sagent's confidential ANDA data reveals about its specific manufacturing process and the results of its 12-to-24-month stability studies.
V. Key Claim Terms for Construction
The Term: "consisting essentially of"
- Context and Importance: This transitional phrase limits the scope of the claim to the specified ingredients and those that do not materially affect the "basic and novel characteristic(s)" of the invention. Practitioners may focus on this term because the core of the invention is achieving antioxidant-free stability. The presence of any unlisted excipient in Sagent's product could become a central issue if it is argued to affect that stability.
- Intrinsic Evidence for a Broader Interpretation: The patent allows for several unlisted components, such as a "pharmaceutically acceptable base" and various types of "tonicity adjusting agents," which may suggest the list of ingredients is not strictly closed to all other conventional, non-material components. (’534 Patent, col. 2:45-47; col. 3:3-6).
- Intrinsic Evidence for a Narrower Interpretation: The specification repeatedly emphasizes the goal of creating an "antioxidant-free" solution and avoiding certain substances, noting that for "the best shelf life sugars are not used." (’534 Patent, col. 1:47-48; col. 2:1-3). This focus could support a narrower construction that excludes any unlisted ingredient that could potentially impact long-term stability.
The Term: "dissolved oxygen in the solution has not been removed"
- Context and Importance: This is a negative limitation defining the manufacturing process. Infringement depends on an action not taken by the defendant. Practitioners may focus on this term because its definition will determine what level of incidental or passive oxygen reduction, if any, is permissible.
- Intrinsic Evidence for a Broader Interpretation (of "removed"): The patent contrasts the claimed invention with prior art methods that use active deaeration, such as "bubbling or blowing an inert gas." (’534 Patent, col. 5:32-38). An argument could be made that "removed" is limited to these specific, active degassing steps, allowing for other process conditions that might incidentally result in lower-than-saturation oxygen levels.
- Intrinsic Evidence for a Narrower Interpretation (of "removed"): The claim language is absolute ("has not been removed"). This could support a construction where any intentional process step designed to lower the dissolved oxygen content of the water or the final solution, however minor, would fall outside the claim scope and thus be non-infringing.
VI. Other Allegations
- Indirect Infringement: The complaint alleges active inducement, asserting that Sagent's proposed product labeling will instruct healthcare professionals to administer the accused product, thereby causing infringement. (Compl. ¶¶ 38, 39).
- Willful Infringement: The complaint alleges that Sagent was aware of the '534 Patent before submitting its ANDA and that it acted without a reasonable basis for believing it would not be liable for infringement. (Compl. ¶¶ 39, 42). This allegation forms the basis for a request for enhanced damages and a declaration that the case is "exceptional" for the purpose of awarding attorneys' fees. (Compl. ¶ Prayer for Relief E).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of process definition: Does Sagent’s manufacturing method, as documented in its confidential ANDA, involve any step that a court could construe as "remov[ing]" dissolved oxygen, as prohibited by Claim 1? The outcome may depend on whether routine water handling techniques are found to meet this negative limitation.
- A second central issue is one of formulation scope: Does the accused generic product "consist essentially of" the claimed components? This question will likely require a factual determination of whether any unrecited ingredients in Sagent’s formulation materially alter the product's fundamental characteristic of long-term, antioxidant-free stability.
- A key evidentiary question will be one of stability equivalence: Does the stability data presented in Sagent's ANDA prove that its product meets the specific long-term clarity, color, and potency requirements of Claim 1? This will likely evolve into a technical dispute between opposing experts over the interpretation of pharmaceutical stability studies.