DCT
1:25-cv-00244
Promega Corp v. Aobious Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Promega Corporation (Wisconsin)
- Defendant: Aobious Inc. (Delaware)
- Plaintiff’s Counsel: Potter Anderson & Corroon LLP
- Case Identification: 1:25-cv-00244, D. Del., 03/03/2025
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Aobious Inc. is a Delaware corporation and is therefore deemed to reside in the district.
- Core Dispute: Plaintiff alleges that Defendant’s sale of chemical compounds known as furimazine, hydrofurimazine, and fluorofurimazine infringes four patents covering these specific molecules and their derivatives.
- Technical Context: The technology involves synthetic bioluminescent substrates (luciferins) that, when combined with specific luciferase enzymes, produce light for use in highly sensitive biological assays for research, diagnostics, and drug discovery.
- Key Procedural History: The complaint details extensive pre-suit correspondence between the parties. Plaintiff alleges it first notified Defendant of its intellectual property covering furimazine via email on July 27, 2020. This was followed by multiple subsequent communications, including a cease-and-desist letter on October 19, 2023, which allegedly put Defendant on actual notice of the asserted patents prior to the filing of the lawsuit.
Case Timeline
| Date | Event |
|---|---|
| 2010-11-02 | ’529 Patent Priority Date |
| 2014-08-19 | ’529 Patent Issue Date |
| 2016-07-28 | ’500 Patent Priority Date |
| 2016-07-28 | ’280 Patent Priority Date |
| 2018-06-19 | ’500 Patent Issue Date |
| 2018-08-23 | ’976 Patent Priority Date |
| 2020-06-02 | ’280 Patent Issue Date |
| 2020-07-27 | Plaintiff allegedly first contacted Defendant by email regarding furimazine IP |
| 2021-04-22 | Earliest academic publication cited in complaint allegedly sourcing furimazine from Defendant |
| 2021-10-14 | Plaintiff allegedly contacted Defendant by courier regarding its patent portfolio |
| 2021-10-15 | Defendant allegedly responded to Plaintiff's letter |
| 2021-11-10 | Defendant's webpage for furimazine allegedly stated the product was discontinued |
| 2022-08-17 | Plaintiff allegedly contacted Defendant again regarding renewed offers for sale of furimazine |
| 2022-12-06 | Plaintiff allegedly contacted Defendant again regarding continued offers for sale |
| 2023-07-04 | ’976 Patent Issue Date |
| 2023-10-19 | Plaintiff allegedly sent a cease-and-desist letter to Defendant regarding hydrofurimazine and fluorofurimazine |
| 2024-11-26 | Most recent academic publication cited in complaint allegedly sourcing furimazine from Defendant |
| 2025-03-03 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,809,529 - Imidazo[1,2-a]pyrazine Derivatives (issued Aug. 19, 2014)
The Invention Explained
- Problem Addressed: The patent describes a need for improved bioluminescent reporters for use in cellular physiology and gene expression assays, noting that existing luciferases and their substrates have various limitations (’529 Patent, col. 1:15-32).
- The Patented Solution: The invention provides novel imidazo[1,2-a]pyrazine derivatives that function as substrates for luciferases, particularly a luciferase derived from the deep-sea shrimp Oplophorus gracilirostris. This combination is designed to produce a bright and sustained luminescent signal, enabling highly sensitive assays (’529 Patent, Abstract; col. 2:1-10). The complaint notes that one such derivative is the molecule known as "furimazine" (Compl. ¶2).
- Technical Importance: These novel substrates were foundational to the development of Plaintiff's NanoLuc® technology, which produces a luminescent signal reported to be millions of times brighter than naturally occurring systems, thereby empowering more sensitive research and diagnostic tools (Compl. ¶6).
Key Claims at a Glance
- The complaint asserts independent claim 25 (’529 Patent, col. 147:10-25; Compl. ¶25).
- Essential elements of claim 25 include:
- A compound of a specific chemical formula (furimazine) or its alternative tautomer. The complaint provides the chemical structure for the compound claimed in independent claim 25 (Compl. ¶25).
- The complaint does not explicitly reserve the right to assert other claims of the ’529 Patent.
U.S. Patent No. 10,000,500 - Coelenterazine Analogues (issued June 19, 2018)
The Invention Explained
- Problem Addressed: The patent's background section notes that many known coelenterazine analogues, used as luciferase substrates, have deficiencies that limit their effectiveness, including cell toxicity, thermodynamic instability, low aqueous solubility, and low cell permeability (’500 Patent, col. 1:35-43).
- The Patented Solution: The invention discloses novel coelenterazine analogues designed to have improved properties. A specific goal is to create substrates that produce red-shifted bioluminescent light, which is preferable for in vivo imaging applications because red light is less attenuated by tissue than blue light (’500 Patent, col. 3:41-54). The complaint identifies one such analogue as "hydrofurimazine" (Compl. ¶2).
- Technical Importance: These new analogues were designed to enhance in vivo applications by offering variants with properties like increased aqueous solubility and bioavailability, expanding the utility of bioluminescence for live-animal studies (Compl. ¶7).
Key Claims at a Glance
- The complaint asserts independent claim 13 (’500 Patent, col. 127:26-130:14; Compl. ¶28).
- Essential elements of claim 13 include:
- A compound selected from a Markush group consisting of 85 specific chemical compounds.
- The asserted species within the group is "8-benzyl-2-(furan-2-ylmethyl)-6-(3-hydroxyphenyl)imidazo[1,2-a]pyrazin-3(7H)-one," which the complaint states corresponds to hydrofurimazine.
- The complaint does not explicitly reserve the right to assert other claims of the ’500 Patent.
U.S. Patent No. 10,669,280 - Coelenterazine Analogues (issued June 2, 2020)
- Technology Synopsis: Like the related ’500 Patent, this patent discloses coelenterazine analogues intended to overcome deficiencies of prior art substrates for luciferase-based assays, such as cell toxicity and low solubility (’280 Patent, col. 1:35-43). The invention provides additional compounds with modified chemical structures for use as improved bioluminescent reagents.
- Asserted Claims: The complaint asserts dependent claim 19, which depends from independent claim 1 and specifies a compound from a list of 16, including "8-benzyl-2-(furan-2-ylmethyl)-6-(3-hydroxyphenyl)imidazo[1,2-a]pyrazin-3(7H)-one" (Compl. ¶31).
- Accused Features: The accused instrumentality is Defendant's hydrofurimazine product (Compl. ¶1, ¶16).
U.S. Patent No. 11,691,976 - Coelenterazine Analogues (issued July 4, 2023)
- Technology Synopsis: This patent discloses a family of coelenterazine analogues specifically designed for improved in vivo performance. The complaint alleges these synthetic variants, such as fluorofurimazine, exhibit increased aqueous solubility, bioavailability, and prolonged brightness when used with NanoLuc® luciferase in vivo (Compl. ¶7).
- Asserted Claims: The complaint asserts independent claim 17 (Compl. ¶34). The complaint displays the chemical structure for the compound claimed in this patent (Compl. p.13).
- Accused Features: The accused instrumentality is Defendant's fluorofurimazine product (Compl. ¶1, ¶16).
III. The Accused Instrumentality
Product Identification
The accused instrumentalities are three chemical compounds offered for sale by Defendant: furimazine, fluorofurimazine, and hydrofurimazine (Compl. ¶16).
Functionality and Market Context
The complaint alleges these products are small molecules supplied for the research market and serve as substrates for bioluminescent assays (Compl. ¶15). Plaintiff alleges that Defendant directly competes in the market for substrates compatible with Plaintiff's NanoLuc® technology platforms (Compl. ¶17). Further, the complaint alleges that Defendant markets the accused products to consumers of Plaintiff's complementary products, citing that a search for "NanoLuc" on Defendant's website yields "furimazine" and "fluorofurimazine" as results (Compl. ¶52, Exhibit Y).
IV. Analysis of Infringement Allegations
U.S. Patent No. 8,809,529 Infringement Allegations
| Claim Element (from Independent Claim 25) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A compound of formula: [depicted chemical structure] or a tautomer or salt thereof. | Defendant makes, uses, offers for sale, sells, and/or imports a compound, furimazine, which the complaint alleges possesses the claimed chemical structure. | ¶16; ¶25; ¶61 | col. 147:10-25 |
U.S. Patent No. 10,000,500 Infringement Allegations
| Claim Element (from Independent Claim 13) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A compound selected from the group consisting of... "8-benzyl-2-(furan-2-ylmethyl)-6-(3-hydroxyphenyl)imidazo[1,2-a]pyrazin-3(7H)-one,"... | Defendant makes, uses, offers for sale, sells, and/or imports a compound, hydrofurimazine, which the complaint alleges is the specific compound recited from the claim's Markush group. | ¶16; ¶28; ¶68 | col. 127:26-67; col. 129:1-4 |
Identified Points of Contention
- Evidentiary Questions: The central dispute appears to be factual rather than one of claim scope. A primary question will be whether chemical analysis confirms that the products sold by Defendant as "furimazine," "hydrofurimazine," and "fluorofurimazine" have the exact molecular structures protected by the asserted patents. The complaint relies on Defendant's own product descriptions and academic publications citing Defendant as the source (Compl. ¶16, ¶36).
- Scope Questions: For composition of matter claims directed to specific chemical structures, claim scope disputes are less common than in other technology areas. The infringement analysis may turn on a direct structural comparison. Therefore, the case may focus more heavily on potential invalidity defenses, which are not detailed in the complaint.
V. Key Claim Terms for Construction
The asserted claims are directed to specific chemical compounds, defined either by an explicit formula ('529 and '976 Patents) or by a specific chemical name within a Markush group ('500 and '280 Patents). In such cases, claim construction is not typically a central point of contention, as the claims' scope is defined by the molecular structure itself. The complaint does not present facts suggesting a dispute over the meaning of any particular term within the chemical names or formulas. The dispute will likely center on whether the accused products are, in fact, the claimed compositions, rather than on the interpretation of claim language.
VI. Other Allegations
Willful Infringement
The complaint makes detailed allegations of willful infringement. It asserts that Defendant had knowledge of the patents based on a multi-year history of correspondence, beginning with an email on July 27, 2020, which allegedly provided actual notice of the '529 Patent (Compl. ¶40). The complaint further alleges that Plaintiff sent a formal letter via courier on October 14, 2021, and a cease-and-desist letter on October 19, 2023, covering the other accused products (Compl. ¶41, ¶47). Plaintiff alleges that Defendant's continued offers for sale, despite these repeated notices, constitute egregious and deliberate conduct justifying enhanced damages (Compl. ¶57, ¶65).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of evidentiary proof: can Plaintiff demonstrate through chemical analysis that the compounds marketed by Defendant under specific names are structurally identical to the compositions claimed in the patents-in-suit?
- A key question for damages will be willfulness: given the extensive history of alleged notice detailed in the complaint, did Defendant's continued commercial activity constitute egregious infringement sufficient to warrant enhanced damages under 35 U.S.C. § 284?
- The case will also likely raise a fundamental question of patent validity: can Defendant establish, through prior art or other means, that the asserted claims covering these specific molecules are invalid, thereby rendering the question of infringement moot?