Inari Medical, Inc. v. Imperative Care, Inc.

CourtDistrict Court, N.D. California
DecidedSeptember 29, 2025
Docket5:24-cv-03117
StatusUnknown

This text of Inari Medical, Inc. v. Imperative Care, Inc. (Inari Medical, Inc. v. Imperative Care, Inc.) is published on Counsel Stack Legal Research, covering District Court, N.D. California primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Inari Medical, Inc. v. Imperative Care, Inc., (N.D. Cal. 2025).

Opinion

1 2 3 4 UNITED STATES DISTRICT COURT 5 NORTHERN DISTRICT OF CALIFORNIA 6 7 INARI MEDICAL, INC., Case No. 24-cv-03117-EKL

8 Plaintiff, ORDER DENYING MOTION FOR 9 v. PRELIMINARY INJUNCTION

10 IMPERATIVE CARE, INC., et al., Re: Dkt. No. 83 Defendants. 11

12 13 This patent infringement action relates to medical devices used to treat blot clots in 14 patients. Plaintiff Inari Medical, Inc. (“Inari”) seeks a preliminary injunction that would require 15 its competitor, Defendant Imperative Care, Inc. (“Imperative Care”), to stop making, using, and 16 selling its devices in the United States. The Court reviewed the parties’ briefs, the relevant 17 authority, and the complete record, and heard argument on Inari’s motion. The Court also 18 requested and reviewed supplemental briefing on developments in the parallel inter partes review 19 proceedings before the Patent Trial and Appeal Board (“PTAB”). For the following reasons, 20 Inari’s motion is DENIED. 21 I. BACKGROUND 22 The two patents asserted in Inari’s motion relate to mechanical thrombectomy systems, 23 i.e., devices used to remove blood clots from veins. This section discusses the medical need for 24 thrombectomy systems and then describes Inari’s and Imperative Care’s competing devices. 25 A. The Relevant Field 26 Inari and Imperative Care sell competing medical devices that treat venous 27 thromboembolism (“VTE”) – that is, blood clots that form in a patient’s veins. “VTE is a 1 United States and millions worldwide.” Merritt Decl. ¶ 6, ECF No. 23-4. When a blood clot 2 forms in a vein, it can block blood flow, which in turn may cause serious health conditions, 3 including strokes and heart attacks. Brown Decl. ¶ 32, ECF No. 23-5. 4 There are two types of VTE: deep vein thrombosis (“DVT”) and pulmonary embolism 5 (“PE”). A DVT clot forms in a patient’s peripheral vasculature, usually in deep leg veins. Merritt 6 Decl. ¶¶ 14, 27. The clot forms on a vessel wall and slowly grows inward to create a blockage. 7 Id. ¶ 13. By contrast, a PE clot is “free floating” – not attached to a vessel wall – and is found in a 8 patient’s lungs. Id. Most commonly, “clots in PE patients are simply deep leg vein clots that have 9 mobilized (meaning they have broken off and traveled to the lungs).” Id. ¶ 27. 10 Traditionally, DVT and PE have been treated with drugs such as anticoagulants (i.e., blood 11 thinners), which help prevent clot formation, and thrombolytics, which “break down and dissolve 12 the clot over hours or days, but do not physically remove the clot material from the body.” Brown 13 Decl. ¶ 39. However, these drugs have limitations and disadvantages. Anticoagulants “are not 14 effective against existing clots,” and they have potential side effects, including “bleeding risk and 15 loss of bone density.” Id. ¶ 41. Thrombolytics “can take many hours to work,” and “because the 16 clots are not actually removed from the body, portions of the clot can break off and travel to a 17 different location within the body rather than being eliminated entirely.” Id. ¶ 40. 18 Although these traditional treatments still dominate, in recent years, thrombectomy 19 procedures have also been used to treat DVT and PE. Id. ¶ 42. Thrombectomy refers to “physical 20 removal of clotted blood . . . from the vasculature.” Id. Here, the relevant devices are catheter- 21 based thrombectomy systems. Id. ¶ 44. To use one of these devices, a doctor inserts a catheter 22 into the patient’s vasculature (i.e., blood vessels) and advances the catheter until it reaches the 23 blood clot. Id. ¶ 48. A doctor may use a combination of methods and tools to remove the clot, 24 including scraping (often used for DVT clots, which are attached to vessel walls) and aspiration 25 (i.e., suction). Aspiration-based devices remove a clot by generating vacuum pressure using a 26 pressure source to suck the clot into the catheter tip and out of the patient’s vasculature. Id. 27 Although “companies have long produced catheter thrombectomy systems for treating clots in 1 B. Inari’s Devices 2 Inari was founded in 2011 and focuses on “developing pioneering treatments for the 3 || removal of blood clots from veins.” Hykes Decl. § 4, ECF No. 23-6. Although Inari asserts many 4 || more patents in this case, for purposes of the present motion, Inari asserts that Imperative Care 5 || infringes U.S. Patent Nos. 11,844,921 (921 Patent) and 11,974,910 (910 Patent). The patents 6 || issued on December 19, 2023, and May 7, 2024, respectively. The relevant patent claims are 7 discussed below. See infra Section III.A. 8 Over the years, Inari has experimented with and refined its devices based on feedback from 9 || doctors. Merritt Decl. {| 42; Brown Decl. The Court focuses on Inari’s fourth generation 10 || FlowTriever device because it incorporates the technology covered by the two patents asserted 11 here. The FlowTriever device is a type of catheter-based thrombectomy system as described 12 above. The following image shows the catheter of a FlowTriever device positioned next to a 13 blood clot. The image also shows the syringe, which generates a stored vacuum. By moving the 14 || stopcock to the “open” position, the user can release the stored vacuum, which rapidly applies 15 suction and, if successful, sucks the clot through the catheter and into the syringe. Inari refers to 16 || this deployment of suction as “WHOOSH.” Merritt Decl. § 34. 3 17 Image 1: Inari’s FlowTriver Device with Vacuum-Generating Syringe! 1g as ~s5 19 — = —— SUS eairitae ca 20 ot ee. : 21 ad ts 22 23 — 24 El 5 ol a

caaulll 27 cam 3

28 ' Brown Decl. [§] 236-237.

1 Inari explains that DVT and PE clots pose special challenges given the large size of the 2 vessels and the location of the clot deep in a patient’s vasculature. See id. ¶ 28. Inari claims that it 3 developed three key innovations to address these challenges, which are relevant to its infringement 4 claims against Imperative Care. First, Inari developed a system for “telescoping” catheters in 5 which a smaller catheter can be advanced through a larger catheter to reach further into a patient’s 6 vasculature and to provide a second aspiration attempt. Brown Decl. ¶ 72. Second, Inari 7 discovered that the use of 16F and 24F diameter catheters are ideal – with the 16F catheter 8 telescoped through the larger 24F catheter.2 Third, Inari developed an improved hemostasis valve. 9 Among other things, a hemostasis valve prevents backflow of blood through the lumen (i.e., the 10 hollow space) of a catheter. Id. ¶¶ 56-57. Inari’s hemostasis valve uses one or more filaments to 11 circumferentially constrict the lumen, in a choking motion. Merritt Decl. ¶ 52 (describing how the 12 valve forms a “garrote”). 13 C. Imperative Care’s Symphony Device 14 Imperative Care was founded in 2015 by a neurosurgeon who pioneered minimally 15 invasive treatments for stroke patients. Nalbone Decl. ¶ 5, ECF No. 79. Imperative Care began 16 developing its mechanical thrombectomy systems in late 2019 and early 2020 by investing in 17 Truvic, which it acquired in 2021. Id. ¶ 8 (explaining that Truvic has now merged into Imperative 18 Care). Imperative Care’s thrombectomy system is called Symphony, and it includes multiple 19 components, including different catheter sizes, tools, and a generator to create vacuum for suction. 20 Scott Decl. ¶ 8, ECF No. 35-3. “Depending on the procedure and the physician’s preferences, the 21 physician may use some or all of these components to treat the patient.” Id. The following image 22 shows a Symphony catheter placed next to a blood clot. 23 24 25 26 27 1 Image 2: Symphony Catheter Removing Blood Clot? Blood vessel 2 ae Symphony” 16F Catheter _—ie : 3 wa Distal portion 4 iin 4 16F catheter i “he 2 Pe 5 ee ae - 6 aM 7 — 7 aA ‘ □□ Me. — Clot material 8 Bes PS Ca 16F catheter 9 gS PS €- 10 & \ ~ 1 2 HATED AN & 13 Pi AAA A A catheter

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