Imperative Care v. Inari Medical — PTAB Invalidates Thrombectomy Patent Covering Embolism Treatment Devices

Background

Inari Medical, Inc. is a medical device company focused on venous thromboembolism — dangerous blood clots that form in the veins, including pulmonary embolism (PE) and deep vein thrombosis (DVT). U.S. Patent No. 11,554,005 covers a system for treating embolism using mechanical thrombectomy devices that capture and remove clot material. Inari asserted this and related patents against Imperative Care, Inc., a competitor also developing endovascular tools for venous clot removal.

Imperative Care filed an inter partes review (IPR) petition with the PTAB challenging the validity of the ‘005 patent. The PTAB instituted review and, after a full trial on the merits, issued its Final Written Decision on June 10, 2026.

The Court’s Holding

The PTAB panel of Administrative Patent Judges Jeschke, Fredman, and Majors found all challenged claims of U.S. Patent No. 11,554,005 unpatentable. The panel concluded that the claims were anticipated by prior art references and/or would have been obvious to a person of ordinary skill in the art at the time of the invention. The entire patent has therefore been cancelled.

This ruling effectively eliminates a key pillar of Inari Medical’s patent portfolio targeting Imperative Care’s thrombectomy products. Inari retains the right to appeal to the Federal Circuit, but a PTAB invalidation that survived full trial review is difficult to reverse on appeal absent clear legal error.

Key Takeaways

• PTAB inter partes review (IPR) remains a powerful tool for accused infringers in medical device litigation: full invalidity at PTAB can eliminate an asserted patent entirely before or during district court proceedings.
• Anticipation and obviousness challenges based on prior art continue to be the primary grounds for IPR success — patents covering mechanical medical devices are vulnerable when prior art describes similar structural approaches to the same clinical problem.
• Companies like Inari Medical that hold large portfolios of related patents should expect competitors to challenge multiple patents through IPR simultaneously; Imperative Care has filed at least 10 IPR petitions against various Inari patents.
• The ruling may affect Inari Medical’s competitive position and stock valuation, as patent protection for its core embolism treatment technology is now materially weakened pending any appeal.

Why It Matters

The venous thromboembolism device market is increasingly competitive, with multiple startups and established companies developing minimally invasive clot-removal systems. Patent protection is critically important in this space because the underlying technology — mechanical thrombectomy mechanisms — is relatively well-defined, making prior art arguments potent. This ruling illustrates how IPR proceedings can be used strategically to clear patent thickets in competitive medical device markets, giving accused infringers continued freedom to operate while appeals play out.

For healthcare investors and biopharma watchers, PTAB Final Written Decisions are important signals about the strength of a company’s IP portfolio. The loss of this patent does not end Inari Medical’s litigation posture — it holds multiple patents — but it demonstrates that patents describing mechanical systems for clot removal can be vulnerable to validity challenges based on pre-existing catheter and retrieval device technologies.