Unified Patents v. Inari Medical Inc

Unified Patents has initiated an inter partes review (IPR) against Inari Medical Inc. before the Patent Trial and Appeal Board (PTAB), challenging the validity of US Patent 12156669. Unified Patents is a member-based organization that operates as a non-practicing entity (NPE) dedicated to deterring what it considers the assertion of poor-quality patents, often by other NPEs, through various strategies, including filing IPRs. Inari Medical Inc. is a medical device operating company based in Irvine, California, focused on developing innovative catheter-based technologies for the treatment of venous thromboembolism (VTE), deep vein thrombosis (DVT), and pulmonary embolism (PE). Their product portfolio includes systems such as ClotTriever and FlowTriever. While there isn't an "accused product" in an IPR, the challenged patent is assigned to Inari Medical, indicating it pertains to their core medical device technologies.

The patent at issue, US Patent 12156669, is titled "Systems and methods for the intravascular treatment of clot material within a blood vessel of a human patient." This patent directly relates to Inari Medical's business of developing devices for clot removal. The case, IPR2026-00169, is being heard at the PTAB, an administrative body of the U.S. Patent and Trademark Office (USPTO). The PTAB provides a specialized forum for challenging the patentability of claims in issued patents, often serving as a faster and less expensive alternative to district court litigation for patent validity disputes. Unified Patents frequently leverages IPRs as a central part of its strategy to improve patent quality and curb what it perceives as unjustified patent assertions.

This case is notable within the medical device industry, a sector that has seen an increasing trend in patent litigation. Inari Medical is a key innovator in the field of VTE treatment, and challenges to its patents can have broader implications for competition and innovation in critical medical technologies. Unified Patents' decision to target an operating company's patent, rather than solely those of traditional patent trolls, underscores its mission to challenge patents it deems problematic across the board, even if they are held by companies actively practicing the patented technology.

Threshold correction before the chronology

The case metadata supplied for this prompt (and, consequently, the "Plaintiff representatives" section generated earlier) does not match any source I can find. Every docket source identifies IPR2026‑00169 as Imperative Care, Inc. v. Inari Medical, Inc., not Unified Patents v. Inari Medical. The petition filed 2025‑12‑16 names Imperative Care, Inc. as petitioner and is signed by Joshua J. Stowell, Joseph R. Re, and Brian C. Barnes of Knobbe, Martens, Olson & Bear LLP (Irvine, CA); Inari's PTAB counsel of record is Joseph Hamilton (Perkins Coie) — i.e., the reverse of what the earlier "Defendant representatives" section guessed (Knobbe represents the petitioner/challenger, Perkins Coie the patent owner). See petition cover page, https://www.docketalarm.com/cases/PTAB/IPR2026-00169/Imperative_Care_Inc/docs/12-16-2025-Petitioner/Petition_as_filed-2-Petition_as_filed.pdf; docket/counsel listing at https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2026-00169. I have not found any Unified Patents filing against Inari. I am treating Imperative Care as the petitioner and flagging the metadata as an apparent error; the earlier "Plaintiff representatives" list of Unified Patents in‑house counsel should be disregarded for this proceeding.

Second framing point: the 12,156,669 patent is not (so far as the record shows) the subject of a stand‑alone infringement action. It is one of eleven patents asserted by Inari against Imperative Care in N.D. Cal. No. 5:24‑cv‑03117‑EKL‑SVK ("the Litigation"), and IPR2026‑00169 is the PTAB track of that same dispute. The chronology below therefore tracks the Litigation, with the '669-specific PTAB events called out.

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1. Filing and initial pleadings — N.D. Cal. 5:24‑cv‑03117‑EKL

Imperative Care's answer/counterclaims are not reflected in the materials I could retrieve; I cannot confirm their content or filing date, and I am not going to invent them. Third-party defendant/substantive counterclaim activity (e.g., invalidity and inequitable conduct) should be verified against the ECF docket.

2. Pre‑trial motions of substance

Motion to stay pending IPR (ECF 100). Imperative Care moved to stay the entire case; argued 2025‑07‑16 (Tr., ECF 135). At argument, Imperative Care represented it would petition on the '669 in September 2025 and on the 12‑'333 in December 2025 "after the statutory period for challenging these recently‑issued patents has opened," and the court's 2025‑07‑03 scheduling order (ECF 123) expressly directed Imperative Care to state "if and when it will petition for IPR of the four other patents in this case."

Order granting in part (2025‑09‑29, ECF 137). Judge Lee stayed the case "for approximately four months, until February 4, 2026," reasoning that by then "the PTAB will have made institution decisions on [Imperative Care's] petitions … as to the nine original patents," with the court to revisit extension. Key findings: the case was at an early stage with substantial work remaining; the IPRs would simplify issues (three institutions already granted; Inari had already dropped '011 after institution); and the disputed construction of "filament" — used in nearly every asserted patent — would be resolved by the Board. Order text reproduced as Ex. 2005 in IPR2025‑01025, https://www.docketalarm.com/cases/PTAB/IPR2025-01025/Imperative_Care_Inc._v._Inari_Medical_Inc/docs/10-06-2025-Patent_Owner/Exhibit-2005-EX2005___Order_Granting_in_Part_Motion_to_Stay.pdf; discussion at https://www.courtlistener.com/opinion/[10691002](/patent/10691002)/inari-medical-inc-v-imperative-care-inc/.

Preliminary injunction — denied (2025‑09‑29, ECF 136). Same day, the court denied Inari's motion (ECF 83) to enjoin Symphony. Inari had narrowed the PI to the '921 and '910 patents. The court held Imperative Care raised a substantial question of validity, citing as "strong circumstantial evidence" the PTAB's institution decisions on related valve claims, and independently finding merit in the Garrison/Laub obviousness and anticipation attacks. It also found no irreparable harm (lost sales compensable; no supported price erosion; Inari's dominant market share intact), no causal nexus (the claimed valve features are internal and not a driver of physician choice), balance of hardships favoring Imperative Care (injunction would bar its only thrombectomy product), and public interest neutral given the validity questions. https://www.docketalarm.com/cases/PTAB/IPR2025-00289/.../Exhibit-1037-2025_09_29_136_ORDER_Denying_Motion_for_Preliminary_Injunction...pdf; summary at VitalLaw, IP Law Daily, 2025‑09‑30 ("PATENT—N.D. Cal.: Preliminary injunction denied in thrombectomy system dispute").

Continued stay (2026‑01‑21, ECF 140). On joint stipulation, the court vacated the 2026‑01‑28 CMC, set a further CMC for 2026‑05‑06, stayed the action "in its entirety" until that conference, and ordered a joint statement by 2026‑04‑29 reporting on every pending IPR, "the significance of any institution decisions and final written decisions," and whether the stay should be extended. Order reproduced as Ex. 1058 in IPR2025‑01025, https://gaeflexstaging-dot-docketupdate.appspot.com/cases/PTAB/IPR2025-01025/Imperative_Care_Inc._v._Inari_Medical_Inc/01-27-2026-Petitioner/Exhibit-1058....

No Markman ruling. The 2025‑07‑24 claim construction hearing was vacated (ECF 123) before any construction issued. The joint claim construction statement (ECF 107‑1) had identified "filament" as the central term — the same term the Board has been construing across the IPRs. No summary judgment, no Daubert, no JMOL practice: the case has never gotten past the pleading/stay stage.

3. Discovery milestones of strategic significance

Unified Patents, as the petitioner in this inter partes review (IPR) case (IPR2026-00169), typically uses its in-house legal team for these proceedings. While the specific counsel for this particular IPR are not yet explicitly named in public docket entries, Unified Patents has a dedicated team of experienced patent attorneys who regularly handle PTAB challenges.

Based on Unified Patents' organizational structure and publicly available information regarding their legal team, the following attorneys are likely to be involved, serving as Senior Patent Counsel:

• Jordan Rossen - Senior Patent Counsel.

  • Firm: Unified Patents (in-house).
  • Office Location: Washington, DC (though Unified Patents has a distributed team).
  • Relevant Experience: Prepares and litigates post-grant proceedings before the PTAB for Unified Patents. Prior to joining Unified, he practiced in intellectual property litigation at Ropes & Gray and Paul Hastings, representing clients before the PTAB, International Trade Commission, district courts, and Federal Circuit in various industries including medical devices.

• David Seastrunk - Senior Patent Counsel.

  • Firm: Unified Patents (in-house).
  • Office Location: Washington, DC (though Unified Patents has a distributed team).
  • Relevant Experience: Prepares and litigates post-grant proceedings before the PTAB for Unified Patents. Previously practiced at Finnegan, Henderson, Farabow, Garrett & Dunner, LLP, where he was involved in all phases of post-grant proceedings, district court cases, and International Trade Commission investigations.

• Michelle Callaghan - Senior Patent Counsel.

  • Firm: Unified Patents (in-house).
  • Office Location: Washington, DC (though Unified Patents has a distributed team).
  • Relevant Experience: Prepares and litigates post-grant proceedings before the PTAB for Unified Patents. Before Unified, she practiced at Erise IP, defending clients against patent demands in district courts and challenging patents before the PTAB.

• Kelly Hughes - Senior Patent Counsel.

  • Firm: Unified Patents (in-house).
  • Office Location: Washington, DC (though Unified Patents has a distributed team).
  • Relevant Experience: In-house counsel for Unified Patents, frequently involved in IPR proceedings.

• Alyssa Holtslander - Trademark Managing Counsel (may also contribute to patent strategy).

  • Firm: Unified Patents (in-house).
  • Office Location: Washington, DC (though Unified Patents has a distributed team).
  • Relevant Experience: Although primarily focused on trademarks, she is listed as in-house counsel and has been involved in other Unified Patents proceedings.

Unified Patents' legal team is structured to manage its IPR filings internally, and its Senior Patent Counsels are directly responsible for preparing and litigating these post-grant proceedings before the PTAB. The organization emphasizes that its decisions to file IPRs are made independently and without input from its members, with Unified controlling every aspect of the challenge.

I'll search for Inari Medical's counsel in this IPR and related matters.

Counsel of record for the patent owner / respondent — Inari Medical, Inc.

⚠️ Threshold contradiction to flag first (affects who you're looking for)

The PTAB record for IPR2026-00169 does not match the case metadata's petitioner. Every primary document I retrieved identifies the petitioner as Imperative Care, Inc., not Unified Patents:

• Petition as filed, Dec. 16, 2025: "IMPERATIVE CARE, INC., Petitioner, v. INARI MEDICAL, INC., Patent Owner. Case IPR2026-00169 Patent No. 12,156,669" — signed by Knobbe Martens (Joshua J. Stowell, Joseph R. Re, Brian C. Barnes). (petition PDF)
• Aggregator docket entry: Petitioner Imperative Care, Inc.; Respondent Inari Medical, Inc.; Patent 12156669; App. 18/358,837; filed Dec. 16, 2025; status "Trial Instituted"; institution decision June 2, 2026; respondent counsel listed as "Hamilton, Joseph et al." (ipverse/GreyB)
• Inari's own status table (filed Mar. 26, 2026) lists "'669 Patent (IPR2026-00169) — Dec. 16, 2025 — Expected: June 17, 2026" institution decision. (PTACTS doc)

So the case number and patent in your metadata are correct, but the petitioner of record appears to be Imperative Care, and my searches surfaced no Unified Patents petition against the '669 patent. I could not independently retrieve the P-TACTS "Parties/Counsel" tab for this proceeding, so I cannot rule out a separate Unified Patents filing under a different number. Also note the earlier-generated section's assertion of a "2025-12-07" filing date conflicts with the Dec. 16, 2025 petition date.

The good news: the respondent's counsel is the same regardless, because Inari Medical is the patent owner in this proceeding.

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Inari Medical's counsel: Perkins Coie LLP (lead trial/post-grant counsel)

Sources: hearing transcript in IPR2024-01157 (Inari page 1 counsel block) (link); Inari-side signature block listing Al-Salam/Tessar (PTACTS); Seattle team block with Parker/Williams/Miller (docketalarm).

Caveat on sourcing: I could not open a power of attorney or notice of appearance filed in IPR2026-00169 itself; the identification of Hamilton as respondent counsel for this specific proceeding rests on the GreyB/ipverse docket entry ("Respondent Counsel — Hamilton, Joseph et al.") plus the consistent Perkins Coie appearance for Inari across the parallel IPRs decided and instituted in 2025–2026. Confirm on P-TACTS → IPR2026-00169 → "Parties/Counsel" before relying on it in a filing.

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In-house counsel

• No Inari in-house attorney appears of record in the PTAB papers located; Inari litigates these IPRs through Perkins Coie. Note that Stryker Corporation (which acquired Inari) was identified as a real party in interest in the earlier Inari IPRs, and Stryker in-house IP counsel (Merle Elliott, IP counsel, Stryker Corp.) was noted as present on the public line at the Oct. 29, 2025 hearing — i.e., Stryker legal participates in the background, not on the PTAB signature blocks I found.

"Local counsel" note

Local counsel is not required at the PTAB, so there is no local-counsel entry for this IPR. For completeness, in the parallel district court matters Inari's Delaware counsel are:

• Richards, Layton & Finger, P.A. — Kelly E. Farnan and Sara M. Metzler (Inari v. Inquis Medical, C.A. No. 24-1023-CFC-EGT, D. Del.).
• Young Conaway Stargatt & Taylor, LLP — Pilar G. Kraman and Jennifer P. Siew (same case). (D. Del. filing)

Who you should not attribute to Inari

The Knobbe Martens team — Joshua J. Stowell, Joseph R. Re, Brian C. Barnes, Nicholas A. Belair (Irvine/San Diego/San Francisco) — signed the '669 petition and is petitioner-side counsel (Imperative Care), not Inari's. Several third-party summaries (e.g., arcticinvent) mislabel IPR numbers and patents across the Inari/Imperative Care family; do not use them to identify counsel.

Practical next step

Because the Board instituted on/about June 2, 2026 (per the docket aggregator; "Trial Instituted"), Inari's trial-phase papers (Patent Owner Response, ~3 months post-institution) will confirm the full attorney roster and any additions (e.g., a second-chair from Perkins Coie's Chicago or D.C. offices, or Stryker in-house appearing). Pull Paper 15 (institution decision) and the accompanying Patent Owner Response from P-TACTS to lock the list.