PTAB challenges

Proceedings overview

There is one AIA trial proceeding on file for US Patent 10947589. This proceeding, IPR2025-01355, has a status of "Institution Denied," meaning a trial was not instituted by the Patent Trial and Appeal Board (PTAB). This outcome indicates that the patent has survived a challenge to its patentability at the institution phase.

IPR2025-01355 — Guardant Health, Inc. v. James Hicks et al

• Type: Inter Partes Review
• Filed: 2025-07-25
• Status: Institution Denied (no trial was ever instituted). This means the PTAB determined that the petitioner did not show a reasonable likelihood of prevailing on at least one challenged claim.
• Judge panel: Administrative Patent Judges Jennifer B. Lim, Brian S. Range, and Elizabeth G. Dougherty.
• Petition grounds: Guardant Health, Inc. challenged claims 1-20 of U.S. Patent No. 10,947,589. The grounds asserted were anticipation under 35 U.S.C. § 102(a) and obviousness under 35 U.S.C. § 103(a), based on various combinations of prior art, including U.S. Patent Publication No. 2011/0263435 (Wang), U.S. Patent Publication No. 2010/0112613 (Fan), and U.S. Patent No. 7,745,108 (Farley).
• Institution decision: Denied on 2026-02-18. The PTAB determined that the Petition failed to establish a reasonable likelihood that Guardant Health, Inc. would prevail in showing the unpatentability of any of the challenged claims. Specifically, the Board found that the petitioner's arguments regarding anticipation and obviousness, particularly concerning the "substantially unique tags" and the "counting" step, did not sufficiently demonstrate unpatentability in view of the cited prior art.
• Final Written Decision (if issued): Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not applicable, as institution was denied.
• Defensive value: The patent owner successfully defended the patent against this IPR challenge. The PTAB's decision to deny institution suggests that the patent's claims, especially those related to "substantially unique tags" and the "counting" method, were not readily deemed unpatentable based on the specific prior art and arguments presented by Guardant Health. This makes an IPR-based defense, at least on the same grounds and art, significantly harder for a future defendant.

Strategic summary

All claims of US Patent 10947589 remain untested on their merits by the PTAB. In IPR2025-01355, the petitioner, Guardant Health, Inc., challenged claims 1-20, but the PTAB denied institution of the trial. Therefore, no claims have been canceled or sustained by a Final Written Decision. This means that all 20 claims of the patent are currently enforceable as granted.

Regarding the estoppel landscape, Guardant Health, Inc. (and any parties in privity with them) is estopped under 35 U.S.C. § 315(e)(1) from asserting in future district court litigation or other USPTO proceedings any ground of unpatentability that they raised or reasonably could have raised in IPR2025-01355. This estoppel specifically relates to claims 1-20 and the prior art cited in their petition (Wang, Fan, Farley, and combinations thereof). For a new defendant facing assertion of this patent, prior art not raised by Guardant Health, or different combinations/interpretations of the same art, would still be available to challenge the patent's claims in a new IPR petition or district court invalidity defense. There is no pattern of aggressive appeals by the patent owner as no final decision was reached, nor is there evidence of multiple IPR filings on this patent by the same petitioner.

Recommended next steps

For a potential defendant, while IPR2025-01355 resulted in an institution denial for Guardant Health, Inc., this does not invalidate the patent. Instead, it indicates that the specific arguments and prior art presented in that petition were insufficient to meet the institution threshold.

• Review the PTAB's Decision Denying Institution for IPR2025-01355 (accessible via the USPTO PTAB E2E system: https://e2e.uspto.gov/e2eclient/ by searching for IPR2025-01355) to understand the Board's reasoning. This decision, dated 2026-02-18, will detail why Guardant Health's arguments regarding the "substantially unique tags" and "counting" step did not establish a reasonable likelihood of unpatentability.
• A new IPR petition would need to present different prior art, or significantly different and more persuasive arguments based on the same or new art, to overcome the Board's previous institution denial and demonstrate a reasonable likelihood of success.

Proceedings overview

There is one AIA trial proceeding on file for US Patent 10947589. This proceeding, IPR2025-01355, has a status of "Institution Denied," meaning a trial was not instituted by the Patent Trial and Appeal Board (PTAB). This outcome indicates that the patent has survived a challenge to its patentability at the institution phase, making it a relatively hardened patent against the specific grounds raised in that petition.

IPR2025-01355 — Guardant Health, Inc. v. James Hicks et al

• Type: Inter Partes Review
• Filed: 2025-07-25
• Status: Institution Denied (no trial was ever instituted). This signifies that the PTAB found the petitioner did not demonstrate a reasonable likelihood of prevailing on at least one challenged claim.
• Judge panel: Administrative Patent Judges Jennifer B. Lim, Brian S. Range, and Elizabeth G. Dougherty.
• Petition grounds: Guardant Health, Inc. challenged claims 1-20 of U.S. Patent No. 10,947,589. The petition asserted grounds of anticipation under 35 U.S.C. § 102(a) and obviousness under 35 U.S.C. § 103(a). The prior art cited included U.S. Patent Publication No. 2011/0263435 (Wang), U.S. Patent Publication No. 2010/0112613 (Fan), and U.S. Patent No. 7,745,108 (Farley), among others, in various combinations.
• Institution decision: Denied on 2026-02-18. The PTAB determined that the Petition failed to establish a reasonable likelihood that Guardant Health, Inc. would prevail in showing the unpatentability of any of the challenged claims. The Board's reasoning centered on the petitioner's arguments regarding anticipation and obviousness, finding that they did not sufficiently demonstrate unpatentability, particularly concerning the features of "substantially unique tags" and the "counting" step as claimed in the patent.
• Final Written Decision (if issued): Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not applicable, as institution was denied, and institution decisions are not appealable under the AIA.
• Defensive value: The patent owner successfully defended the patent against this IPR challenge at the institution phase. The PTAB's decision to deny institution indicates that the patent's claims, specifically in relation to the "substantially unique tags" and the "counting" methodology, were deemed sufficiently distinct or the prior art arguments were found unpersuasive for institution based on the evidence presented by Guardant Health. This outcome makes it more challenging for a future defendant to pursue an IPR on the same claims using the same or substantially similar prior art and arguments.

Strategic summary

All claims of US Patent 10947589 remain untried on their merits by the PTAB. Guardant Health, Inc.'s petition to challenge claims 1-20 in IPR2025-01355 was denied institution on 2026-02-18. Consequently, no claims of the patent have been canceled or sustained by a Final Written Decision, and all 20 claims remain active and enforceable as originally granted.

Regarding the estoppel landscape, Guardant Health, Inc., and any parties in privity with them, are estopped under 35 U.S.C. § 315(e)(1) from challenging claims 1-20 in future district court litigation or other USPTO proceedings on any ground of unpatentability that they raised or reasonably could have raised in IPR2025-01355. This applies specifically to the combinations of prior art (Wang, Fan, Farley, etc.) that were presented in their petition. For other defendants facing assertion of this patent, prior art not raised by Guardant Health, or substantially different arguments and combinations of the same art, would still be available for challenging patentability in a new IPR petition or as a defense in district court. There is no discernible pattern of multiple IPR filings by the same petitioner or aggressive PTAB appeals by the patent owner, as the only proceeding resulted in a denial of institution.

Recommended next steps

For a defendant considering challenging US Patent 10947589:

• Carefully review the PTAB's Decision Denying Institution for IPR2025-01355. This decision, dated 2026-02-18, is crucial for understanding the specific weaknesses identified in Guardant Health's arguments regarding the "substantially unique tags" and "counting" steps. Access to this decision can be gained through the USPTO PTAB E2E system by searching for IPR2025-01355.
• Any new IPR petition would need to overcome the Board's reasoning in the institution denial by presenting new and compelling prior art, or by crafting significantly different and more persuasive arguments based on existing or new art, to meet the "reasonable likelihood of prevailing" standard for institution. This requires a thorough analysis of the prior institution decision and the patent's claims.