PTAB challenges

Proceedings overview

Two AIA trial proceedings have been filed against US patent 12,308,087 by Samsung. One Post-Grant Review (PGR) is currently active after the Patent Trial and Appeal Board (PTAB) instituted trial, while a concurrent Inter Partes Review (IPR) was denied institution. This presents a mixed but threatening landscape for the patent; while it survived one challenge unscathed, the active PGR proceeding creates a significant risk that some or all of the challenged claims will be found unpatentable.

PGR2025-00071 — Samsung Electronics Co., Ltd. et al. v. Netlist Inc.

• Type: Post-Grant Review
• Filed: 2025-08-25
• Status: Trial Instituted. This means the PTAB determined that it is more likely than not that at least one of the challenged claims is unpatentable. The proceeding is active.
• Judge panel: I am unable to confirm the specific Administrative Patent Judges on the panel for this proceeding with high confidence based on available public information.
• Petition grounds: I do not have access to the specific claims or prior art asserted in the petition. PGRs can be based on any ground of patentability, including novelty (§ 102), non-obviousness (§ 103), and patentable subject matter or written description (§ 112).
• Institution decision: The trial was instituted, meaning the petitioner, Samsung, successfully demonstrated to the Board that it was more likely than not that at least one challenged claim would be found invalid. The decision was likely issued shortly before the last modified date of 2026-05-11.
• Final Written Decision: Not yet issued. A Final Written Decision (FWD) is statutorily due within one year of the institution date, placing the deadline in approximately May 2027.
• Settlement / termination: The proceeding is currently active with no public record of settlement.
• Appeal: Not applicable.
• Defensive value: This active proceeding represents the most significant current threat to the validity of the patent's claims. A defendant should monitor this case closely, as a finding of unpatentability for any asserted claim would be dispositive. The institution decision itself can provide significant leverage in licensing negotiations.

IPR2025-01402 — Samsung Electronics Co., Ltd. et al. v. Netlist Inc.

• Type: Inter Partes Review
• Filed: 2025-08-25
• Status: Institution Denied. The PTAB concluded that the petitioner did not show a reasonable likelihood of prevailing on its challenge.
• Judge panel: I am unable to confirm the specific Administrative Patent Judges on the panel for this proceeding with high confidence based on available public information.
• Petition grounds: I do not have access to the specific claims or prior art asserted in the petition. IPRs are limited to patentability challenges based on novelty (§ 102) and non-obviousness (§ 103) using only patents and printed publications.
• Institution decision: Denied. The PTAB found Samsung's arguments and evidence were insufficient to establish a reasonable likelihood that it would prevail in proving any of the challenged claims unpatentable. The decision was likely issued on or around the last modified date of 2026-03-21.
• Final Written Decision: Not applicable because no trial was instituted.
• Settlement / termination: Not applicable.
• Appeal: A petitioner cannot appeal a decision to deny institution to the Federal Circuit.
• Defensive value: This decision strengthens the patent against the specific prior art and arguments raised in the IPR petition. For the petitioner (Samsung) and its real-parties-in-interest, statutory estoppel now bars them from raising these same grounds, or any other grounds they reasonably could have raised, in a district court, ITC, or subsequent PTAB proceeding. However, the victory for the patent owner is limited, as evidenced by the concurrent institution of the PGR.

Strategic summary

As of today, 2026-05-14, no claims of US patent 12,308,087 have been CANCELED or formally SUSTAINED through a Final Written Decision. All claims remain valid and enforceable, but a subset is currently under review in PGR2025-00071. The ultimate status of those claims will not be known until the PTAB issues its final decision around May 2027.

The estoppel landscape is important. Due to the denial of institution in IPR2025-01402, the petitioner (Samsung) is now estopped under 35 U.S.C. § 315(e)(1) from challenging the same claims at the PTAB on the same grounds. More critically for litigation, once the PGR (PGR2025-00071) concludes with a Final Written Decision, Samsung will be estopped under 35 U.S.C. § 325(e)(2) from asserting in any civil action any invalidity ground that it raised or reasonably could have raised during the PGR. This "could have raised" standard is broad for PGRs. For any defendant other than Samsung or its privies, all prior-art grounds remain available.

The pattern of a parallel IPR and PGR filing by the same challenger (Samsung) is a common, aggressive strategy. It allows the petitioner to hedge its bets, using the broader scope of a PGR (which allows more prior art types and invalidity theories) while also pursuing a more traditional IPR. The split outcome—PGR institution and IPR denial—suggests the successful challenge in the PGR may rely on grounds unavailable in an IPR, such as § 112 indefiniteness/written description issues, or on non-patent/publication prior art.

Recommended next steps

For a defendant facing an assertion of US patent 12,308,087, the most critical action is to monitor the active PGR proceeding.

• Track Key Milestones: The Final Written Decision for PGR2025-00071 is the most important event. It is expected approximately one year from the institution date (circa May 2027). You can follow the proceeding's status and access public documents via the USPTO's PTAB E2E portal: https://ptab.uspto.gov/ by searching the proceeding number.
• Leverage Institution Decision: Obtain and analyze the Institution Decision in PGR2025-00071. The Board's reasoning for instituting trial provides a preliminary roadmap to the patent's weaknesses and can be powerful leverage in settlement or litigation, such as in arguing for a stay of any co-pending district court case.
• Do Not Rely on IPR Denial: While the patent owner prevailed in IPR2025-01402, this is a minor victory in light of the instituted PGR. The grounds for institution in the PGR were evidently strong enough to meet the "more likely than not" standard, which is a higher bar than the "reasonable likelihood" standard for IPRs. A defense strategy should not be built around the failed IPR.