PTAB challenges

Proceedings overview

There has been one AIA trial proceeding filed against US patent 8268847. This proceeding, IPR2025-01139, resulted in a discretionary denial of institution, meaning no claims were challenged on the merits. This outcome leaves the patent's claims sustained as originally granted, suggesting a hardened defensive posture for the patent owner.

IPR2025-01139 — United Therapeutics Corporation v. Actelion Pharmaceuticals Ltd

• Type: Inter Partes Review
• Filed: 2025-06-10
• Status: Discretionary Denial. The petition was not instituted due to procedural reasons, specifically under the "settled expectations" doctrine.
• Judge panel: The institution decision was issued by the USPTO Director, John Squires, as part of a series of summary denials. Specific Administrative Patent Judges (APJs) for this panel were not identified in the summary denial.
• Petition grounds: The exact grounds (specific claims, prior art, statutory basis) raised in the petition are not detailed in the available summary denial information. However, IPRs typically challenge patentability under 35 U.S.C. §§ 102 and/or 103 based on patents or printed publications.
• Institution decision: Denied on October 31, 2025. The Director issued a "summary notice" denying institution of thirteen IPR petitions, including IPR2025-01139, without providing a detailed explanation for each individual denial. However, it is inferred that the denial was based on the "settled expectations" doctrine because the patent (US8268847) was issued on September 18, 2012, making it older than six years at the time of the denial. This doctrine suggests that institution may be denied if the challenged patent issued at least six years prior, thereby giving the patentee a settled expectation of validity.
• Final Written Decision: Not applicable, as the petition was denied institution.
• Settlement / termination: Not applicable, as the proceeding was denied at the institution stage.
• Appeal: No Federal Circuit appeal has been identified for this denial of institution. Institution decisions are generally not appealable.
• Defensive value: This proceeding indicates that, at least in this instance, a challenge to US8268847 via IPR was unsuccessful on discretionary grounds. While the claims were not evaluated on their merits, the patent owner successfully defended against institution, meaning the patent's validity remains unchallenged in this specific PTAB context. A future IPR against this patent might face similar discretionary denial arguments, particularly regarding patent age.

Strategic summary

All claims of US8268847 remain SUSTAINED as originally granted. The single AIA trial proceeding, IPR2025-01139, resulted in a discretionary denial of institution, meaning the claims were not subjected to a merits-based review by the PTAB. Therefore, no claims have been canceled or narrowed through PTAB proceedings.

The estoppel landscape for future petitioners remains largely open. Since IPR2025-01139 was denied institution on discretionary grounds (specifically, the "settled expectations" doctrine related to the patent's age), the petitioner (United Therapeutics Corporation) and its privies are not estopped under § 315(e)(2) from raising prior-art grounds they raised or reasonably could have raised. This is because no inter partes review was actually "instituted" and no "final written decision" on the merits was issued. Therefore, most prior-art grounds remain available for a future challenger.

Regarding pattern signals, the discretionary denial in IPR2025-01139 aligns with a broader trend observed in late 2025, where the USPTO Director began issuing summary denials of IPR and PGR petitions, often citing the "settled expectations" doctrine for patents older than six years. This indicates a shift in PTAB policy towards discretionary denials, which could influence future challenging strategies for similar patents.

Recommended next steps

For a defendant facing assertion of US8268847 today, the fact that IPR2025-01139 was denied institution on discretionary grounds means all claims remain patentable. Any infringement theory built on these claims stands, as their validity has not been undermined by this PTAB proceeding.

While no active proceedings are currently pending on the USPTO Open Data Portal for this patent, the absence of a merits-based decision in IPR2025-01139 implies that future IPRs are not necessarily foreclosed. However, any new petition would need to carefully address potential discretionary denial arguments, particularly the "settled expectations" doctrine, given the patent's issue date of September 18, 2012. Petitioners may need to present compelling reasons why settled expectations should not apply or highlight intervening events that disrupt such expectations.