PTAB challenges

Proceedings overview

As of May 29, 2026, there are no AIA trial proceedings (Inter Partes Review, Post-Grant Review, or Covered Business Method review) on file for US Patent 8,374,358. This indicates that the patent has not been challenged at the Patent Trial and Appeal Board (PTAB) via these post-grant review mechanisms.

Strategic summary

Currently, all claims of US patent 8,374,358 remain untested in AIA trial proceedings at the PTAB. There are no claims that have been canceled, sustained, or modified through IPR, PGR, or CBM reviews. This means that a defendant currently facing assertion of this patent would not benefit from any prior invalidations at the PTAB. All original claims (1-20) are presumed valid by the PTAB for the purposes of these proceedings, as no challenges have been successfully mounted.

The absence of PTAB activity suggests that either the patent has not been heavily asserted in scenarios that would provoke an IPR filing, or potential challengers have opted not to pursue such avenues. This leaves the entire scope of the patent's claims open for challenge in district court or for future PTAB petitions.

Recommended next steps

Since there is no PTAB activity, a defendant facing assertion of US Patent 8,374,358 would need to consider a de novo validity challenge. This could involve:

• Filing an Inter Partes Review (IPR) petition: If the defendant identifies prior art consisting of patents or printed publications that raise a reasonable likelihood of unpatentability under 35 U.S.C. §§ 102 or 103 for any of the claims. An IPR can be filed after 9 months of the patent grant (February 12, 2013).
• Conducting a thorough prior art search: A comprehensive search for prior art beyond what was considered during prosecution, especially given the "Obviousness" analysis provided earlier, could uncover strong grounds for an IPR or a validity defense in district court.
• Evaluating Post-Grant Review (PGR) or Covered Business Method (CBM) eligibility: While less likely given the technology, a careful analysis should be done. PGR allows challenges on any ground of invalidity under 35 U.S.C. § 282(b)(2) or (3), but must be filed within 9 months of the patent's grant (which has passed for this patent). CBM review applies to patents claiming methods or apparatus for performing data processing used in financial products or services, which this patent does not appear to be, and it also requires the petitioner to have been sued or charged with infringement.
• Monitoring future PTAB filings: Keep an eye on the USPTO's Patent Trial and Appeal Case Tracking System (P-TACTS) for any new petitions filed against this patent.
• Coordinating with ongoing district court litigation: As there is a known district court case (Cerence Operating Company v. Amazon.com, Inc. et al., Case Number: 2:2026cv00373), any decision to file an IPR would need to consider the district court's schedule and the potential for a stay of litigation pending PTAB review.