PTAB challenges

As a senior PTAB practitioner, my analysis of US Patent 11,566,276 reveals a clean slate at the Patent Trial and Appeal Board.

Proceedings Overview

There are zero AIA trial proceedings on file for US patent 11,566,276. This defensive posture means that a defendant is not blocked by any prior failed attempts to invalidate the patent at the PTAB, but also that the patent's claims have not been tested or "hardened" by a PTAB review.

No PTAB proceedings were found for US patent 11,566,276.

Strategic Summary

The claims of US patent 11,566,276 are entirely untested at the PTAB. All claims, including independent claims 1, 19, and 28, are currently sustained as issued by the USPTO and have not been canceled or narrowed through an IPR or PGR. For a defendant, this is a double-edged sword. On one hand, the patent has not survived the intense scrutiny of a PTAB trial, a process that often strengthens a patent by confirming its validity over the asserted prior art. This lack of a defensive history might suggest that a well-crafted IPR petition could be the first and only one needed.

On the other hand, the absence of any challenges to date is itself a data point. This patent issued in early 2023 and is being actively asserted in district court litigation against at least one party, Element Biosciences, as of May 2026. Typically, patents involved in significant litigation attract validity challenges at the PTAB. The fact that none have been filed could indicate that potential challengers have not yet identified prior art that presents a strong case for invalidity. Consequently, a defendant would have a full spectrum of prior art grounds available for a potential IPR petition, as no § 315(e)(2) estoppel has been created against any party.

Recommended Next Steps

For a defendant currently facing an assertion of US patent 11,566,276, the key takeaway is that an invalidity challenge at the PTAB remains a fully available option.

• No PTAB Activity: A comprehensive search of USPTO records and public dockets confirms there are no Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) proceedings filed against this patent.
• Path Forward for Defense: Because no prior challenges exist, a defendant can pursue an IPR petition without concerns about statutory estoppel from a previous proceeding. The first step would be to conduct a thorough prior art search to identify grounds that would support a petition showing a reasonable likelihood of prevailing in invalidating one or more patent claims.
• Monitor District Court Litigation: The recently filed case 10x Genomics, Inc. and President and Fellows of Harvard College v. Element Biosciences, Inc. (D. Del., Case 1:2026cv00538) should be closely monitored. The defendant in that case, Element Biosciences, may file an IPR petition as part of its defense strategy. The outcome of any such future proceeding would be highly instructive for any other party facing this patent.