Key Points

• On March 26, 2026, the Patent Trial and Appeal Board (PTAB) ruled against The Regents of the University of California, University of Vienna, and Emmanuelle Charpentier (collectively, CVC).
• The PTAB once again decided that The Broad Institute, MIT, and Harvard (collectively, Broad) have priority rights to the CRISPR-Cas9 gene-editing technology in eukaryotic cells after a federal appeals court remanded the PTAB’s earlier decision for reanalysis.
• Related patent disputes (interferences) involving ToolGen and Sigma-Aldrich are still paused. It could take several more years and legal proceedings before it’s clear who ultimately owns the rights to use CRISPR-Cas9 in eukaryotic cells.

Background

The first patent interference between CVC and Broad concluded in 2018 after an appeal to the Federal Circuit appeals court. The Federal Circuit held that the parties’ claims did not interfere because Broad’s claims to CRISPR-Cas9 in eukaryotic cells were not obvious over CVC’s broader CRISPR claims that were not limited to a specific environment or organism.

The PTAB declared a second interference, in June 2019, that involves 14 patent applications from CVC and 13 patents plus one application from Broad, all claiming CRISPR-Cas9 technology in eukaryotic cells. In February 2022, the PTAB awarded priority to Broad, finding sufficient evidence that Broad’s inventors had reduced the invention to practice by October 5, 2012, and that CVC had failed to prove it had conceived the invention even earlier. CVC subsequently appealed this decision to the Federal Circuit.

In May 2025, the Federal Circuit vacated the PTAB’s decision on conception and remanded the case for reconsideration under the proper legal framework. The court held that the PTAB erred by focusing almost exclusively on CVC’s scientists’ experimental difficulties and failing to properly consider routine methods and ordinary skill in the art.

PTAB’s March 2026 Judgment

On remand, the PTAB reaffirmed its earlier decision and again awarded priority to Broad. The PTAB found that CVC failed to establish an earlier conception of CRISPR-Cas9 in eukaryotic cells—even after considering the state of the art and the level of skill at the time—and again entered judgment against CVC.

In response to the Federal Circuit’s holding of legal error in the PTAB’s prior analysis, the PTAB explained that all evidence must be considered. On the merits, the PTAB concluded that CVC did not prove an earlier conception, which requires that only ordinary skill be necessary to reduce the invention to practice without extensive research or experimentation.

The PTAB defined a person of ordinary skill as “a practicing Ph.D. research scientist familiar with routine techniques and methods.” It noted that implementations by certain third-party labs with specialized eukaryote expertise did not support a finding that only ordinary skill was sufficient.

Additionally, the PTAB found that CVC’s and third-party labs’ 2012 work reflected ongoing experimentation and uncertainty rather than a definitive, successful implementation of a eukaryotic CRISPR system. Consequently, more than ordinary skill and extensive experimentation were necessary to achieve a working system at that time.

What’s Next?

CVC may request a rehearing by the PTAB within one month or appeal to the Federal Circuit within nine weeks. However, CVC faces a challenging path to overturn the priority ruling. The PTAB expressly explained how it applied the proper legal standards in its current decision—making CVC’s winning argument in the prior appeal less likely to succeed this time—and the Federal Circuit is generally deferential to the PTAB on factual questions, so a reversible fact error is harder to prove on appeal.

Further Considerations

Implications for Related Interferences: ToolGen and Sigma-Aldrich

Parallel interferences involving ToolGen and Sigma-Aldrich remain suspended pending final resolution between CVC and Broad. These proceedings involve similar priority issues for CRISPR-Cas9 in eukaryotic cells. Both ToolGen and Sigma are the senior parties in their respective interferences, and it could take several additional rounds before patent ownership is conclusively determined.

Notably, the PTAB’s March 2026 decision specifically references these parallel cases and acknowledges that the Kim lab (ToolGen) and Chen lab (Sigma) successfully demonstrated CRISPR-Cas9 gene editing in eukaryotic cells during the relevant timeframe. These parallel proceedings warrant close monitoring as the ongoing legal disputes continue to develop, and their outcomes will be important in shaping the overall CRISPR-Cas9 patent landscape.

Patent Term

Patent applicants receive day-for-day term restoration for time spent in interference proceedings. Given the lengthy delays, successful applicants may gain several additional years of patent term, especially if one of the stayed interferences ultimately determines the winner.

Conclusion

The eukaryotic CRISPR-Cas9 patent landscape remains highly complex and unsettled. Organizations developing CRISPR-Cas9 technologies should closely monitor these legal cases, as they may significantly impact freedom-to-operate and licensing strategies.

For questions regarding patent strategies, please contact Lou Lieto, Clark Lin, or any member of Wilson Sonsini’s Patents and Innovations practice.

Angel Wang and Rick Torczon assisted in the preparation of this alert.