Another key patent on the CRISPR genome editing technology is facing a legal challenge. On Tuesday, St. Louis-based Benson Hill Biosystems, a privately held agriculture biotech company, filed a petition for post-grant review with the U.S. Patent and Trademark Office, arguing that a CRISPR patent granted to the Broad Institute of MIT and Harvard in 2017 and licensed by Editas Medicine (EDIT) is invalid.
The challenged patent (number 9,790,490) covers CRISPR systems that use not the original Cas9 enzyme but a family of enzymes that the Broad’s Feng Zhang and his colleagues discovered in 2015. Originally called Cpf1 and now known as Cas12a, this family of enzymes cleave DNA at a target site, as Cas9 does. But Cpf1 has several advantages over the original, including working at regions of the genome that are inaccessible to Cas9 and being able to cut DNA without the addition of a molecule called tracrRNA.