Keeping PACE With CRISPR

Written by:Justin J. Gillett and Bailey R. Arenberg

AGILENT TECHNOLOGIES, INC. v. SYNTHEGO CORP.

Before Prost, Linn, and Reyna. Appeal from the Patent Trial and Appeal Board.

Summary: Obviousness does not require all claimed limitations to be expressly disclosed in a primary prior art reference.

Synthego petitioned for inter partes review of two Agilent patents. Those patents were directed to chemically modified guide RNAs (“gRNA”) and their use in the CRISPR-Cas system, which permits selectively cleaving DNA at particular target sites. Some dependent claims recited specific PACE and thioPACE nucleotide modifications of the claimed gNRAs.

The Board found certain challenged claims were anticipated by a published PCT application. It reasoned the PCT application both disclosed a functional gRNA and was enabling. The Board found the remaining claims obvious over the PCT application in view of either of two scientific articles that disclosed the claimed PACE and thioPACE modifications. Agilent appealed.

The Federal Circuit affirmed. Regarding anticipation, the court found substantial evidence that the PCT application expressly disclosed the claimed functional gRNA and found no error in the Board’s conclusion that the PCT application was enabling. Regarding obviousness, Agilent argued that the asserted ground failed because the PCT application did not mention PACE or thioPACE modifications with the claimed functionality. The Federal Circuit rejected this argument by distinguishing the concept of anticipation from obviousness, noting that the Board’s obviousness determination did not require all the claimed limitations to be expressly disclosed in the PCT application. The court also ruled that substantial evidence supported the Board’s finding that a person of ordinary skill in the art would have reasonably expected to succeed in combining the PCT application with either scientific article.

Editor: Sean Murray