Johnson & Johnson (NYSE:JNJ) may file new claims in a surgical stapler patent case brought by Intuitive Surgical (NSDQ:ISRG) against J&J’s Ethicon unit.

The original patent was granted in 2015. Ethicon sued Intuitive in Delaware in 2017,  alleging that with the EndoWrist stapler Intuitive developed for its da Vinci robot-assisted surgery platform, Intuitive violates seven Ethicon patents covering its Echelon Flex line of endocutters and staplers.

In response to that lawsuit, Intuitive challenged Ethicon’s patent claims on the Ethicon Flex stapler in May 2018, asking for an inter partes review.

The U.S. Patent Trial and Appeal Board (PTAB) granted the review in December 2018 and held a hearing in September. On Tuesday, the board ruled that Ethicon could substitute 20 new patent claims for the 20 that Intuitive was challenging. Intuitive argued that the substitutions would broaden the original claims, but the PTAB disagreed, according to the decision.

“We… hold that Petitioner has not shown by a preponderance of the evidence that proposed claims 21 –40 are unpatentable,” the board wrote. “Accordingly, we grant Patent Owner’s Motion to Amend to substitute claims 21–40 for claims 1–20 in the ’601 patent.”