Merck’s Patent Loss to Gilead May Have Big Impact on Drugmakers

Merck & Co.’s failed patent infringement case against Gilead Sciences Inc. has important implications for the pharmaceutical and biotech industries, according to lawyers watching the case.

The precedential Oct. 30 ruling by the U.S. Court of Appeals for the Federal Circuit suggests those patents must be written more narrowly, and it potentially exposes existing patents to new challenges from competitors in the field, said Charles Duan, a patent lawyer and director of technology and innovation for the R Street think tank in Washington, D.C.

“It opens up a new line of attack on existing drug patents,” Duan said.

At issue ...