The U.S. Supreme Court has upheld changes to patent law made by Congress in 2011 that can make it easier for generic drug manufacturers to invalidate patents.

Though the actual case, Cuozzo Speed Technologies v. Lee, had nothing to do with brand name pharmaceuticals, its trade group had argued in the case it would “stifle innovation” by making the results of years of drug research and development harder to protect.

The issue is a process called inter partes review created by Congress in 2011. Rather than having to challenge patents through court litigation, they could be reviewed by an appeals board within the U.S. Patent and Trademark Office.

The result, according to the Wall Street Journal, has been patents been partially or completed invalidated in more than 80 percent of the cases brought before the board.

In writing the court’s opinion, Justice Stephen Breyer says the inter partes review is a “reasonable exercise” of the Patent Office’s rulemaking authority.

“For one thing, construing a patent claim according to its broadest reasonable construction helps to protect the public. A reasonable, yet unlawfully broad claim might discourage the use of the invention by a member of the public,” Breyer wrote.

Pharmaceutical Research and Manufacturers of America (PhRMA), who had backed Cuozzo in the case, said it was “disappointed” in the ruling, and maintained inter partes review sets up a process which mimics a courtroom, yet interprets patents differently.

“This dual standard threatens the predictability and strength of the protections that the patent system is supposed to provide to innovators,” PhRMA said in a statement.

Generic drug manufacturers, however, applauded the decision, arguing brand name drugmakers exploited the patent system for years to keep prices high.

“By protecting and reaffirming the importance of the inter partes review, the Court recognizes the vital need for an efficient patent review process—one that promotes a competitive, affordable prescription drug market for consumers,” said Generic Pharmaceutical Association president and CEO Chip Davis.