Pharmaceutical companies must have flexibility to conduct research into potentially groundbreaking new medicines, the Supreme Court was told Wednesday, as it heard arguments on how far a patent can go to thwart a rival firm’s efforts to develop new drugs.

The Court considered the case of Integra LifeSciences Holdings Corp., which accuses Germany’s Merck KGaA of infringing a patent it holds on certain molecules Merck is using for research. Merck, which isn’t related to the U.S. company, says a federal law gives it leeway to experiment.