The Supreme Court has declined to temporarily block a lower court ruling that opens the world’s best-selling multiple sclerosis drug to competition from generic rivals.

The order Friday from Chief Justice John Roberts is a victory for rivals challenging the maker of the drug Copaxone, Teva Pharmaceutical Industries Ltd.

Teva claims the U.S. Court of Appeals for the Federal Circuit wrongly overturned five of its patents for the drug. That ruling allows rivals Mylan Inc., Momenta Pharmaceuticals Inc. and Sandoz Inc. to start selling cheaper generic versions next month instead of September 2015.

The Supreme Court has agreed to hear the case, but arguments won’t take place until its new term begins in October. Teva said it would suffer irreparable harm if the appeals court decision was not postponed.